# data[].attributes.body
Harnessing the Mekong or Killing It?

Dams are rising all along the Mekong. The people of Southeast Asia need the clean electricity—but also the fish and rice that an undammed river provides.

# data[].attributes.attachment_link.readable_text
Pumee Boontom lives in northern Thailand, but he tunes his television to the Chinese weather forecast. A big storm in southern China means a big release of water from the Chinese dams upstream-and, in turn, a good chance his village will be flooded. The Chinese government is supposed to warn downstream countries. In Boontom's experience, that warning tends to arrive too late or not at all.

"Before the dams, the water would go up and down gradually, with the seasons," he says. "Now the water goes up and down drastically, and we don't know when it's going to change-unless we watch the storms."

Boontom is the leader of Ban Pak Ing, a scattering of cinder block houses and unpaved streets that reach from the precipitous west bank of the Mekong toward a quiet, well-cared-for Buddhist temple. Twenty years ago, like many of his neighbors, Boontom caught fish for a living. But as China completed one, then two, and then seven dams upstream, the few hundred residents of Ban Pak Ing saw the Mekong change. The sudden fluctuations in water levels interfere with fish migration and spawning. Though the village has protected local spawning grounds, there are no longer enough fish to go around.

# data[].attributes.attachment_link.description
Pumee Boontom lives in northern Thailand, but he tunes his television to the Chinese weather forecast. A big storm in southern China means a big release of water from the Chinese dams upstream-and, in turn, a good chance his village will be flooded. The Chinese government is supposed to warn downstream countries.

# data[].attributes.body
The implementation of the various options which are available for flood management and mitigation as outlined here are not likely to be feasible without an integrated approach which ensures that at all levels coordination exists in planning appropriate flood mitigation measures which are related to monitoring, investments and preparedness.

# data[].attributes.body
To define flood mitigation measures, to monitor annual floods and to improve national and local preparedness for floods, the National Flood Management Unit has to be reinforced and inter-ministerial capacity increased to effectively coordinate and implement national actions in flood management.

# data[].attributes.body
At national level a better understanding is required of the flood behaviour and the various options to manage and regulate more effectively excess waters. Such national flood management plans and strategies will include:

an assessment and classification of areas effected by regular flooding;

a monitoring system to assess on a continuous basis the areas each year effected by floods; and

an overall flood control management plan to manage recurrent and exceptional floods and to have in place emergency measures to reduce and overcome the damage of exceptional floods.

# data[].attributes.attachment_link.title
FLOOD MANAGEMENT AND MITIGATION IN THE MEKONG RIVER BASIN

# data[].attributes.attachment_link.description
It is becoming increasingly apparent how important flood management is in our Mekong Basin. This appears particularly true for the Lao PDR, given its strong economic dependence on agriculture. In a least developed and landlocked country, its reliance on natural resources, particularly water and related resources, is uncomfortably high.

# data[].attributes.body
Survey data were transferred to the existing maps of 1:50 000 scale. In order to improve the quality of the surveys and to develop thematic maps to allow a more versatile use, the survey data were to be produced in a geographical information system (GIS). The GIS facilities available at other government institutions and accessible to the Irrigation Department were reviewed, and a method to elaborate the analogue maps into a GIS-system was proposed to further enhance the interpretation of flood data and to provide possibilities for better spatial analysis. The necessary hardware was purchased for the Irrigation Department and special GIS training organized. The analogue maps were digitized and transferred into the GIS system.

# data[].attributes.body
The flood surveys have obvious shortcomings, as they are time consuming, have a restricted validity and data become available long after emergencies have been solved. There is an obvious need for faster ways to obtain reliable information on the extent of any flooding event.

Aerial photography and photogrammetry - based on new coverage - is time consuming and expensive and takes time to mobilize. In order to assess the viability of derivation of flood data by satellite and contour data the potential of using Radarsat imagery for more precise hypsographic data has been investigated. Although efforts of the project to obtain and process Radarsat images for the 1997 flood have not been successful, ample attention is given to further assess the viability of the method.

# data[].attributes.body
The size of the Mekong Basin makes international cooperation imperative and any flood monitoring and forecasting needs to be made in close cooperation with the five countries sharing the Mekong Basin through the MRC.

At present, flood forecasting is carried out only during the monsoon season using the Streamflow Synthesis and Reservoir Regulation (SSARR) model that MRC has been using since early 1970s. It was developed by the US Army Corps of Engineers and it has been reviewed in an earlier consultancy report. Essentially, it consists of three sub-models, namely, riverflow synthesis, river routing and reservoir routing and it operates from synoptic data received from 41 rainfall and 35 water level stations located in the LMB. The model has served a useful purpose for some 25 years with a forecasting accuracy of 10%–15% but requires urgent updating using the median concepts of river modelling.

Mathematical simulation models can be very useful in evaluating the effects of reservoirs and their operation on the Mekong River floods. In general, flood forecasting models are of great help in improving the operation of reservoirs and avoiding unnecessary spilling of water. Mathematical models can also lead to an improved understanding of the flood phenomena and provide insight into the causes of flooding. In this manner, more appropriate measures can be taken to reduce flood damage.

Several models are presently commercially available in flood forecasting and management models, and several have been proposed to replace the existing SSARR model. The replacement of the existing model will provide an unique opportunity for the MRC staff in Bangkok and the DOI staff in each MRC country to be trained in the use of the selected state-of-the-art flood forecasting and management model. Transfer of technology is essential to the MRC countries at the turn of the century. Further details on model upgrading or replacement are included in studies undertaken by Delft Hydraulics and hopefully will lead to concise proposals and resources to assist the MRC in this important task.

# data[].attributes.body
A more permanent option to reduce the destructive effects of floods is desirable. Therefore, long term investment in various types of flood control works are required, which may include:

gates preventing back up of high flood waters;

reservoirs and retention dikes to protect urban areas and agricultural lands;

widening and deepening of tributaries and natural drains;

diversion channels; and

retention ponds and retarding basins.

The benefits of the flood protection works need to be further evaluated in terms of increased crop production and in reducing the areas subject to regular flooding, and also the negative environmental effects in relation to the ecological value of wetlands and the increased risks of flood hazards in adjacent areas.

Investments in gates and protection dikes will provide long-term solutions for more durable protection of agricultural lands and infrastructure. In addition to local investment studies, a flood management plan will be required to assess the effectiveness of flood investment works and to provide a basis for identifying and prioritizing essential investments for rehabilitation and construction of flood control and other water management infrastructure.

The flood control works carried out under EU financing in the Vientiane Prefecture may serve as an example of the beneficial effects of flood control: farming and social patterns changed - houses previously built on stilts or located on higher ground are now constructed at ground level and cropping has changed from mainly flood resistant rice to rice and other crops (vegetables, tree and other crops). However risks have become more significant as any dike breach will result in considerable losses, especially as the area is surrounded by a dike, making drainage more difficult.

Protection works are needed all along the Mekong River to protect the low lying agricultural areas that are inundated by each flood. Furthermore, an important additional benefit of flood protection works is the potential for retention of water for irrigation in the dry season. The DOI has built several flood protection structures such as flood dikes and flood control gates along the Mekong and some of its tributaries, but their overall effect on the annual loss of paddy and other crops appears to be negligible so far. Therefore, a flood protection project in Laos deserves top priority.

# data[].attributes.body
Considerable traditional local knowledge exists on the behaviour of floods. Farmers faced with regular flooding have developed various practices and techniques to overcome such recurrent floods which affect large areas in the lower flood plains of the Mekong River and its tributaries. By making an inventory of this local knowledge and stimulating communities to propose their own solutions in terms of local infrastructure works, more cost effective and sustainable solutions can be found to improve protection against floods and to provide agricultural alternatives to recover from production losses due to flooding.

Where needed technical and financial assistance can be provided to assist the local communities in the realization of flood mitigation measures. At district and village level, communities should be encouraged in the implementation of self-help flood control projects making use of the considerable local knowledge and traditional technologies.

Furthermore, to compensate recurrent losses. farmers need to be encouraged to diversify agricultural production and to extend their production basis to irrigated crops during the dry season.

Irrigation provides an optimal means to stabilize and broaden the production basis of the small holder farmer and constitutes an alternative against the vagaries of the monsoon season. However, public irrigation development has been problematic in Laos and many of the medium and large scale irrigation schemes have proved uneconomic and not sustainable.

# data[].attributes.body
An attractive solution to reduce the negative impacts on agricultural production due to floods is the promotion of dry season irrigation. Such a solution can be found in small community irrigation projects and in particular in the introduction of simple, low-cost irrigation technologies. Pump units driven by small combustion or electric motors or operated by hand or foot can now be made available at prices acceptable to small farmers and would provide a very attractive tool to expand and diversify agricultural production. Water can be pumped either from perennial rivers (Mekong and tributaries), seasonal ponds and water-filled depressions or from traditional open wells which could be improved or developed by simple borehole drilling techniques.