Aguablanca Dike along the Cauca River, Cali, Colombia

Aguablanca Dike along the Cauca 

River, Cali, Colombia 

Diagnosis and recommendations 

Final 

NL Agency 

The Netherlands Ministry of Foreign Affairs / Colombia Transition Facility 

January 2013

Aguablanca Dike along the 

Cauca River, Cali, Colombia 

Diagnosis and recommendations 

Final 

file : BB2984 

registration number : LW-AF20130064 

version : final 

classification : 

NL Agency 

The Netherlands Ministry of Foreign Affairs / Colombia Transition Facility 

January 2013 

© HaskoningDHV Nederland B.V. No part of these specifications/printed matter may be reproduced and/or published by print, photocopy, microfilm or by any other means, without the 

prior written permission of HaskoningDHV Nederland B.V..; nor may they be used, without such permission, for any purposes other than that for which they were produced. The quality 

management system of HaskoningDHV Nederland B.V.has been approved against ISO 9001.

Royal HaskoningDHV 

CONTENTS 

PAGE 

EXECUTIVE SUMMARY 3 

1 INTRODUCTION 7 

1.1 Extreme rainfall in Colombia has led to alarm for possible dike failure 7 

1.2 Scope of work 8 

1.3 Project team 8 

2 HYDROLOGY AND HYDRODYNAMIC MODELLING 9 

2.1 Discharge of Rio Cauca under influence of Salvajina reservoir 9 

2.2 Analysis of extremes leads to lower expected maxima than previously calculated 10 

2.3 Identification of dike locations with critical elevation level 12 

2.4 Flood modelling results 12 

3 FLOOD RISK MANAGEMENT: COST OPTIMIZATION 13 

4 IMPROVEMENT OF DIKE SAFETY, IMMEDIATE AND SHORT-TERM STRATEGY 15 

4.1 Analysis of present conditions 15 

4.1.1 Dike crest level of the main dike 15 

4.1.2 Dike conditions of Canal Sur and Rio Cali 17 

4.1.3 Water levels and river bed management 17 

4.1.4 Freeboard discussion 17 

4.1.5 Dike strength 17 

4.2 Immediate and short term strategy 18 

4.2.1 Immediate actions 18 

4.2.2 Short-term strategy 0 19 

5 LONG-TERM APPROACH FOR FLOOD PROTECTION CALI 22 

5.1 Anticipate on impact of economic and regional developments and possible climate change effects22 

5.1.1 Spatial developments 22 

5.1.2 Economic development 22 

5.1.3 Climate change 23 

5.2 Ongoing and increased need for flood protection 23 

5.2.1 Risk based approach for flood protection for Cali 23 

5.2.2 Combination of flood risk and earthquake risk 23 

5.3 Strategies for maintaining and improving flood protection 24 

5.3.1 Flood protection level 24 

5.3.2 Strategy 1: Controlled retention upstream of Cali and on east bank 25 

5.3.3 Strategy 2: Total reliance on Jarillón Aguablanca 25 

5.3.4 Choice of strategy 26 

6 GOVERNANCE AND WATER AUTHORITY 27 

7 REFERENCES 28 

ABBREVIATIONS 30 

8 COLOPHON 31 

NL Agency/Aguablanca Dike along the Cauca River, Cali, Colombia 

31 January 2013, version final 

LW-AF20130064 - 1 -


APPENDICES 

1 Hydrology 

2 Longitudinal dike profiles and hydrodynamic modelling results 

3 Hydrodynamic modelling, methodology 

4 Flood risk management methodology 

5 Field assessment of the conditions of the Aguablanca dike 

6 Structural stability and analysis of failure mechanisms 

7 Inspection plan 

8 Water governance and regional water authorities in the Netherlands (partially derived 

from [14]) 

9 Ownership of the Aguablanca dike 

10 Table of damage and investment costs 



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EXECUTIVE SUMMARY 

Commissioned by Agency NL 1 , Royal HaskoningDHV in collaboration with Colombian consultant 

Corporación OSSO, and supported with input by Dutch Waterboard Aa and Maas has made an analysis of 

the status of the Aguablanca Dike along the Cauca River near Cali, and elaborated recommendations for a 

short and long term strategy to improve its safety level. 

Our main conclusions are the following: 

1. The Aguablanca Dike is basically a good dike, but enforcement and maintenance of the dike and river 

profile over the past 50 years has been insufficient. This lack of maintenance leads to a number of 

immediate and short term measures to be taken. 

2. The protected area has developed over 50 years from an agricultural area into a densely populated 

urban area. This leads to the necessity for an increase in flood protection level as a long term 

objective. 

3. Legally, at least until October 2012, CVC has been owner of the dike since its construction, but 

responsibility for maintenance and control of the dike are not transparent. 

Ad. 1 

The present state of river flood protection of Cali has fallen below the standard of the original dike design 

of the Aguablanca Dike in 1958 (T=100 + 1.5 m freeboard). With relatively limited effort this original flood 

protection can be restored. The short-term strategy 0 (reference strategy) is aimed at this original 

protection. 

A serious point of attention is the lack of maintenance of the main pumping station in the dike body. 

Immediate action is required to repair a number of the outer valves that are essential for flood prevention, 

before a threatening situation may occur. EMCALI is owner of this pumping station. 

Ad. 2 

Since 1958, 700,000 to 800,000 people have come to live and work in the flood prone area of Cali. 

Therefore the flood protection of these people and there economic activities needs to increase. In other 

words, the Jarillón Aguablanca needs to be raised and strengthened. 

Ad. 3 

We have verified that, at least until recently, CVC has been the legal owner of the dike (see Annex 9). 

During presentation of the results of this study on December 7, 2012, it came to our attention that CVC 

may have signed away its ownership to the City of Cali during October or November 2012, but this has not 

been verified through documents. Anyhow, more organisations are involved in decisions regarding 

constructions on and near the dike. In this situation it is not transparent which organisation has ultimate 

responsibility for the dike, leading to a questionable lack of maintenance and increase of inundation risk. 

To have a solid defence against inundation from the Cauca River, it is a prerequisite to have only one 

organisation ultimately responsible for control of the dike. Over the years, the involvement of CVC in 

maintenance and control of the dike has diminished. Various structures in the dike body belong to other 

1 Financed through the Transition Facility which is supported by the Ministry of Economic Affairs, 

Agriculture and Innovation and the Ministry of Foreign Affairs 



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entities like EMCALI and DAGMA. The different authorities lack communication on important issues of 

design of new constructions and maintenance issues. 

We have defined an action plan including technical and non-technical issuesactions to be taken and 

strategies to follow. 

Tabel 1 

Urgent: 

Action plan 

1. Rehabilitation of pumping station 

The condition of the closing systems of the pumping station Paso del Comercio is alarming. They are 

either out of order or malfunctioning. Immediate action to repair broken or malfunctioning valves is 

required to ensure maximum flood protection. This action cannot be postponed 2 . 

2. Rehabilitate 6 critical points in the Aguablanca dike and low points in the dike of Canal Interceptor Sur 

Where the dike crest level is the most important parameter in flood protection, immediate action is 

recommended to rehabilitate the lowest points in the Aguablanca dike : 

1 km 128+581 

2 km 134+581 

3 km 136+081 

4 km 140+781 

5 km 142+281 

6 km 143+281 

In addition it is recommended to rehabilitate the low points of the dike of Canal Interceptor Sur, which 

have been identified in the longitudinal profile of Annex 2. 

3. Remove ant nests and fill the cavities caused by these nests 

The cavities of ant nests (hormiga arriera) need to be filled. Shallow nest cavities can easily be repaired 

by digging out and applying new clay filling. Deeper nests should be filled, preferably with bentonite. 

Short term: 

1. Raise the security level of the dike 

We recommend a security level for a return period of 500 years with a freeboard of 0.5 m. The extra costs 

for a safety level with a return period of 500 years as compared to 100 years are relatively small. 

2. Resettlement of house on the dike and in the berm of the dike 

Approximately 15000 families are living on the dike and berm which need to be resettled. 

3. Install by law one entity with ultimate responsibility for the dike 

This entity should have responsibility for maintenance, inspection and supervision of all construction in 

the dike, and have the technical and financial resources to perform its task properly. 

4. Introduce a maintenance system 

Develop a system for maintenance of the dike, including norms for interventions, constructions, housing, 

2 In a letter to Dr. M. Guerrero, the Mayor of Cali, dated December 17, 2012, EMCALI has confirmed that it 

is envisaged to repair the damaged valves in January 2013 



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industries and a plan for periodic inspection. 

5. Evaluate existing plans for dike re-enforcement 

There are existing plans by EMCALI for dike re-enforcement around the drinking water plant. We 

recommend an evaluation of these plans in cooperation with CVC and investigate alternatives in order to 

reduce costs. 

6. Control further spreading of the ant species “Arriera” 

Regular inspection should be aimed at eradication of the ants. Ant nests should be dug out as soon as 

observed. 

7. Action for river bed and flood plain maintenance and construction debris control 

Enforcement of river bed maintenance needs to be improved. This is on one hand predominantly a 

government issue, on the other hand economical incentives and technical possibilities can help. 

Especially the dumping of construction debris needs to be stopped. 

8. Review the operation rules of the Salvajina reservoir 

We recommend a review of the operation rules to attempt a further optimization of compliance with the 

different objectives of the reservoir, i.e. reduce peak discharge, supply a certain minimum discharge for 

environmental purposes and produce energy. This will require a simulation study based on historic 

discharges, where we suggest to use stochastic modelling and use of generated synthetic time series. A 

special point of focus is the time scale to be used, and possible use of meteorological forecasting. 

Medium term and long term: 

1. Improve land use planning 

Water safety should be a leading principle in an integral approach of land use planning by the municipality 

and regional authorities. It is therefore an important issue related to the institutional issues. Enforcement 

of spatial management and assessment of spatial developments on consistency with the long-term flood 

approach needs to be implemented. The analysis of this study should be incorporated into the land use 

planning strategy of the municipality. 



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In addition to the action plan, we have the following recommendations: 

1. Research into climate change effects 

We recommend further research into the effects of the trend in the ONI (Oceanic Niño Index) on extremes 

of the Cauca river discharge. 

2. Research into fluvial morphodynamics 

We recommend that the fluvial morphodynamics of the river Cauca be studied in order to have a better 

understanding of its morphodynamics and the influence of the human activities on the morphological 

developments. 

3. Further research into river hydrodynamics 

Develop an integrated hydrodynamic model of the river Cauca starting at Salvajina reservoir. In this model 

the overtopping and flooding should be included. The model should be calibrated in order to reproduce the 

last flooding events for instance by comparing the inundated area with aerial photographs. 

We have understood that this model will be constructed in another project [5] and advise the local team to 

participate in this study. 

4. More soil investigation for strength parameters related to dike slope stability 

We recommend doing more triaxial tests on undisturbed clay samples of the dike body to gain a better 

insight into the strength parameters along the profile of the Aguablanca dike. We suggest making and 

executing a detailed plan, based on a number of indicative borings. 

5. River bed and flood plain maintenance and construction debris control 


government issue, on the other hand economical incentives and technical possibilities can help. Especially 

the dumping of construction debris needs to be stopped. A strong recommendation is to invest in debris 

crusher systems to convert waste debris into raw construction materials, ready for re-use. 



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1 INTRODUCTION 

1.1 Extreme rainfall in Colombia has led to alarm for possible dike failure 

Extreme rainfall in 2010 and 2011 has resulted in extreme river discharges and water levels in various river 

basins in Colombia and has disrupted the lives of more than three million Colombians, uprooted thousands 

from their homes and destroyed swathes of farmland. 

In Cali, the threat of a possible breach of the existing dike system has alarmed the highest authorities. The 

impact of such a breach on the city and the country has led President Santos to put urgent action to 

improve the Aguablanca Dike protecting the city as top priority. The Aguablanca Dike along the Cauca 

River in the municipality of Cali has a length of approximately 17 km. It is the only structural flood 

protection of the city of Cali against floods from the Cauca River. 

Juanchito 

Figure 1 

Schematic situation of Aguablanca Dike together with dike of Canal Interceptor 

The dike was originally built in the late 50’s and early 60´s in order to habilitate the Aguablanca´s low lands 

for agricultural purposes. However these areas have witnessed significant urban development. During the 

last four decades the city has spread towards the river. Dwellings have been built on the dike crest, as well 

as in the floodplain. Today almost 20% of the population of the city is settled in flood plain and around 

15.000 people live directly over the dike structure. The largest water treatment plant that supplies around 

60% of the city is also located in this area. The main pumping station of the city, Paso del Comercio, is 

located in the lowest part of the city at the end of the principal drain channel. 

A population of over 700.000 people in the District Aguablanca is currently at risk from flooding. Climate 

change and progressive anthropogenic impacts in the upper basin of the Cauca River will only further 

increase these risks. 



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1.2 Scope of work 

The scope of work has included the following activities: 

1. Assessment of the physical condition and structural stability of the current dike. This includes: 

● a field survey over a distance of 18 km; 

● application of geotechnical software; 

● review of previous surveys of the dike; 

● training of the Colombian engineers of CVC during the process of dike inspection 

2. Calculations using a hydrodynamic model to model inundations of different 

frequencies (1:100 year 1:250 year, 1:500 year). 

3. Estimation of the optimum dike height in terms of the costs of dike improvement and the flood 

damage avoided. 

4. Development of action plan and strategies for short term an medium term measures 

5. Prioritization of sections of the dike that should be reinforced. 

6. Organisation of a workshop with presentations of dike management in the Netherlands, preliminary 

results of the inspection of the Aguablanca Dike, presentation of a dike inspection manual in Spanish. 

1.3 Project team 

The project team consisted of the following persons: 

Hans Leenen (Royal HaskoningDHV): team leader and senior expert in hydrology and risk management 

Michel Tonneijck (Royal HaskoningDHV): senior dike expert 

Marcela Busnelli (Royal HaskoningDHV): senior expert in hydrodynamic and morphological modelling 

Steven Sjenitzer (Royal HaskoningDHV): geotechnical expert 

Joop de Bijl (Waterboard Aa and Maas): senior dike expert. For this project Joop de Bijl of Waterboard Aa 

and Maas has participated to include expertise of a leading Dutch Waterboard. 

Royal HaskoningDHV has collaborated with Colombian counterpart Corporación OSSO in Cali, whom we 

greatly thank for its professional and kind cooperation. 

Team members of OSSO were: 

Carlos Regalado, geotechnical engineer and outstanding help in translation issues 

Angela Cabal, specialist in hydraulic modelling 

Jorge Mendoza, civil engineer 

Henry Peralta, general coordinator 

Andres Velasquez, socio-economist 



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2 HYDROLOGY AND HYDRODYNAMIC MODELLING 

2.1 Discharge of Rio Cauca under influence of Salvajina reservoir 

The discharge of the Cauca River along the Aguablanca dike is influenced by the operation of the 

Salvajina Dam, 139 km upstream of the hydrometric station of Juanchito (Figure 2). Juanchito is the most 

important hydrometric station along the Aguablanca dike with water level data going back to 1934 and a 

continuous time series since 1945. The Salvajina reservoir was put into operation in 1985 and is a multipurpose 

reservoir with the objectives of energy production and attenuating flood peaks on the Cauca 

River. 

Figure 2 

Location of Salvajina Reservoir 

The operation rules of Salvajina Reservoir are primarily on a monthly basis (but may be adjusted daily) and 

are controlled by the Committee of Operation. Decisions are agreed upon by CVC and EPSA (Empresa de 

energía del Pacífico S.A.). During the first days of each month the Committee defines the water release for 

the month based on a set of operation rules, which will not be treated here in detail [1]. The monthly 

strategy will be maintained as much as possible, but may be modified on a daily basis. One objective is to 

maintain the discharge at Juanchito station between 130 m 3 /s and 900 m 3 /s. The objective of the minimum 



LW-AF20130064 - 9 -


flow is dilution of contamination. This flow can be regarded as an environmental flow. The envisaged 

maximum flow provides a safe level against inundations by overtopping of the Aguablanca dike. As 

observed in recent years, the applied operation of Salvajina has not been able to prevent much higher 

flows at Juanchito station (see Annex 1) of up to an estimated discharge of 1148 m 3 /s in 2011. 

The operation of Salvajina reservoir does not have strict optimization rules. We recommend a study to 

optimize the operation regime, by applying simulation modelling of the reservoir using stochastic methods, 

for instance with synthetic flow generation based on a Thomas-Fiering model. Such a modelling effort 

should take into account the different conflicting objectives of the reservoir, i.e. generating energy on one 

side, reducing flood peaks on the other, and also allowing for a certain environmental flow. 

2.2 Analysis of extremes leads to lower expected maxima than previously calculated 

In order to evaluate dike safety on the long term, it is common practice to apply a statistical approach on 

existing data (Appendix 1) and determine return periods for different discharges, based on the best fit of a 

certain probability function. This has also been done in previous studies, a.o. by the Universidad del Valle 

[2]. To define return periods and discharges for the present conditions the data of water levels and related 

discharges at Juanchito before 1985 cannot be used because of the influence of Salvajina reservoir. So 

only the years since 1985 have been used in the analysis of return periods. The Universidad del Valle [2] 

has applied a Gumbel distribution to the data, resulting in higher discharge data for return periods of 25 

years and more, than what is calculated under the present study. The reason for the differences is that the 

Gumbel distribution gives a rather poor fit to the data. Under the present study a number of probability 

distributions have been compared for quality of fitting the data. The Log Pearson 3 provided the best fit, 

based on statistical grounds (K-S statistic, see Table 2). A quick way to assess the applicability of various 

probability functions is the so-called Moment-Ratio diagram, which shows differences between statistical 

characteristics of the observed values and the theoretical distributions. (see Moment-Ratio diagram in 

Annex 1). From this diagram it is clear that the Gumbel distribution is not suitable in this particular case. 

Table 1 shows the differences that occur for return periods higher than 25 years. The difference between 

the discharges for the return period of 100 years leads to a difference in water level of 0.67 m according to 

the current calibration table for the level-discharge relationship (Annex 1). Our conclusion is that previous 

studies have overestimated the discharges related return periods above 25 years. 

As a basis for the hydrodynamic modelling the present study will apply the results from the Log Pearson 3 

distribution as presented in Table 1, graphically presented in Figure 3. 

Table 1 

Return period 

Comparison of estimated return periods (station Juanchito) with previous studies 

Ref. [2]: Gumbel distribution 

Discharge [m 3 /s] 

Present study: Log Pearson 3 distribution 

Discharge [m 3 /s] 

5 839 925 

10 961 1016 

25 1115 1107 

50 1229 1161 

100 1342 1206 

200 1244 

250 1255 

500 1286 



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Return period estimates: Extreme discharges Juanchito-since 1985 

[m3/s] 

Observed Gumbel Weibull 

LP3 Normal LN2 

Gamma Logistic LN3 

2500 

2000 

1500 

1000 

500 

0 

1 10 100 1000 10000 

Return period [time units] 

1250 

4000 

Figure 3 

Return period estimates for extreme discharges at Juanchito 

Table 2 Kolmogorov–Smirnov test statistic 

Probability function 

KS-Statistic 

KS-critic (0.10) 0.232 

LP3 0.093 

Weibull 0.099 

LN3 0.105 

Gumbel 0.128 



LW-AF20130064 - 11 -


2.3 Identification of dike locations with critical elevation level 

The discharge data as extrapolated with the LP3 distribution (Table 1) have been used to estimate the 

water levels along the Aguablanca dike for various return periods. The Universidad de Valle [2] applied a 

one dimensional model to estimate water levels for different return periods. In all modelling efforts, the right 

bank of the Cauca River has been modelled as an infinitely high wall without inundation possibility. These 

levels have been used as input for the estimation. In this estimation Juanchito station has been used as a 

reference to adjust all levels along the Aguablanca dike accordingly. The water levels associated with 

different return periods have been compared with the latest longitudinal dike profile, measured in 2012 

(Annex 2). In doing so, the critical points along the dike in terms of level, were identified: 

1 km 128+581 

2 km 134+581 

3 km 136+081 

4 km 140+781 

5 km 142+281 

6 km 143+281 

Based on these critical points inundation simulations were carried out with the 2D-model CCHE2D of the 

University of Mississippi to establish a basis for damage estimates (see Annex 2). 

2.4 Flood modelling results 

The 2D-model CCHE2D of the University of Mississippi of the river Cauca (between the Canal Interceptor 

Sur and the river Cali) has been applied in this study [3]. The model was recalibrated based on the 

updated statistics of discharges and water levels. The hydrodynamic model provides insight in flood 

characteristics, such as water depth and flow velocity. Three scenarios were defined and simulated as 

input for the risk management assessment (Chapter 3): Flooding due to breaking by overtopping for a 

return period of 1:100, 1:250 and 1:500. The graphical results of the computations for a return period of 

1:100 are presented in Annex 2. Numerical results of the computations are presented in Table 3. These 

flooding characteristics have been applied in the risk-based analysis to obtain the damage costs 

corresponding to a certain flooding probability. 

Table 3 Characteristics flooding scenarios 

Return period Maximum inundated area [km 2 ] 

100 20.36 

250 22.83 

500 24.28 



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3 FLOOD RISK MANAGEMENT: COST OPTIMIZATION 

Initial costs of relocation of dike dwellings play an important role in total costs 

In this study we apply the principles used in the Netherlands for risk-based design of flood protection 

systems to the Aguablanca area. In this economic optimization, the investments in more safety are 

balanced with the reduction of the risk to find an optimal level of flood protection. 

We have assumed that the dike will only fail because of overtopping. The strength of the dike is 

subsequently designed in such a way that the dike does not fail at water levels below the design water 

level, for all possible failure mechanisms such as piping and lack of stability. The assessment of the 

physical conditions and structural stability of the dike is described in detail in Annex 5, and Chapters 4 and 

5. If the water level is above the design water level, the dike might fail and breach. 

The places where overtopping might occur in the river Cauca (between Canal del Sur and river Cali) for a 

given return period were obtained by plotting the crest height and the water levels corresponding to a 

given return period. The flooding scenario for a return period of 100 year was defined by comparing the 

height of the dike with the water level for a return period of 100 year. 

The locations where defined from a preliminary longitudinal profile of the dike. The OSSO-team corrected 

this profile after reviewing it. The locations of possible breaching of the dike were determined by the 

OSSO-team. The longitudinal profile of the dike at the left bank of the river Cauca shows sectors where the 

height of the dike is close to or lower than the water level for a return period of 100 years. Five locations 

were defined. In these locations the water level is higher than the dike or the free-board is less than 1 m. A 

free-board of 1 m is recommended by CVC. 

Table 4 shows the locations where overtopping might occur. The dimensions of breaching of the dike were 

obtained from the analyses of failures of dikes occurred in the past in Colombia [13]. 

Table 4 

Location 

No. 

Locations where overtopping might occur 

Crest of 

the dike 

Abscisa [m] 

Water level [m] 

Tr 100 Tr 250 Tr 500 

1 K134+581 952.5 952.06 952.30 952.45 

2 K136+081 951.6 951.61 951.85 952.00 

3 K140+781 950.6 950.76 951.00 951.15 

4 K142+281 950.5 950.20 950.44 950.59 

5 K143+281 950 949.82 950.06 950.21 

The 2D hydrodynamic model has been applied to determine the flooding characteristics. These flow 

characteristics and the land use maps were combined in GIS with the stage-damage functions and 

maximum damage costs to determine the damage costs corresponding to a flooding probability. 

The current yearly risk (probability x damage) has been converted to a present value by dividing by the net 

discount rate. A real discount rate of 8% is calculated from the interest rate of 11% minus inflation 3%. 

The damage will increase because of economic growth. Neglecting economic growth would lead to an 



LW-AF20130064 - 13 -


underestimation of the future risk. We have assumed a economic growth of 1% per year. This number is 

estimated on the basis of future expectations and is therefore uncertain. 

In a cost-benefit analysis also the costs of rising and reinforcing the dikes are important. The costs of 

relocating the families living on the dike are also taken into account in the investments. The results of the 

analysis are presented in Figure 4. An important feature of this calculation is that the increase in 

investments costs as a function of the return period is relatively small. This is because the costs of 

relocation the families living on the dike are the highest investment costs. This aspect leads to the 

consideration, that from the purely economic point of view of this method, it would be better to make a 

choice for the highest return period, leading to the lowest total expected costs. From a practical point of 

view, any choice above 500 years would seem sufficient. The background data of this calculation are 

presented in Annex 10. 

Figure 4 

Results of economic optimization for the Aguablanca dike 



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4 IMPROVEMENT OF DIKE SAFETY, IMMEDIATE AND SHORT-TERM STRATEGY 

4.1 Analysis of present conditions 

The objective of the assessment of the present conditions of the dike is to investigate crest levels, stability, 

and all human or other impacts, that may reduce the safe level of the dike. Comparing these conditions 

with required conditions leads to conclusions about possible strategies and necessary actions to take. 

4.1.1 Dike crest level of the main dike 

The original design crest level for the Jarillon de Aguablanca was based on T=100 + 1.50 m. This dike 

protected a predominantly agricultural area between Cali and the Cauca River. The dike was constructed 

in an era (1950s) that T=100 could not be well calculated, but only be estimated [15]. The present crest 

level is presented in Figure 5 The estimation of the 1950's shows very good compliance with the now 

calculated T=100 in this report 3 . 

From the analysis we have the following observations: 

1. Crest level measurements show that the crest level could not be maintained all along the dike. 

2. The protected area has changed from agriculture into urban area and therefore requires a higher 

protection level (see paragraph 4.1.3). 

3. The original 1.50 m freeboard could well be reduced since the expected water levels can be 

calculated more accurately. 

Perfil Longitudinal del Jarillón del río Cauca y Nivel de agua para diferentes periodos de retorno 

Level [msnm] (Versión revisada con datos de campo, septiembre 20 de 2012) 

956 

water level T=10 water level T=25 

955 


water level T=500 

dike crest level 

954 

T=100 + 0,50 m freeboard T=500 + 0,50 m freeboard 

T=250 + 0,50 m freeboard original design T=10 + 2,50 

953 

952 

951 

950 

949 

948 

Canal Sur 

km 127 + 724 m 

Juanchito 

km 139 + 259 m 

Rio Cali 

km 146 + 300 m 

947 

127 

128 

129 

130 

131 

132 

133 

134 

135 

136 

137 

138 

139 

140 

141 

142 

143 

144 

145 

146 

147 

---> x -coordinate [km] 

Figure 5 Dike crest level (orange) and different water levels + freeboard (see also Annex 2) 

3 With the few data the engineers had in 1958, they estimated the level corresponding to a return period of 

T=100 years + 1.5 m, to coincide approximately with a level corresponding to a return period of T=10 years 

+ 2.5 m 



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Table 5 

possible 

protection 

levels 

Dike lengths to be raised for distinguished flood protection levels 

freeboard 

[m] 

T = 10 yrs 1.50 

dike length 

to be raised 

[m] 

almost 

total 

T = 100 yrs 0.50 4300 

T = 250 yrs 0.50 7200 

T = 500 yrs 0.50 9800 

cm to be 

raised 

generally 

< 20 cm 

generally 

< 35 cm 

generally 

< 40 cm 

remarks 

with the knowledge of today's water level 

calculations the dike doesn't meet the 

originally set requirements; 

an extra check on the datum is required, 

since there is no straightforward explanation 

for why the Jarillón Aguablanca has fallen so 

far below its original standard 

with today's more accurate water level 

calculations, flood protection level of T=100 

could be guaranteed with a freeboard of 

0.50 m 

with the change of the protected area from 

agriculture into urban area, a higher 

protection level needs to be considered and 

should be a result of an economic analysis 

idem 

From this it is clear that the discussion about the safety level is 

1. on one hand a matter of the establishment of an economical optimum return period, but 

2. on the other hand a technical freeboard discussion among engineers about the reliability of the water 

level calculations. 

Accurate dike levels and accurate water levels. 

In the course of the assignment it turned out to be very difficult to establish the correct dike level from the available data. 

Level data were either outdated or, more important, taken from different periods in which the reference level (datum) 

had changed. CVC and OSSO have assured that the presently available dike level is correct. 

The hydraulic river model for water level calculations is by definition not exact, since not all riverbed data are available, 

nor can calibration and verification be done. Still the possibilities for establishing a more or less correct water level are 

way better than at the time of dike construction. A river model for the whole Cauca River should be made available. First 

of all, river behaviour downstream is very much affected by what happens more upstream. The acceptance of one base 

for transboundary decisions (between states, between municipalities depend very much on the acceptance of one base 

model as the true water level predictor. 

Still the reproduction of the original dike design (Figure 5) shows that the dike has dropped considerably below its 

original design value (water level T=10 + 2.50 m). This is not in line with the feeling and view of experienced local 

engineers. We recommend that this item will be investigated: 

1. re-evaluate datum changes in the course of years 

2. attribute each available measurement to the correct datum 

3. describe the history of datum levels and measurements in a separate report 

4. open archives to establish certainty about the really constructed dike level: T=10 + 2.50 m indeed? 

5. compare the starting point T=10 (1958) and T=10 (2012) 

6. investigate the possibility that the dike subsoil has consolidated so much. 



LW-AF20130064 - 16 -


4.1.2 Dike conditions of Canal Sur and Rio Cali 

There are no records of failure of the dike along Canal Sur. Stability calculations for these dikes have also 

indicated that they comply with the minimum strength requirements [13]. Corporación OSSO has done field 

work for the dikes of the two tributaries Canal Sur and Rio Cali resulting in the longitudinal profiles 

presented in Annex 2. 

The field observations show a significant impact of human interventions along these dikes in the form of 

waste and rubble deposits. In addition there are nests of the ant species “arriera” in various locations, 

impacting the permeability and stability [13]. 

From the profiles it follows that there are some parts below the T=100 level that is defined at the point of 

inflow into Rio Cauca. The right embankment along Rio Cali seems everywhere, except a small part close 

to the Rio Cauca, well above the T=100 level as defined at the point of inflow into the Rio Cauca. 

4.1.3 Water levels and river bed management 

Because of the intense urbanization, the river bed and flood plains condition is very much under pressure 

of sand mining and dumping of construction debris. Uncontrolled erosion and upward trends in water levels 

are a result. Of course CVC and Cali municipality are fully aware of this problem. The solution of the 

problem is not just a technical item, but is found in a much wider socio-economic and administrative 

approach. 

4.1.4 Freeboard discussion 

In the Netherlands river dikes require a minimum freeboard of 50 cm. This freeboard allows for 

● wave run-up, 

● river water level model uncertainty and 

● firm dry ground above the water level in extreme conditions for emergency measures. 

In the situation of the Cauca River and the Jarillón Aguablanca, wave run-up may be neglected. The width 

of the river is relatively small and there are no big cargo ships. The model uncertainty however needs to be 

regarded more in detail. For the moment we assume that model uncertainties fit well within the 0.50 m 

allowance for the freeboard. 

4.1.5 Dike strength 

The crest level is the most important and direct factor for the flood level protection of Cali. However, a 

weak dike or weak points in the dike may result in failure, even if the water level is lower than the design 

water level. 

The dike inspection has resulted in 5 important observations. 

1. Dike crossing hydraulic constructions Water and Sewer Treatment Plants and Pumping Station do 

not fulfil safety requirements. Especially the pumping station at the downstream side of the dike is in 

an alarmingly bad condition. Failure of the pumping station in its flood defence function cannot be 

excluded and is estimated much worse than a failure probability of 1/100 per year (T=100). Also the 

drinking water inlet and waste water treatment plant need upgrading. For a more elaborate 

description see Annex 5, Field assessment of the conditions of the Aguablanca dike. 



LW-AF20130064 - 17 -


2. At high water levels some water seepage near the pumping station of Paso del Comercio has been 

observed, most likely due to a construction error and not to slope instability. Signs of piping effects 

have not been observed. 

3. Ants have infested the dike and its environment (hormigas arrieras). They make their dwellings in the 

dike, causing cavities and weakening the dike. 

4. Under the top clayey and silty layers there are some locations with a layer of liquefiable sands. 

Earthquake induced liquefaction may put the dike as a water retaining function out of order for long 

time. However, the risk of a coincidence of a major earthquake and a flood is negligible compare to 

the risk of the event of either a major earthquake or a major flood. Minor earthquakes in the past 

have not lead to liquefaction. Therefore liquefaction is not considered an issue. 

5. The dike is quite densely inhabited, predominantly at the northern stretch. Housing, foundation and 

cellars and trees cut into essential minimum design profile. Living on a dike is almost the safest place 

in a flood prone area. The major problem is when housing or other human activities harm the integrity 

of the dike body: cut into the body itself, damage the revetment, thus reducing the water retaining 

capacity and creating initiation points for erosion. 

4.2 Immediate and short term strategy 

4.2.1 Immediate actions 

Low spots 

Where the dike crest level of the main dike is the most important parameter in flood protection, immediate 

action is recommended to raise the lowest points in the Aguablanca dike that are very local: 

1 km 128+581 

2 km 134+581 

3 km 136+081 

4 km 140+781 

5 km 142+281 

6 km 143+281 

In addition it is recommended to rehabilitate the low points of the dike of Canal Interceptor Sur, which have 

been identified in the longitudinal profile of Annex 2. 

Pumping station maintenance 

The condition of the pumping station is alarming. A number of the outer valves of the pumping station are 

not functioning. Although the pipes have inner valves, the defence against flooding should not just rely on 

these inner valves. During a flood, there will be unnecessary pressure inside the pipes, and increase the 

risk of inundation. Immediate action is required to ensure flood protection 4 . 

4 In a letter to Dr. M. Guerrero, the Mayor of Cali, dated December 17, 2012, EMCALI has confirmed that 

it is envisaged to repair the damaged valves in January 2013. 



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4.2.2 Short-term strategy 0 

This short term strategy consists of 5 components: 

a. Maintaining dike level at T=100 

b. River bed and floodplain maintenance 

c. Hydraulic constructions 

d. Dike slope stability 

e. Harmful activities from humans and ants 

f. Institutional issues 

These will be elaborated below (Institutional issues are discussed separately in Chapter 6). 

The short term strategy should be considered as a base strategy (maintaining the status quo is not an 

option). This mix of components should be implemented in a coherent way. Only maintaining the dike level 

at T=100 will improve safety conditions but will not be effective in the long run if components b, c,d, and e 

are not taken care of at the same time. 

a. Maintaining dike levels at T=100 

For the short term strategy 0, the measures are aimed at realising the originally intended protection level of 

T=100. The measures respond to the findings of the dike inspection for the Aguablanca dike on 18/19 

September 2012 and 2 October 2012. As regards the dikes along Canal Sur and Rio Cali, we recommend 

the same immediate action, i.e. to bring the levels up to the corresponding T=100 level of the Rio Cauca. 

Considering that the intended flood protection level of the Jarillón Aguablanca was T=100 + freeboard we 

recommend for the short term to rehabilitate the dike to this flood protection level. Since the protected area 

has changed from agricultural land into urban area, this protection level should at least be maintained. This 

recommendation implies raising 4300 m of the dike. In doing so, we assume that with the present statistics 

and calculation methods a freeboard of 0.50 m is sufficient. 

NB. If it would be decided to raise the dike, the reinforcement could well be combined with the longer term 

recommendation at little extra costs. 

The T= 100 does not necessarily need to be motivated with an economical analysis. Rather, the situation 

of Cali is such that the opposite river bank is lower and in much worse condition than the Cali side. This is 

for Cali a preferential situation. There is so much retention on the opposite river side that Cali is virtually 

safe. In this situation Cali or CVC could buy time: as long as developments upstream and/or the opposite 

river bank do not go so far that Q or h near Cali will rise, the Jarillón Aguablanca will provide virtually 

unlimited flood protection (as long it is strong enough, mind e.g. the pumping station). 

b. River bed and flood plain maintenance and construction debris control 


government issue, on the other hand economical incentives and technical possibilities can help. Especially 

the dumping of construction debris needs to be stopped. A strong recommendation is to invest in debris 

crusher systems to convert waste debris into raw construction materials, ready for re-use. 



LW-AF20130064 - 19 -


Figure 6 

Debris crusher system 

c. Hydraulic constructions 

From the safety assessment of the Pumping Station immediate action is required. 

In general we recommend a situation in which the owner of the construction (EMCALI) and the owner of 

the dike (CVC) are equally responsible for the construction part that crosses the flood defence line. This is 

predominantly a governance issue to enforce this kind of collaboration, but it is also an issue of behaviour 

of the engineers of both organisations (see also Chapter 6). 

Technically we recommend EMCALI and CVC to co-operate on the ongoing projects for improvement. 

From a flood defence perspective a number of design issues in the rehabilitation of the structures need to 

be standardised: 

1. construction level should be in conformity with – future – dike protection level; preferably far beyond 

the planning period (dike 50 yrs ahead, constructions – more expensive to adapt – 100 years ahead); 

2. overall stability of the construction must fulfil stability requirement as of the dike (water levels, piping); 

3. seepage screens next to and under the construction are required; 

4. integrity of the construction within the flood defence line must be guaranteed, preferably the parts of 

the construction in the flood defence line must be stronger than parts outside the defence line; e.g. a 

steel pipe crossing the dike must partly be stronger in the dike: if a pipe under pressure would fail, 

that would be rather outside the dike than inside; 

5. transition constructions from e.g. concrete to soil need to be well designed, monitored and 

maintained. 

EMCALI has projects running. From the dike perspective the hydraulic constructions need upgrading in the 

short term strategy. Where total rehabilitation does not fit into the life cycle economics of the structure, 

measures should be taken to ensure the flood protection part of the structure. Assessment and design 

aspects have been mentioned above. 

d. Dike slope stability and liquefaction 

The Jarillón Aguablanca has geotechnically relatively steep slopes. During the – still relative low – 

2011 flood dike instabilities have been observed. In order to technically guarantee dike stability under 

design conditions the slopes should be more stable. I.e. the dike needs gentler slopes. Example 

geotechnical calculations show that a slope of 1:2½ to 1:3 will be required. 



LW-AF20130064 - 20 -


Secondly the presence of liquefiable sands adds earthquake risk to the dike construction. Soil investigation 

made available shows that the omnipresent sand layer is not always liquefiable. 

We recommend to do density tests and test on grain size distribution and water content to localise the 

potential liquefaction areas. 

Given the Cali situation two options need to be investigated: 

● "adding cohesion" to the liquefiable soil 

● adjustment of the dike profile, so that deformation caused by liquefaction will not affect the water 

retaining integrity of the dike (PLAXIS-calculations). 

e. Harmful impacts from humans and ants 

Houses and trees cutting into essential parts of the dike profile should be either removed or the dike profile 

needs adaptation. We recommend the establishment and registration of minimum essential water retaining 

dike profile for each section. This dike profile should have a legal status by which CVC is capable of 

enforcing measures to maintain the minimum profile. 

The cavities of ant nests (hormiga arriera) need to be filled. Regular inspection should be aimed at 

eradication of the ants. Ant nests should be dug out as soon as observed. Shallow nest cavities can easily 

be repaired by digging out and applying new clay filling. Deeper nests should be filled with preferably 

bentonite. 



LW-AF20130064 - 21 -


5 LONG-TERM APPROACH FOR FLOOD PROTECTION CALI 

The long term approach for flood protection depends strongly on future developments of natural causes 

and human activities. In this chapter developments are mentioned briefly. Essential for the developments 

is that they are beyond control of the dike authority as well as local and regional authorities. Yet they are 

an important factor that has implications for the way the flood protection in the future should be managed. 

5.1 Anticipate on impact of economic and regional developments and possible 

climate change effects 

We consider scenarios as developments beyond control of the dike authority and other authorities for the 

region. Climate changes, effects of El Niño and La Niña, urban development population growth, economic 

developments are not within the immediate control of the dike authority and set boundary conditions for the 

dike. 

5.1.1 Spatial developments 

Spatial development is an item that is not directly within the competence of a dike authority. This is rather 

the domain of the municipalities, “departamentos” and provinces. With respect to flood protection spatial 

development is an essential asset. 

1. Room for – natural – river inundations needs to be maintained to control river water levels. Not only 

in the area Aguablanca, but more important upstream of Cali. 

2. Where Cali is an important area to be protected, the opposite bank still has a lot of land of lower 

economic investment; the flood protection of Cali can well benefit from maintaining this situation: 

keep the protection level at the opposite bank lower than on the Cali side. In terms of spatial 

planning: make sure that the east side of the river can remain an emergency overflow basin. 

3. Upstream developments and climate effects will in the future cause higher river water levels near 

Cali, requiring higher and wider dikes. The dike authority CVC should be given authority to claim and 

free the land adjacent to the dike. 

Water safety should be a leading principle in an integral approach of land use planning by the municipality 

and regional authorities. It is therefore an important issue related to the institutional issues 

5.1.2 Economic development 

Figure 7 

Urbanization development 



LW-AF20130064 - 22 -


Economic and spatial developments go hand in hand. Figure 7 shows the development of 50 years. More 

than climatic change, land use is a driver for an increased flood protection level. In Chapter 3 we have 

presented a method for economical analysis to define an optimum flood protection level. Dike construction 

and dike reinforcement require major investments and have major impact on the environment. It should 

also be considered that creation of a flood protected environment will attract more investments within the 

protected area, thus causing a greater need for good flood protection. 

5.1.3 Climate change 

Data that were analyzed in the recent study of the inundations in la Mojana [16], have shown a positive 

correlation between the occurrence of La Niña and extreme discharges in the Rio Cauca, while it has also 

been shown that the there is a trend in the ONI (Oceanic Niño Index), indicating an upward trend in the 

occurrence of La Niña. The conclusion was that the statistical characteristics of the Cauca River are 

changing. We conclude that besides the change of land use the occurrence of floods in the Cauca Valley 

is also influenced by climatic effects, the extent and magnitude of which is yet unknown. We recommend 

further research into the effects of the trend in the ONI on extremes of the Cauca river discharge. 

5.2 Ongoing and increased need for flood protection 

5.2.1 Risk based approach for flood protection for Cali 

A flood is a major disaster in term of risk for loss of life, flood damage and setbacks in a long-term 

economic development. 

The Netherlands have adopted a risk based approach for flood protection. The basic philosophy is that the 

authorities of the flood prone area have a responsibility in "insurance of economic development, life and 

flood protection". For a society as a whole it is then economically attractive and feasible to invest in a 

sound flood protection. In the case of Cali it is therefore economically attractive to invest in river works and 

dikes. 

For the long term we therefore recommend the risk based approach. This comprises several actions: 

1. acquisition of knowledge on risk based approach in flood protection 

2. implementation in guidelines for dike design 

3. implementation in practical operation CVC 

4. thorough implementation of a risk based assessment for the Cali situation (project) 

5.2.2 Combination of flood risk and earthquake risk 

In an area exposed to major natural disasters the combined disaster risk is important. Cali is a disaster 

prone area regarding floods and earthquakes. The Colombia government has established a Construction 

Code requirement regarding earthquakes. A design earthquake of 7.8 on the Richter scale, resulting in 

0.25 g ground accelerations is an important design factor for constructions. For Cali this design earthquake 

has a design return period of T = 475 years. We have the following observations: 

1. living in Cali, exposure to an earthquake cannot be avoided; 

2. flood risk adds to the exposure for people to disasters; 

3. expected flood damage will add to the expected damage from disasters, 

4. earthquake damage remains dominant 



LW-AF20130064 - 23 -


A severe earthquake may result in considerable damage to the dike, which – besides all other damage to 

the city - would require immediate attention. Since the time of construction of the dike, no damage has 

been observed due to earthquake. To evaluate the risk of liquefaction due to an earthquake, we 

recommend more research into liquefaction prone areas. 

Looking at the risk of exposure to a disaster, the combination of a T=100 years flood protection with a 

T=475 years earth quake risk, would result in probability of disaster, which is high relative to a person’s life 

expectancy. A person, living 80 years in a flood and earthquake prone area runs the risk of 68% to be hit 

by at least one of the two. Where the earthquake can hardly be avoided once living there, reduction of this 

exposure is well possible by increasing the flood level protection. For instance, the combination of a T=500 

year flood risk with a T=475 year earth quake risk, would result in a probability of 28% of being hit by at 

least one of the two disasters in a period of 80 years. 

From the damage point of view the earthquake risk is quite high. Considering that a dike breach would not 

result in very high inundation depths in Cali, damage is severe, but would still be limited in comparison with 

a major earthquake. Economic optimisation will therefore decide on the optimum flood protection level. 

In Chapter 3 we have shown that, having done the initial investment for dike improvement (predominantly 

resettlement), a high flood protection level is economically attractive. The small differences in cm between 

the low frequency water levels (T=100 to T =2000 and higher) demand little extra cost for great value in 

avoided damage. 

5.3 Strategies for maintaining and improving flood protection 

From the above considerations two main strategies for the Jarillón Aguablanca can be formulated. 

1. The first strategy aims at "keeping the pressure on the dike low". Mitigation of rising river water levels 

is the guideline for this strategy. This involves sound spatial planning. 

2. The second strategy assumes that spatial development can hardly be controlled when it comes to 

flood protection. Retention capacity more upstream and opposite to Cali will gradually disappear for 

other developments, forcing Cali to rely more and more on the flood protection of the Jarillón 

Aguablanca. 

5.3.1 Flood protection level 

Based on the scenarios, the right margin of the Cauca River will probably become economically more 

valuable than at present. It is therefore expected that the right margin will also be better protected against 

floods. Socio-economic developments more upstream will lead to the construction of more upstream flood 

protection works. As a result the flood protection level of Cali that is provided by the dike at its present 

level will decrease. After all, reduction of room for inundation of river water will decrease the upstream 

retention capacity and therefore have an upward trend in river water levels at Cali. This goes along with an 

increased need for flood protection: economic development and growth of population and properties in Cali 

will demand safety. 

From the economic analysis it is clear that an economic optimum can be found in raising the protection 

level of the Jarillón Aguablanca to at least T=500. Higher protection levels can be acquired at little extra 

costs. 



LW-AF20130064 - 24 -


5.3.2 Strategy 1: Controlled retention upstream of Cali and on east bank 

Based on the present behaviour of the river water levels there is still sufficient room for retention of river 

water upstream of Cali and on the right bank. A good 2D river model would need to be developed to 

confirm this. In the calculation of river water levels at lower frequencies (T=250, 500, 2000 etc) the right 

margin has been modelled as a infinitely high dike and a statistically extrapolated inflow from upstream. 

Reality will be that Jarillón Aguablanca is the strongest point and that at lower frequencies, higher 

discharges water levels will show little rise because of inundations elsewhere. 

Water authorities in the States Valle de Cauca and Cauca might be able to maintain the upstream river 

retention capacity, although experience shows that spatial development is rather difficult to control. 

This strategy therefore comprises: 

1. upgrading of the Jarillón Aguablanca according to strategy 0 

2. further upgrading of the Jarillón Aguablanca to a higher protection level T=500 up to T=2000; this 

further upgrading needs to be done along with strategy 0 to avoid double initiation costs; it needs to 

be based on a good new 2D river model; relocation of all housing may even be avoided; 

3. CVC and their upstream colleagues will need to co-operate intensively, the same holds for the State 

authorities 

4. Enforcement of spatial management and assessment of spatial developments on consistency with 

the long-term flood approach needs to be implemented. Special areas – now being part of the river 

retention area already – need to be dedicated for controlled flooding at large scale. 

Figure 8 

The three strategies shown in the flood-frequency graph 

5.3.3 Strategy 2: Total reliance on Jarillón Aguablanca 

The assumption for strategy 2 is that spatial management and maintaining retention areas available for 

flood protection fails. As a result Cali will face higher extreme water levels. Cali will need to raise the 

Jarillón Aguablanca to maintain – and raise – its flood protection level. Also in this strategy Cali's flood 

protection level depends on upstream developments and on its own way of operating the right margin of 

the Rio Cauca at Cali. 

This strategy comprises: 



LW-AF20130064 - 25 -


1. upgrading of the Jarillón Aguablanca according to strategy 0 

2. further upgrading of the Jarillón Aguablanca to a higher protection level of T=500 up to T=2000 

3. resettlement of all houses on the dike and in the berm of the dike cannot be avoided; 

4. considerable enlargement (widening) of the dike needs to be accounted for 

5.3.4 Choice of strategy 

The presented strategies were developed with an open mind not wanting to limit ourselves a priori, and 

without looking at financial or institutional implications. Taking a closer and more realistic look at the 

possibilities, we recommend the choice for strategy 2. This strategy is included in the action plan. We 

recommend a safety level with a return period of T=500 years. The arguments are the following: 

1. Spatial development is a process which is very difficult to control and includes too many parties. 

The strategy which includes use of designated retention areas may therefore prove impossible to 

realize or be unreliable in the future. 

2. The extra costs involved in going from a protection level with T=100 year to T=500 years are 

marginal as compared to the overall costs 



LW-AF20130064 - 26 -


6 GOVERNANCE AND WATER AUTHORITY 

The organisational framework for river and dike management for the Cauca River, its tributaries and the 

dikes, is scattered. In 1993 river and dike management were divided along political and administrative 

boundaries. The Corporación Autónoma Regional del Valle del Cauca (CVC) was split in terms of both 

geographical authority and content wise. Cauca was separated from Valle del Cauca and environmental 

was separated from technical contents. This had very adverse effects on dike maintenance and 

management, resulting in deterioration of the dike. Part of this deterioration has been caused by illegal 

housing and other illegal activities on and around the dike. 

Officially CVC is owner of the dike body 5 and should still have responsibilities for maintenance and 

management. In practice this is not the case and at the same time CVC does not have sufficient technical 

staff to fulfil such a task. However, within the Colombian setting of authorities, CVC comes closest to being 

a regional authority involved in water management, although its tasks related to management of the dike 

are not clearly described. Authorities like EMCALI are responsible for certain constructions in the dike 

body, such as the main pumping station, and the drinking water intake. However, there is hardly any 

consultation with CVC about their activities for renovation and status of the construction works, whereas 

these constructions are part of the defence of the dike. 

It follows that there is no protocol for dike management and maintenance because obviously there is no 

organization that holds complete responsibility. We recommend that maintenance and control of the 

Aguablanca dike comes under one authority only that has the legal mandate to do so, respected by all 

other organisations. This authority should have the legal right to inspect, monitor, evaluate plans and grant 

permissions of any construction that is part of the dike and thus part of the defence against inundations. 

There is more to this issue than management of the dike near Cali alone. It is about management of the 

whole Cauca River from the Salvajina Dam up to and beyond Cali that should be managed by one 

authority, and regulated by law. We recommend a dialogue between the parties concerned, led by the 

mayor of Cali, or by the central government, to resolve this issue. 

As an example of a water authority framework Annex 8 presents an introduction of the Dutch organization 

of regional water authorities. 

5 At the time of writing the draft report in November, this still appeared to be the case, i.e. until November 

7, 2012; on December 6, 2012, we were informed that CVC has signed of its ownership to the municipality, 

but we have not seen the documents to confirm this. 



LW-AF20130064 - 27 -


7 REFERENCES 

[1] Caracterización y modelación matemática del Río Cauca - PMC FASE III; Evaluación y optimización 

de la regla de operación del embalse de Salvajina, VOLUMEN XVI, Universidad del Valle, Facultad de 

Ingeniería, Escuela de Ingeniería de Recursos Naturales y del Ambiente, Santiago de Cali, mayo de 

2007. 

[2] Modelación matemática del sistema Rio Cauca-Humedales; Universidad del Valle, Facultad de 

Ingeniería, Escuela de Ingeniería de Recursos Naturales y del Ambiente, Grupo Hidráulica Fluvial y 

Marítima – HIDROMAR, Santiago de Cali, Agosto de 2009; Convenio Interadministrativo 144 de 2008 

entre la CVC y la Universidad del Valle. 

[3] Lit 1. Modelación de amenaza por inundaciones en la ciudad de Cali por el Río Cauca y tributarios, 

incluye mapa de amenazas, batimetría y topografía en ambos costados. Informe final. Versión 01. 

Hidro-Occidente S.A. 

[4] Lit. 2. Modelación matemática del sistema Río Cauca – Humedades. Volumen 1. Universidad del 

Valle. Facultad de Ingeniería. Escuela de Ingeniería de Recursos Naturales y del Ambiente. Octubre 

2009. 

[5] Lit. 3. Proyecto Corredor del Río Cauca (CVC). 

[6] Lit. 4. Best Practise Guidelines for Flood Risk Management. The Flood Management and Mitigation 

Programme, Component 2: Structural Measures & Flood Proofing in the Lower Mekon Basin. 

Deltares, Royal Haskoning and UNESCO-IHE. Draft final report. May 2010. 

[7] Lit. 5. Penning-Rowsell, Chatterton, J.B. (1977). The benefits of flood alleviation – a manual of 

assessment techniques, Saxon House, ISBN 0566001908. 

[8] Lit. 6. Dutta, D., Herath S., Musiake K. (2003). A mathematical flood loss estimation, Journal of 

Hydrology, 277:24-49. 

[9] Lit. 7. Kok M., Huizinga H.J., Vrouwenvelder A.C.W.M., Van den Braak W.E.W. (2005). 

Standaardmethode2005 schade en slachtoffers als gevolg van overstromingen, HKV report 

PR.999.10. 

[10] Lit 8. Jonkman S.N., Bockarjova M., Kok M., Bernardini P. (2008) Integrated Hydrodynamic and 

Economic Modelling of Flood Damage in the Netherlands, Ecological Economics 66, pp. 77-90. 

[11] Lit. 9. Metodología de Modelación Probabilista de Riesgos Naturales. Informe Técnico ERN-CAPRA- 

T1-5. Vulnerabilidad de edificaciones e infraestructura. ERN. Consorcio Evaluación de Riesgos 

Naturales – América Latina. Consultores en Riesgos y Desastres. Tomo I. 

[12] Rijkswaterstaat 2005. Standaardmethode2004. Schade en Slachtoffers als gevolg van 

overstromingen. Kok M., Huizinga H.J., Vrouwenvelder A.C.W.M., Barendregt A. DWW-2005-005 

[13] Informe de avance n° 2. Contrato de consultoría n° 101 de 2012 celebrado entre el fondo adaptación 

y corporación observatorio sismológico del sur occidente contrato de consultoría n° 101 de 2012 



LW-AF20130064 - 28 -


celebrado entre el Fondo Adaptación y Corporación Observatorio Sismológico del Sur Occidente; 

Corporación OSSO, Cali, octubre 29 de 2012 

[14] Water governance, The Dutch regional water authority model; Unie van Waterschappen, 2011 

[15] Aguablanca Project 18 November 1958, Hadjikoulas, Kirpich, Corporación Autonoma Regional del 

Cauca 

[16] Flood risk management for La Mojana; Deltares, Royal HaskoningDHV, HKV; august 2012; Agency 

NL 



LW-AF20130064 - 29 -


ABBREVIATIONS 

Table 6 List of abbreviations 

Abbreviation Explanation 

CVC 

Corporación Autónoma Regional del Valle del Cauca 

DAGMA Departamento Administrativo de Gestión del Medio Ambiente (del Municipio de Cali) 

EMCALI Empresas Municipales de Cali 

EPSA 

Empresa de energía del Pacífico S.A. 

ONI 

Oceanic Niño Index 



LW-AF20130064 - 30 -


8 COLOPHON 


LW-AF20130064 

Client 

Project 

File 

Length of report 

Author 

Contributions 

Internal check 

: NL Agency 

: Aguablanca Dike along the Cauca River, Cali, Colombia 

: BB2984 

: 31 pages 

: Hans Leenen 

: Marcella Busnelli, Michel Tonneijck, Steven Sjenitzer, Joop de Bijjl 

: Erik Arnold 

Project Manager 

: Martijn van Elswijk 

Project Director : 

Date : 31 January 2013 

Name/Initials : 



LW-AF20130064 - 31 -

HaskoningDHV B.V. 

Laan 1914 no. 35 

3818 EX Amersfoort 

P.O. Box 1132 

3800 BC Amersfoort 

The Netherlands 

T +31 33 468 2000 

F +31 33 468 2801 

www.royalhaskoningdhv.com


ANNEX 1 

Hydrology 

NL Agency/Aguablanca Dike along the Cauca River, Cali, Colombia appendix 1 

LW-AF20130064 - 1 -


Table 7 

Juanchito hydrometric station: maximum annual level and discharge 

Year Maximum discharge (m3/s) Maximum level (m local reference) Reference level (m.s.l) Actual level (m.s.k) 

1945 674.0 5.08 943.63 948.71 

1946 684.0 5.08 943.63 948.71 

1947 715.0 5.20 943.63 948.83 

1948 676.0 4.95 943.63 948.58 

1949 798.0 5.54 943.63 949.17 

1950 1,044.0 6.40 943.63 950.03 

1951 676.0 4.74 943.63 948.37 

1952 710.0 4.88 943.63 948.51 

1953 870.0 5.67 943.63 949.30 

1954 822.0 5.36 943.63 948.99 

1955 822.0 5.30 943.63 948.93 

1956 878.0 5.59 943.63 949.22 

1957 823.0 5.20 943.63 948.83 

1958 647.0 4.55 943.63 948.18 

1959 621.0 4.41 943.16 947.57 

1960 839.0 5.67 943.16 948.83 

1961 622.0 4.40 943.16 947.56 

1962 692.0 4.79 943.16 947.95 

1963 711.0 4.87 943.16 948.03 

1964 688.0 4.64 943.16 947.80 

1965 736.0 5.06 943.16 948.22 

1966 1,059.0 6.47 943.16 949.63 

1967 817.0 5.40 943.16 948.56 

1968 749.0 5.06 943.16 948.22 

1969 766.0 5.10 943.21 948.31 

1970 936.0 5.93 943.21 949.14 

1971 1,074.0 6.48 943.21 949.69 

1972 792.0 5.11 943.18 948.29 

1973 912.0 6.42 942.45 948.87 

1974 996.0 6.85 942.45 949.30 

1975 950.0 7.01 942.45 949.46 

1976 876.0 6.55 942.45 949.00 

1977 637.0 5.00 942.45 947.45 

1978 770.0 5.74 942.45 948.19 

1979 859.0 6.24 942.45 948.69 

1980 463.0 3.84 942.45 946.29 

1981 791.0 5.86 942.45 948.31 

1982 868.0 6.29 942.45 948.74 

1983 770.0 5.74 942.45 948.19 

1984 1,026.0 7.12 942.45 949.57 

1985 619.0 4.69 942.45 947.14 

1986 619.0 4.81 942.45 947.26 

1987 506.4 3.94 942.45 946.39 

1988 943.0 6.40 942.45 948.85 


LW-AF20130064 - 2 -


Year Maximum discharge (m3/s) Maximum level (m local reference) Reference level (m.s.l) Actual level (m.s.k) 

1989 743.2 5.34 942.45 947.79 

1990 560.6 4.38 942.45 946.83 

1991 428.0 3.58 942.45 946.03 

1992 318.4 2.78 942.45 945.23 

1993 760.5 5.83 942.45 948.28 

1994 769.5 5.89 942.45 948.34 

1995 574.6 4.59 942.45 947.04 

1996 726.0 5.63 942.45 948.08 

1997 974.2 7.03 942.45 949.48 

1998 818.5 6.19 942.45 948.64 

1999 991.0 7.25 942.45 949.70 

2000 887.2 6.74 942.45 949.19 

2001 568.0 4.79 942.45 947.24 

2002 694.4 5.58 942.45 948.03 

2003 530.6 4.52 942.57 947.09 

2004 574.0 4.82 942.57 947.39 

2005 636.0 5.23 942.57 947.80 

2006 902.8 6.84 942.57 949.41 

2007 954.0 7.14 942.57 949.71 

2008 1,022.0 7.56 942.57 950.13 

2009 786.0 6.16 942.57 948.73 

2010 1,007.6 7.48 942.57 950.05 

2011 1,148.0 7.94 942.57 950.51 

[m3/s] 

1400 

Current water level - discharge relation 

(from table and fitted equation of third order) 

y = 0.008x 3 + 6.621x 2 + 83.775x + 15.511 

R 2 = 0.9998 

Table 

Formula 

1200 

1000 

800 

600 

400 

200 

0 

3 4 5 6 7 8 9 

---> water level [m local reference] 

Table 8 

Current water level – discharge relation from table and fitted equation of third order 


LW-AF20130064 - 3 -


Table 9 Juanchito: Current water level – discharge relation (provided by CVC, 14.09.2012) 

H Q 00 1 2 3 4 5 6 7 8 9 

0.10 53.00 53.10 53.20 53.30 53.40 53.50 53.60 53.70 53.80 53.90 

0.20 54.00 54.40 54.80 55.20 55.60 56.00 56.40 56.80 57.20 57.60 

0.30 58.00 58.68 59.36 60.04 60.72 61.40 62.08 62.76 63.44 64.12 

0.40 64.80 65.61 66.42 67.23 68.04 68.85 69.66 70.47 71.28 72.09 

0.50 72.90 73.81 74.72 75.63 76.54 77.45 78.36 79.27 80.18 81.09 

0.60 82.00 82.80 83.60 84.40 85.20 86.00 86.80 87.60 88.40 89.20 

0.70 90.00 90.80 91.60 92.40 93.20 94.00 94.80 95.60 96.40 97.20 

0.80 98.00 99.00 100.00 101.00 102.00 103.00 104.00 105.00 106.00 107.00 

0.90 108.00 109.00 110.00 111.00 112.00 113.00 114.00 115.00 116.00 117.00 

1.00 118.00 118.90 119.80 120.70 121.60 122.50 123.40 124.30 125.20 126.10 

1.10 127.00 127.90 128.80 129.70 130.60 131.50 132.40 133.30 134.20 135.10 

1.20 136.00 136.90 137.80 138.70 139.60 140.50 141.40 142.30 143.20 144.10 

1.30 145.00 145.90 146.80 147.70 148.60 149.50 150.40 151.30 152.20 153.10 

1.40 154.00 155.10 156.20 157.30 158.40 159.50 160.60 161.70 162.80 163.90 

1.50 165.00 165.90 166.80 167.70 168.60 169.50 170.40 171.30 172.20 173.10 

1.60 174.00 175.00 176.00 177.00 178.00 179.00 180.00 181.00 182.00 183.00 

1.70 184.00 185.00 186.00 187.00 188.00 189.00 190.00 191.00 192.00 193.00 

1.80 194.00 195.10 196.20 197.30 198.40 199.50 200.60 201.70 202.80 203.90 

1.90 205.00 206.00 207.00 208.00 209.00 210.00 211.00 212.00 213.00 214.00 

2.00 215.00 216.40 217.80 219.20 220.60 222.00 223.40 224.80 226.20 227.60 

2.10 229.00 230.00 231.00 232.00 233.00 234.00 235.00 236.00 237.00 238.00 

2.20 239.00 240.10 241.20 242.30 243.40 244.50 245.60 246.70 247.80 248.90 

2.30 250.00 251.00 252.00 253.00 254.00 255.00 256.00 257.00 258.00 259.00 

2.40 260.00 261.00 262.00 263.00 264.00 265.00 266.00 267.00 268.00 269.00 

2.50 270.00 271.30 272.60 273.90 275.20 276.50 277.80 279.10 280.40 281.70 

2.60 283.00 283.70 284.40 285.10 285.80 286.50 287.20 287.90 288.60 289.30 

2.70 290.00 291.50 293.00 294.50 296.00 297.50 299.00 300.50 302.00 303.50 

2.80 305.00 306.40 307.80 309.20 310.60 312.00 313.40 314.80 316.20 317.60 

2.90 319.00 320.10 321.20 322.30 323.40 324.50 325.60 326.70 327.80 328.90 

3.00 330.00 331.10 332.20 333.30 334.40 335.50 336.60 337.70 338.80 339.90 

3.10 341.00 342.10 343.20 344.30 345.40 346.50 347.60 348.70 349.80 350.90 

3.20 352.00 353.60 355.20 356.80 358.40 360.00 361.60 363.20 364.80 366.40 

3.30 368.00 369.00 370.00 371.00 372.00 373.00 374.00 375.00 376.00 377.00 

3.40 378.00 379.00 380.00 381.00 382.00 383.00 384.00 385.00 386.00 387.00 

3.50 388.00 389.40 390.80 392.20 393.60 395.00 396.40 397.80 399.20 400.60 

3.60 402.00 402.60 403.20 403.80 404.40 405.00 405.60 406.20 406.80 407.40 

3.70 408.00 410.00 412.00 414.00 416.00 418.00 420.00 422.00 424.00 426.00 

3.80 428.00 429.20 430.40 431.60 432.80 434.00 435.20 436.40 437.60 438.80 

3.90 440.00 441.80 443.60 445.40 447.20 449.00 450.80 452.60 454.40 456.20 

4.00 458.00 459.70 461.40 463.10 464.80 466.50 468.20 469.90 471.60 473.30 

4.10 475.00 476.00 477.00 478.00 479.00 480.00 481.00 482.00 483.00 484.00 

4.20 485.00 486.50 488.00 489.50 491.00 492.50 494.00 495.50 497.00 498.50 

4.30 500.00 501.00 502.00 503.00 504.00 505.00 506.00 507.00 508.00 509.00 

4.40 510.00 511.80 513.60 515.40 517.20 519.00 520.80 522.60 524.40 526.20 

4.50 528.00 529.30 530.60 531.90 533.20 534.50 535.80 537.10 538.40 539.70 

4.60 541.00 541.90 542.80 543.70 544.60 545.50 546.40 547.30 548.20 549.10 

4.70 550.00 552.00 554.00 556.00 558.00 560.00 562.00 564.00 566.00 568.00 

4.80 570.00 572.00 574.00 576.00 578.00 580.00 582.00 584.00 586.00 588.00 

4.90 590.00 591.40 592.80 594.20 595.60 597.00 598.40 599.80 601.20 602.60 


LW-AF20130064 - 4 -


H Q 00 1 2 3 4 5 6 7 8 9 

5.00 604.00 605.60 607.20 608.80 610.40 612.00 613.60 615.20 616.80 618.40 

5.10 620.00 621.00 622.00 623.00 624.00 625.00 626.00 627.00 628.00 629.00 

5.20 630.00 632.00 634.00 636.00 638.00 640.00 642.00 644.00 646.00 648.00 

5.30 650.00 650.90 651.80 652.70 653.60 654.50 655.40 656.30 657.20 658.10 

5.40 659.00 661.10 663.20 665.30 667.40 669.50 671.60 673.70 675.80 677.90 

5.50 680.00 681.80 683.60 685.40 687.20 689.00 690.80 692.60 694.40 696.20 

5.60 698.00 699.20 700.40 701.60 702.80 704.00 705.20 706.40 707.60 708.80 

5.70 710.00 712.00 714.00 716.00 718.00 720.00 722.00 724.00 726.00 728.00 

5.80 730.00 731.00 732.00 733.00 734.00 735.00 736.00 737.00 738.00 739.00 

5.90 740.00 741.90 743.80 745.70 747.60 749.50 751.40 753.30 755.20 757.10 

6.00 759.00 761.10 763.20 765.30 767.40 769.50 771.60 773.70 775.80 777.90 

6.10 780.00 781.00 782.00 783.00 784.00 785.00 786.00 787.00 788.00 789.00 

6.20 790.00 791.20 792.40 793.60 794.80 796.00 797.20 798.40 799.60 800.80 

6.30 802.00 804.30 806.60 808.90 811.20 813.50 815.80 818.10 820.40 822.70 

6.40 825.00 826.50 828.00 829.50 831.00 832.50 834.00 835.50 837.00 838.50 

6.50 840.00 841.80 843.60 845.40 847.20 849.00 850.80 852.60 854.40 856.20 

6.60 858.00 860.20 862.40 864.60 866.80 869.00 871.20 873.40 875.60 877.80 

6.70 880.00 881.80 883.60 885.40 887.20 889.00 890.80 892.60 894.40 896.20 

6.80 898.00 899.20 900.40 901.60 902.80 904.00 905.20 906.40 907.60 908.80 

6.90 910.00 912.00 914.00 916.00 918.00 920.00 922.00 924.00 926.00 928.00 

7.00 930.00 932.00 934.00 936.00 938.00 940.00 942.00 944.00 946.00 948.00 

7.10 950.00 951.00 952.00 953.00 954.00 955.00 956.00 957.00 958.00 959.00 

7.20 960.00 961.00 962.00 963.00 964.00 965.00 966.00 967.00 968.00 969.00 

7.30 970.00 972.80 975.60 978.40 981.20 984.00 986.80 989.60 992.40 995.20 

7.40 998.00 999.20 1000.00 1001.00 1002.00 1004.00 1005.00 1006.00 1007.00 1008.00 

7.50 1010.00 1012.00 1014.00 1016.00 1018.00 1020.00 1022.00 1024.00 1026.00 1028.00 

7.60 1030.00 1032.00 1035.00 1037.00 1040.00 1042.00 1045.00 1047.00 1050.00 1052.00 

7.70 1055.00 1057.00 1060.00 1062.00 1065.00 1067.00 1070.00 1072.00 1075.00 1077.00 

7.80 1080.00 1082.00 1085.00 1087.00 1090.00 1092.00 1095.00 1097.00 1100.00 1102.00 

7.90 1105.00 1107.00 1110.00 1112.00 1115.00 1117.00 1120.00 1122.00 1125.00 1127.00 

8.00 1130.00 1131.00 1132.00 1133.00 1134.00 1135.00 1136.00 1137.00 1138.00 1139.00 

8.10 1140.00 1141.00 1142.00 1143.00 1144.00 1145.00 1146.00 1147.00 1148.00 1149.00 

8.20 1150.00 1152.00 1154.00 1156.00 1158.00 1160.00 1162.00 1164.00 1166.00 1168.00 

8.30 1170.00 1172.00 1174.00 1176.00 1178.00 1180.00 1182.00 1184.00 1186.00 1188.00 

8.40 1190.00 1192.00 1194.00 1196.00 1198.00 1200.00 1202.00 1204.00 1206.00 1208.00 

8.50 1210.00 1212.00 1214.00 1216.00 1218.00 1220.00 1222.00 1224.00 1226.00 1228.00 

8.60 1230.00 1232.00 1234.00 1236.00 1238.00 1240.00 1242.00 1244.00 1246.00 1248.00 

8.70 1250.00 1252.00 1254.00 1256.00 1258.00 1260.00 1262.00 1264.00 1266.00 1268.00 

8.80 1270.00 1272.00 1274.00 1276.00 1278.00 1280.00 1282.00 1284.00 1286.00 1288.00 

8.90 1290.00 1292.00 1294.00 1296.00 1298.00 1300.00 1302.00 1304.00 1306.00 1308.00 

9.00 1310.00 


LW-AF20130064 - 5 -


30 

Moment Ratio Diagram 

Gumbel 

Weibull 

LP3 

Observed 

LN2 

Normal 

Gamma 

Logistic 

25 

Ck (Kurtosis coefficient) 

20 

15 

10 

5 

0 

-2.0 -1.0 0.0 1.0 2.0 3.0 4.0 5.0 

Cs (Skewness coefficient) 

Figure 9 

Moment-ratio diagram of observed extremes and theoretical probability distributions 

Note: For a given distribution, conventional moments can be expressed as functions of the parameters of 

the distributions. It follows that the higher order moments can be expressed as functions of the lower order 

moments. Figure 9 presents the moment-ratio diagram of the Skewness coefficient en the Kurtosis 

coefficient for a number of well known distributions, as well as for the observed values of the maxima of 

the Rio Cauca at Juanchito (the blue dot). For some of the distribution functions the ratio follows a curve, 

for others it is a distinct point in the graph. This merely is a characteristic of the particular distribution. The 

figure shows that the Skewness-Kurtosis ratio for the observed values practically coincides with the 

theoretical value for the LP3 distribution. Furthermore it shows that the Skewness-Kurtosis ratio for the 

Gumbel distribution is far off the ratio of the observed values. The conclusion is that the momentcharacteristics 

of the observed values correspond much better with the LP3 distribution than with the 

Gumbel distribution. 


LW-AF20130064 - 6 -


ANNEX 2 

Longitudinal dike profiles and hydrodynamic modelling results 


LW-AF20130064 - 1 -

Crest level of Jarillón Agua Blanca and calculated water levels + required freeboard 


(Versión revisada con datos de campo, septiembre 20 de 2012) 

Level [msnm] 

956 


955 


water level T=500 

dike crest level 

954 

T=100 + 0,50 m freeboard T=500 + 0,50 m freeboard 

T=250 + 0,50 m freeboard original design T=10 + 2,50 

953 

952 

951 

950 

949 

948 

Canal Sur 

km 127 + 724 m 

Juanchito 

km 139 + 259 m 


km 146 + 300 m 

947 

127 

128 

129 

130 

131 

132 

133 

134 

135 

136 

137 

138 

139 

140 

141 

142 

143 

144 

145 

146 

147 

---> x -coordinate [km]


Figure 10 

Inundation modelling 

Location of breaching 

Scenarios return period 1/100 years 

Location No. 6 






Breaching in all the locations 

Location No.1 


LW-AF20130064 - 2 -


Location No. 2 Location No. 3 


LW-AF20130064 - 3 -


Location No. 4 Location No. 5 



LW-AF20130064 - 4 -


ANNEX 3 

Hydrodynamic modelling, methodology 


LW-AF20130064 - 1 -


Calibration of the model 

The model was recalibrated to fit the water level at the station Juanchito for the different return periods. 

The roughness coefficient in the main channel was tuned. Furthermore the bathymetry at the right margin, 

where the data is less accurate, was adjusted. The water levels in the station Juanchito for the different 

return periods were reproduced with an error of approximately 10 cm. Besides the water levels at a 

location upstream of the station Juanchito were compared with the values obtained from the hydrological 

analysis of the data of the station Juanchito and the translation to locations upstream and downstream by 

applying the water slopes calculated with a 1D-model [4]. The maximum difference calculated is about 10 

cm. 

Modelling of the flooding scenario’s 

In order to simulate the flooding scenario’s the boundary conditions upstream and downstream were 

defined. 

Upstream the flood hydrograph was defined on the basis of the measured hydrograph in 2011. For every 

return period a flood hydrograph is obtained. These flood hydrographs are shown in Figure 11. 

Downstream the water levels were obtained from the Q-h relation in Juanchito and after that they were 

extrapolated to the location downstream. These water levels are shown in Figure 12. 

The locations of overtopping were modelled as a change in the bathymetry. To our knowledge it is not 

possible to include in the CCHE2D model constructions such as weirs (sub-grid modelling of 

constructions). Due to that fact, the grid has been refined to reproduce the height of the dike. 

Figure 11 

Upstream boundary condition 


LW-AF20130064 - 2 -


Figure 12 

Downstream boundary condition 

Recommendations 

There are uncertainties in the numerical modelling but also in the data. Monitoring of water levels and 

discharges should be continued. We advise to include more measurement locations, upstream and 

downstream station Juanchito. Furthermore it is important to determine for which levels flooding have 

occurred upstream Juanchito because this flooding has influence on the water levels and discharges in 

station Juanchito. 

The following recommendations are given concerning the hydrodynamic model in order to improve the 

accuracy of the modelling results: 

1. Update the digital elevation data to improve the model results. The bathymetry to the right margin 

should be included. Furthermore mainly due to human actions the bathymetry of the main channel and 

floodplains might have changed and needs to be updated. 

2. Develop an integrated hydrodynamic model of the river Cauca starting at Salvajina reservoir. In this 

model the overtopping and flooding should be included. The model should be calibrated in order to 

reproduce the last flooding events for instance by comparing the inundated area with aerial 

photographs. These simulations will give more insight in the discharges through the river Cauca since 

also overtopping and flooding would be included. We understand that this model will be constructed in 

another project [5]. We advise the local team to participate in this study so that the experience gained 

in the modelling of the river Cauca along the city of Cali can be shared, in order to improve the 

modelling system. 

3. In choosing the numerical model, we recommend that constructions such as weirs and roads be 

accurate schematized. 


LW-AF20130064 - 3 -


Considerations concerning fluvial morphodynamics 

During the study and conversations with the local team some morphodynamic issues arose. Amongst 

these issues we list the following: 

1. Local erosion: for instance in the location “Nuevo Amanecer” erosion in the left margin has occurred 

probably as result of a bank protection carried out at the right margin. 

2. Bank erosion related to natural meandering of the river may affect the stability of the dikes. 

3. Dredging activities (illegal) are carried out in this part of the river Cauca. These dredging activities may 

lead to erosion of the river bed. However there is no clear indication of large scale erosion of 

sedimentation of the river Cauca. 

4. The construction of the Salvajina reservoir will have had an influence on the morphological 

developments of the river Cauca due to the changes in the discharges and sediment loads. 

5. There are indications of changes in discharges and sediment load in the Canal Interceptor del Sur due 

to human activities such as deforestation that may also have influence on the morphological 

developments of the river Cauca. 

6. The bed in some parts consists of a hard soil deposit (mixture of clay, silt and sand), which is in Cali 

called “Caliche”. Due to this soil the bed level has remained rather stable. Between this hard soil, there 

is sand that can be eroded. Local erosion occurs in those sections. 

We recommend that the fluvial morphodynamics of the river Cauca be studied in order to have a better 

understanding of its morphodynamics and the influence of the human activities on the morphological 

developments. We have the following recommendations: 

1. Monitoring the bed evolution of longitudinal profiles of the main river. Is there a trend (erosion, 

sedimentation of stable) in the bed level? 

2. Monitoring bank erosion since it might influence the stability of the dikes and banks. 

3. Obtain information over the soil and subsoil of the main river. Critical locations are where a sand layer 

in the subsoil may be cut by ongoing erosion. Such locations ask for more extensive monitoring. 

4. Obtain information of the dredging activities: dredging site, dredged volumes, properties of the dredged 

material. 

5. Prepare a plan for managing the bed levels where also dredging activities are carried out in a control 

manner, by defining where it is possible to dredge and how much. Geotechnical stability of dikes and 

banks needs to be guaranteed, and therefore the riverbed should not incise too much. Such demands 

to the riverbed require that the river manager needs to assess the development of the bed and to 

intervene in the river system if necessary. 


LW-AF20130064 - 4 -


ANNEX 4 

Flood risk management methodology 


LW-AF20130064 - 1 -


Concepts 

The word risk refers in general to the probability of loss or harm. In the context of flood risk management it 

denotes the combination of the probability of a flood and its consequences. In this context also the terms 

hazard and vulnerability are often used. Hazard refers to the source of danger, i.e. the probability of 

flooding. Vulnerability relates to potential consequences in case of an event [6]. 

Integrated flood risk management is an approach to identify, analyze, evaluate, control and manage the 

flood risks in a given system. Figure 13 presents a general scheme for flood risk management. The 

following steps are defined: 

● Definition of the system, the analyzed hazards and the scope of the analysis. 

● A quantitative analysis where the probabilities and consequences are assessed and 

combined/displayed into a risk number, a graph or a flood risk map. 

● Risk evaluation: with the results of the former analysis the risk is evaluated. In this phase the decision 

is made whether the risk is acceptable or not. 

● Risk reduction and control: dependent on the outcome of the risk evaluation, measures can be taken in 

order to reduce the risk. Measures could concern structural and non-structural measures. It should also 

be determined how the risks can be controlled and managed, for example by monitoring, inspection or 

maintenance. 

The scheme focuses on minimization of flood risks to an acceptable level. The approach could also be 

used to assess the overall hydrological performance of the system (e.g. minimization of drought, 

maximization of water quality and ecological quality). Then the approach will focus on multiple objectives: 

not only to minimize the risk, but also to maximize the performance. 

Figure 13 

General scheme for flood risk management 


LW-AF20130064 - 2 -


Approach for economic damage assessment 

Scope of the analysis 

The scope and level of detail of the damage evaluation has been defined on the basis of the spatial scale 

of the study and the availability of data. Due to the fact that very precise methods require more effort (i.e. 

time and money) than less detailed approaches and that the resource are usually limited, the most precise 

methods are often restricted to small areas under investigation, while studies with a research area of 

regional or even national size mostly have to rely on less detailed methods. 

The area of the study is the flood area of the city of Cali, at the left margin of the river Cauca between 

Canal Interceptor del Sur and the river Cali. At the right margin of the river Cauca lays the city of 

Calendaria, where there is no bathymetric information available for the study. 

In this study we focus on the priced direct damages. This category of damage constitutes the largest part 

of the total damage. For example in the standardized damage method that is used in the Netherland the 

following main damage categories are considered: land use, infrastructure, households, companies and 

other. Within each main categories, sub-categories are distinguished (e.g. agriculture, urban area, or 

recreation within the main category land-use). 

Direct damage assessment 

Methods for the estimation of the direct economic damage to objects, such as structures, houses are well 

established, and the use of so-called damage functions is widespread ([7], [8], [9], [10]). 

The procedure for the estimation of direct physical damages [12] is illustrated in Figure 13. The procedure 

comprises three main elements: 

- Determination of flood characteristics 

- Assembling information on land use data and maximum damage amounts 

- Application of stage-damage functions. 

We describe these elements in more detail below. 

Determination of flood characteristics 

Flooding patterns are in general simulated with a two dimensional hydrodynamic model. The existent 2Dmodel 

of the University of Mississippi of the river Cauca between the Canal Interceptor Sur and the river 

Cali was applied for this study. This model was recalibrated since the statistics of discharges and water 

levels was updated in this study. The water levels in the station Juanchito for the different return periods 

were reproduced with an error of less than 10 cm. The model runs were carried out by Angela Cabal of the 

corporation OSSO (local partners in Colombia). A complete description of the model is given in [3]. The 

model has some limitations but there are also restrictions on the available data mainly in the flooding area. 

For instance there is not information of the bathymetric on the right margin of the river Cauca and therefore 

the inundation of the city Candelaria is not included. 

In this study we applied the existent 2D-model and we made recommendations for a more accurate 

modelling system and for the required data collection for future studies. 

The hydrodynamic model provides insight in flood characteristics, such as water depth, flow velocity and 

the rate at which the water rises. All these characteristics can be depicted on a map. 


LW-AF20130064 - 3 -


Flood risk assessment 

Definition 

In the risk assessment the results of hazard and damage assessments are combined. Flood risk is 

generally defined as follows: 

Risk = Probability x Damage 

For example, if an area has a probability of flooding of 1% per year (or 1/100 per year) and the damage is 

100 million COP, the risk equals 1 million COP per year. As this risk number reflects the average expected 

economic damage per year, it is also referred to as yearly expected economic damage. 

The flood scenarios can be defined depending on their return period, i.e. the average recurrence interval 

between the occurrence of two floods with a certain flood level and corresponding damage value. It is also 

possible to determine the probability of exceedance of an event with certain damage. That is the 

probability (per year) that a certain damage value will be exceeded so that: 

Probability of exceedance = 1 / return period 

This means that the event a 100 year return period has a probability of exceedance of 1/100 per year. 

Economic optimization 

The economic optimization approach is applicable to determine an optimal level of protection when 

investments in the protection and the risk are dependent on the level of protection. This is for example the 

case for flood prone areas that are protected by dikes. In that case the decision problem becomes the 

choice of the height of the dikes and thus the choice for the protection level that de dikes provide. 

According to the method of economic optimization, the total costs in a system are determined by the sum 

of the expenditure for a safer system and the expected value of the economic damage. In this economic 

optimization the incremental investments in more safety are balanced with the reduction of the risk. The 

investments consist of the costs to strengthen and raise the dikes. In a simple approach it is assumed that 

flooding could only occur due to overtopping of the flood defences. Thereby each dike height corresponds 

to a certain probability of flooding (the higher the dikes the smaller the probability of flooding) and an 

associated damage. By summing the costs and the expected damage or risk, the total costs are obtained 

as a function of the safety level. A point can be determined where the total costs are minimal, the so-called 

optimum (Figure 14). In the optimum the corresponding dike height is known. Because the statistics of the 

water levels are also known, the corresponding protection level in terms of a probability can be defined. 

The economic optimization approach was applied to flood protection systems by the Delta Committee in 

the Netherlands. This Committee investigated possibilities for new safety standards after a major flooding 

caused enormous damage in the Netherlands in 1953. Eventually these results have been used to derive 

safety standards for flood defences in the Netherland. For coastal areas protection has been chosen with 

exceedance probabilities of 1/4,000 per year and 1/10,000 per year. For the Dutch river areas the safety 

standards were set at 1/1,250 per year and 1/2,000 per year. 


LW-AF20130064 - 4 -


Figure 14 

Principle of economic optimization 


LW-AF20130064 - 5 -


ANNEX 5 

Field assessment of the conditions of the Aguablanca dike 


LW-AF20130064 - 1 -


Introduction 

Three dike visits were made. On Wednesday 19 th of September a boat visit was made followed by an dike 

visit by car on Thursday 20 th of September. On Tuesday 2 nd of October a final visit has been made to the 

pumping station Paso del Comercio and the PTAR (drinking water treatment plant). 

The objective of these visits was to have a visual inspection of the physical condition in general and of the 

envisaged problems at two structures in particular. As a general observation we conclude that the dike is 

deteriorated by lack of maintenance, sewerage systems and roads that cross the dike, and ant invasions 

and tree roots. Later on the constructions through the dike were studied and geotechnical calculations 

done. The inspection is documented by photos and technical information. The main goal of the inspection 

was to locate the weakest spots and to make an inventory of the most needed and effective short term 

measures. 

Boat visit (Wednesday 19th of September) and dike visit (Thursday 20th of September) 

The inspections of the dike resulted in 8 points of attention 

1. Debris dumping 

There has been a lot of debris dumping on riverside of the dike. This dumping of debris becomes an 

obstacle for the river during a flood and will raise the water level. It is therefore important to stop illegal 

dumping of debris. 

Cali acknowledges the problem and has already started with the removal of the debris, but the 

problem continues. It is recommended to search for alternative dumpingsites. Debris does not have to 

be a waste material, but can be used as base material. Therefore a debris crusher instalation is 

needed. 


LW-AF20130064 - 2 -


2. Crest level 

Historic information by Hidro-Occidente (Guillermo Regalado) provides the following: 

When the Aguablanca dike was designed in 1957, the consultants only had 10 years of data available. 

With these data they estimated the maximum of those years to have a return period of 10 years. They 

also estimated that with a freeboard of 1.0 m, the crown of the dike could manage a water level 

corresponding with a return period of 100 years. An important issue, confirmed by Ingeniero Jorge 

Llanos, who participated in the studies, is that during construction of the dike, another 1.5 m was 

added to the crown level, corresponding with a return period of 100 years. It thus follows that the dike 

was constructed with a freeboard of 2.50 m above the level of a return period of 10 years. 

(Original communication by Guillermo Regalado: 

Los consultores, con los pocos datos existentes (1946-1957) estimaron que la creciente de los años 

50 tenía un Tr de 1 en 10 años. Estimaron también que si se adoptaba un borde libre de 1.0 m el 

nivel del agua, coincidiendo con el nivel de la corona o cresta del dique, podría manejar una creciente 

de Tr= 1 en 100 años. 

Algo muy importante, confirmado con el ingeniero Jorge Llanos que estuvo en el proceso de estudios, 

es que para construcción se incrementó en 1.5 m el nivel del dique con relación al nivel del agua 

adoptado para una creciente de 1 en 100 años (ver punto C, página 4 del informe de los consultores 

Kirpich y Hadjiluokas). Ese incremento se realizó; es decir que con relación a los niveles de agua de 

1 en 10 años (creciente de los años 50), la corona o cresta del dique quedó construida con un borde 

libre (freeboard) de 2.50 m) 

Nivel_TR10 Nivel_TR25 Nivel_TR100 

Nivel_TR250 Nivel_TR500 Dike level 


Level [msnm] (Versión revisada con datos de campo, septiembre 20 de 2012) 

956 

955 

954 

953 

952 

951 

950 

949 

948 

Canal Sur 

km 127 + 724 m 

Juanchito 

km 139 + 259 m 


km 146 + 300 m 

947 

127 

128 

129 

130 

131 

132 

133 

134 

135 

136 

137 

138 

139 

140 

141 

142 

143 

144 

145 

146 

147 

---> x -coordinate [km] 

Figure 15 

Longitudinal profile of the Aguablanca dike based on direct field monitoring, and 

water levels corresponding with different return periods 


LW-AF20130064 - 3 -


3. Hydraulic constructions 

During the dike inspection it was noticed that a few construction show damage and some other 

constructions can potentially cause damage in the future. The constructions are mostly owned by 

corporations or parties that are not primary responsible for the safety of the dike. 

The construction which shows the most damage is the pumping station Paso del Comercio. An extra 

visit was made at this construction on Tuesday 2 nd of October. 

4. Land side slope is steep 

The slope of the dike on the land side is mostly between 1:1.5 (66%) and 1:2 (50%). Considering 

safety requirements of T = 100 or better the slope is considered to be quite steep. 

It is recommended to create a gentler slope on the land side of the dike. For an optimum slope, 

geotechnical calculations have to be made. In the Netherlands often a minimum slope of 1:3 (33%) is 

used. This has a lot of positive effects: 

• maintenance of a 1:3 slope is better, damage of people, animals is less probable 

• a gentle slope will better resist overflowing or overtopping water (erosion control) 

• where a thin cohesive top layer and short distance to the river coincide, land side slope 

stability and piping is more of a problem. A more gentle slope will accomplish more safety 

on these failure mechanisms 

• earthquake induced liquefaction will yield less damage for gentler slopes 

5. Animal activity 

During the dike inspection it has been noticed that there is a lot of activity of ants. These ants cause a 

lot of damage by digging holes in the dike. These holes can cause water transportation through the 

dike followed by erosion of the dike. 


LW-AF20130064 - 4 -


It is recommended to exterminate ant activity as much as possible. Therefore the following activities 

are needed: 

• Implement consequent monitoring of ant activity and anthills (e.g. every month) 

• maximum intervention level of displaced soil, e.g. 50 to 100 liters 

• filling of anthill cavities, preference bentonite 

• consequent killing of ants 

6. Earthquake and flood 

It is not probable that an earthquake and a flood coincide. However, one may take into account that a 

flood might come within a year after a major earthquake. Considering that a major earthquake might 

induce liquefaction, resulting in serious dike deformation, it is recommended to identify potential 

liquefiable areas and limit the problem. 

7. Housing and trees on the dike 

It has been noticed that housing and trees cut into essential minimum design profile. This makes the 

dike more vulnerable for stability and piping problems. 


LW-AF20130064 - 5 -


It is recommended to 

• work with theoretical minimum design profile (fulfilling height and stability requirements) 

• when dike is wider (over dimensioned), houses need to be outside theoretical minimum 

profile 

• dead trees should be removed, including the root system 

8. Dike inspection plan 

At the start of the project no coherent dike inspection plan was available. It is very important to make 

sure that the people who will be executing the inspections will have the same base and points of 

focus. A inspection plan has been written in Spanish which can be used to execute the inspection in 

the direct future. The inspection plan was presented during a work shop on September 27 and is 

attached in Annex 7. 

Visit dike constructions October 2nd 

After the first dike inspections it appeared there were some concerns with the constructions in the dike. 

Therefore an extra visit was held to the pumping station Paso del Comercio and the drinking water 

treatment plant (PTAR). 

Pumping station Paso del Comercio 

The pumping station Paso del Comercio is the bigger one of the 2 pumping stations of Cali. It is situated in 

the lowest part of the city. This makes it a very important pumping station that is essential for controlling 

the water level in the city of Cali. 

The construction has 4 different units: 

• The most Northern unit is a gravity outlet (G) 

• South of the gravity outlet is pumping unit 2 (2) 

• South of pumping unit 2 is an emergency pumping unit (E) 

• The most southern is pumping unit 1 (1) 

G 

2 1 

E 


LW-AF20130064 - 6 -


In 2010 and 2011 river levels were extremely high resulting in various damages that were observed. Wells 

with transportation of soil were observed on the water side of the pumping station. This means that there is 

a hydraulic connection between the land side and the riverside of the dike. Not only is it possible that the 

water flows from the land side to the riverside. The other way around is possible as well. Emergency 

measures were taken and the gravity outlet has been shut down by building a closing dike on the river side 

of the outlet. At the moment a floating pumping unit is in place to pump water from the gravity outlet tot the 

riverside outlet of pumping unit 2. In our opinion, this supposedly temporary construction will be used for a 

longer time. 

During the floods major damage caused by erosion developed at the riverside outlet of pumping unit 2. 

The damage occurred 2 years ago and is worsening ever since and will keep on worsening in the future if 

no measures are taken. 

The 

emergency 

outlet has had 

some problems during the river flood as well. The water outlet pipe has no closing system on the river side. 

During the flood, the pipes were filled with water causing some leakage through the concrete construction 

on the landside of the dike. 

The most southern pumping unit is pumping unit 1. This unit had the same kind of problems as pumping 

unit 2. Emergency measures were taken by putting a lot of soil in the water outlet of this unit. The problem 

of this measure is that the water has no free outflow. This can cause problem if maximum capacity is 

needed. Another risk is formed by the broken valves on the river side of outlet pipe. At flood level on the 

river this will cause unnecessary water pressure on the pipe and land side construction. At the moment 


LW-AF20130064 - 7 -


EMCALI only relies on the valves on the inside of the pipes. This is a situation that poses an unnecessary 

risk. Immediate action is required to repair / replace these broken valves 

Drink water treatment plant 

During the visit of the water treatment plan, it was explained that there was no risk of inundation of the land 

behind the dike, but the top level of the treatment plan is lower than the level of the dike behind the 

treatment plant. During the flood the water almost got into the pumping pit. This would have caused the 

plant to stop working. 

Plans are made to make a concrete wall on top of the plant on the water side. On both side sheet pilings 

are planned to connect the structure to the dike. At the downstream side this will be on a distance of circa 

20 meters and will provide an gentle transition construction. This appears to be a good solution. On the 

upstream side of the plant a sheet pile of circa 200 meters is planned. The reason for this, is an existing 

problem with erosion in the river bent. First impression of this solution is that this is an expensive solution. 

It is likely that less expensive solutions are available, for instance with enforcement of the rockfill with 

asphalt. 


LW-AF20130064 - 8 -


ANNEX 6 

Structural stability and analysis of failure mechanisms 


LW-AF20130064 - 1 -


Macro stability, micro stability and land side dike slopes 

The stability of the dike on the landside is most vulnerable during flood periods. This is caused by the 

combination of high external water pressures on the dike that have to be resisted and high internal water 

pressures in the dike, that causes lower effective stresses and therefore lower shear stresses of the soil in 

the dike. This makes the dike more vulnerable for slope instability. 

To make a good stability analysis a thorough soil investigation is needed together with monitoring of 

groundwater levels. Although soil investigation was done, the number of strength parameters test was 

insufficient for a thorough stability analysis. To come to a judgment of the slope stability a quick analysis 

was made with the slope stability software D-GeoStability. 

We recommend to do more triaxial tests on undisturbed clay samples of the dike body to gain a better 

insight into the strength parameters along the profile of the Aguablanca dike. We suggest to do at least 

one boring per kilometre. 

Stability analyses preformed 

In the analyses the impact of variations in the strength parameters, width of the outer berm and thickness 

of the top-layer on the land side of the dike are examined. For the calculation the parameters below have 

been applied. 

Strength parameters 

̊ 

Strength parameter based on limited number (6) of provided triaxial tests 

Material cohesion phi 

Sand, medium dense coarse grain 0 kPa 33.7 

̊ 

̊ 

̊ 

̊ 

̊ 


Sand, fine grain 0 kPa 35.5 

Clay, high void ratio, high plasticity 0.2 kPa 21 

Sand, fine grain (bit loamy) 0 kPa 29 


̊ 

̊ 

Assumptions strength parameter based on Dutch standards (NEN6740) 


Sand hard dense, coarse grain 0 kPa 35 

Sand, loose dense, fine grain 0 kPa 30 

̊ 

̊ 

Clay (soft) 2 kPa 17.5 

Clay (medium) 10 kPa 17.5 

Strength parameters used in calculations 


̊ 

̊ 

̊ 

Sand, medium dense, coarse grain 0 kPa 35 

Sand, fine grain 0 kPa 30 

Clay 2 kPa 21 

Hydraulic loads 

Water level river: dike crest level 

Water level landside 0.50 meter below ground level 


LW-AF20130064 - 2 -


Water level sand layer: crest level dike on outside riverside of the dike decreasing with a slope of 1:20 in 

the direction of the landside of the dike with a minimum of 0.5 meter below ground level 

Geometry 

Geometry of the dike: based on a drawing without date or identification (provided by the local authorities) 

Calculation results 

̊ 

Description Parameters Result 

Most conservative situation: 

Thickness of the top clay layer = 2 meter SF=0.7 

weight top clay layer = 14 kN/m 3 

Strength top clay layer = c=2 ; phi=17.5 

wideness river side bank = 8 meter 

Stability sufficient with thick top layer Thickness of the top clay layer = 6 meter SF=1.0 

Stability sufficient with strong top layer Cohesion clay = 6 

Weight clay = 16 

Stability sufficient with wide river side Wideness river side bank = 38 meter 

bank 

SF=1.0 

SF=1.0 


LW-AF20130064 - 3 -


Figure 16 

Schematic representation of calculation 

Conclusions: 

There are 3 parameters that have a big influence on the dike stability. 

• Thickness of the top clay layer on the landside of the dike 

• Strength parameters of the top clay layer on the landside of the dike 

• Length of the wideness of the river side bank 

Heave, sand boil and piping and seepage 

The safety of the dike on the fail mechanism piping (backward erosion) is influenced by mostly 2 important 

parameters. 

1. Width of the outer bank 

2. Thickness of the top clay layer on the landside of the dike 

If the outer bank is wide, the length of the potential pipe will be too long and no backwards erosion can 

develop. For the conditions along the River Cauca this mean that if the outer bank is 45 meter wide no 

piping can develop. 


LW-AF20130064 - 4 -


If the top clay layer is thick the pipe is not able to break through the top layer and no backward erosion 

can develop either. For the situation along the River Cauca no piping can develop if the top layer has a 

minimum thickness of 4.0 meter. 

Piping analysis 

Use the formula of Bligh (Dutch method) 

Width outer bank variable meter 8-60 meter 

Width outer slope 

8 meter 

Width crest 

6 meter 

Width inner slope 

6.5 meter 

Total piping length (L) 

20.5 meter 

Thickness clay layer landside of the dike (d) variable meter 2-6 meter 

Mass of clay layer 14 kN/m 3 

Creep-factor ( C ) 

18 (see tabel above) 

Ground level landside of the dike 

0 meter 

Maximum water level river 4 meter (crest level) 

Water level difference (∆H) 

4 meter 

Width outer bank 

Thickness clay layer landside 

2 3 4 5 6 

8 Fail Fail Good Good Good 








LW-AF20130064 - 5 -


40 Fail Good Good Good Good 

45 Good Good Good Good Good 




Liquefaction and deformations 

No calculations on this failure mechanism were made. Although failure of the dike due to liquefaction is 

possible when an major earthquake occurs, the probability of a major earthquake coinciding with an 

extreme flood event is negligible as compared to the probability of occurrence of a major earthquake 

alone. 

Erosion control and slope revetment 

During conversations with local authorities the erosion of the rockfill has been mentioned. Although locally 

this may be a problem, in general the river has a good protection against erosion. This conclusion is based 

on the dike visits that were made. If enforcement of the rockfill is necessary, this can be done by applying 

asphalt to the rockfill. 

Macro stability river side slope 

No analyses were done on the stability of the riverside slope. The reason is that the stability of the 

riverside slope is only a problem during a quick drop of the water level on the river. If this is the case, there 

is no danger for inundations. 


LW-AF20130064 - 6 -


ANNEX 7 

Inspection plan 


LW-AF20130064 - 1 -

PLAN DE INSPECCIÓN DE DIQUES 

Una guía para: 

• mantenimiento 

• vigilancia 

• prueba de inundaciones 

• evaluación a los requisitos de ley 

• inspección durante un nivel extremo 

Joop de Bijl 

Michel Tonneijck 

Hans Leenen 

Waterschap Aa en Maas 



Version 27 septiembre 2012

1. INTRODUCCCION Y PROPOSITO 

El Plan de Inspección del Dique describe el proceso de inspección, la aplicación de todas las etapas 

del mismo la planeación del mantenimiento y medidas de rehabilitación sugeridas durante el proceso 

de diagnostico. 

El marco para el plan de inspección son las leyes, reglamentos, políticas e instrumentos 

Las inspecciones tienen su fundamento en la Ley del Agua de Holanda, en reglamentos y en políticas 

establecidas. Directrices tanto nacionales como locales están disponibles para la implementación de 

las inspecciones. 

Las siguientes herramientas son necesarias para la implementación de las tareas de inspección. 

• Ley de Aguas, establece el marco legal para la entidad que ejerce autoridad sobre el dique 

• Reglamento (decreto),determina las reglas aplicables por la autoridad del agua, (Anexo 1) 

• Mapa base. Establece las características espaciales y funcionales del dique. En conjunto con 

el reglamento representa la base legal para las tareas ejecutadas por la autoridad del agua o 

del dique (Anexo 1) 

• Plan de manejo del dique. Este plan traduce las políticas nacionales y regionales, las leyes y 

regulaciones para el área de gestión. Es la base de todas las actividades de manejo: 

inspección, concesión de licencias, mantenimiento, mejoras y ensayos; 

• Plan de manejo de inundaciones. Este plan describe el monitoreo de las inundaciones, las 

etapas de escalamiento del monitoreo del dique (situación de inundación) y las actividades de 

inspección del dique y de la organización asociada. (Anexo 1) 

OBJETIVO DE LAS INSPECCIONES 

El plan de inspecciones multipropósito 

1. Mantenimiento del dique 

2. Vigilancia de la integridad del dique: garantizar el cumplimiento del reglamento y del mapa 

base, incluido el cumplimiento de las condiciones asociadas a permisos emitidos. 

3. Dique a prueba de inundaciones: controlar si el dique, incluyendo las estructuras que lo 

cruzan (considerando procedimientos de cierre de válvulas y compuertas) se encuentran en 

condiciones aptas para la temporada de inundaciones. 

4. Evaluación del dique requerida por ley. Determinación de la altura y resistencia actual de 

las estructuras de defensa contra inundaciones, con respecto a condiciones hidráulicas de 

frontera actualizadas cada 6 años 

5. Inspección del carillón durante inundaciones y medidas de emergencia asociadas. 

Figura 1 Falla de estabilidad 

2

2. LAS OPCIONES DE INSPECCIÓN 

1. INSPECCION DE MANTENIMIENTO 

Mantenimiento reducido tiene el objetivo de extender la vida útil del dique y la prevención de 

nuevos daños. Información sobre todas las categorías de dique se establecen para 

determinar las medidas de mantenimiento. En particular se trata del registro de la condición 

de resistencia a la erosión del revestimiento en grama del dique, de cualquier daño del dique 

y de las condiciones operacionales de los mecanismos de cierre de estructuras hidráulicas. 

Esta inspección usualmente se realiza después de la temporada de invierno. 

El plan de mantenimiento puede ser elaborado con base en la información obtenida en esta 

etapa. El monitoreo de la ejecución del mantenimiento hace parte de esta inspección. 

2. INSPECCIÓN SOBRE EL CUMPLIMIENTO DE LAS REGLAS 

Situaciones ilegales se determinan durante una “inspección de cumplimiento”. La información 

requerida es un inventario de acciones ilegales en contra del reglamento estatutario y el 

incumplimiento de obligaciones de mantenimiento. El requisito de información se define en 

estrecha colaboración con el Departamento de Cumplimiento. 

La frecuencia de inspección depende en parte de la intensidad de las violaciones. Al menos 

se debe llevar a cabo una vez al mes, de lo contrario se generan derechos adquiridos debido 

a la tolerancia demasiado duradera. 

A partir de la aplicación del cumplimiento de las reglas se pueden requerir medidas 

necesarias para restaurar la condición original del dique. 

Figura 2 

¿¿¿Cumplimiento de las reglas??? 

3. INSPECCIÓN ANTES DE LA EPOCA INVERNAL 

Se debe inspeccionar la capacidad de retención de agua de los diques antes de las temporadas 

de invierno. El desempeño de los mecanismos de cierre de las estructuras en los diques son 

probados mediante ensayos de cierre. En los Países Bajos hay una temporada de inundaciones 

al año, en Cali dos. 

3

Figura 3 Daño de hormigas 

4. EVALUACIÓN DEL DIQUE TENIENDO EN CUENTA TODOS LOS MODOS DE FALLA 

Los perfiles hidráulicos utilizados para el diseño del dique deben ser actualizados cada 10 años. 

Todos los factores que generan modificaciones deben ser incluidos en la evaluación: 

• Cambios en el río y en las planicies de inundación que afecten los niveles de agua 

• Efectos del cambio climático 

• Mayor demanda de protección contra inundación a causa de rápido desarrollo espacial y 

económico en el área protegida 

En este proceso todos los modos de falla son reconsiderados. Esta evaluación puede llevar a 

concluir que el carillón necesita refuerzo, en ese caso se haría necesario un programa de 

reconstrucción del dique. 

4

5. INSPECCIÓN DURANTE INUNDACIONES 

El dique debe ser inspeccionado durante eventos de nivel alto del río. 

El dique debe ser reparado o reforzado inmediatamente en caso de identificarse una 

condición de colapso inminente. 

Figura 4 Inundación 

5

3. INSPECCIÓN 

Observaciones durante la inspección tienen por objetivo capturar ciertas características de un 

dique relacionadas con su estado de mantenimiento y el estado de la seguridad del mismo 

(integridad). 

3.1 PROPÓSITO 

El propósito de la observación es la detección, identificación y registro de ciertas características 

del dique. 

3.2 MÉTODODEOBSERVACIÓN 

Identificarlas técnicas de inspección y observación a ser utilizadas, por ejemplo: 

Inspección visual 

La observación visual es la esencia de las inspecciones. Un inspector experto puede juzgar las 

características importantes del dique de un vistazo. Es difícil que los resultados de esta 

inspección sean los mismos que los de un colega. Las observaciones visuales se basan en gran 

parte en el conocimiento y la experiencia personal y por lo tanto tienen un carácter subjetivo. 

Para garantizar que las inspecciones visuales sean tan objetivas como sea posible, es importante 

asegurarse que los inspectores sean entrenados para reconocer y clasificar los elementos 

observados. 

Técnicas instrumentales de inspección 

Las inspecciones no se limitan a observaciones visuales. Las mediciones son cada vez 

importantes en las inspecciones. Esto se refiere no sólo a mediciones de la altura de la cresta del 

dique(GPS, nivelaciones, altimetría láser, monitoreo remota), sino también a la medición de los 

parámetros en los diques. 

Figura 5 

Fuente de arena, indicación del inicio de tubificación 

6

3.3 HOJA DE RUTA PARA LA INSPECCIÓN DEL DIQUE 

PASO 1: 

DETERMINAR QUE SECCIÓN DE DIQUE SE VA A INSPECIONAR Y DEFINIR EL MÉTODO DE 

INSPECCIÓN 

En este caso, la elección debe hacerse a partir de las siguientes categorías: 

• Inspección de mantenimiento 

• Inspección sobre el cumplimiento de las reglas 

• Inspección de capacidad de resistencia a inundaciones 

• Evaluación global del dique 

• Monitoreo y reparación de emergencia durante inundaciones 

PASO 2: 

DETERMINAR LA CALIDAD Y CLASIFICACIÓN DE URGENCIA DE LAS OBSERVACIONES 

(Cuadros 3.1 y 3.2) 

CUADRO 3.1 CLASIFICACION DE CALIDAD 

Grado 

Bueno 

Raonablemente 

suficiente 

Pobre 

Malo 

Descripción 

El elemento cumple a cabalidad con los requerimientos 

estructurales y de funcionalidad 

El elemento cumple con los requerimientos estructurales y de 

funcionalidad 

El elemento no cumple con suficiencia con los requerimientos 


El elemento no satisface ninguno de los requerimientos 


TABLE 3.2 CLASIFICACIONDE DAÑOS 

Urgency Class Description 

1 Recuperación de Se considera que la resistencia y/o estabilidad del dique 

emergencia 

representa un peligro inminente. Recuperación debe ser 

llevada a cabo urgentemente (1-2 días) 

2 Recuperación 

urgente 

3 Restaurar antes 

de la temporada 

invernal 

4 El estado del 

dique no se 

encuentra en peligro 

inminente 

Se considera que la resistencia y/o estabilidad del dique no 

representa un peligro inminente. Recuperación debe ser 

llevada a cabo con cierto grado de urgencia (1-2 meses) 

Se considera que la resistencia y/o estabilidad del dique no 

representa un peligro inminente y no tiene potencial de 

empeorarse en un corto plazo. Recuperación debe ser llevada 

a cabo antes del comienzo de la temporada invernal. 

Se considera que la resistencia y/o estabilidad del dique no no 

se encuentran comprometidas bajo normas de operación 

establecidas y no tiene potencial de empeorarse en un corto 

plazo. Recuperación debe ser llevada a cabo en un plazo más 

largo. 

PASO 3: PREPARAR INFORMES DETALLADOS DE LA INSPECCIÓN 

PASO 4: TOMAR FOTOS 

PASO 5: PREPARAR UN CRONOGRAMA PARA LA RECUPERACIÓN 

7

4. DIAGNOSTICO 

PROPOSITO 

El objetivo del diagnóstico es reducir los datos de modo que pueda conocer el estado o condición 

actual del carillón para poder determinar la urgencia de las medidas de recuperación y las acciones 

de aseguramiento del cumplimiento de normas correctamente. 

DEFINICIÓN 

Para el diagnóstico, los valores observados o resultados de mediciones se comparan con los 

umbrales predeterminados o niveles determinados que ameriten intervención (por ejemplo, altura, 

volumen de material removido por hormigas, perfil de evaluación). 

MÉTODO 

Los siguientes métodos se deben implementar: 

• Mapa base y reglamento 

• Resultados de observaciones 

• Guías técnicas de diseño y umbrales de intervención 

CLASIFICACIÓN DE URGENCIA 

Los cuadros 3.1y 3.2 determinan los niveles de modificación del dique y la clasificación de urgencia 

de reparación. Un programa de reparación/restauración puede ser preparado con base en esta 

clasificación. 

8

5. PLANEACION E IMPLEMENTACION 

Los resultados de la inspección, incluyendo la planificación de las medidas de reparación necesarias, 

se informan en este subproceso. 

PROPÓSITO 

El propósito de la fase de Planificación y Ejecuciónes definir, priorizar y realizar las acciones 

necesarias a fin de que la modificación del carillón sea reparada. 

PLANIFICACIÓN 

En esta etapa las medidas requeridas son definidas, priorizadas e incorporadas en un programa. El 

informe debe determinar los recursos que son necesarios para las medidas de recuperación del 

dique. 

IMPLEMENTACIÓN 

Mantenimiento 

Operaciones de emergencia. 

La realización de las operaciones de emergencias lleva a cabo durante todo el año. El daño debe ser 

restaurado inmediatamente después de descubrimiento; 

Mantenimiento menor. Realizar reparaciones menores, todo el año. Las reparaciones de deben 

realizar hasta un máximo de 3 meses después de la observación. Incluir control de las hormigas 

simultáneamente con la realización de trabajos secundarios de mantenimiento. 

Mantenimiento mayor. Se necesita establecer un programa multianual. La duración del programa 

depende de los recursos disponibles y la urgencia de reparación. 

Cumplimiento de las regulaciones 

Urgente. Los asuntos que requieren atención urgente son inmediatamente transmitidos; 

No es urgente. Observaciones que determinen condiciones que no son urgentes deben comunicarse 

dentro de un plazo no mayor que seis meses 

Invocación de entidades en deuda. Las entidades con atrasos en cumplimiento de sus compromisos 

recibirán una carta con observaciones sobre la cartera de compromisos, las acciones requeridas y los 

períodos de ejecución. 

Refuerzo 

Si un nivel mayor de estándar de seguridad es requerido entonces se debe proponer una acción de 

mitigación. 

En esta fase de un programa de recuperación debe ser preparados. 

9

ANEXO 1 REGLAMENTO, MAPA BASE Y PLAN DE PROTECCION DE INUNDACIONES 

Reglamento 

La autoridad del agua (o del dique) trabajan con leyes y regulaciones. Por ley se les permite hacer 

establecer ciertas reglas y regulaciones para apoyar las tareas asignadas. 

Estas regulaciones salvaguardan la función del dique y protegen los diques de las actividades ilegales 

tales como la excavación y la construcción en lugares no aptos. Por lo tanto, las autoridades protegen 

las zonas adyacentes y deben reservar el espacio para obras futuras para refuerzo del dique. 

Estas zonas protegidas se identifican como tales en el Mapa Base del dique. El mapa base es por lo 

tanto importante para el ámbito de aseguramiento de cumplimiento de normas relacionadas al dique. 

Mapa Base del dique 

La Ley del Agua obliga a las autoridades a tener Mapa Base del dique 

- La autoridad del agua es responsable de la generación de un Mapa Base, en el que se describe 

cómo se debe comportar el dique y como son diseñados: localización, geometría, tamaño y 

construcción. 

- En este mapa también se establecen las entidades en deuda y las obligaciones de mantenimiento 

- La ubicación del dique, las zonas adyacentes de protección y zonas reservadas para el futuro deben 

indicarse en mapas de localización 

Plan de protección de inundación 

Este plan de control maneja las calamidades que puedan surgir en períodos de inundación. 

El control adecuado tiene como base un modelo de escalada. Cada fase responde a los progresos de 

la inundación y el estado de las estructuras de protección de inundación en conjunto con el avance 

del despliegue de los cuerpos de emergencia. 

Se distinguen las siguientes fases: 

Fase 0 actividades anuales, 

Fase 1 Mayor vigilancia (en particular, el cierre de estructuras que cruzan el dique), 

Fase 2 Vigilancia del dique y reparación menor 

Fase 3 Vigilancia permanente del diquey trabajos de reparación mayor para prevenir daños o 

rompimiento del dique 

Control de las defensas contra inundación por lo general se llevará a cabo mediante el despliegue de 

personal y recursos de la autoridad del agua. En situaciones extremas, las autoridades del agua 

inicialmente deberán trabajar con contratistas. Además, para acciones específicas con las organismos 

de socorro, tanto a nivel local como regional, tales como el cuerpo de bomberos. En casos extremos, 

el despliegue de unidades de emergencia nacionales podría ser necesario. 

La colaboración con otras autoridades y contratistas debe ser planeada y simulada con mucha 

antelación. Esta organización y el simulacro forman parte del plan de protección contra inundaciones. 

10

ANEXO 2 INSTRUCCIONES DE TRABAJO 

Este anexo contiene un ejemplo de trabajo. 

PREPARACIÓN 

Cada inspector debe tener: 

1. Mapas 

2. Lista de los carillones que indican abscisado y longitudes 

3. Esta Observación de Instrucción 

4. Planificación del trabajo concreto 

5. Cámara 

6. Indicador de escala 

7. Computador de campo 

8. GPS 

9. Dotación de vestido adecuada 

Cada inspector debe tener la siguiente información: 

1. Vestimenta adecuada, identificación apropiada 

2Nuevos desarrollos en la política, regulación 

3 Manual de operaciones de computador y equipo GPS 

REQUISITOS DE DESEMPEÑO 

1 Implementación de las observaciones es realizada por lo menos por 2personas. 

2 Que al menos una de las personas cumpla con los siguientes requisitos: 

2.1 Educación mínima: 

2.1.1 Educación secundaria a nivel técnico, orientada a ingeniería civil o ingeniería agrícola; 

2.1.2 Ser calificado como inspector de diques, dos cursos (incluyendo la patrulla del dique); 

2.1.3 Curso de actualización anual 

2.1.4 Curso sobre cómo atender quejas 

2.2 Nivel de experiencia: experiencia como interventor, evaluador de trabajos. 

2.3 Área de conocimiento: Los encargados de la inspección deben tener conocimiento local de la 

zona inspeccionada 

2.4 No tener limitaciones físicas 

2.5 Medios de transporte para acceder áreas remotas 

3 La segunda persona debe tener las siguientes cualidades: 

3.1 No tener limitaciones físicas 

3.2 Ser calificado como inspector de diques, un curso 

4 Las inspecciones se realizan a pie. El inspector va sobre la corona mientras el acompañante 

camina a lo largo de la zona húmeda. 

OBSERVACIÓN 

Requisitos de los informes de observación 

5 Fotografías deberán cumplir los siguientes requisitos: 

5.1 Uso del indicador de la escala 

5.2 Hacer una toma en la que toda la imagen comprenda el daño 

5.3 Crear una visión global 

5.4 Evaluar si son necesarias más fotografías 

6 Observaciones de los daños para capturar imágenes en centímetros. 

7 Una rareza no es necesariamente un tipo de daño. Cuando exista la duda, capturar la 

imagen. 

8 Cuando este lloviendo es lógico que se vean zonas húmedas en el campo. Registre la 

localización y vuelva más tarde para ver si las zonas húmedas persisten después de un 

período seco y registre las condiciones climáticas en el informe de inspección. 

11

Empresa 

Dirección 

Waterschap Aa en Maas Pettelaarpark 70, Den Bosch 5201 GA, Holanda; T +31.73.6156905 

Royal HaskoningDHV Laan 1914, No. 35, Amersfoort 3818 EX, Holanda T +31.88.3483383 

12


ANNEX 8 

Water governance and regional water authorities in the 

Netherlands (partially derived from [14]) 


LW-AF20130064 - 1 -


The regional water authorities are the oldest form of democratic government in the Netherlands. The first 

regional water authorities date back to the 13th century, which is all to do with the geographic situation of 

the country. More than half the country would be flooded but for the dunes and dams that protect human 

beings, livestock and properties against storm floods coming from the sea and torrential rivers. Extreme 

rain, too, can cause great inconvenience. The many dikes, locks, pumping stations, weirs, canals and 

ditches keep the Netherlands habitable. 

The regional water authorities are responsible for the water management on a regional and local level. The 

concept of ‘water governance’ can be described as that part of public care that relates to flood protection, 

the water regime (surface water and groundwater in both the quantitative and qualitative sense) and the 

waterways. It focuses on the habitability and usability of the land and the protection and improvement of 

the living environment. From this description it is also apparent that, in the execution of their tasks, the 

regional water authorities fulfil the provisions of Article 21 of the Dutch Constitution: ‘Government care is 

aimed at the habitability of the country and the protection and improvement of the environment. 

The importance of good water governance is growing as a result of the rising sea level, climate change, 

land subsidence and urbanisation. Six regional water authorities are also charged with road management. 

Although strictly speaking this duty is not related to water management, it falls within the somewhat 

broader concept of ‘Public Works and Water Management ’. 

Water governance is realised by means of infrastructural works: water control works such as rivers, lakes, 

canals, ditches, dikes, pumping stations, locks, weirs, culverts, bridges and sewerage treatment plants. 

These works are crucial for keeping the Netherlands habitable. The regional water authorities draw up byelaws 

(Keur) to safeguard the correct maintenance and functioning of these structures. For example, it is 

generally prohibited to carry out activities such as building, excavating or planting greenery, on, in, over or 

under water control works without the permission of the regional water authority. The crucial importance of 

these infrastructural works is also clear from the Dutch Criminal Code, which makes deliberately damaging 

such works punishable. 


LW-AF20130064 - 2 -


APPENDIX 9 

Ownership of the Aguablanca dike 


LW-AF20130064 - 1 -


Figure 17 

Page 1 of the Act of Sales of Aguablanca 


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Figure 18 

Page 2 of the Act of Sales of Aguablanca 


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Figure 19 

Rio Cauca 

Page 13 of the Act of Sales of Aguablanca: CVC stays owner of the left bank of the 


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APPENDIX 10 

Table of damage and investment costs 


LW-AF20130064 - 1 -



LW-AF20130064 - 2 -

Aguablanca Dike along the Cauca River, Cali, Colombia

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