Rapid Assessment for Resilient Recovery and ... - GFDRR

To support the monitoring and maintenance of this critical infrastructure, a strong data and
information management system is essential. Establishing a centralized point to hold river
basin information is critical to assessing the health of the basin, its ability to withstand
development stress and detect emerging trends and potential challenges. This can also be
linked with the flood early warning system.
Finally, the revision of land use policies may be necessary to avoid further, inappropriate
encroachment onto flood plains and will be a key point for the IWRM policy framework to
address.
Effective flood forecasting and early warning systems that communicate flood forecasts
and emergency information to the public is essential. New knowledge of the climate system
is beginning to make these medium-term forecasts more feasible and accurate on the
national and sub-national scale. Several river basins in Europe have flood early warning
systems that combine meteorological forecasts with detailed knowledge of the local hydrology
and topography to forecast the occurrence of floods some days in advance.
Dikes, dams and other structures regularly, successfully protect lowland inhabitants from
floods. It is likely that they will continue to be an important means of coping with increasingly
frequent and high river flows resulting from climate change. This is very relevant in
Thailand’s Chao Phraya River Basin, though alone, insufficient; there is a strong need to
improve flood water management. One clear, prudent option is to improve water retention
through an increased number and capacity of water reservoirs. The country has at present
about 1,000 cubic meters of water storage capacity per inhabitant whereas the United States
and Australia have over 5,000 cubic meters. The dams of the Colorado River in the United
States and the Murray-Darling Rivers in Australia, for example, can hold 900 days of runoff.
By contrast it has been estimated that the dams in Thailand can store runoff for just 100
days. Additionally, creating ‘room for the river’, as is recommended in the Royal Initiative for
Flood Mitigation would allow for increased areas for flood waters to roam. Figure 8 describes
an example of best practice for this type of initiative.
Figure 8: Room for the
River – Best Practice
from the Netherlands
Figure 8: Room for the River – Best Practice from the Netherlands
High discharge rates from the Rhine and Meuse Rivers in 1994 and 1995 led to a significant
shift in managing river flood safety in The Netherlands. The age-old practice of raising and
strengthening embankments along the rivers was replaced with a new approach, which gives
more room to high waters. This so-called “room for rivers “ policy contains a wide range of
measures, such as lowering floodplains, the creation of side channels, lowering of groynes, river
dredging and the realignment of dikes. As opposed to past practice, dike strengthening
has become a last option, only to be considered if other interventions prove to be technically or
financially impossible. Most of these measures will have significant consequences on regional and
local spatial planning, making public participation in planning of flood management strategies
crucially important. It also calls for a more integrated approach to planning, combining safety
objectives with other policy and development goals, such as nature development, landscape
quality improvement and economic prosperity. The new management policy is now being
implemented across the Dutch areas of Rhine and Meuse in a multi-billion Euro program. In
addition to practical innovations in river management, the program has taken a creative
approach to planning its ‘central direction and decentralized implementation’ arrangements.
This has created opportunities for innovative public-private partnerships, such as Design &
Construct agreements, in which planning and implementation is dealt with through one contractor.
This approach has required great adaptation skills from both contractor and government
agencies, and led all on a path of trial and learning. The program is expected to finish in 2015.
Source: Deltaris
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