Hydro 2011 report PDF - International Journal on Hydropower and ...

Practical solutions for a 

sustainable future 

A broad-based agenda at HYDRO <strong>2011</strong> led to lively and constructive discussions among more than 1300 international experts. Topics 

ranged from micro hydro for rural areas of Nepal, to the 42 000 MW Inga scheme in DRC now reaching a major milestone in its 

development, with prefeasibility studies recently approved. The 33 sessions included nine high level panel discussions, providing opportunities 

for open debate on topics such as approaches to finance, research on carbon emissions from reservoirs, the increasing importance of 

pumped storage, the safety of high hazard energy infrastructure, capacity building and communications. 

Global challenges for the hydro profession were 

addressed by more than 1300 representatives of 

the world hydropower community during 

HYDRO <strong>2011</strong> in Prague. More than 75 nations were 

represented, making the pool of expertise and experience 

quite unique for a meeting focusing on hydro. 

Alongside technical topics, such as the latest developments 

in turbine and generator technology and in 

civil engineering, discussions included some new 

issues, such how to encourage young people into the 

hydro profession, managing the risks of high hazard 

structures (with input from the nuclear, oil and gas 

industries), and how governments can manage the economic 

risks of long-term concession agreements. 

The <strong>report</strong> which follows attempts to cover briefly 

some of the main outcomes of the various sessions, 

and has been compiled in conjunction with those who 

chaired the sessions (whose names are given below the 

topic). For this overview, we have grouped session 

<strong>report</strong>s together under common general themes, rather 

than <strong>report</strong>ing them in the order in which they took 

place at the conference. 

Opening ceremony 

In her welcome message to HYDRO <strong>2011</strong> delegates, 

Alison Bartle of Aqua~Media <strong>International</strong> commented 

that the leading countries for hydropower development 

were participating in the sessions, including, for 

example, China, India, Laos, Malaysia, Bhutan, Iran, 

Turkey, Ethiopia, Brazil, Canada, and Portugal. Of the 

937 GW of hydropower in operation, she said, 90 per 

cent was in countries which were represented at the 

conference, and of the 185 GW currently under construction, 

87 per cent was in countries represented in 

Prague. 

To set the scene for the discussions to follow, Bartle 

then gave an overview of how hydro had progressed 

over the past ten years (since the era of the WCD 

<strong>report</strong>). Since that time, capacity under construction 

had doubled in South America and Europe, she said, 

but even more impressive was a five-fold inrease in 

hydro capacity under construction in Africa. She then 

gave some examples of major schemes around the 

world which were currently under construction, and 

likely to make a major impact on power supplies in 

their respective countries. 

She referred to some of the main challenges which 

would be addressed in the sessions, and noted that 

among the speakers, were many with experience of 

developing hydro schemes in some of the most challenging 

conditions, who would be ready to share their 

expertise with others now embarking on major development 

programmes. Also present were delegates 

from some of the less developed countries, where per 

capita electricity consumption remained well below 

500 kWh/year, and where future hydro development 

would be the key to enhancing socio-economic development. 

The world’s leading engineering companies, 

financial experts, environmental specialists and 

machinery providers were also well represented, 

which paved the way for some concrete achievements 

during the three days of talks. 

Vladimir Hlavinka, Member of the Board and Chief 

Production Officer of the Czech utility CEZ (co-host 

of HYDRO <strong>2011</strong>) then welcomed participants on 

behalf of his company and his country. He outlined 

CEZ’s portfolio of power facilities, drawing attention 

to the cascade of hydro schemes on the Vltava river, as 

well as the major pumped-storage stations. About 2 

TWh/year was currently produced by hydro, Hlavinka 

said, which represented about 600 000 households in 

the Czech Republic. Current emphasis, he continued, 

was on progressively uprading the hydro and pumpedstorage 

plants. Efficiency was expected to increase by 

about 5 per cent for large hydro plants, and up to 10 

per cent in the case of small plants. By 2020, it was 

Left: Prof V. Broza, 

President of 

CZCOLD, who 

traced the history of 

water resources 

development in the 

Czech Republic. 

Right: V. Hlavinka, 

Chief Production 

Officer of CEZ, who 

described the 

current upgrading 

programme. 

Alison Bartle drew 

attention to the 

global increase in 

hydro development 

in recent years, 

during her welcome 

address at 

HYDRO <strong>2011</strong>. 

<strong>Hydro</strong>power & Dams Issue Six, <strong>2011</strong> 29

Above: ICOLD 

Secretary-General 

Michel de Vivo gave 

some global statistics 

to underline the role 

of dams. 

Centre: Dr Andy 

Hughes, UK, said 

experienced hydro 

engineers had a 

responsibility to pass 

on their expertise to 

younger generations. 

Right: Alessandro 

Palmieri, World 

Bank, suggested 

ways of improving 

stakeholder 

involvement in 

decision-making for 

dams. 

anticipated that production could increase by around 

60 000 MWh/year, and the decrease in CO 2 emissions 

would be about 60 000 tonnes. 

Prof V. Broza, President of CZCOLD, spoke of the 

historical tradition of hydraulic works in the Czech 

Republic, which, he said, dated back to the 12th century. 

During the 16th century, some quite complex 

waterways had been constructed, and in that era about 

70 000 small dams existed, mainly for fish production 

and flood protection. Water power development had 

begun in the latter part of the 19th century, and had 

peaked in the second half of the 20th century. Today 

the potential for hydro development was limited, 

Broza said, but he drew attention to the important role 

of pumped storage for the country, noting that more 

than half of the country’s peak load today was covered 

by pumped-storage stations. 

On behalf of ICOLD, one of the main supporting 

organizations of HYDRO <strong>2011</strong>, Secretary-General 

Michel de Vivo set out some world statistics which 

underlined the important role of dams. He pointed out 

that there were currently about 50 000 large dams in 

the world, and about one million small ones. He 

looked at trends in dam construction in Asia, and in 

some of the emerging countries such as Brazil. 

He noted that the world population was expected to 

reach 9 billion by 2050, and there would be a major 

concentration in the cities, leading to significantly 

increased electricity consumption. In addition, the living 

standards of the emerging countries, and the 

impacts of new technology would lead to additional 

major increases in electricity demand. It was predicted 

that water consumption would double by 2050, and 

electricity consumption would triple, De Vivo said. At 

the same time, water supplies could be more unevenly 

distributed as a result of the effects of climate change. 

It was urgent, in these circumstances, to address these 

challenges, and to develop more large-scale water storage 

facilities, he said. 

De Vivo anounced that a World Declaration on Dams 

and Reservoirs for Human Sustainable Development 

was being drawn up, in conjunction with the other professional 

associations related to water, and this would 

be signed at the next ICOLD Congress in Kyoto in 

June 2012. The aim was to encourage all stakeholders 

to be ready to face the water and energy challenges of 

the coming years. 

Dr Andy Hughes of Atkins, UK, gave an opening 

address which expressed concern about whether there 

would be enough engineers in the future with the right 

skills for the profession. This was currently an issue in 

many parts of the world, he felt, and the situation seemed 

to be getting worse. In a recession, he noted, training and 

R&D could often be sacrificed to save money. 

Apart from the need for adequate investment, 

Hughes said, there was also a need to attract young 

people to the dam and hydro profession, and to promote 

the aspects of the work which were interesting 

and rewarding. Another problem, Hughes contiunued, 

related to the status of the engineer in society. People 

tended to regard engineers as those who mended televisions 

or cars, and were often unaware of the skills 

and responsibilities of the dam engineer. 

He stressed the need for management strategies to 

ensure that the necessary skills base could be retained 

within companies, and that adequate resources could 

be allocated to training. Experienced engineers, 

Hughes felt, should have personal targets to pass on 

their expertise to junior staff. 

Alessandro Palmieri, Lead Dam Specialist at the 

World Bank, gave a keynote address in which he 

reflected on the past few decades of decision-making 

in the field of dams, current practice, and what could 

be in store for the future. 

He predicted that decision-making concerning dams 

was always likely to remain somewhat controversial, 

as a lot was at stake when a large structure was built. 

But on the other hand, the multipurpose function of a 

large dam and reservoir was unique, and could not be 

replaced. The key to reducing the controversy, 

Palmieri said, was to focus on the decision-making 

process, which in his opinion had three essential ingredients: 

• a good needs assessment; 

• the involvement of stakeholders; and, 

• an analysis of alternatives. 

Decision making for dams, Palmieri said, had steadily 

progressed from involving engineers only, to bringing 

on board economists, then environmental impact 

assessments, with the integration of environmental and 

social experts, and finally, in recent decades, involving 

affected people. 

Today the concept of holding a stakeholder forum 

was common, and while this could sometimes be inefficient, 

Palmieri observed that nothing better had yet 

been found to replace it. To make the process more 

30 <strong>Hydro</strong>power & Dams Issue Six, <strong>2011</strong>

efficient, he suggested that two main associated risks 

should be addressed: 

• low commitment and responsiveness in terms of 

timely outcomes (long talks with no focus on specific 

needs); and, 

• excessive focus on perceptions rather than facts. 

On this last point, he added that the engineering profession 

clearly had a responsibility to make sure that 

scientific facts were incorporated in the decision-making 

process; in effect, efforts should be made at least to 

base decisions on “fact-informed perceptions”. 

Regarding stakeholder involvement, Palmieri 

stressed the importance of reaching out to the real 

voices of local people. “Civil society voices are often 

confused with the loudest voices”, he said, adding 

that it was important to listen to all voices, but to 

devote the maximum resources to project-affected 

stakeholders. 

He also underlined the importance of improving 

project benefit flows, and in particular, bringing some 

of the benefits to local people before the start of construction, 

for example training or the development of 

programmes around the project. 

Turning to a few aspects of the very broad topic of 

environmental management, Palmieri advocated a 

catchment area approach, noting that even small projects 

could lose their beauty when spread over a whole 

catchment. Cascade developments could be a good 

alternative, he said, adding that cumulative impact 

assessment could optimize this kind of development. 

In the case of storage schemes, adaptive management 

was important, for example to address the issue of 

changes in downstream flow regimes. 

Storage conservation was also essential, Palmieri 

said, so sedimentation management should be fully 

taken into account. He also suggested that carbon 

finance could be used to mitigate unforeseen impacts 

during operation of a project. 

In conclusion, Palmieri said that it was important not 

to forget the basics. “Dam engineering is a very challenging 

profession covering a lot of skills”, he said. “It 

is multidisciplinary and you cannot do everything 

alone”. He added that teamwork and knowledge sharing 

were essential, and in this respect conferences such 

as HYDRO <strong>2011</strong> played an important role. 

Financial and economic aspects 

Approaches to project finance 

J-M. Devernay, EDF, France 

The first session of HYDRO <strong>2011</strong> was a panel discussion 

addressing some of the barriers that governments 

and developers have to overcome to secure finance, 

especially in the poorest countries. 

The panel brought together a diversity of experience 

and views, including the World Bank and EBRD’s perspectives. 

Those attending the session also contributed 

very actively to the debate. 

It was recalled that according to the recent IPCC special 

<strong>report</strong> on renewables, hydropower’s contribution 

to the world energy mix is expected to double by 2050. 

The corresponding funding requirements are likely to 

be more than US$ 40 billion each year over the next 

decades. It is therefore critical that private equity and 

loans be extensively mobilized along with more traditional 

public funds, under public private partnership 

arrangements. Several key recommendations emerged 

from both the panel and the floor, including: 

• the need for governments to reinstall economic 

analysis on the top of their strategic decisions, and not 

let those be governed only by financial considerations; 

• a fair, transparent and realistic allocation of risks 

between the various parties involved, whether public 

or private; 

• a strong regional collaboration between countries, 

which is often necessary ito extract the full value of 

the natural resource, especially for multiple purpose 

schemes; 

• comprehensive project preparation; and, 

• it was strongly recommended that the current trend 

towards EPC or turnkey contruction contracts be systematically 

questioned, as EPC may not always be the 

best model to achieve risk mitigation, cost effectiveness 

and quality. 

Financial and commercial aspects 

Judith Plummer, The World Bank/University of Cambridge, UK 

The commercial session continued smoothly from the 

earlier session on finance, with papers on the roles of 

the different documents involved in a hydropower 

finance transaction, as well as the role of a publicly 

owned company in public-private partnerships, and 

the performance of hydropower in the carbon finance 

market. Specifically, the first paper considered the 

legal and financial documents underpinning the Nam 

Theun 2 project, the nature of each and their importance 

to the stakeholders in the project. 

Left: Ian Brown of 

EBRD reviewed his 

bank’s activities in 

RE financing, and 

called for a thorough 

approach to 

managing risk, to 

smooth the way to 

hydro project 

financing. 

Above: One of the 

panels on finance, 

chaired by Jean- 

Michel Devernay 

(shown left), stressed 

the benefit of 

regional 

collaboration, and of 

comprehensive 

project preparation. 

Also shown: 

panellists Judith 

Plummer, Chris Head 

and Peter J.Rae. 


Above left: 

Xaypaseuth 

Phomsoupha from 

the Lao Ministry of 

Energy focuses on 

project finance in his 

country. 

Centre: E. Branche 

of EDF demonstrates 

hydropower’s good 

performance in the 

CDM process. 

Right: Judith 

Plummer, World 

Bank/Cambridge 

University underlined 

the importance of 

economic analysis. 

The second paper considered the performance of 

hydropower in the carbon finance market and pointed 

out how much more efficient than some other renewables 

hydropower had been at delivering the carbon 

emission reductions estimated in its agreements. This 

showed that if well prepared and well designed, a 

hydropower project had limited operational risks and 

the ability to control its output, resulting in a wide 

range of capacity factors. Thus hydropower has been 

the most successful emissions reduction category in 

the Clean Development Mechanism (CDM) to date in 

terms of registered projects. Furthermore, hydropower 

is seen to be the strongest performer among all renewable 

energy projects, reflecting the high quality, reliability 

and maturity of this technology. Biomass and 

wind projects have performance indicators similar to 

hydropower, but with a lower reliability. 

The third paper considered the role of a public energy 

company in a robust and growing energy market 

such as Brazil. For a public company with the technical 

know-how and the necessary leverage to draw private 

enterprise into partnerships, questions still remain 

as to the best approach and most important considerations. 

The lessons learned from the ventures to date are 

that such public companies should: 

• know each project in depth through thorough investigations 

and information sharing; 

• pay close attention to planning, returns and cost control; 

and, 

• manage risks and ensure that they have a say in the 

ventures’ control and governance. 

The participants and audience then had a fascinating 

interchange on a range of questions, and also picked 

up on some of the areas remaining from the earlier discussion 

on finance. These concluded with a discussion 

of whether “finance” (bankers) or “projects” were to 

blame for the failure of projects to reach financial closure. 

The responses pointed to the fact that many projects 

were not well enough prepared nor did they have 

a well managed risk profile with which to attract 

finance. 

The session pointed at a change in the nature of discussions 

on finance and commercial issues with a 

greater concentration on detail and lessons learned 

now that there is a wider range of transactions from 

which to learn. 

How can governments ensure they are getting the best 

value for their hydro resources? 

Chris Head, Consultant, UK 

The Chairman of this session, Chris Head, began by 

pointing out that in most countries the hydro industry 

was evolving from a situation where the private sector 

was simply substituting for the national power utility 

in the generating role, to one where private companies 

were being licensed to develop hydro resources for 

onward sale to third parties. In the former situation, the 

power was sold back to the domestic consumers 

through the utility; in this closed loop situation there 

was no need to value the hydro resource explicitly 

because the State would generally not seek to levy 

heavy royalties which would adversely impact on the 

tariff. 

However, the position changes when the direct relationship 

between the State, as the owner of the 

resource, and its citizens, as consumers, is broken. 

This occurs in the case of export projects, or captive 

projects (auto-producers), or merchant plants. In such 

open-loop situations, the interests of the host government 

are best served by ensuring that energy is sold at 

the highest possible price, as this improves the 

prospect for a strong flow of royalties and taxes. In this 

respect the concession process is similar to granting a 

licence to a mining or oil company: the experience of 

these extractive industries has some relevance to that 

of the hydro industry. 

However, hydropower poses a number of unique 

problems, including the extremely long concession 

periods that are needed to make projects feasible for 

Chris Head, UK 

(left) chaired a panel 

on long-term 

concessions. Richard 

Metcalf of Norton 

Rose (centre) 

contributed a legal 

perspective to the 

discussions, and José 

Matola represented 

Mozambique on the 

panel. 


private investors, and the fact that most projects are 

captive in the sense that their output cannot be freely 

traded. This means that concessions being negotiated 

now under current market conditions may still be valid 

in 2040 and beyond. There must inevitably be some 

concerns over how robust they will prove to be in 20- 

30 years time. 

A high level panel with representatives from the different 

type of organisations involved in negotiating 

hydro concessions was assembled to discuss these 

issues. It included: 

• Bruno Trouille, Vice President, MWH Consulting 

Engineers (USA); 

• Richard Metcalf, Partner, Norton Rose LLP, 

Lawyers (UK); 

• Chhewang Rinzin, Managing Director, Druck Green 

Power Corporation (Bhutan); 

• Xaypaseuth Phomsoupha, Director General, 

Department of Energy Promotion and Development 

(Laos); 

• Peter Rae, Principal, PJR Consulting (Canada); 

• Sandy Tickodri Togboa, Chairman, Uganda 

Electricity Generating Company Ltd; and, 

• José Matola, Senior <strong>Hydro</strong>logist, Hidroelectrica de 

Cahora Bassa (Mozambique). 

In his introductory remarks, one panellist spoke of 

the need to capture the wider benefits of hydropower, 

pointing out that most market models failed to value 

ancillary services and other multipurpose benefits in 

monetary terms. This would need to change as 

hydropower increasingly becomes a tradable commodity, 

and governments strive to recover the full value of 

their resource. 

Speaking from the perspective of a lawyer with experience 

of both the power and extractive industries, 

another panellist drew attention to the fact that ultimately 

most concession agreements allowed a host 

nation to repossess a project on the basis of fair valuation. 

This appeared to be occurring more frequently, 

but there were serious problems in agreeing the terms 

for re-possession, particularly in the case of captive 

hydro projects where there may be no alternative offtaker. 

The power sales arrangements for the 2075 MW 

Cahora Bassa project in Mozambique were cited as an 

illustration of the way in which PPAs could be overtaken 

by events. Most speakers agreed that inflexibility 

of concession agreements posed a problem, and 

acknowledged that there were generally insufficient 

mechanisms in place for reviewing royalties and tariffs 

in the face of changed circumstances. This was not 

solely a monetary problem, but also one relating to the 

freedom of host governments to alter water resources 

management priorities over time. 

When it came to concession models, it was suggested 

that a private hydro scheme could be treated as a 

process plant where the owner had no interest in the 

downstream sale of the power. Comparisons with the 

extractive industries might be useful, and there could 

be benefit in looking at production sharing contracts 

used in those industries. However, the consensus view 

was that there was no ready-made solution to be 

derived from external sources, and one speaker who 

had worked in both mining and hydropower cautioned 

against taking the mining industry as a model for concession 

arrangements. 

One advantage that the extractive industries had over 

most private hydro projects, it was pointed out, was 

that their product could be sold on international markets 

for hard currency at prices that could be benchmarked. 

This is generally not the case for most private 

hydro projects in the developing world, although the 

situation is improving as transmission links are 

extended and regional power pools are becoming better 

established. This will increase the urgency for governments 

to have a clearer understanding of the value 

of their hydropower resources, but it should also make 

it easier to build more flexibility into long-term concession 

arrangements. 

Climate, environment and carbon emissions 

Climate change and hydrology 

Prof. Luis Berga, Hon President, ICOLD; and UPC, Spain 

The implications of climate change to the hydrological 

cycle and to water infrastructure and hydropower were 

analysed in the session. Trends observed during the 

20th century and the projected changes for the 21st 

century relating to climate change with regard to 

floods and hydropower generation were discussed. 

Important uncertainties concerning the projected 

changes relating to climate change were also outlined. 

In general, it was agreed that there is no evidence 

from the last decades that the upward trend of floods, 

and extreme floods has been caused by climate 

change, rather than natural variability. The dominant 

drivers of the upward trend in flood damage are socioeconomic, 

such as land-use change, economic growth, 

and increases in population and in the wealth concentrated 

in vulnerable areas. The projected changes show 

that it is likely that floods will increase in intensity and 

frequency in most regions of the world, increasing 

flood risk, although, it is difficult to disentangle the 

Far left: Dr Sandy 

Tickodri-Togboa of 

UEGCL, Uganda, 

added experience 

from Bujagali to the 

panel on concessions. 

Prof Luis Berga of 

Spain chaired the 

session on climate 

change and 

hydrology. He 

pointed out that there 

was a need for more 

clear evidence 

concerning the 

upward trend in 

flooding, and the 

various possible 

drivers of climate 

change. 


Dr Asit K. Biswas 

gave a powerful 

keynote address on 

‘<strong>Hydro</strong>power, 

poverty alleviation 

and climate 

change’. 

climate change component from strong natural variability 

and direct human impacts. 

<strong>Hydro</strong>power and climate change affect each other in 

two ways. On the one hand, it was agreed, hydro, 

which is a clean renewable and environmental friendly 

source of energy, produces on average 3348 

TWh/year, yields 16 per cent of the world’s generated 

electricity, which represents about 90 per cent of 

renewable electricity generation, and prevents the 

emission of more than 2 × 10 9 tonnes of CO 2. On the 

other hand it is likely that climate change will alter 

river discharge, resulting in impacts on water availability 

and regularity, particularly hydropower generation. 

In general, the impacts of climate change on 

hydropower generation could be locally variable 

depending on the changes in the flow regimes, and on 

the effects of the glaciers and snow melting. At world 

level (IPCC SRREN <strong>report</strong> <strong>2011</strong>) it has been concluded 

that the overall impacts of climate change on existing 

global hydropower generation are expected to be 

small, or even slightly positive. However, results also 

indicate the possibility of substantial variations across 

regions and even within countries. In conclusion, the 

analysis, assessments and projections of impacts of 

climate change are uncertain, and in some cases contradictory. 

Climate change poses a conceptual challenge 

to water and hydropower managers by introducing 

uncertainty in future hydrological conditions. The 

projections cannot provide decision-makers with exact 

information on the rate of future changes, but they can 

offer very useful general information, and could serve 

for a preliminary assessment. It was important, Berga 

said, that the trends and data on hydropower generation 

should be well monitored and analysed closely in 

the future to implement well informed adaptive management. 

The presentations of the session began with a 

keynote address by Dr. Asit K. Biswas on ‘<strong>Hydro</strong> - 

power, poverty alleviation and climate change’. Dr. 

Biswas showed that there were considerable direct 

linkages between hydropower, economic development 

and poverty alleviation, and he described the significant 

case of Bhutan. <strong>Hydro</strong>power developments in 

Bhutan had significantly improved the socio-economic 

status of people. Biswas remarked that in addition to 

the uncertainties of climate change, the water profession 

sgould address many other uncertainties that were 

likely to be faced in the future. Among these were the 

rate and the structure of the future population growth 

in different parts of the world, economic growth rates 

of the future, food and energy requirements and how to 

manage them, and the development of numerous feedback 

loops caused by economic, social, and political 

factors. He concluded that for developing countries, it 

was imperative to build additional infrastructure to 

store water: they simply had no other choice. Whether 

climate change takes place or not, and irrespective of 

the magnitude of these changes, such countries will 

have to construct storage structures simply to account 

for the ‘normal’ climatic fluctuations. If there were 

more extreme rainfall events because of climate 

change, such structures would be even more necessary 

in the future. However, all such storage structures 

should be built in an environmentally friendly and 

socially acceptable manner, Biswas added. 

Another speaker described the design of a diversion 

scheme and flood management during the construction 

of an RCC dam in Laos, showing the advantages of 

RCC in relation to hydrological safety. Other papers 

refer to the technical design of the hydrological monitoring 

system for the Jinsha river closure at the 

Xiangjiaba hydroscheme in China, and the streamflow 

prediction based on satellite and in situ measurements 

for hydropower operations in central Chile. Also the 

incorporation of global warming into design flood was 

analysed and discussed for the case of Bagatelle dam 

in Mauritius. 

Finally, a summary of a guidance document on the 

potential impacts of climate change on dams was presented. 

These guidelines provide a structured approach 

that can be used by dam owners and operators to evaluate 

the potential impacts of climate change on their 

dams and reservoirs. One of the key conclusions of the 

study was that the risk assessment and evaluation of 

adaptation measures could be carried out rapidly and 

efficiently using this document, in a way that was 

designed to fit in with the existing management 

processes. In most cases the majority of the risks could 

be screened out rapidly, and the remainder could be 

evaluated to an acceptable level using lookup tables, 

outline guidance and hydrological information provided 

through national level <strong>report</strong>s or existing studies. In 

the shorter term, adaptation responses would generally 

only involve changes in monitoring and pro-active 

maintenance, unless there was significant, known vulnerability 

to weather variations. 

Environment 

Cecilia Tortajada, <strong>International</strong> Centre on Water and Environment, 

Spain; and Maria Antonieta Gomez Balandra, IMTA, Mexico 

This session included the presentation of case studies 

from Brazil, Finland, Iran, Laos, Mexico and Zambia. 

The main issues raised in the presentations referred to 

environmental losses and economic gains of existing 

hydropower plants, environmental impact assessments 

(EIAs) for cascade systems at the basin level, impacts 

of dam construction on wetlands, ecological restoration 

of impacted areas, importance of impounded vegetation, 

importance of preserving tropical fish biodiversity 

both at the regional and local levels, protection 

and control of invasive species, and innovative technologies 

which protect aquatic life. 

It was clear that there is a need to move forward from 

conventional approaches to more innovative ones, to 

balance the economic benefits and environmental 

impacts of hydropower plants. For example, Brazil 

uses economic and environmental indices that provide 

a ratio between environmental impacts and economic 


gains and thus, at least theoretically, an idea of the 

dams that are better than the others. The ideal combination 

for a hydroelectric plant would be one that minimizes 

the flooded area and implementation costs, but 

equally installs the maximum capacity. However, as 

important as indices are, it is necessary to analyse the 

information behind them. For example, it has been 

found that mega projects (more than 5000 MW) could 

be less attractive because of their total implementation 

costs, even when these implementation costs include 

mitigation of environmental impacts, which are representing 

a higher percentage of the total cost of the 

project. Equally, old projects could be more attractive 

in terms of costs, except that these had less consideration 

for environmental impacts. On an overall assessment, 

mega projects (5000 MW) have environmental 

and economic costs similar to those that produce 

between 3000 and 5000 MW, and even ordinary projects. 

Based on this conclusion, mega projects should 

be supported. Nevertheless, it is the benefit of the project, 

and its environmental and financial costs for each 

installed megawatt, which should be consider on every 

project. 

Moving forward to a more integrative, regional and 

long-term assessment would be more useful for some 

governments or state energy companies, to promote 

more realistic opportunities to improve the quality of 

life of local communities, protect the environment and 

promote hydro development. Scientific and practical 

solutions applied in Brazil have provided long-term 

work to affected and local population at the same time 

that environmental responses are followed under an 

adaptive approach. 

The accomplishment of environmental regulations is 

an important issue to be fulfilled for all projects, but it 

is not a warranty that they can be considered successful. 

Many projects are developed in poor areas where 

more concerns are on primary human needs rather than 

on ecological preservation. Therefore, environmental 

education is being considered an important part of 

their wellbeing and potential local work. 

<strong>International</strong> agreements on freshwater and the protection 

of forest ecosystems have made hydropower 

developers realize the importance of working with 

several public and private sectors (water, environment, 

agriculture, forestry and fisheries, among others) in the 

development of socio-environmentally sound regional 

plans that include hydropower development (Strategic 

Environmental Assessment SEA) as engines for 

regional development. 

Problems at basin level are very complex and have 

multiple causes. Therefore, concerns and individual 

actions for natural resources preservation like wetlands, 

terrestrial flora and aquatic fauna, are not 

enough to achieve the integrative conservation goals at 

basin level. It is important that governments, society 

and academic institutions work towards practical solutions 

and long-term research that go beyond the EIA 

and do not depend only on hydro promoters’ budgets 

but on those of the states, national and international 

agencies and universities. 

On the issue of clearing of vegetation from reservoirs 

before impoundment to improve water quality and 

reduce GHG emissions, it was agreed that the main 

source of biomass comes from soils rather than flooded 

vegetation. In fact, leaving vegetation seems to 

have less impact than cutting it or burning it off. In any 

case, this situation needs to be reviewed case by case. 

Some advances in a 3D hydraulic model to reduce 

fish mortality in turbines were presented as an example 

of the complex solutions that the hydro industry 

has developed in this regard. On this same subject, 

results of a methodology developed to evaluate fish 

mortality risk and diminish impacts on native ichthyofauna 

were also discussed. 

The discussions during the session demonstrated 

once again the importance of inter- and trans-disciplinary 

work in terms of hydropower development and 

environmental protection. Practical and innovative 

solutions are needed to improve the environmental 

performance of hydro in the long-term. 

Managing reservoir emissions 

Niels Nielsen, IEA <strong>Hydro</strong>power 

More than 20 years ago, studies identified that the 

inundated area behind dams was a potential source of 

gaseous emissions, and during the last decade this 

issue broadened to include the role of reservoir GHGs 

in the climate change debate. 

The session began with presentations of the three 

submitted papers. The first speaker questioned 

whether the issues relating to GHG emissions from 

reservoirs were being dealt with appropriately. He 

identified a number of potential concerns, including 

the importance and difficulty of assessing the net 

emissions attributable to reservoir inundation, the spatial 

and temporal behaviour of these emissions and the 

challenges associated with measurements of degassing 

through turbines and other hydraulic discharges. 

Anthropogenic emissions not attributable to the reservoir 

need to be determined and taken into account, as 

well as the effects of reservoir operation on GHG 

emissions. 

The second speaker discussed the monitoring and 

evaluation of a hydro project under construction in 

Left: Dr Cecilia 

Tortajada, co-chairing 

the session on 

environment: “Practical 

and innovative solutions 

are needed to improve 

the environmental 

performance of hydro in 

the long term”. 

Dr Maria Antonieta 

Gomez Balandra, cochair 

of the session, 

called for a multidisciplinary 

approach to 

protecting ecosystems, 

and advocated strategic 

environmental 

assessment as an engine 

for regional 

development. 


Niels Nielsen, IEA, 

chairing the 

workshop on carbon 

emissions from 

reservoirs. “The 

science is evolving 

from a generalized 

assessment of 

reservoir emissions to 

specific and focused 

investigations of all 

variables, and their 

influence on 

hydropower 

development”. 

Right: Prof M. 

Aurelio dos Santos of 

Brazil presented a 

paper questioning 

whether the issue of 

emissions was being 

dealt with effectively. 

central Brazil. Monitoring would cover the river, soil 

coverings and hydro plant discharges over the full 

range of variable parameters. Measurement of CO 2, 

NH 4 and N 2O has already started in the prefilling 

phase of the project and will continue both during 

and after impounding. Analysis will investigate the 

variables that affect the emissions of GHG from the 

reservoir. 

The final speaker noted that as much information on 

reservoir emissions emanates from South America, 

gathering data from other parts of the world is an 

important task. He presented an update of findings and 

modelling from three hydropower projects in Laos. 

These projects vary in age from 40 years to recent construction 

and also have a variety of pre-impoundment 

land-uses and have undergone different inundated-area 

clearance practices. Analysis and modelling of the 

results show significant variability, with the older 

reservoir nearing equilibrium, and the younger ones 

still being carbon sources. 

The panel discussion generally focused on the work 

of the IEA <strong>Hydro</strong>power research project which is 

investigating reservoir emissions. This involves an 

extensive programme of monitoring and analysis of 

GHG emissions, and will develop a predictive model 

covering their management. 

Dr J. Damazio (Brazil) provided a summary and 

update of the IEA research project. He noted that 

Volume 1 of the Guidelines for Quantitative Analysis 

of Net GHG Emissions from Reservoirs had been 

drafted and would soon be distributed for review. 

Volume 2 covering modelling would be initiated next 

year, he said. The extensive measurement programme 

on eight existing and three new reservoirs, over a period 

of two years, was well underway, with preliminary 

results being analysed. A complex database had been 

developed to collect and analyse all the data, and for 

eventual linkage with the models. 

Dr Jukka Alm (Finland) discussed the gaps in GHG 

data and approaches. These covered areas such as 

what should be measured or evaluated, the gaps in 

available data for gross, net and anthropogenic contributions, 

challenges in the estimation of the unrelated 

anthropogenic sources (UAS), and testing the data 

and approaches through external review. In the latter 

category, themes to be covered in a review would 

include: 

• clarification of the state-of-the-art of global know - 

ledge; 

• identification of the major issues missing from that 

know ledge; and, 

• testing of the applicability of the present approaches 

with data so far collected under different conditions. 

Tormod Schei (Norway) briefly summarized the 

IPCC Special Report on Renewable Energy Sources 

and Climate Change Mitigation (SRREN), issued in 

May <strong>2011</strong>, of which he was a principal author of the 

chapter on hydropower. In the analysis of reservoir 

emissions, one of the conclusions reached had been 

that additional carbon may be introduced to the reservoir 

from human sources. Carbon and nutrient contributions 

from these UASs may be considerable, based 

on the land use practices in the catchment and discharges 

to the reservoir. An example was given of a 90 

year-old reservoir in a temperate region of Europe, 

where significant emissions were still occurring, especially 

on warm summer days. 

Alm and Schei jointly discussed the three-part decision 

tree they were developing for estimating GHG 

emissions resulting from impoundment of a reservoir: 

• Tree 1. Determining net GHG emissions caused by 

impoundment. 

• Tree 2. Estimating the anthropogenic contribution to 

gross GHG emissions from the reservoir and downstream 

reach. 

• Tree 3. Identifying the nutrient and carbon load for 

GHG emissions caused by UAS. 

Dr Alain Tremblay discussed a hydropower project 

in a boreal area of Canada, where measurements had 

been taken over seven years. By far the greatest proportions 

of emissions were found to be through surface 

diffusion. Lessons learned, he said, included: 

• Sampling techniques are not an issue. Similar results 

were obtained using three different techniques. 

However, a good sampling strategy is important. 

• Aquatic systems must be measured. A cost-effective 

means is through an automated system. 

• Terrestrial ecosystems (forest and peat land) can be 

estimated with data obtained from the literature 

Dr Brennan Smith (USA) provided an overview of 

GHG reservoir measurements in his country. In the 

first year of a three-year programme, measurements 

and analysis of net emissions had been obtained from 

one reservoir in the eastern USA. Initial results had 

indicated that temporal variations were greater than 

spatial variations, emissions were comparable to similar-aged 

boreal and Western US reservoirs, and seasonal 

hypoxia existed in the tailwater of dams with 

elevated CO 2 emissions 

The 2012 sampling in the southeast of the USA 

would involve a synoptic survey of multiple reservoirs 

during summer stratification to examine the degree of 

‘between reservoir’ variability. The longer term objectives 

of the programme, he said, were to investigate 

carbon cycling as a function of reservoir age and 


analyse trends in carbon cycling behaviour through 

monitoring 

Prof Pinguelli Rosa (Brazil) presented a proposed 

alternative to the Global Warming Potential (GWP) 

index, which had been adopted and developed by the 

IPCC to compare the greenhouse effect of different 

gases. It is believed that GWP does not appropriately 

represent the relative contribution of the different 

greenhouse gases to climate change, that is, its use 

may overemphasize and erroneously stress the importance 

of greenhouse gases that remain in the atmosphere 

for only short periods of time, such as methane. 

The Global Temperature Potential (GTP) provides an 

alternative approach, by comparing global mean temperature 

change at the end of a given time horizon. 

Compared with the GWP, the GTP gives equivalent 

climate response at a chosen time, while putting much 

less emphasis on near-term climate fluctuations caused 

by emissions of short-lived species. 

Overall, the presentations and panel discussions covered 

the history, scientific arguments, policy suggestions 

and case histories from around the world. Key 

issues of note included: 

• The need for a coordinated approach to develop 

solutions that meet IPCC protocols 

• The acknowledgements that reservoirs emit GHGs 

and bury carbon as part of their life-cycle. At any point 

in time, and based on many variables, they may be net 

emitters or sinks. 

• It is important to understand and distinguish 

between gross emissions, net emissions, and unrelated 

anthropogenic sources, as they relate to reservoirs. 

In summary, it was noted that the science is evolving 

from a generalized assessment of reservoir emissions 

to specific and focused investigations of all the variables, 

their influence on the behaviour and ultimately 

their potential impacts on hydropower developments. 

The work of IEA <strong>Hydro</strong>power, IHA and individual 

companies and research institutions is converging 

through workshops such as the session in Prague, to 

deliver this understanding. 

Social issues, cultural heritage and 

communications 

Social aspects 

Lori Nielsen, IEA <strong>Hydro</strong>power 

The papers presented in this session reflected, in a 

variety of ways, two of the themes of Alessandro 

Palmieri’s Keynote address at the Opening Session: 

that in looking to the future we must recognize the 

importance of engaging all stakeholders in the 

hydropower development process, and that the role of 

communications is a vital one. 

The first speaker gave an account of the stakeholder 

engagement process adopted by Hidroeléctrica de 

Mphanda Nkuwa in the development of the Mphanda 

Nkuwa run-of-river scheme, 60 km downstream of 

Cahora Bassa dam in Mozambique. It is considered the 

priority project for the development of the region’s 

hydropower potential. 

The more intensive engagement process than usual 

had resulted in benefits for the ESIA process and, 

consequently, for the project and for its sustainability. 

The sequence of meetings held with stakeholders 

had allowed early identification of issues of concern, 

and suggestions for enhanced benefits and alternatives, 

which could be properly addressed in the 

<strong>report</strong> and also in the subsequent meetings. 

Stakeholders could then verify that their issues had 

been captured, and doubts could be progressively 

clarified, improving the presentations and, specifically, 

the visual materials used for communications 

about the project. 

The major outcome was an increase in trust in the 

process, and in the project, which is crucial for its 

social licence to operate. 

The necessity of engaging stakeholders with “soft 

voices” as well as those with “loud voices”, was 

addressed jointly by two speakers, arguing that unless 

all stakeholders were engaged, it would be impossible 

to carry out a full economic assessment of a project or 

identify all potential conflicts. In fact, if the full potential 

of a project is to be realised, it is not an option for 

large, key political or expert stakeholders not to 

engage in serious dialogue with less powerful stakeholders. 

The problem, however, is that the need to evaluate a 

project in economic terms using social cost-benefit 

analysis raises questions which are tricky using conventional 

methods, particularly when addressing losses 

sustained by stakeholders displaced by the project. 

In addition, given the complexity involved (the know l- 

edge and socio-cultural, or even linguistic, gaps 

between stakeholders) the particular local knowledge 

of local stakeholders may be wasted if they are not 

brought into the decision-making process at an early 

stage. 

The authors of one paper described their innovative 

approaches to these challenges: a simulation gaming 

model developed at Stanford Civil Engineering 

Department which had been used in several educational 

institutions worldwide, and which they see has a 

potential application in the hydropower development 

context. 

Far left: Dr A. 

Tremblay of Canada 

and Prof L. Pinguelli 

Rosa of Brazil, who 

presented their 

research and views 

concerning carbon 

emissions from 

reservoirs. 

Lori Nielsen, IEA, 

chaired a session on 

social aspects. She 

stressed the 

importance of 

engaging all 

stakeholders in the 

hydropower 

development process, 

and of having an 

effective system of 

communications. 


Karin Seelos of 

Statkraft, Norway, 


cultural heritage. “It 

is the hydropower 

sector’s legacy of 

combining 

innovation, pride and 

technical skills which 

has led to this 

discussion on 

challenges relating to 

the management of 

historically valuable 

hydropower plants”. 

The game involves ‘characters’ covering some 50 

roles, from policy makers, to beneficiaries and 

observers. The authors acknowledged that there were 

weaknesses and limitations of such forms of interaction 

and that considerable further work needed to be 

done in the field both to develop and test more effective 

gaming and simulation models, but they stressed 

that such a tool could provide valuable assistance in 

exploring the complexities of multi-objective, multicriteria, 

multi-stakeholder environments. 

If any large stakeholders are using such methods, the 

authors would like to hear from them. 

This was followed by a paper on how EDP is dealing 

with the negotiation of compensation measures relating 

to the socio-economic impact of the Fridão project 

in Portugal, in three counties in particular. 

The approach has been not only to compensate for 

the direct physical impact of the dam, but to improve 

on some local gaps that already existed. Prior to the 

negotiation process, experts in socio-economic issues 

had been hired to characterise the affected populations, 

identify these gaps and come to an understanding of 

individual needs and expectations in terms of compensation 

measures. The company’s goal was to create a 

situation where regional development projects would 

benefit the social and economic sustainability of the 

region. This will include improving the mobility of the 

populations, transforming some direct impacts of the 

project on roads and bridges (there are six bridges that 

need to be replaced), into better connections, reducing 

the isolation and enhancing local community life. 

In the case of the inundation of houses, the creative 

solution has been not only to provide new housing, but 

to create a new community with recreation facilities: a 

beach, harbour, artificial islands, and a slalom course 

on the dam. 

EDP has recognized the importance of establishing 

an open communication channel, believing that this is 

the best way to ensure that final solutions serve all parties, 

and the only way for them to feel involved in the 

project and became partners and not objectors. The 

author stressed the role of a good communication campaign 

and gave examples of the various formats and 

locations of these efforts. 

There will be a socio-economic monitoring programme 

throughout the development of the project, to 

ensure all measures are being accomplished. EDP is 

confident that its approach to, and design of, compensation 

measures will provide the basis for sustainable 

development of this whole region of the country. 

The session concluded with a paper on the implementation 

phase of resettlement, stressing that changes 

which lead to resistance go well beyond simply change 

of location. 

Resettlement has traditionally been seen as a physical 

relocation of people from areas impacted by a 

reservoir or construction into new or host villages, 

towns or cities. Less effort has been made regarding 

the process of rehabilitation in the long-term, and the 

creation of new, viable societies. 

The speaker went on to discuss the challenges to the 

success of resettlement ranging from changes in agricultural 

practices at one level, to the loss of historical 

context for the community and individuals, on another, 

with many examples from the Nam Theun 2 project 

in Laos used as illustrations. A prime example was the 

effect of the change in political order, with small 

groups from remote areas with limited government 

presence, being brought into the nation state with all 

the regulations and taxes that this entails. The bottom 

line was that people wanted freedom, and resettlement 

was involuntary even if what was being offered to 

those being resettled was an improvement to the material 

well being of communities. 

Compensation is a critical issue with the need to preempt 

exploitation and dependency. Research shows 

that the track record for resettlement in the long-term 

is not good. Although national regulations have 

improved, there is a need for more specialists such as 

sociologists to work on these challenges if outcomes 

are to improve overall. 

The papers provoked much discussion between the 

audience and the speakers on various aspects of their 

papers and the issues that were raised. 

Cultural heritage 

Karin Seelos, Statkraft, Norway and David Fleetwood, Historic 

Scotland, UK 

It is the hydropower sector’s legacy of combining 

innovation, pride and technical skills, which led 

HYDRO <strong>2011</strong> to address, for the first time in its conference 

history, the challenges related to the management 

of historically valuable hydropower plants. 

This came about as a result of collaboration between 

regulators and operators from nations where 

hydropower has played a pioneering role in the economic 

development of the country more than a century 

ago, such as Norway, Scotland, Canada, the USA 

and Sweden. 

The aim of this session was two-fold: to provide a 

platform to exchange experience on good practice; 

and, to establish a network to share this expertise on an 

ongoing and worldwide basis. 

Although the reasons why the first hydropower 

plants were built are unique, the challenges are similar 

when it comes to deciding which parts of our industry’s 

heritage should be preserved and how this should 

be done without causing an additional burden to the 

owner and operator. In many areas, hydropower was 

the first renewable energy source to supply power for 

the development of the basic industrial activities necessary 

to support the living standard of modern societies, 

such as railways, shipyards, aviation, mining, 

pulp and paper, fertiliser and aluminium production, 

sanatoriums and hospitals, or for the operation of ship 

locks on inland navigation channels, or simply to light 

up cities and households. 

In this session, regulators, hydro plant owners and 

operators, and museum managers presented the les- 


sons they have learned with respect to identifying and 

managing hydropower schemes of historic value. They 

also demonstrated how it is possible to create mutually 

beneficial situations by preserving important parts 

of our industry’s value creation for future generations 

without imposing further restrictions to renewable 

power generation. 

Government representatives from Norway and 

Scotland underlined the importance of developing a 

long-term management strategy for industrial heritage. 

The first step of such an endeavour is to gain a comprehensive 

overview of the existing assets through 

appropriate mapping and the establishment of a 

national inventory of industrial patrimonial sites. 

Second, they highlighted the close collaboration with 

the owners and operators at all steps of the classification 

and preservation process as a key element for success. 

The session also looked at the vital importance of recognizing 

the needs and requirements of the modern 

power sector, in considering and designating sites. The 

value of creating a partnership approach to future management, 

to ensure that any protection is sustainable for 

the industry, was a key theme. This will allow for partners 

both to celebrate and protect the historic and cultural 

interest of a site in the most effective way, by 

ensuring it remains at the cutting edge of active use. At 

the same time, it makes the recognition of industrial heritage 

a commercially and culturally attractive option. 

The case studies portrayed in this session illustrate 

that different approaches can be used. Examples were 

presented of government-led preservation initiatives, 

such as in Norway and Scotland, and of initiatives led 

by the local population, such as in Sweden. 

In Norway, the government and the King adopted a 

resolution in 2006, which compels each state-owned 

sector to elaborate a national preservation plan of their 

industrial heritage. This plan is an agreed-upon document 

in which the owner, the administrator and the 

cultural heritage authorities have the following common 

goals: 

• to take care of cultural, historical and architectural 

qualities of buildings; 

• to raise awareness about industrial history and value 

creation; and, 

• to lay the foundations for the different preservation 

modalities; 

Factors for success, from the operators’ viewpoint 

were identified as follows: 

• The best form of conservation is to keep the building 

or objects to preserve in use. 

• Clear assignments of responsibilities is key for the 

preservation of industrial and technical heritage 

throughout the whole organization: from leaders to 

those who operate and maintain the facilities. 

• A coherent internal management system comprising 

a corporate directive on industrial heritage protection, 

assessment methods and criteria to evaluate an installation’s 

industrial or technological heritage value, procedures 

for the elaboration of inventories, for maintenance 

and rehabilitation activities as well as to perform 

internal audits has proven to be an effective tool. 

• The assignment of a specialist who is knowledgeable 

about building structures, hydropower operation 

and maintenance activities as well as about industrial 

and technical heritage issues to support various managers 

in the implementation of internal management 

tools has given good results. 

• Databases were useful tools to administer the documentation 

related to sites and material of heritage 

value to guide managers who are responsible for these 

assets and to prove due diligence; 

The importance of raising awareness among the population 

about the value of hydropower in society was 

also discussed. Making a site accessible to the public 

was considered the most important condition for success, 

alongside the following: 

• guided tours organised in collaboration with local 

associations; 

• creation and administration of museums and conference 

centres; 

• thematic festivals, concerts and exhibitions or; 

• the possibility to rent the plants for special celebrations 

like weddings or other events; 

• internet sites which offer the possibility to visit the 

whole site and show important places as a 360º degree 

panorama via web cams, for example; 

• interactive web-sites for school children offering the 

opportunity to learn more about the local history, 

geography, the environment, physics and technology; 

• linking the site and its programme of guided tours, 

for example to regional touristic itineraries; 

• creating a local itinerary of interest for tourists and 

school children in collaboration with the local community 

to learn more through direct experience and 

site visits about regional development and the role of 

hydropower in supporting other local activities such as 

fisheries, industries, tourism, navigation or recreation. 

For example, the powerhouse of the Tyssedal hydro 

station, is used as a hall for concerts, exhibitions and 

for weddings. A national museum for hydropower and 

industry has been created nearby, as well as a confer- 

David Fleetwood of 

Historic Scotland, 

who contributed to 


cultural heritage. 

He stressed the need 

to collate information 

on how significant 

individual sites and 

schemes were, in a 

national and 

international context.. 

He announced that 

the session was 

spearheading an 

international initiative 

entitled ‘Digitising 

Heritage’. 

Creating public 

interest for 

hydropower: the 

89 MW Tyssedal 

plant in western 

Norway, built 

between 1906 and 

1918, is used as a 

venue for concerts, 

exhibitions and 

weddings. It is part of 

an application for 

recognition as a 

UNESCO World 

Heritage Site. 


Above: Gerhard 

Wedam of Enerjisa, 

Turkey, who discussed 

an advanced 

approach to 

population relocation, 

during the discussion 

on communications. 

Centre: Prof David 

Williams, CEO of 

BHA, who discussed 

ways to improve the 

image of hydro. 

Far right: Geraldine 

Schroeder of 

Storengy, Germany, 

who led the 

discussion. She felt 

the hydro industry 

was “somewhat late 

in the game of turning 

to communications 

issues”, which were 

essential in seeking to 

gain both public and 

political support for 

hydro. 

ence centre, and the site is part of the European Route 

of Industrial Heritage; recently a climbing trail called 

‘Via Ferrata’ has been set up above the power station. 

It allows people to discover new viewpoints on the 

fjord, the valley and hydropower, by climbing up a 400 

m-long and steep, rocky mountain wall on which the 

penstocks had to be fixed by hand 100 years ago. 

Besides presenting various national perspectives 

relating to operating hydro plants of historic value, this 

session also provided an overview of the international 

framework, which is currently structuring cultural heritage 

activities at the various national levels. 

The international organization responsible for 

administrating cultural heritage is UNESCO. The 

<strong>International</strong> Council on Monuments and Sites (ICO- 

MOS) formally advises UNESCO, but because ICO- 

MOS does not have expertise on Industrial and 

Technical Heritage, the <strong>International</strong> Committee for 

the Conservation of the Industrial Heritage (TICCIH) 

was mandated in 2000 to take on the role of advising 

ICOMOS on industrial matters. 

The UNESCO World Heritage Programme was 

founded with the Convention Concerning the 

Protection of World Cultural and Natural Heritage. 

The General Conference of UNESCO adopted this in 

1972. Since then, 186 states have ratified the convention. 

The definition of heritage comprises both natural 

and cultural dimensions of sites which demonstrate 

outstanding universal value from the point of view of 

history, art or science. 

Twenty years after the adoption of this convention, 

a review identified a lack of balance with respect to 

the type of protected properties and the geographic 

region. As a result, new categories of World Heritage 

Sites have been promoted, such as cultural landscapes 

and industrial heritage. It has thus been 

acknowledged that the preservation of industrial heritage 

such as hydro stations is clearly under-represented 

in the nomination of World Heritage Sites, 

because of a lack of assessment expertise. Who will 

sustain UNESCO in capacity building and in reaching 

a more balanced representation of different cultural 

heritage categories, if not experts from the 

hydropower sector? 

The session provided an opportunity to set this 

process in motion, by sharing good practice and making 

a bold statement that the sites which operators 

work on across the world on a day-to-day basis are not 

just assets in terms of their generation capacity, but are 

also highly significant for local and national culture 

and heritage. 

The manifest interest in the subject among the conference 

delegates makes it highly likely that next 

year’s conference in Bilbao will devote a session to 

industrial heritage management issues. All participants 

of the session in Prague concurred that the sharing of 

good practices and lessons learned is of particular 

value, especially in emerging domains such as the 

management of historic powerplants. This pioneering 

session created a strong response among the conference 

delegates, so that there might even be a need to 

arrange an expert meeting before the next <strong>Hydro</strong> conference 

in Spain, which is likely to take place in 

Scotland in early 2012. 

It is hoped that in future a panel on cultural heritage 

will not represent the shock of the new, but a continuing 

discovery of the value of the old. 

Communications issues for hydropower projects 

Geraldine Schroeder, Storengy, Germany 

Another new feature in the <strong>Hydro</strong> Conferences’ panel 

portfolio, was this year’s Panel on Communications, 

dealing with hydropower projects worldwide. It 

brought together an expert panel from the fields of 

public relations and public awareness, the legal profession 

and human resources, with a genuinely interested 

audience. 

The lively discussion showed that the much-underrated 

topic of communications surrounding large infrastructure 

projects struck a chord, and triggered a necessary 

discussion calling for continuation. 

The panellists and subsequent debate covered aspects 

such as: How can we join forces in ‘selling’ hydropower's 

many advantages? Which are the ways to introduce 

<strong>Hydro</strong> in students’ curricula? Also: How to create 

effective strategies for communications and public 

awareness in the face of sometimes false accusations 

and deliberate inaccuracies voiced by very professionally-acting 

adversaries to hydro projects? 

The panel highlighted the challenges of finding creative 

ways to win public and political support for large 

infrastructure projects in a changing public environment. 

Also, it was asserted that the hydro industry is somewhat 

late in the game to turn to the communications 

issues, and the necessity was stressed to join forces to 

build international leadership and alliances, as well as to 

put together sound arguments, and to have persistence 

and patience to disseminate them in an effective way. 

Of course, unsolved questions remained, but a number 

of shared experiences and even some ‘quick wins’ 

produced during the open discussion proved that the 


panel’s topic was a much needed one that should be 

built on at future events. 

Safety of water and energy infrastructure 

Safety of high hazard structures – After Fukushima, 

what about dam safety? 

Harald Kreuzer, Consultant, Switzerland 

This panel brought together experts from three high 

hazard structures: dams; nuclear powerplants; and, offshore 

oil platforms, to compare their similarities and 

differences regarding safety guidelines. 

The panellists were: 

• Horst-Michael Prasser, Professor for Nuclear 

Energy Systems at the Swiss Federal Institute of 

Technology (ETH) in Zürich, Switzerland; 

• Peter Burgherr, Head of the Technology Assessment 

Group at the Paul Scherrer Institute (PSI), the largest 

research centre for natural and engineering sciences in 

Switzerland; 

• Norihisa Matsumoto, Executive Director of the 

Japan Commission on Large Dams, Japan; 

• Alessandro Palmieri, Lead Dam Specialist, the 

World Bank; 

• Desmond Hartford, Engineering Scientist and expert 

for risk management at BC <strong>Hydro</strong>, Canada; and, 

• Harald Kreuzer, Engineering Consultant and Session 

Chairman. 

The question posed to the panel was: “What went 

wrong at Fukushima and in the Gulf of Mexico, and 

what could go wrong for dams?” 

“Similar problems, different practices”, according to 

Des Hartford; and this was the heart of the matter. 

It was interesting to hear about the widely diverse 

nuclear regional safety requirements. An example was 

that the envisaged safety upgrade at Fukushima after 

the disaster, corresponds to long-standing requirements 

in most European countries. One element of the 

failure chain in Fukushima was the flooding of the 

diesel unit, an incident which would not be possible at 

Swiss nuclear plants because safety standards require 

that the diesel units are classed equally to the reactor 

building: they are bunkered in a container which could 

withstand an air crash, earthquake, or a major flood. 

To mitigate tsunami damage, the Japanese 

Geotechnical Society (JGS) had suggested relocating 

residential areas as shown in the Figure (right). 

The overall performance of dams during the M9.0 

Tohoku earthquake was satisfactory against severe 

shaking with an extremely long duration of the motion. 

It did cause, however, the failure of an old (1949) 

small earth dam, resulting in eight fatalities. 

Fascinating to hear about was the well organized 

emergency planning for public transport. Railway traffic 

was stopped immediately after the quake, by preearthquake 

triggered alarms and by automatically activated 

emergency brakes at the high-sped Shinkansen 

line, avoiding passenger fatalities. 

A central cause for the accident at the Deepwater 

Horizon (DWH) oil platform (at el. 1520 m, one of the 

deepest of 4000 in the Gulf of Mexico) was the failure 

of a cement barrier to ensure the well’s integrity, leading 

to unusually high well pressure and subsequent 

blowout at this platform 400 km from the shoreline. 

The loss of life and pollution from the DWH accident 

was the result of: 

• a series of last-minute changes; 

• violation of safety procedures; 

• poor risk management and emergency planning; 

• failure to observe and respond to critical indicators; 


• inadequate well control response. 

This supports the notion that devastating accidents 

are rarely mono-causal. Recent research at PSI also 

indicates that deep and ultra-deep offshore installations 

used for exploration exhibit elevated accident 

risks reaching the threshold of technical mastery. 

Now, how does this compare with dams? 

Similarities to a common dam safety culture is that 

safety is becoming increasingly a political issue, no 

longer left to engineers alone, mitigating failures 

Panellists discussing 

approaches to risk 

concerning high 

hazard structures. 

Far left: Dr Des 

Hartford (BC <strong>Hydro</strong>) 

and Chairman Dr 

Harald Kreuzer 

(Consultant); centre, 

Prof N. Matsumoto 

(JCOLD); and above 

Prof H-M. Prasser 

(ETH, Zurich). 

Relocation of the 

population proposed 

by the Japanese 

Geotechnical 

Society, to mitigate 

tsunami damage. 


Far right: Michel 

Poupart, France, 


dam safety. “Dam 

safety is not just a 

theoretical concept, 

but a concrete set of 

arrangements taken 

by states, regulators, 

owners and operators. 

These include 

engineering and 

operational activities 

on the one hand, and 

management systems 

to organize these on 

the other”. 

On the left of the 

photo, 

M. Kalabegishvili of 

Georgia, who 

discussed geological 

problems at Enguri 

dam. 

needs a systems approach, that means, it needs a coordinated 

reaction between engineering, maintenance 

and operation activities. This leads inescapably to a 

risk-informed approach including risk-based decision 

criteria, which stand up to legal and public scrutiny. 

Uncertainties should be (but rarely are) built into the 

construction specifications and lifecycle safety planning 

is mandatory (surveillance and operation). A certain 

complacency is spreading in safety management, 

and the profession experiences an intrinsic difficulty in 

preparing disaster response plans, conceptualizing an 

event occurring under an unpredictable chain of situations. 

This is a problem: many accidents are caused not 

by design-basis event failures but ‘unusual combinations 

of usual conditions’. 

However, one thing considered unique to dam safety, 

and unlike the nuclear and oil industry, was that the 

impact of human error could not be evaluated statistically 

for quantitative safety assessments. Social equity 

considerations are not always in favour of safety budgets, 

and sometimes fatalistic and inconsiderate curtailing 

of pre-construction expenditure (study of alternatives, 

geological and hydrological investigations), eliminates 

the possibility to manage post-construction risk. 

More and more common is finance-driven scheduling, 

by increasingly non-engineering stakeholders, to curb 

the impact of market volatility. Large numbers of smaller 

dams may be ‘left in oblivion’ with a failure probability 

(6.10 -4 ), two orders of magnitude higher than for 

large (ICOLD) dams. Another category which does not 

exist within the other two high hazard structures is the 

shift of construction into developing countries, with 

reductions in qualified staff and technical training, 

diminishing the attention paid to dam surveillance. 

It was found beneficial to repeat this “looking over 

the hedge” debate at future HYDRO conferences as 

the discussion highlighted additional dimensions of 

operational safety which could be considered for 

inclusion in dam management practices. 

Dam safety issues 

Michel Poupart, Consultant, France 

The session began with a rhetorical question from the 

Chairman: “What is behind the words, dam dafety?” 

He pointed out that dam safety was not a theoretical 

concept, but rather a concrete set of arrangements 

taken by States, regulators, owners or operators to 

ensure a good safety level. These arrangements 

include two main aspects: a set of engineering and 

operational activities on one hand, and management 

systems to organize these activities on the other hand. 

Management systems were the subject of an ICOLD 

bulletin to be issued soon, he said, and it would be the 

basis for those who wished to know more on the subject, 

and, it is hoped, put it into practice. Topics as 

important as policy and objectives at corporate level, 

organizational issues, assigning tasks and responsibilities, 

developing a dam safety programme, and so on, 

are described in this bulletin. But engineering and 

organizational activities were important as well, 

Poupart pointed out, and the ICOLD Bulletin 59, 

issued in 1985, was still a good tool in this respect. 

One fundamental point to note, Poupart said, was the 

importance of decision making for all activities related 

to dam safety. Traditionally it was based on meeting 

criteria, such as safety factor or maximum admissible 

strength. These criteria may be set through State regulations, 

international technical guidelines, or by the 

owner himself; this was the so-called ‘deterministic’ 

approach. Risk assessment was a new approach, based 

on failure mode identification, and making it possible 

to take into account all aspects of dam safety, including 

human and organizational aspects, hydromechanical 

equipment reliability, and so on. Risk assessment 

was rather a probabilistic approach, either qualitative 

or quantitative. The ICOLD Bulletin 130 issued in 

2005 constituted one of the best references of the 

application of risk assessment for dam safety. 

Regarding the 12 papers prepared for this session, 

Poupart noted that two groups of subjects could be 

identified: 

In the first, the papers dealt with the structural safety 

of dams, and presented specific cases where potential 

safety problems had been identified. In some cases, 

appropriate and sometimes novel corrective actions 

had been developed and implemented. One common 

topic for all the cases presented was the central role of 

surveillance for the safety of existing dams, either for 

detecting abnormal behaviour and allowing a precise 

diagnosis, or for monitoring the efficiency of remedial 

works. For example, the safety assessment of the 

Enguri dam foundation, in Georgia, had been based on 

accurate monitoring of the right bank fault width variation; 

at Catagunya gravity dam in Tasmania, monitoring 

had been an important tool to assess the efficiency 

of newly installed tendons, making it possible to assess 

how important relaxation was, and what the general 

behaviour of the dam was during the tensioning of tendons. 

The cases of Lake Sarez (Usoy dam) and the 

Zhiulevskaya hydropower plant are slightly different, 

as in the first case extensive geotechnical investigations 

haad been undertaken to assess the nature and 

possible evolution of this ‘landslide made’ dam, and in 

the second the dynamic soil propagation of vibrations 

induced by the spillway had been analysed to modify 

the spillway operating rules to reduce the residential 

building vibrations to acceptable levels. 

But even the best and most comprehensive data were 

of limited application if not accompanied by methods 

and models for analysis and interpretation. In this 

respect, several papers drew attention to the use of 

elaborate mathematical models, with dynamic analysis 

and non-linear material properties: these tools had 

been used at the Messochora CFRD dam (Greece), 

where, it was <strong>report</strong>ed, upstream concrete slab cracking 

was feared during the first impounding, and preventive 

joint cutting was implemented. At the Kinta 

RCC dam (Malaysia) the seismic stability of the dam 

had been assessed using non-linear joints between the 


Far left: Bryan 

Leyland of New 

Zealand, who 

chaired the session 

on powerplant 

safety. 

Dr E. Bellendir 

discussed 

approaches to 

ensuring the safety 

of hydraulic 

structures in Russia. 

dam and its foundation, thus making it possible to take 

into account opening and sliding of this joint during 

the seismic shaking.This focus given to seismic 

aspects of dam safety, to obtain better knowledge of 

this natural hazard and assess the response of the dam 

is not surprising in the context of recent major earthquakes 

in the past few years. 

The second group of papers dealt with global 

methodologies and criteria developed on topics as different 

as assessing the consequences of dam failures, 

the design of dams in seismic areas, and setting safety 

criteria instrumental values for monitored hydraulic 

structures. 

Finally, it is worth mentioning that several of the specific 

cases presented were identified and prioritized 

through a dam portfolio risk assessment. 

In conclusion, it was recognized that all the papers 

were highly relevant regarding the current trends in 

dam safety concerns: surveillance and portfolio risk 

assessment as tools for the detection of developing 

safety problems; and reliable mathematical models as 

an essential complement to providing an appreciable 

help to engineering judgement. All the presented 

papers contributed to addressing safety-related issues 

for dams, and can be considered highly beneficial for 

the sharing of knowledge and experiences among the 

dam engineering community. 

Powerplant safety 

Bryan Leyland, Consultant, New Zealand 

The session constituted a comprehensive discussion on 

powerplant safety, with topics ranging all the way 

from problems with concrete to the safety of transformers. 

The first paper covered an analysis of a power station 

suffering from alkali-aggregate reaction (AAR). The 

station had been commissioned in 1972 and problems 

with AAR had been noticed after a few years. The 

presentation discussed a detailed analysis of the stresses 

in the branch pipes between the penstocks and turbines 

and so formed an excellent introduction to the 

problems that can be experienced with AAR. It 

appeared that little could be done to stop the AAR 

itself and that, as time went on, the problem would get 

worse. Quite obviously expensive modification to the 

branch pipes would be needed in the near future. 

The next presentation, from Russia, discussed the 

management of safety and reliability of hydropower 

stations. It was a useful introduction to the subject and 

made the point that a very large number of hydro stations 

in Russia were in need of major refurbishment 

and most of the others needed refurbishment of some 

kind. Obviously, there was a large backlog of work to 

be done and managing the work and ensuring that the 

money was well spent would be a very challenging 

problem. 

Risk management of hydroelectric plants was covered 

in the next paper. It discussed a structured 

approach to risk management where the risks and consequences 

of failure were assessed and weighed in a 

manner that indicated where money could best be 

spent. The approach should be of use to other operators 

in the hydropower business. 

This was followed by a presentation describing how 

hydraulic transients had been analysed using a very 

general and powerful computer program (SIMSEN). 

The program was is suitable for hydraulic analysis, the 

analysis of power systems and many other studies in 

which transients were involved. The effect of upgrading 

a hydro scheme in Switzerland on waterhammer 

pressures was clearly explained. The analysis brought 

out very strongly the fact that a trip from full load does 

not necessarily produce the highest pressures. The 

presentation also described what was being done to 

mitigate the hydraulic effects of the increased flow. 

Another Russian paper discussed ways of improving 

the hydrological safety of various dams in Russia. 

Virtually all of them could not pass the increased flood 

flows predicted by more recent hydrological analysis. 

The presentation discussed ways of handling the 

increased flood flows and two innovative proposals for 

spillway gates that were inherently safe and operated 

in the absence of manual intervention and without any 

need for an external power supply. It would be interesting 

to learn of further developments in this field at 

a future conference. 

There were then two presentations on power transformers. 

The first discussed a device that could substantially 

reduce the probability of the failure of a 

transformer tank as a result of an internal explosion. 

The device has been tested and many were in service 

in France. It would seem that everyone with large 

transformers, especially if they were underground, 

should become familiar with the technology and, if 

judged suitable, adopt it. The next presentation was by 

the Compagnie National du Rhône and discussed 

problems experienced in providing spare transformers. 

They have a large number of power stations with a 

wide range of transformers. After careful analysis, it 

had been concluded that two transformers (one rated 

for 225 kV and the other for 63 kV) could act as universal 

spares and cover most of the power stations. 


A wide variety of 

research projects 

were presented in 

the first session on 

hydraulic 

machinery, chaired 

by Prof Hermod 

Brekke of Norway, 

pictured above. 

Above right: Dr K. 

Winkler of Andritz 

<strong>Hydro</strong>, who 

discussed hydroabrasive 

erosion in 

Pelton runners. 

Panel of speakers 

during one of the 

sessions on 

hydraulic 

machinery. 

Any organisation with similar problems would certainly 

benefit from reading this paper. 

Overall, the presentations covered many of the safety 

and reliability problems faced by the owners of 

hydropower schemes. They provided comprehensive 

analyses and interesting solutions and discussed the 

lessons they had learned. It was a most worthwhile 

session. For a future conference, it would be interesting 

to see more coverage of the long-term safety problems 

of hydropower plants and, in particular, large 

dams. 

<strong>Hydro</strong> plant technology 

Hydraulic machinery – Modelling and research 

Prof. Hermod Brekke, Emeritus Professor, NTNU, Norway 

In this session, the varied research presented provoked 

much useful and wide-reaching discussion. Research 

on draft tube flow by CFD analysis, using a large computer 

cluster considering Reynolds Average Navier 

Stokes (RANS) simulation, compared with model tests 

in the draft tube of a large model turbine with scale 

1:3.1 to the prototype, raised questions about predicting 

energy loss in draft tubes of different designs, and 

also on the code applied during the research. 

Another paper presented a test of a 265 mm-diameter 

Kaplan bulb turbine model, without a normal diameter 

of a generator bulb. 

A presentation based on installation of a ring gate in 

a reversible pump-turbine element during emergency 

closure as a sealing device dealt with the calculation of 

the static and dynamic focus acting on the ring at different 

fixed ring gate positions. The flow simulation 

had been carried out within the limits of 3D RANS 

equations with K-E modelling of a flow area of the 

gate. Questions were raised about the implementation 

of the research, and why it had been required, as a ring 

gate would normally close into balanced flow, thus 

cavitation would not be a concern. 

Numerical and experimental research on the performance 

characteristics of hydrokinetic turbines 

was presented. The paper described model tests of a 

propeller turbine installed on a relatively small 

testrig. Two types of blade had been tested on the 

simplified model cylindrical runner chamber without 

draft tube showing a difference of the two blade 

shape in the turbine. A computer program for calculation 

of the performance had been validated by the 

experiments. 

A paper on hydro-abrasive erosion prompted lively 

discussion, including a query about whether diamond 

dust could be used to coat runner blades to prevent 

erosion. The speaker described the problems of hydroabrasive 

erosion in powerplants where one important 

key factor was the water quality and the influence 

from various parameters such as grain size and hardness 

of the sand in question. A detailed description of 

erosion tests in a newly built test rig at Andritz <strong>Hydro</strong> 

concentrating on the flow of sand-laden water against 

a model of the splitter in a Pelton bucket, revealed a 

new finding in the influence of particle size. 

Discussion arose on whether the findings of erosion on 

a Pelton unit, which indicated a large jump of between 

70 and 120 mm, could be extrapolated to include 

Francis units, as well as why a graph shown during the 

presentation, indicated a break in the grain size versus 

abrasion curve. 

A paper on active flow control in Francis turbines 

described the requirement for an increasing range of 

operation of hydro turbines at part load, where rough 

operation occurs. As a result of this demand, a pitching 

of the guidevanes was proposed as a counter 

action to the oscillations of flow and pressure that 

occurred in the runner, and created unacceptable 

oscillations in the whole hydraulic system. 

Interesting theoretical analysis by CFD and tests had 

proved that the research worked. Lively discussion of 

this paper ensued with questions being raised about 

the effect of guidevane pulsing on upstream pressure 

fluctuations, as penstock resonance must be avoided. 

A question on the influence of pitching guidevane 

flow having influence on the efficiency of the turbine 

was answered by the speaker, who said that the point 

had been studied numerically and the efficiency variation 

could be negative or positive depending on 

pitching parameters, and was so far assumed to be in 

the order of the magnitude of -0.5 per cent. The 

speaker said that the study was on-going, and the 

point would be addressed more precisely. The study 

indicated the approximation of the pressure oscillation 

if the frequency was equal to the draft tube oscillations. 

This prompted a question on whether the 

guidevane mechanism presented a situation where 

the flow oscillation would cause oscillations at the 

guidevanes, thus creating a self-amplification effect. 

The speaker was also asked whether his method of 

guidevane oscillations, created cracks in the runner 

as a result of resonance, and whether he could compare 

his methods (oscillating the guidevanes) with air 

adaptation. The speaker explained that the developed 

method could be used to avoid resonance phenomena 

by shifting the natural frequency out of the critical 

range. 


Hydraulic machinery - Low head units and 

operational issues 

John Gummer, <strong>Hydro</strong>-Consult Pty Ltd, Australia 

The sealing of the runner blade trunnions of Kaplan 

units has always been somewhat problematic. 

Although sealing well when new, seals tend to leak 

when in use for some years, leading to polluting oil 

leakage from the hub mechanism into the waterways, 

with potentially serious environmental consequences. 

The first speaker’s presentation discussed his company’s 

unique sealing method, which had been successfully 

used in various Kaplan units worldwide. 

Continuing on the Kaplan theme, the next presentation 

described an original method of estimating the 

flow through a Kaplan turbine by using only the measured 

runner blade angle. Calibration of the method 

against model test or index test results was necessary, 

however, once calibrated. According to the presenter, 

his proposed method would give reliably accurate flow 

values provided that the runner cam relationship was 

maintained. In answer to a question from the floor, it 

was explained that the accuracy of his method was far 

better than that of the Winter Kennedy method at low 

flows and hence was preferred. 

Project designers are always looking for good reliable 

machine data during the inception stage of a project, 

to examine the myriad of alternative arrangements 

and sites typically considered at that stage. There is 

quite a dearth of good layout and selection data on 

bulb turbines, which the third presentation has adequately 

filled, with up-to-date data on speed selection, 

sizing and setting of these units. 

Although not of significant importance in many 

schemes, the selection of fish-friendly turbines can be 

paramount in others. A combined presentation from 

two organisations gave an interesting case history of 

the Mayenne river scheme, in which the original 

exposed very low head unit had been substituted with 

a modern totally submerged unit, which after testing 

with eels, had proved to be extremely fish friendly. 

Kaplan discharge rings lead a very hard life being 

subjected to pulsating hydraulic loads and cavitation 

from the turbine runner leading, in some instances, to 

cavitation damage and fatigue cracking. One of the 

speakers presented a very opportune summary of the 

causes of Kaplan discharge ring damage, together with 

case histories on the use of pressure measurements in 

FEM analyses to determine the structural adequacy of 

discharge rings, together with the methods used to 

repair and strengthen damaged rings. 

Typically, turbine designers assume that because of 

the accelerating boundary in the spiral case, upstream 

penstock flow conditions have no influence on the turbine. 

This assumption was questioned in a presentation, 

which took the example of a relatively long penstock 

with two bends and calculated using CFD, the 

flow and pressure distribution at the entry to the turbine 

spiral casing. Strong vortex activity was evident 

which continued on to the spiral case and through the 

stayvanes. The next part of the study is to examine the 

effects of these turbulences on turbine performance. 

There have been several recorded instances of wiping 

of the white metal of thrust bearing pads resulting 

from a lack of an adequate oil film. One speaker presented 

such a case and described the techniques used 

to measure the oil film thickness across the operating 

range of the unit, including startup, normal stop and 

load rejection. The results were compared with a 

numerical simulation of the bearing, with good correlation 

between the calculated and the measured values. 

Cracking of Francis turbine runner blades is a wellknown 

problem, which many in the hydro industry 

thought had been solved. However, the presentation on 

this issue demonstrated that this certainly is not the 

case, and recent examples were cited in which runner 

cracking had been a problem. The speaker described 

the various factors that can lead to runner cracking and 

how they corresponded to his various examples. After 

a discussion from the floor, he concluded that it was 

possible that CFD and FEM methods currently 

employed for runner design, did not tell the whole 

story and preferably a more conservative design 

approach was required from manufacturers. 

The theme of runner cracking and failure of turbine 

components was continued in the next presentation. 

The speaker discussed fatigue strength of components 

needed to resist dynamic forces experienced in operation, 

together with the need for good inspection procedures 

to identify minor growing flaws before they 

become dangerous cracks. The speaker also talked of 

the methods available to ensure that a hydraulic turbine 

governor was stable in both the hydraulic and 

electrical systems and the proven measures to correct 

instabilities should they occur. 

The chairman acknowledged that there was a tendency 

to concentrate on cavitation in turbines and pumps 

and forget that it could occur in other hydromechanical 

structures. The next speaker presented a very pertinent 

example of cavitation damage downstream of a wheeled 

intake gate. The gate had been used in the cracking 

Far left: John 

Gummer, chairing a 

session on hydraulic 

machinery which 

focused mainly on 

operational issues. 

He commented during 

the session that there 

was a tendency to 

focus on cavitation in 

turbines and pumps, 

and to overlook that it 

can occur in other 

hydro-mechanical 

components. 

Above: D. Dolenc of 

Litostroj, Slovenia, 

and H. Bjørndal of 

Norconsult, Norway, 

who contributed to 


hydraulic machinery. 


F. Coellho da Rocha 

e Silva (Consultant, 

Portugal) and 

J. Teyssieux of 

Tractebel 

Engineering, France, 

who co-chaired the 

session on operation 

and maintenance. 

They noted the trend 

towards the 

increasing use of 

elaborate software 

systems to support 

the human 

management of 

hydro plants. 

mode for filling of an empty penstock. The cracking 

opening had been too small, resulting in considerable 

cavitation damage to the sill plate, steel lining and concrete 

downstream of the gate. The speaker fully 

described the damage and the measures taken to repair 

it. To avoid similar problems both with the repaired gate 

and others used for cracking, the presenter recommended 

that the crack opening and hence jet velocity be such 

as to ensure that cavitation would not occur. 

Silt damage to the turbine hydraulic parts is a constant 

problem in some river systems. The problem is 

becoming more acute as prime hydro sites with silt 

free water are becoming a rarity in some countries, 

hence less desirable sites have to be developed. Siltresistant 

coatings can help extend the operating range 

of a turbine in silty water; however, there is a certain 

silt concentration and size above which the units cannot 

operate. To determine that the limiting condition 

has been reached, a reliable measuring system is necessary. 

One speaker spoke of the current state-of-theart 

in using ultrasonic flowmeters for this purpose. He 

described the problems of identifying various sizes 

and types of silt, and in particular the difficulty of distinguishing 

silt from air entrainment and cavitation 

bubbles. The research work is ongoing, but there has 

been some success to date. 

Ring gates have been used as a substitute for turbine 

inlet valves for some decades. A ring gate takes up far 

less room in the powerhouse than an inlet valve, which 

can result in considerable cost savings, especially in 

the case of an underground powerhouse. Also the 

equipment cost of a ring gauge should be less than that 

of an inlet valve, especially for a high head unit, which 

will demand a spherical type valve. However, for all 

their advantages, ring gates have not enjoyed the general 

acceptance that they deserve, because of the possibility 

that their descent will be uneven, causing the 

gate to jam halfway, at the very time they are needed 

for emergency closure. A solution to this dilemma was 

presented by the final speaker, which involved a master/slave 

approach to servomotor deployment. The 

solution required no complicated electronic or 

mechanical synchronisation equipment and being 

completely passive, would appear to satisfy past misgivings 

concerning the reliability of operation of ring 

gates. 

Operation and maintenance 

F. Coelho da Rocha e Silva, Consultant, Portugal; J. Teyssieux, 

Tractebel Engineering, France 

This session comprised a balanced proportion between 

the importance of operation and maintenance, and 

showed a trend towards the increasing use of elaborate 

software tools to support the human management of 

hydropower plants in view of the increasing complexity 

of the stakeholders, environment, safety and efficiency. 

The conclusions can be summarized by three main 

points: 

• The challenge to those in the hydro industry to take 

action in the definition of their own software systems 

regarding project management gains on efficiency, 

accuracy and coherence. 

• More technology is being researched, developed and 

put in the hands of the end users at the hydro plant, 

which could be considered of vital importance, as it 

could improve safety and efficiency of operation and 

maintenance staff, decision makers and utility owners. 

• There is enormous interest in knowing and following 

the results and evolution of what could be regarded 

as another face of operation and maintenance: dealing 

with mega plants, with their particular complexities. 

The session prompted the reaction that in future it 

may be prudent to dedicate a session or panel to an 

international exchange of experience relating to three 

or four very large projects in the context of operation 

and maintenance. 

The opening presentation explained the success of 

the advanced control system for eight sluice gates at 

the Nam Theun 2 plant in Laos, to regulate the flow 

rate of the large amount of water added to the river, to 

protect the owner’s investments as well as to meet the 

interests of environmental and ecological stakeholders. 

A paper in which the positive results of the implementation 

of a ‘lean programme’ of human resources 

was then presented. It looked at increasing efficiency 

as an issue in companies seeking excellence, particularly 

when it can be difficult to engage and involve all 

relevant parties. 

The challenge to the hydro industry of defining its 

own software systems for project management to 

achieve gains in efficiency, accuracy and coherence 

was discussed based on an interesting presentation in 

which the speaker gave examples of the steps to uniformity 

carried out by other industries. This was followed 

by a talk on a system developed and in use at 20 

power stations, which automatically carries out a large 

number of tests and measurements, calculating and 

recording essential data, and providing a high level of 

accuracy. It was demonstrated that this could save time 

and enhance efficiency in the management and maintenance 

of hydro plants. 

Another speaker explained a strategy to ensure the 

safety and stability of the generator units operating at 

the Three Gorges plant in China, in situations which 

had no parallel historically. This provided an opportunity 

to gain valuable experience for the future. 

One presentation explained the development of 

advanced control and protection systems for 

hydropower waterway systems, intended to tackle 

some specific problems characteristic of Norwegian 

hydro plants, in view of the new unregulated production 

from wind, small hydro and so on, and where traditional 

AGC (automatic generating control) and the 

LFC (load frequency control) systems seem unable to 

cope. 


Another speaker shared experience of the pressuretime 

method for flow measurement in hydraulic turbines, 

and a development by his company based on 

20th century methodology. He presented the progress 

and routine that the new system allowed, showing that 

good results had been achieved in the area of efficiency. 

There was a talk on investigations and physical 

model tests for the Lunerseewerk plant in Austria, in 

connection with a recent overhaul project, to maximize 

power and operational capacity. 

An efficiency analysis, and optimization of the generating 

units at Three Gorges was the subject of another 

presentation, which was illustrated by tables and 

graphs and led to the conclusion that the problems had 

been solved by the use of a method called ‘differential 

of relative efficiency curves’. The method had been 

provided from within the company. 

The final speaker discussed turbine flow measurement 

in intakes: a cost-effective alternative to measurement 

in penstocks, which had been used at the 

G.M. Shrum hydro plant in northern British Columbia, 

Canada; the method had been found to be particularly 

useful for cases where more than one unit was to be 

tested. 

Powerplant upgrading and refurbishment 

Francis Griffin, Mott MacDonald, UK 

A range of presentations in this session made it possible 

to examine this area from a number of perspectives 

including owners, designer (consultant) and contractor. 

The first paper gave an owner’s perspective of the 

refurbishment of six powerplants in Macedonia. The 

paper explained how the work had been carried out in 

stages, as funds became available. First the turbines 

had been refurbished with new equipment, which provided 

additional output and efficiency. Then the generators 

and transformers had been uprated to allow the 

additional turbine output to be realised. A shortage of 

funds had delayed the work, and by the time it is completed 

in 2013, it will allow for the generation of an 

additional 48 MW and a resulting increase in average 

annual energy of 40.5 GWh. The work is considered a 

great success and will allow for the displacement of 

45 000 tonnes of CO 2 per year. 

The second speaker described a number of events 

which had occurred during the refurbishment of a 

pumped- storage station. The presentation was quite 

brave, as it exposed the people involved to potential 

criticism about the events occurring that might, in a 

perfect world, have been anticipated and corrected in 

advance. However, the point was made that even when 

good budgets were available for design review and 

supervision, it was not possible to review every aspect 

of the original design. Some of the problems which 

had occurred were caused by errors in the original concept 

which had previously been corrected, but the 

modification had not been properly recorded, and 

hence it re-occurred when circumstances repeated 

themselves. This paper started some lively discussion 

as a result of the the author’s candour. 

Another paper described how improvements to the 

implementation of the nozzles of six-jet Pelton turbines 

had led to a significant (1 per cent) gain in the 

efficiency of these machines. The paper described how 

flow through the individual nozzles of the original turbines 

had been unbalanced, and this had led to the 

mussel (hill) diagram of the machines having two high 

points. By adjusting the shape of the pipes leading to 

the nozzles, all the turbine jets had become balanced, 

and this had led to a significant increase in the overall 

performance. The increased efficiency was in addition 

to earlier improvements that had been achieved when 

the runners were replaced. This paper demonstrated 

that careful analysis of the performance of existing 

machines could allow for their fine-tuning. 

This paper described work that had been completed 

on more than 60 Kaplan turbines installed on the Volga 

river in Russia. The extent of the refurbishment had 

been broad and as well as new runners the turbines 

were equipped with new distributors and guidevanes 

and runner servomotors. The governor oil pressure had 

been increased from 25 to 63 MPa, allowing a significant 

reduction in oil volume. In addition to the Kaplan 

turbines a pair of large bulb units had also been 

upgraded. An improvement in efficiency of 2 per cent 

and output from 10.6 to 11.4 MW was obtained by 

replacing the original hydraulic equipment.The modifications 

included the installation of a larger runner, 

which is a challenging modification to undertake. 

The fifth presentation described the work that had 

been carried out on the Cobb power station and included 

some interesting anecdotal evidence of how dangerous 

power stations can be. Although not part of the 

current work, photographs were shown of water blasting 

from the rear of the powerhouse when it was accidentally 

released during maintenance work. 

This presentation gave a high-level review of the 

benefits that can be obtained from replacing an existing 

plant with equipment of a modern design. This is 

particularly relevant in the Czech Republic, as most of 

the hydro potential there has been realized, and so 

refurbishment and upgrading is of the utmost important. 

The final presentation focused on the Lochaber 

scheme and highlighted the difficulties associated with 

having to undertake work in a power station where 

records were old and sometimes inaccurate, and 

because of the complex nature of the penstocks and 

their interconnections, a detailed laser based survey 

had to be completed to allow for careful planning of 

the work. 

Pumped storage 

Bruno Trouille, MWH, USA; and Gaudenz Koeppel, Alpiq, Switzerland 

In view of the increasing important of pumped-storage 

worldwide, pumped-storage issues were discussed in 

three sessions throughout the conference, chaired by 

Bruno Trouille of MWH, and Gaudenz Koeppel of 

Alpiq. The sessions were very well attended, with a 

Shown left in the 

photo: Francis 

Griffin of Mott 

MacDonald, UK, 

who chaired a 

session on upgrading. 

Speakers viewed the 

subject from the 

perspectives of 

owners, designers 

and contractors. 

Beside him: 

I. Nikolov of ELEM, 

FYR Macedonia, who 

described the 

rehabilitation of six 

hydro plants in his 

country. 


Left: Bruno Trouille, 

(MWH, USA) and 

centre: 

Dr Gaudenz 

Koeppel, (Alpiq, 

Switzerland) who 

co-chaired the panel 

discussion on 

pumped storage. 

They stressed the 

increasing 

importance of the 

subject, which had 

warranted convening 

two full sessions and 

the panel discussion. 

Topics included 

trends in 

developments, 

innovations in 

technology, revenues 

from ancillary 

services, investment 

risks, and the need 

for better models to 

study operational 

response and 

economic 

performance. 

Right: José Freitas of 

EDP, Portugal, who 


hydro in synergy with 

other renewables. 

This focused 

particularly on the 

interaction of hydro 

schemes with wind 

and solar systems. 

The question of 

balancing markets 

was identified as a 

key issue. 

turnout of more than 250 people during the first two 

sessions, highlighting the significance of pumped storage 

within the hydro industry. A series of 16 technical 

presentations were made during the first two sessions. 

Unique technical features of several projects were 

described, along with presentation of detailed computer 

simulations and the results of physical model testing 

and prototypes. 

Another talk provided a global overview of pumped 

storage needs and potential over the next 30-50 years. 

It was followed by presentations on the identification 

and reconnaissance studies of potential sites in 

Germany and Sri Lanka. 

The third session on pumped-storage took the form 

of a panel discussion, and focused on planning and 

operational aspects of pumped-storage plants. Experts 

from Europe and the USA discussed the following six 

questions, complemented with many valuable comments 

from the audience: 

• What trends do you see in the operational dispatch 

of existing pumped-storage projects in meeting 

changes in electricity demand and supply (especially 

with increasing penetration of wind and solar)? 

• What technological innovations may be required in 

the future from pumped-storage projects? 

• In your region, what are the various revenues associated 

with ancillary services? How are these revenues 

expected to evolve in the future? 

• What are the major drivers to build new pumpedstorage 

projects in your region? Is your pumped-storage 

project considered a generation, transmission or an 

energy storage asset by the regulators? 

• What are the major investment risks and uncertainties 

associated with new pumped-storage development? 

How do you mitigate these risks? 

• Do existing computer models accurately model technical 

operational response of pumped storage and 

quantify economic and financial performance? What 

are your recommendations for required enhancements? 

The discussion started with experiences from today’s 

changing dispatch of pumped-storage powerplants and 

went on to both necessary technical requirements and 

the possible evolution of revenues from ancillary services, 

which are often considered an important income 

stream for pumped-storage. The discussion continued 

with drivers for investments in pumped-storage and 

the involved risks and uncertainties. The session 

closed with a short discussion on modelling aspects. 

Conclusions from the presentations and discussions 

were as follows: 

• The sessions were extremely well attended, demonstrating 

the strong design and construction activities 

especially in Europe and interests in many countries. 

• Pumped-storage technology is constantly being 

refined and improved and is more responsive to integration 

of wind and solar as well as the power system 

requirements for reliability and stability. 

• Pumped storage will play an important role both for 

frequency/voltage balancing and for energy balancing, 

that means, being able to cover several days without 

wind/solar production. 

• Financing of pumped-storage is very challenging, 

particularly with the uncertainty about the markets for 

ancillary services and the lack of models to predict 

future revenues. 

• The continuously changing regulatory framework 

makes the required long-term investment planning 

very difficult. 

• Social acceptance is one of the major barriers to new 

projects. 

• New models are required, probably going back to 

least cost planning and based on portfolio aspects. 

Solely focusing on markets is apparently not sufficient 

to quantify/justify these long-term projects. 

<strong>Hydro</strong> in synergy with other renewables 

José Freitas, EDP, Portugal 

The session focused on the interaction of hydro with 

other renewable energy sources.With the increase of 

intermittent sources of electricity, especially wind generation, 

over the last few years, there was a new and 

strong challenge for hydropower, it was agreed 

Pumped-storage plants are the best way to store energy 

efficiently, and to provide balancing services with a 

proven machine technology. In the session, some specific 

examples of the synergy between wind and hydro 

were given, focusing on technical and economic 

aspects of this collaboration. 

New perspectives for the markets, such as balancing 

markets, were discussed, and the feeling among the 

audience and speakers was that this issue would 

become part of very focused discussions from now on, 

into the future. This session made clear the important 

role hydro generation can and will play in supporting 

other sources of renewable generation. 

Electrical engineering 

Prof. J-J. Simond, EPFL, Switzerland 

During this session, seven papers were presented dealing 

with network stability analysis, calculation and 

experimental research on large hydro-generator thrust 


Far left: Prof J-J. 

Simond of EPFL, 

Switzerland, who 

chaired the session on 

electrical engineering; 

topics ranged from 

network stability 

analysis, to research 

on thrust bearings and 

ventilation and 

cooling systems. 

bearings, ventilation and cooling, a new type of tidal 

in-stream energy converter and small hydro plants 

using superconducting generators. 

An interesting contribution showed that parallel 

operation of hydro generating units connected to a 

weak grid can lead to large reactive power oscillations, 

in case of an inappropriate tuning of the power system 

stabilizer. Another paper proposed improving the grid 

stability through a frequency and automatic time error 

correction. One speaker presented an interesting 

overview on design and experimental works on large 

thrust bearings with PTFE-coated pads. Two presentations 

were concerned with the ventilation and cooling 

problems in large electrical machines. Another contribution 

showed how to optimize hydro generators cooling 

systems, ito extend the lifetime and to save water. 

One speaker’s presentation dealt with ventilation and 

cooling optimization of high speed machines based on 

modern calculation tools and field measurements. 

There was also a paper on a new type of tidal in stream 

energy converter. The first prototype will be installed 

in 2012 after various scale model tests have been carried 

out to confirm the calculation results and to mitigate 

the technical risks. The final presentation proposed 

increasing the output of small hydro power 

plants using superconducting generators. This futuristic 

proposal could have some difficulties in competing 

on the future small hydro market, it was felt 

This session provoked lively discussion between the 

audience and the speakers, on questions related specifically 

to the papers and research, as well as to broader 

topics concerning electrical engineering for hydro - 

power. 

Developments in small hydro 

<strong>International</strong> Small <strong>Hydro</strong> Development 

Dr Hu Xiaobo, <strong>International</strong> Center on Small <strong>Hydro</strong>power, China 

This session covered a broad range of topics around 

small hydro development. The first presentation, given 

by the Chair, gave a general introduction on China’s 

practice in small hydro. China has achieved tremendous 

development in small hydro, with 45 000 stations 

and 59 GW of installed capacity by 2010. Dr Hu 

explained its evolution, classification, management, 

financing model, and policy, as well as challenges, and 

put forward some recommendations. China will implement 

the National Programmes of Fuelwood by 

Electricity, New Rural Electrification and Efficiency 

Improvement and Refurbishment, to achieve sustainable 

development in the coming years. She introduced 

ICSHP’s strategy to promote small hydro, and shared 

Chinese experience in implementing rural electrification 

systems based on SHP. 

Another presentation drew attention to the issue that 

small hydro does not mean less risk. The speaker gave 

examples of some critical technical issues, which if not 

carefully addressed, could have significant influence 

of the risk in a small hydro investment. He concluded 

that the investment decision should be made based on 

comprehensive consideration of both technical risks 

and economic risks. 

One speaker discussed how small hydro could play a 

crucial role in distributed generation (DG), and called 

for the creation of a suitable regulatory framework 

favourable to the integration of RES in smart grids. He 

reviewed the main problems of small hydro adapting 

to the DG from legislation, generation and grid perspectives. 

Sometimes support from local government was 

required to develop innovative mechanisms to encourage 

investment. Chansaveng Boungnong, Director of 

the <strong>Hydro</strong>power Planning Division of the Department 

of Electricity (DOE) in the Ministry of Energy and 

Mines (MEM) in Lao PDR, introduced the unique 

‘batchwise approach’ promoted by the Government of 

Laos (GOL) together with ADB, to address the challenge 

of lack of progress in SHP development. The 

programme will generate a pipeline of 15-20 projects, 

and it is envisaged that GOL will offer the first four 

projects to the market in a competitive bidding process 

during 2012. 

A case study of the 14 MW Tina river hydropower 

project in the Solomon Islands was presented. The 

speaker discussed the six options available for the 

scheme development at the feasibility stage, and how 

the optimum scheme is determined. By comparing the 

unit cost for the hydro scheme to the unit cost of diesel 

Dr Hu Xiaobo of the 

<strong>International</strong> Center 

on Small <strong>Hydro</strong>power, 

who chaired a session 

on international small 

hydro. She also 

outlined the major 

developments in this 

field in her country, 

pointing out that 

China had 45 000 

small hydro plants 

totalling 59 GW in 

operation by 2010. 

Some of the panel 

discussing small 

hydro development 

worldwide. 


ESHA officers 

Marko 

Gospodjinacki 

(President) and Prof 

Bernhard Pelikan 

(Vice President) 

exchange views 

during the session 

they co-chaired on 

European small 

hydro development. 

“Although hydro 

technology in 

Europe is often 

referred to as 

mature”, said Prof 

Pelikan, “its 

maturing does not 

stop!”. 

generation (US$337/MWh), he demonstrated that all 

options provided significant cost savings compared 

with diesel, further demonstrating that small 

hydropower could be a cost-effective replacement to 

diesel generation, providing both cheaper power and a 

reduced impact of oil price fluctuation. 

Dr Jaroslav Pollert from the Czech Technical 

University in Prague then <strong>report</strong>ed a new type of sand 

separator under development for small hydropower, to 

protect runners of the turbine, based on the principle of 

two pipes above each other connected with a slit. The 

advantages of the new separator are to make sedimentation 

management effective as well as achieving 

cheap construction and less ground work. 

Another presentation described the Alliance for 

Rural Electrification’s approach to promoting the 

development of off-grid renewable energy solutions 

for rural electrification in the developing countries, in 

collaboration with the private sector in particular. The 

speaker gave an overview of global small hydro development 

and pointed out that enormous small hydro 

potential remains in the developing countries: the 

installed capacity by 2020 will be 200 GW. 

Nevertheless, efforts to strengthen capacity building, 

education and training, as well as securing financing 

remain the key barriers to be overcome, and she called 

for collaboration to explore fully the resources, open 

new markets and propose a sustainable solution to the 

underdeveloped and unelectrified rural areas. 

The final presentation described how a micro 

hydropower plant in Nepal had been found to be economically 

attractive. The speaker analysed the net 

present value, economic rate of return, benefit cost 

ratio, payback period, sensitivity and risk, following 

the ADB guidelines based on the latest software. 

Overall, the presentations demonstrated that small 

hydropower provides a practical solution for rural 

electrification in the developing countries as well as a 

cost-effective alternative to diesel generation in some 

countries. It was noted that these activities might need 

the support of the local or regional governments to 

develop innovative tools and create institutional, legal 

and financial framework to encourage investment. 

An underlying message from the session was that the 

technical, environmental and social aspects of SHP 

should be fully evaluated and carefully addressed, 

especially in the early planning stages. 

Last but not least, it was agreed that it is of great 

importance to build partnerships and collaboration in 

SHP development at national, regional and international 

level. 

Small hydro in Europe 

Prof Bernhard Pelikan and Marko Gospodjinacki, ESHA 

This session was one of two on small hydropower, the 

other having a more technical focus. 

Although hydropower technology in Europe is often 

referred to as mature, thus giving the perception that it 

is old and fully developed, its maturing does not stop. 

There is continuous technological development which 

is improving energy production, while reducing the 

negative environmental impact with one of the cleanest 

ways to produce electricity. 

The speakers showed case and research studies covering 

construction innovations, very low to medium 

head, multipurpose and storage utilization, and even a 

new demolition method. 

Traditionally, storage has generally been used with 

large hydropower plants to maximize, optimize and 

shape electricity production. Small hydropower has 

tended to be more dependent on the inflow, with more 

or less seldom use of storage capacity. The investment 

costs could potentially increase to the limit of profitability, 

but the electricity purchase and grid services 

would have to be negotiated with both the trader and 

grid operator. In the times of centralized energy production, 

all of those aspects could sometimes be overlooked 

by grid operators. 

As times change and the production becomes decentralized, 

with intermittent technologies such as wind 

power, local grid services are becoming very important, 

calling for a stronger backup energy. Here, small 

hydropower can significantly contribute with tapping 

the storage potential, which in Switzerland ranges 

between 150 and 190 MW of new power. There is also 

a big potential for pumped-storage, between 80 and 

220 MW. As one speaker pointed out, it is not “a single 

technology debate” any more, and that calls for 

certain quick adjustments of the financial instruments, 

among which, he pointed out, were the FIT, labelling 

of green electricity, TGC and CO 2 compensation. 

Storage potential should also be examined in the 

most promising part of Europe, southeast Europe. As 

one speaker pointed out, the most important energy 

source in southeast Europe was hydropower. He 

underlined the importance of combining hydropower 

with water management, where as a result of the crosscutting 

interests of the RES and Water Framework 

directives, common environmental criteria should be 

defined. 

The implementation of the MCA tool would be an 

appropriate way to determine the optimal SHP 

exploitation scheme and the Haltflood model could be 

used to reduce downstream flooding risks. 

The multipurpose use of water is a wise approach at 

sites that allow it, such as on the Vltava river in the 

Czech Republic. R. Vlach from Siemens presented the 

new utilisation of the Troja needle weir, now already 

part of shipping channel, and sports activities (kayak 

slalom). The limited construction site had restricted 

the investor’s options to construct the intake. 

However, an interesting solution had been used in the 

intake with the installation of Zaruba baffling wings. 

The engineers followed the results of university model 

testing and managed to eliminate the head losses by 

reducing the turbulence in the intake curved channel. 

The intakes are becoming part of a bigger concern for 

engineers, because of both environmental requirements 

(fish protection by reducing the trashracks 

clereance) and concerns for increased efficiency of the 


powerplant. A PhD study at the Norwegian university 

(NTNU) conducted by H. Nøvik is examining the 

effect of back flushing of the trashrack. The model 

testing showed it is an efficient method even in icy 

conditions, and we can expect a successful full size 

implementation. 

In general, a lot of small hydro potential in Europe is 

at low-head sites. Turbine technology is developing 

significantly, exactly for this head range. R. Pospisil of 

Mavel described the long tradition of small hydro in 

Czech Republic, where 1400 small plants are aready 

installed, leaving a limited potential for new capacity. 

However, an interesting potential lies at very low 

head sites, ranging between 0.8 and 2.2 m. The 

Lovosice hydro plant has the installed head of 1.9 m, 

but is still producing a significant output of 2.6 MW, 

swallowing 160 m 3 /s with four pit turbines. The engineers 

took good care of the environmental requirements, 

especially fish protection, installing a light and 

electronic noise barrier, while constructing a 'bio-corridor' 

fish pass. 

Low head sites may also be appropriate for installing 

the Archimedian screw, as it operates in the range of 1 

- 10 m and is suitable for the installed flows of 0.1 - 10 

m 3 /s. A speaker from the company GESS presented its 

applicability and claimed it achieves the 74 per cent 

efficiency already at 20 per cent of Q i. Among the 

advantages of the device are its low maintenance, fish 

and debris friendliness, and easy installation in old 

mills, for example, where most of the usually historic 

value construction may remain unaltered. 

Of course, the advantages and disadvantages of each 

technological solution may represent a nightmare for 

every investor. While some are looking for simplicity, 

others want peak performance. For the latter, the Swiss 

research and production company MHylab started the 

Diagonal Turbine Project. Combining aeronautical 

knowledge and hydraulics, their engineers set themselves 

a heavy task: to develop an optimal turbine 

solution for medium head that would achieve high 

efficiency, while showing low cavitation behaviour 

and meet specific requirements for small hydro. 

As the speaker showed, they managed to combine the 

benefits of Kaplan and Francis turbines. By placing the 

anti-cavitation lips and adjusting the angles of the 

guidevanes and the leading edge, the efficiency 

increased to 92.8 per cent. 

Technological development is still on-going in the 

field of generators as well. A paper was presented on 

the latest experiences and trends, while focusing on the 

dilemma of choosing salient versus smooth pole 

rotors. While the first is smaller in size, cheap when 

produced in series, and has better cooling characteristics, 

the latter is larger, cheaper per unit, and shows 

better performance, if one can accept worse cooling, 

which in turn results in higher noise and pollution for 

using the cooling systems. 

The bearings, noise and vibration are additional 

points to check when deciding on an appropriate generator 

for small hydro plants, it was pointed out, 

although ultimately, the price often represents the 

deciding factor for an investor. 

The Water Framework Directive is turning out to be 

a major obstacle for the development of hydropower. 

The water administrations in the EU Member States 

are much more inclined to use other renewable technologies 

instead of hydropower, but are still in favour 

of refurbishing the existing powerplants, under strict 

environmental conditions. A paper was presented on 

the refurbishment project of the Nymburk plant, where 

ta 33 per cent increase in installed capacity had been 

achieved. An interesting part of the refurbishment was 

a concrete demolition method, where a saw had been 

used instead of the usual pneumatic hammer. 

This session demonstrated that small hydropower 

can significantly contribute, not only to energy production, 

but also to grid services needed for compensating 

production cuts of other renewable energy 

sources. The continuous research and development is 

encouraging, although the European Comission pointed 

out the lack of applications for the research and 

development funds. ESHA, the European Small 

<strong>Hydro</strong>power Association, understood the importance 

of the opportunity and responded by organising a seminar 

on EU projects funding. 

Regional sessions 

<strong>Hydro</strong> development in Asia 

Chhewang Rinzin, Druk Green Power Company, Bhutan; Selim Sayah, 

Lombardi Engineering, Switzerland 

The topics covered by the papers in this session 

prompted a lot of interest, and discussion between the 

audience and the speakers. Four papers covered hydro 

development in Laos with perspectives on the present 

status and future plans, studies on the sustainable 

development of small hydro, and management experiences 

in the implementation of an independent power 

project. A fifth paper touched on the cascade development 

of the Upper Dniester and Tisa rivers in the 

Ukraine, for the multipurpose use of water resources, 

and another paper on the optimization of the development 

of the Zap river in Turkey. There were two 

papers on hydro development in Pakistan, as well as 

others on hydro in Iraq, Nepal and Georgia. 

In countries like Laos and Bhutan, hydro is the most 

important resource, and the governments are developing 

this resource in the most judicious and sustainable 

manner to maximize benefits with minimum negative 

social and environmental impacts, but accelerating the 

pace of development so as to reap the benefits sooner 

rather than later. Despite the limited domestic demand, 

advantage is being taken of the huge shortage in electricity 

in the neighbouring countries, with many of the 

hydro resources being developed with the sole intent of 

exporting power. While there are legal, financial, and 

physical hurdles to overcome in such cross-border 

power trading, these countries see the market beyond 

Co-chairs of the 

regional session on 

Asia. Shown left, 

Dr Selim Sayah of 

Lombardi 

Engineering, 

Switzerland; in 

another session, he 

described the design 

of the complex 

waterways for the 

Theun Hinboun 

expansion project in 

Laos. 

Right: Chhewang 

Rinzin of Druk Green 

Power Corporation, 

Bhutan, who 

described hydro as the 

most important 

resource for his 

country, adding that it 

needed to be 

developed in a 

judicious and 

sustainable way. 


Speakers from the 

regional session on 

Asia. From left: 

Peter J. Rae, 

Consultant, 

Canada; 

Hatsady Sisoulath, 

Ministry of Energy 

& Mines, Laos; 

Francis Griffin, 

Mott MacDonald, 

UK, and D.B. Singh, 

Ministry of Energy, 

Nepal. 

its borders as the means to achieve its development 

plans and to play a critical role in poverty alleviation. 

The proceeds from the sale of electricity constitute a 

major part of the revenues to these countries. 

From the perspective of constructing hydropower 

projects in countries such as Laos, the need to understand 

and properly manage the financial closure, 

including power purchase and concession agreements, 

contracting, monitoring during construction, operation 

and subsequent maintenance was presented from the 

experience of the project management. From the 280 

MW Theun Hinboun hydropower project implementation 

in Laos, it was clearly demonstrated that hydro - 

power projects could be constructed on schedule and at 

cost if proper management systems were envisaged and 

put in place. In the management of contracts, it was 

also highlighted that, while complex, risks had to be 

shared between the client and the contractor, depending 

on the type of risks. The sharing of risks helped the 

smooth implementation of hydro projects. It was felt 

that while EPC-type of contracts were preferred by 

many of the IFIs, a hydro project was best executed 

using a mixture of EPC and BOT concepts based on 

site conditions in terms of geology and also on the 

capacity of the client/contractor. 

In terms of sustainable development of small hydro 

in Laos, the importance was stressed of interacting and 

taking the local people into confidence from the study 

stages. While it was important to note the views of the 

ever-expanding NGOs on hydro, it was recognized 

that ultimately the local people in the vicinity of the 

projects were most affected and their concerns should 

be addressed. 

On the multipurpose use of water resources beyond 

electricity generation, such as flood control, irrigation, 

drinking water, and tourism/recreation, as in the case 

of the Upper Dniester and Tisa rivers in the Ukraine, it 

was important that all such benefits were considered 

from the stages of the feasibility studies. Once the 

water resource is harnessed for one or another end use, 

it becomes difficult at a later stage to incorporate other 

uses, to maximize the benefits. The difficulty, how ever, 

was in the priorities that different governments 

were faced with and the likelihood of long-term gains 

being overlooked. It was also important to have a 

proper understanding of the investments and the costsharing 

of the initial investments, based on anticipated 

end uses so that one sector does not become less viable 

on account of having to bear part or all of the development 

costs. 

In Turkey, the detailed feasibility study of the Zap 

river had resulted in a recommendation to implement a 

number of smaller dams instead of the large dam 

which had been envisaged in the earlier masterplan for 

the development of the river, without compromising 

energy output. The detailed study not only optimized 

the use of the river, but there were also cost savings in 

addition to avoiding submergence of some villages 

and other infrastructure. River development plans 

must be reviewed thoroughly by different groups of 

experts to ensure that the best options, at least at that 

period of the decision making process, are considered. 

Often experts become rigid in their views and optimal 

use of the hydro resource may be compromised. 

From the presentations on hydro development in 

Asia and the ensuing discussions, the important areas 

for Asia and the hydro groups to give priority to, 

appeared to be the following: 

• Many of Asia’s new hydro developments required 

some expertise and experience from the North, such as 

in the case of the Theun Hinboun scheme in Laos, 

extending from initial studies, through contracting, to 

project management and operation and maintenance. 

If hydro development in Asia was to remain sustainable, 

it was agreed, there was a greater need for the 

North to pass on its expertise to the South and bridge 

the knowledge gap. 

• Reconsideration and more detailed studies were 

resulting in optimization of the use of the scarce water 

resources including multipurpose hydro development 

(irrigation, fisheries, flood control and recreation) on 

top of power production, the core subject of the conference. 

Time should be taken to ensure that adequate 

studies were undertaken so that the benefits are maximized 

for the present and future, including the provision 

of more pumped-storage plants. This would 

require a consideration in conjunction with the longterm 

sustenance of the thermal/nuclear powerplants 

and other sources of renewables. 

• The majority of the remaining hydro potential to be 

tapped, requiring huge investments, was in Asia, it was 

agreed. The potential and the market for hydro existed 

within the boundaries of the countries, or otherwise the 

energy could be exported. The financing of hydro projects 

in Asia was complex and difficult, considering the 

financial strength of many of these Asian countries, 

some of which were the poorest in the world. It was 

felt that the North and the richer countries, including 

the IFIs, needed to consider investing in the development 

of hydro in Asia in a more indulgent manner, noting 

that these projects were financially viable on their 

own, without having to consider the economic benefits 

to make them more fundable. 


<strong>Hydro</strong> activities in Europe 

Oivind Johansen, Ministry of Energy and Petroleum, Norway 

Seven papers on various aspects related to hydro power 

development and operations showed that Europe is a 

very mature hydropower continent, where more than 

70 per cent of the potential is developed. The issues 

facing Europe are therefore, in many ways, different 

from the emerging hydropower markets. 

Some overarching variables, which have emerged over 

the last decade or two, were highlighted in the session. 

The growing deployment of intermittent sources, 

such as wind and solar power, puts more stress on the 

power system and the requirement for balancing 

capacity is increasing. <strong>Hydro</strong>power with storage or 

pumped storage is excellent for this purpose. A novel 

concept of small pumped hydro has been introduced, 

and may be an interesting concept which can help balance 

the growth of solar power in the Czech Republic. 

In several countries and regions, the market decides 

the power price. Advanced production planning is 

therefore more important than ever to maximize the 

operations and the benefits to society. One paper 

underlined the need for comprehensive modelling to 

optimize bid volume. The SHOP model is a tool for 

economic optimization of the assets in a system consisting 

of several reservoirs and generating units, taking 

into account spot and balancing market and licensing 

conditions. However, such systems depend on the 

quality of the input and scrutiny of the operators. 

Two papers on tidal power projects in the 

Netherlands and the UK demonstrated that there is an 

interesting potential which can be deployed within the 

foreseeable future, given the right incentives and lowering 

of costs. There are challenges, but also potential 

positive effects related to shipping traffic, ecology and 

proximity to Ramsar sites. 

Many countries have a ‘maturing’ fleet of hydropower 

plants. This requires an increased focus on maintenance 

and well planned upgrade and investment programmes, 

as well as ecological considerations. 

<strong>Hydro</strong>power offers opportunities for restoration, and 

with smarter environmental solutions for developed 

water courses one can increase the power production 

and at the same time enhance the ecological qualities. 

In the policy area, it was underlined that various EU 

directives may work against each other. For instance, 

the Water Framework Directive, promoting better ecology 

of rivers may lead to losses in production and thus 

have negative implications on the very ambitious RE 

Directive, which is promoting renewable energy and 

calling for a massive deployment of more renewable 

energy by 2020. In some cases, stricter environmental 

regulations and various EU directives may change the 

way hydropower is operated. In the re-licensing 

processes, it is important to bear this in mind to avoid 

loss of production capacity. 

The value of ancillary services from hydropower, 

such as flood protection, balancing power, and so on, 

is often not fully appreciated. There is therefore a call 

for a better understanding of the unique nature of 

hydropower among regulators and policy-makers. 

Important lessons that the chairman encouraged people 

to take from the session included: being creative, 

and looking for solutions that could optimize existing 

production facilities; and, making use of new hydro 

technologies. Smart software and modelling are important 

tools in planning for the future, taking various 

uncertainty factors into account. Optimizing the use of 

whole watercourses, which are already developed, 

requires good planning and can generate benefits both 

for power production and the ecology. Tidal power 

projects can have positive multipurpose effects ,and 

studies have to be carried out in open and transparent 

ways. Water and energy authorities should engage in 

closer dialogue, both with each other and with the 

hydropower industry. This will ensure a better understanding 

on how to optimize the value of hydropower 

and water services, and avoid policies that work 

against each other. The water-energy nexus could be a 

relevant theme for the upcoming conferences. 

Capacity building in Africa 

Adama Nombre, Burkina Faso, Chairman, ICOLD Committee on 

Capacity Building 

This was the third session devoted to Africa during the 

conference. The objectives of this panel discussion 

were to offer the opportunity for experts coming from 

Africa and other regions, and from the industry, to 

exchange experience on the issue of capacity building 

in the hydro sector in Africa, and to support the current 

trend for the development of the untapped potential for 

the benefit of people, for economic growth and social 

development. Successful experiences in this field were 

shared by participants. 

The panel discussion was chaired by Adama Nombre 

of Burkina Faso, and the panel was made up of eminent 

experts from around the world, included: Freddy 

Isambert, ISL France; Dr Andy Hughes, Director of 

Atkins Water, Past Chairman of the British Dam 

Society and Vice President of ICOLD; Prof Sandy 

Tickodri-Togboa, Chairman of the Uganda Electricity 

Generation Co; and, Azeb Asnake Project Manager of 

the Gibe III hydroelectric project (EEPCo), Ethiopia. 

The session was well attended with around 80 participants, 

and important participation in the discussion 

from the floor. 

Oivind Johansen of 

Norway’s Ministry 

of Energy and 

Petroleum, chaired 

a regional session 

on Europe. He 

called on water and 

energy authorities to 

engage in closer 

dialogue, both with 

each other, and with 

the hydropower 

industry, to achieve 

better optimization 

of hydro 

development and to 

avoid conflicting 

objectives, 


Adama Nombre led a 

discussion on capacity 

building needs for 

Africa, which he 

stressed was all the 

more urgent in view of 

the new pace of 

development in the 

region. “Capacity 

building is a long and 

complex process, 

needing constant and 

renewed efforts from 

various stakeholders, 

led by governments, 

professional 

associations and 

others”. 

Freddy Isambert presented the successful experience 

of Morocco in capacity building in dam and 

hydropower engineering. He focused on the following 

main aspects: 

• strong political will and commitment for the development 

of water resources at government level; 

• strong public involvement and partnerships with the 

industry and profession from developed countries; 

• motivation of key partners in the process of capacity 

building; 

• development of universities and good quality 

schools of engineering; 

• adaptation to the evolving environment of the profession; 


• knowledge transfer with cooperation. 

His main conclusion was that capacity building is a 

long process needing the contribution of all partners. 

Dr Andy Hughes, in his introductory presentation, 

focused on the status of capacity building in dam engineering 

in Europe, and specifically in the UK. He gave 

a short review of the evolution of the profession from 

the 1950s to the present day, with trends in the deterioration 

of the profession’s image and conditions. He 

pointed out the failure of the professional institutions 

to promote and defend the image of the profession, the 

impacts of the privatization in the early 1980s and the 

current procurement method, which was based on the 

lowest price. He also pointed out that capacity building 

is a long and continuous process. 

Dr Sandy Tickodri-Togboa focused on the key role of 

the universities and schools of engineering in the 

process of capacity building. He also referred to the 

global change introduced by the process of privatization 

in the sector since the early 1980s. He pointed out 

the need to reinforce the situation, and to attract young 

competent students in the fields of engineering. 

Azeb Asnake focused on the role of regional cooperation 

and the need to create centres of excellence for 

the capacity building process in Africa; she highlighted 

the cooperation between Ghana and Ethiopia as a 

successful example of this. 

The introductory talks were followed by numerous 

valuable contributions from the audience. Discussions 

were intense and the available time seemed too short. 

The main conclusions and recommendations raised 

from the discussions were the following: 

• The hydropower sector in Africa is characterized by 

a new pace, with large projects under construction in 

many countries and major investments planned, 

including the Grand Inga complex with its huge capacity. 

The main constraints slowing development are 

related to funding and the capacity to plan, develop, 

operate and maintain these critical infrastructures in 

the context of Africa, where needs are urgent. 

• Building capacity in the hydropower and dams sector 

is one of the major challenges facing Africa to sustain 

and speed the new developments with the ongoing 

and planned major investments in the hydro sector. 

• Capacity building is a long and complex process, as 

the experience of developed countries shows, needing 

constant and renewed efforts from various stakeholders, 

led by governments, professional associations and 

institutions. The case of Europe and other developed 

countries, which are facing difficulties in maintaining 

and renewing their hydro capacity, represents valuable 

experience, which needs to be studied. 

• Political will and commitment at government levels 

is of the utmost importance in the process of capacity 

building. In the context of Africa and the new economic 

and privatization environment, this is important 

to create the appropriate framework, education and 

training facilities and to ease the access of the young 

generation to the skills and required qualification in a 

sufficient number. The experience of the 1950s-70s in 

Europe and in Morocco were success stories, highlighting 

this issue. 

Capacity building is a wide-reaching issue which 

requires actions and contributions from various partners 

in several areas: 

• governments at national and regional levels; 

• IFIs; 

• owners and project developers; 

• universities and R&D institutions; 

• contractors, suppliers and consulting firms; and, 

• professionals institutions and associations. 

Each partner should play his specific role. 

Promotion of the engineering professions and adapting 

the profession to the new environment (economic, 

cultural and social) is of key importance. The discussions 

showed that the profession today is quite different 

from that of the early 1950s and 1970s. Today 

engineers are part of a multidisciplinary team during 

the project development process, and need to have the 

culture and ability to interact with and understand others 

partners and actors. The engineering schools and 

institutions should play a major role in the process of 

adaptation. 

Capacity building should be included in project 

development and implementation as a full component, 

and not only as an accompanying measure. This would 

ensure the availability of funds and measures for the 

success of the process and for the durability of the 

infrastructure, and will ease the development of ownership 

pattern. 

Regional cooperation and integration will be necessary 

in Africa for the development of educational and 

training facilities, the organization of the private sector 

to ensure the development of large firms and contractors 

at regional level with enough activities, which is 

necessary to build capacity. As one French proverb 

says: “C’est en forgeant que l’on devient forgeron” 

(practice makes perfect). Regional cooperation is also 

the best way to share knowledge and experiences at 

regional level. 

The need for strategic planning for capacity building 

in the hydropower and dams sector at national and 

regional level was also emphasized in the session. 

At future conferences, a focus on the role of professional 

institutions and associations in capacity build- 


ing, and the promotion of the image of the profession 

and the specific role of the industry in capacity building, 

would be an interesting topic. Focusing on these 

themes will allow the session to provide a forum for 

sharing experiences in detail. 

Potential and current developments in Africa 

Azeb Asnake, EEPCo, Ethiopia; 

Michel de Vivo, Secretary-General, ICOLD 

During this session there were presentations on potential 

and development in DRC, Kenya, Cape Verde, 

Burundi, South Africa, Sudan and Uganda, covering 

schemes on all scales, from Merowe in Sudan to mini 

hydro in Uganda The opportunity to listen to experiences 

of developing potential in a variety of countries, 

each with common goals and difficulties, but also with 

individual challenges, was a rich experience. 

Co-chair, Azeb Asnake, Project Manager of Gibe III 

of EEPCo, Ethiopia, opened the session by discussing 

the huge potential for hydropower in Africa, but also 

the stark realization that Africa would remain in poverty 

for the foreseeable future, unless that potential was 

developed. She drew attention to the difficulties 

African countries faced when fulfilling the criteria of 

the funding agencies, as well as the complexity of the 

funding process, which was hindering rather than 

helping progression. She discussed the need for 

increasing capacity. By educating local engineers and 

construction workers on new techniques, current technologies, 

and other industry practices, she felt that a 

significant barrier in developing Africa’s potential 

could be overcome. She urged that all organisations 

involved in the development of hydro in Africa attempt 

to mitigate negative impacts rather than ignoring them, 

adding that a “synergy of resources” was needed. She 

also acknowledged the importance of government support 

and dedication to the success of African projects, 

drawing on experience from her own country, 

Ethiopia, and the Government’s five-year plan to 

develop 7000 MW of hydropower. 

The presentations in this session covered a range of 

topics with regard to development and potential, including 

current feasibility studies of previously evaluated 

sites, selecting the best sites for development, and learning 

from the experiences of plants already developed. 

In closing, co-chair Michel de Vivo drew attention to 

the range of countries, and their experiences, represented 

in the session, and the enthusiasm of the African 

countries to make progress in developing hydropower, 

despite the challenges. His closing message was his 

belief that “Africa is on the road to success. This century 

will be the century of Africa”. 

Azeb Asnake commended the useful exchange of 

experience and ideas that had taken place in the session, 

noting that many of the significant challenges 

facing Africa with regard to developing potential, had 

been raised. She emphasized the potential of the continent, 

but added that Africans could not develop this as 

quickly or successfully as was necessary, without support 

from the hydropower industry. Her ‘take-home 

message’, that the industry must grow and move forward 

together, was a hopeful and determined one. 

Inga: the potential powerhouse of Africa 

This high level panel discussion, chaired by ICOLD 

Secretary-General Michel de Vivo, provided a comprehensive 

insight into plans to develop Inga 3 and Grand 

Inga. An opening address was given by the Technical 

Advisor to the Ministry of Energy of DRC, who conveyed 

his Government’s commitment to moving ahead 

with both major schemes in parallel. Delegates heard 

presentations from the AECOM-EDF Consortium 

based on their pre-feasibility studies which had been 

approved by the DRC Government in Kinshasa just a 

few days before HYDRO <strong>2011</strong>. 

Discussions focused on technical challenges of 

damming the Congo river, and of creating energy highways 

to transmit power from Inga across the African 

continent; studies to assess future demand (both 

national and regional), and design features of the proposed 

scheme. 

In view of the importance of this project, the panel 

discussion is <strong>report</strong>ed in full on p61. 

<strong>Hydro</strong> activities in Latin America 

Jose Rojas Morales, ICE, Costa Rica 

Four cases, two from Brazil, one of Peru and one from 

Costa Rica, were analysed and despite their varying 

Left: Azeb Asnake of 

EEPCo, Project 

Manager of the Gibe III 

scheme, joined the 

panel on capacity 

building, and also cochaired 

another session 

on Africa. She drew 

particular attention to 

the difficulties African 

countries faced in 

fulfilling the complex 

criteria of the funding 

agencies. She called for 

a “synergy of 

resources” in helping 

Africa to develop its 

vast hydro potential. 

Above: Some of the 

panel discussing the 

42 000 MW Inga 

project in DRC, for 

which prefeasibility 

studies had been 

approved a few days 

before the conference 

(see full <strong>report</strong> on p61). 

J. Rojas Morales of 

ICE, Costa Rica, who 

chaired the regional 

session on hydro 

activities in Latin 

America. He 

commented on the 

major advances in 

dam building 

technology in the 

region, and the 

greater demands 

placed on 

manufacturers of 

large-scale generating 

equipment. 

<strong>Hydro</strong>power & Dams Issue Six, <strong>2011</strong>

Above: The panel of 

speakers for the 

session on 

developments in civil 

engineering. 

Shown to the far right, 

session chairman Dr 

Yannis Thanopoulos 

of PPC, Greece, who 

commented that civil 

works required a 

variety of engineering 

skills and also a high 

level of specialization. 

Also shown, R. Ross 

of Lahmeyer 

<strong>International</strong>, 

Germany, who spoke 

of site management of 

projects in developing 

countries, referring to 

his experience as 

project manager of 

Merowe in Sudan. 

topics, there were some basic agreements and starting 

points for useful discussion. 

It was clear from the presentations that dam building 

technology has advanced well in South America, 

specifically in the application of best construction protocols 

dedicated to diversion schemes, dykes, channels 

and tunnels; examples can be seen of this in the cases 

of the Simplicio and Anta projects in Brazil. 

Greater demands on machinery, to meet challenging 

conditions for large hydro plants, and the corresponding 

critical role played by the manufacturers of condition 

monitoring equipment to ensure the long-term 

reliability of the plants, was reflected in some talks. 

Third, the evolution of the South American hydro 

industry towards environmental engagement was 

agreed to be high, specifically as regards river restoration 

techniques through a system of regulated ponds 

and natural river bed material, both measures providing 

better hydraulic conditions for the river and maintaining 

the required minimum flows. 

Finally a wide review was presented of installed 

capacity, potentials, plans and portfolios for investment 

in the industry of renewable energies in Central 

America. A general conclusion was the need to encourage 

hydro developers to considering technical, environmental 

and socio-economic dimensions of a scheme. 

Developments in civil works 

Civil engineering 

Dr Yannis Thanopoulos, PPC, Greece 

A variety of civil engineering subjects were discussed 

in this session, covering topics such project management 

in developing countries, dam design, construction 

and repair works making use of some quite ‘new’ 

materials and techniques. Civil works are a fundamental 

part of a hydro scheme and their design and realization 

mobilizes the skills of a variety of disciplines, 

and often an innovative approach and a high level of 

specialization are needed. 

One paper presented demonstrated that on-site management 

of large infrastructure projects in developing 

countries implies much wider contractual and technical 

involvement and more comprehensive tasks than in 

other cases. At the Merowe dam project in Sudan, efficient 

project management within the framework of the 

adopted more flexible FIDIC type contract, helped in 

completing the 1.25 GW multipurpose project within a 

time period of six years. 

A paper on rehabilitation with exposed poly - 

vinylchloride (PVC) foil and its performance after 

eleven years of reservoir operation at the Moravka 

asphalt faced dam in the Czech Republic was presented. 

The exposed PVC geomembrane system had withstood 

very low temperatures, with a thick layer of ice 

covering the reservoir in winter, as well as, the 1000 

year flood with the associated impact of debris after 

the snow melt. Geomembranes have proved to be efficient 

and reliable in repairing dam defects and improving 

safety by effectively controlling internal seepage 

and monitoring water pressure behind the drainage 

layers. 

In a third presentation, the application of roller compacted 

concrete (610 000 m 3 of RCC) in construction 

was discussed. The utilization of flyash in the mix had 

reduced cement consumption to 65 kg/m 3 , resulting in 

large savings of natural aggregates and cement. 

The operation of inflatable dams/gates in cold weather 

was the subject of another presentation. The speaker 

explained that inflatable gates could provide solutions 

to discharge large flows under very low hydraulic 

heads. However, the operation of inflatable gates in the 

on/off mode requires a control structure with adequate 

mechanical gates to regulate the upstream water level 

when the powerhouse discharge capacity is exceeded. 

It appears that, under certain harsh winter conditions, 

one might expect difficulties related to ice blocks and 

snow accumulation. Necessary precautions should be 

taken, including preventive deflations and adjustment 

of the downstream spillway slope. 

Analytical determination of thermal conditions of 

high rockfill dams with asphalt concrete cores in 

regions of extremely adverse climates was discussed 

in another presentation. The temperature field within 

the dam body stabilized according to model prediction 

after 90 years of operation with negative temperatures 

in the core persisting for most of the dam’s life. In the 

subsequent discussion it was pointed out that asphalt 

technology can remediate the negative effects of low 

temperature if the bitumen mix design is adjusted to 

maintain its ductility. 

Hydraulic physical modelling in the laboratory is 

fully justified in addressing complex tasks related to 

the design and safety assessment of old dams. 

Estimating the condition of overflow spillways and 

associated old structures and their potential for 

upgrading for maximum flood routing was presented 

by another speaker. 

An original tidal project layout for a 12 MW scheme 

was then presented. The innovative Severnaya tidal 

plant is composed of large concrete caissons, prefabricated 

offshore and transported to the site. These power 

units have a compound vertical shaft with three vertical 

orthogonal turbines, placed one above other. 

It was shown in the session that, as dam technology 

progresses, ‘new’ materials are becoming available to 


the civil engineer. These are tested, and experience is 

gradually accumulated, creating confidence for their 

performance. The concrete mix design for RCC dams 

is moving ahead towards the use of limes to replace 

cement; asphalt core dams are increasing in height, and 

their design is more exigent with bitumen synthesis 

able to be adapted to extreme temperatures. Exposed 

geomembranes are proving reliable in remediating 

dam defects, enduring ageing with better performance. 

It is also clear that innovative technology may enable 

wider scale construction of single-basin tidal barrages 

at any site with major tidal potential, although production 

costs are likely to remain high in comparison with 

other energy sources. 

Tunnels, penstocks and gateworks 

P. Erbisti, Consultant, Brazil 

The papers presented in this session mainly focused on 

tunnels and penstocks. The first paper analysed the 

design criteria and methods for the design of reinforced 

concrete linings for pressure tunnels. Concrete 

lining, although reinforced, may crack and permit leakage 

from the pressure tunnel. However, the authors 

highlighted the fact that that an optimized reinforcement 

limits the effective permeability of the liner and 

yields lower hydraulic pressures at the lining-rock 

interface, thus proving beneficial in the control of leakage 

and build-up of external pore pressures. 

A very unusual aspect of hydropower tunnel operation 

was presented by another speaker, concerning the 

possibility of water freezing in the headrace and/or 

tailrace tunnels lying at shallow depths near the surface 

in permafrost regions, in the event of water flow being 

stopped as a result of operational problems. By estimating 

the heat loss from the flowing water, the minimum 

water flow could be determined by a 3D finite 

element modelling methodology, to prevent water temperature 

from dropping below freezing. 

The Chairman presented a paper describing the various 

types of gates used for emergency shutdown of 

powerplant intakes. He focused on safety issues and 

practical solutions which could be implemented during 

the early stages of the project, regarding operation, 

inspection and maintenance of the hydromechanical 

equipment. Also, he underlined the convenience of 

using draft tube stoplogs downstream of guard gates of 

Kaplan and bulb turbines to allow for inspections and 

maintenance of the main gate wheel tracks and guides 

in dry conditions. 

Another paper analysed the first results of an extensive 

research programme being developed by Austrian 

powerplant owners, steel manufacturers and research 

institutions on the fatigue resistance of existing steel 

penstocks of hydropower plants in Austria, both experimentally 

and also using FE analysis. Three different 

types of penstock reinforced openings were investigated. 

The results of one specific case were presented, and 

further results are to be published subsequently. 

The final speaker described the challenges of designing 

a long and complex waterways system for the 

Theun Hinboun expansion project in Lao PDR, where 

the total head losses should not exceed 3 per cent of the 

total available head. The penstock consists of a 235 m- 

long underground steel-lined section and a 685 m-long 

section, where the penstock is encased with reinforced 

concrete and covered later by compacted material. The 

penstock diameter varies from 5.8 to 5 m. 

A general overview of the scheme and relevant 

design aspects were presented. 

Spillways 

F. Lempérière, <strong>Hydro</strong> Coop, France 

Three main points were analysed in the session: the 

wide utilizations of Piano Key (PK) Weirs, the possibility 

to build spillways over embankments, and the 

complexity of problems for increasing the discharge 

capacity at existing dams. 

Two presentations covering 20 examples, showed the 

very different possible applications of PK Weirs: for 

new free-flow large or small spillways where the 

length of a traditional spillway may be divided by three 

or the loss of storage halved; for improving existing 

free-flow spillways; or, associated with gated spillways. 

Many applications have been realized or are 

under design in very different sites. Very large structures 

are under construction or design in Vietnam. The 

design at Inga (DRC) for 120 000 m 3 /s includes a 

50 000 m 3 /s discharge by an 800 m-long PK Weir. 

Another <strong>report</strong> presented, underlined the different 

possibilities for placing spillways over embankment 

dams. The solution has been dismissed because of concerns 

that serious settlement of the embankment could 

not be avoided. But great progress in design, control, 

and compaction equipment has greatly reduced the 

possible settlement, and the quality of the embankment 

may often be as good and better known than the quality 

of materials in the river bank. 

The <strong>report</strong> underlined two points: 

• The great variety of possible solutions such as grass 

cover, tiles, RCC chutes, reinforced concrete cement 

stabilized chutes. The choice may vary according to 

specific discharge, climatic and site conditions. 

Left: Dr Paulo Erbisti 

of Brazil, who chaired 

the session on tunnels, 

penstocks and 

gateworks. He also 

presented a paper 

recommending 

solutions for the 

emergency shutdown 

of powerplant intakes, 

advocating measures 

which could be 

implemented at an 

early stage of project 

design. 

Right: F. Lempérière 

of <strong>Hydro</strong>-Coop, 

France, who chaired 


spillways and gave a 

talk on PK Weirs. He 

said the session had 

indicated the great 

variety of possible 

solutions for flood 

discharge works, 

depending on specific 

discharge, climate, 

and site conditions. 

Risks associated with 

floating debris and 

lack of maintenance 

were highlighted. 


The panel of speakers 

on sedimentation, 

which was chaired by 

Sultan Alam of 

France (shown left). 

He also presented a 

paper on studies he 

had undertaken for 

the Karnali project in 

Nepal, which 

underlined that 

sedimentation 

management was a 

key topic for the 

Himalayan river 

systems. 

• The great care necessary for the design. As an example, 

the discussion during the meeting underlined the 

risks caused by floating debris, lack of maintenance or 

local defects. 

Other <strong>report</strong>s in the session illustrated various examples 

of the complexity of problems for increasing the 

discharge of existing dams. 

Beyond the technical choice of the discharge control 

(gates or various weirs), the problems of downstream 

protection, environmental impacts, schedule of works, 

and risks associated with the additional works can be 

complex and many solutions should be examined 

before choosing a solution which is safe, cost-effective 

and locally acceptable. The cost of studies may thus be 

a much larger percentage of the cost of works than for 

new dams. 

Sedimentation 

Sultan Alam, Consultant, France 

Altogether eight papers treating various practical 

aspects of hydro sedimentation problems and their 

solutions were presented by the authors and discussed 

with the audience. 

The Chairman presented the first paper on the Upper 

Karnali hydro project. This is a high head run-of-river 

project: plant discharge is 675 m 3 /s and the total head 

is 150 m. One of the main problems of the Himalayan 

rivers is the management of its sediment transport to 

assure sediment-free water to the turbines. Almost all 

existing projects in Nepal and India use settling basins 

with limited success, and in case of excessive sediment 

influx, the plant is simply shutdown. 

In the case of a conventional underground settling 

chamber concept, the solution would consist of four 

200 m-long, 21 m-wide, and 21.75 m-high chambers. 

The flow velocities would be around 0.44 m/s and thus 

sediment particles entrained into the turbine discharge 

could be 0.4 mm or more. The cost of rock excavation 

alone for this arrangement would be about US$ 22 

million. 

The alternative solution retained consists of using the 

upper pool as the settling basin with a gated diversion 

tunnel diverting any discharge in excess of the plant 

discharge up to a total river discharge of 1425 m 3 /s. 

The flow velocities under this condition with the upper 

pool at el. 637 m are 0.25 to 0.30 m/s, and the particle 

size entering the water intake could be between 0.20 

and 0.25 mm. It can thus be concluded that the upper 

pool solution is more efficient and would require less 

initial investment. 

However this solution, after a few years of operation, 

would require the removal of bed load and some 

deposited suspended load from the critical areas of the 

upper pool. One of the means would be removal by 

hydro-suction, either through the diversion tunnel or 

directly downstream of the diversion dam, so that in 

case of operation of the spillways there would be no 

massive accumulation of bed load in the area of the 

upper pool in the vicinity of the turbine water intake. 

The model study is still in progress at Sogreah’s 

hydraulic laboratory in France, and it is expected that 

this study will enable the development of optimum 

solutions necessary for satisfactory performance. 

The second paper stressed the importance and need 

for hydraulic model studies of hydro project headworks, 

especially for projects in the Himalayan region 

where river bed slopes are often very steep and sediment 

inflows are sporadic and massive. Most projects 

are run-of-river, with relatively high heads. Problems 

to be solved are: satisfactory design of the headworks 

to ensure: riverbed stability; sediment-free water supply 

to the turbines; and, energy dissipation downstream 

of the structure assuring safety of the structure. 

The next presentation described innovative methods 

for assessing the erosion of sediment diversion tunnel 

inverts used for diverting heavier bedload materials 

away from the reservoirs. Two research projects are 

described: one of optimization of the transport rate so 

that the tunnel is neither clogged nor the velocities are 

so high that rate of abrasion of the tunnel invert is 

excessive. The ideal condition would be bedload moving 

over a layer of bedload. But this would mean that 

water discharge and bedload discharge would be perfectly 

balanced, which may be very difficult in the 

prototype. The other aspect of the research is to develop 

hydro-abrasive-resistant materials for protecting 

tunnel inverts. As a byproduct, a new sediment transport 

measurement apparatus called Geophone has been 

used. It allows for detection of the transport rate of single 

grains at different flow velocities. These subjects 

of research are very interesting and could help to 

improve bypass tunnel design. 

The next speaker discussed the multi-pronged strategy 

adopted for sediment management at the Karcham 

-Wangtoo project in India, with an 88 m head. 

Typical run-of-river projects over the last decades in 

the region operate using hourly or daily regulating 

ponds to supply peak energy. The main reason for this 

type of development is probably to avoid the construction 

of large reservoirs which have more environmental 

impacts. Often these reservoirs are not on the main 

stream, and are almost blind ponds filled up with water 

containing large quantities of fine sediment (clay and 

silt) without the possibility of flushing, which is often 

not very efficient and requires a lot of water. Also 

sometimes the ponds are lined with plastic membranes, 

and sediment deposits cannot be removed by 

using heavy mechanical means. 

La Garita hydro project was commissioned in 1958 

and is the first hydropower plant built by Instituto 

Costarricense de Electricidade (ICE). Its reservoir is 

shallow and wide and cannot be flushed efficiently. 

Dredging could remove 100 000 to 150 000 m 3 but 

would be very expensive. Diesel consumption would 

be in the order of 2 l/m 3 . 

<strong>Hydro</strong>-suction, which uses gravity as the driving 

force, is much more energy-efficient, and uses less 

water than dredging. At Cebadilla reservoir, the 

SediCon Dredge has been used successfully and sediment 

concentrations as high as 20 per cent by volume 

were obtained and average capacity with a 10 to 12 in 


pipe was around 120 m 3 /h. In Costa Rica and other 

South American countries, this concept may be successfully 

used. 

The next paper discussed the challenges presented in 

designing the 60 MW Khimti run-of-river hydro project 

in Nepal, with a high head (680 m), including: constructing 

the intake in a steep mountain stream carrying 

large boulders; and, the sporadic high concentrations 

of sediment load containing cobbles, gravels and 

sand. 

Its de-sander was designed using a 1:15 scale 

model and is performing fairly satisfactorily with 

fewer than average abrasion problems. The S4 sediment 

flushing system apparently had some problems 

as a result of heavy sediment deposits in the transition 

zone, and manual cleaning was necessary; since 

the installation of SediCon Sluicer the system is 

operating satisfactorily. 

At the downstream end of the headrace tunnel there 

is also a tunnel desander, which traps about 500 m 3 of 

sediment up to 50 mm in diameter during the monsoon 

season. Two SediCon sluicers enable flushing of this 

desander which discharges through a pipe going 

through the bulkhead and out through the adit tunnel, 

where the sediments are dewatered in a separate basin. 

These sediments are often used as concrete aggregate 

by the local population. The Khimti hydro station has 

provided a major and stable proportion of the power 

supply to Nepal for more than 10 years, and is considered 

as a successful investment. Its innovative design 

features will benefit many future projects in the 

Another speaker discussed the development of special 

technologies for the extraction and disposal of 

sediment from reservoirs. 

Various types of impact of reservoir sedimentation 

were enumerated and possible local remedial measures 

were assessed. The cost of sediment removal from the 

reservoir and the cost of loss of live storage or eventual 

shortage water supply are complex problems and 

have only partly been solved. 

Bottom sediment monitoring, methods of sediment 

removal, the development of equipment, disposal and 

recycling of sediments in the context of the Czech 

Republic were covered in the paper. 

The final presentation looked at sediment monitoring 

technology for turbine erosion and reservoir siltation 

applications. A precise estimation of sediment transport 

is very important in the design of large dam projects 

and hydro, whether run-of-river or large storage 

projects. The equipment developed by Sequoya 

Scientific Inc, USA, has contributed significantly in 

improving the quality and speed with which it is now 

possible to obtain highly precise sediment data in the 

field. Real-time sediment data collection and analysis 

is now possible, and this should improve the safety of 

the project operation against excessive turbine abrasion 

damage and better assessment and management 

of reservoir sedimentation. 

The authors explained in some detail the principle of 

the laser diffraction system, which enables an assessment 

to be made of local particle size distribution, as 

well as concentrations of the sediment transport in a 

river flow. It is hoped that widespread use of this 

equipment will enhance the quality of sediment management 

at future hydro and reservoir projects. ◊ 

A view of the closing 

session of HYDRO 

<strong>2011</strong>, where some 

key participants and 

session 

Chairpersons 

highlighted a few of 

the key outcomes. 

Delegates relax 

listening to a concert 

featuring music of 

Dvorak, Smetana and 

other European 

composers, at a 

concert in the 

Municipal Hall of 

Prague, prior to the 

Welcome Reception. 

This hall is one of the 

most outstanding 

examples of Art 

Nouveau architecture 

in the city. 

Networking 

continued in the 

major HYDRO <strong>2011</strong> 

Technical Exhibition, 

where more than 200 

hydro companies 

participated, 

reflecting the stateof-the-art 

of their 

dynamic industry.

Hydro 2011 report PDF - International Journal on Hydropower and ...

Create successful ePaper yourself

Delete template?

Save as template?