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Sri Lanka Projects -> River Basin, Mahaweli -> Water Resources Issues Water Management in the Mahaweli River Basin
Summary and background SummaryA brief description of water management practices in the Mahaweli River Basin are described based on interviews with Mahaweli Authority Officials, review of project reports and independent studies. In particular, questions relating to the potential for the use of climate information in water management and the particular format that it is needed in is addressed. Background:Rice or Paddy is the principal subsistence crop in Sri Lanka which needs large amount of water. Rice cultivation is carried out in the main Maha season from October to March and in the subsidiary Yala season from April to September. Both seasons begin with the ITCZ rainfall in September-October and April-May. However, the monsoon system in Sri Lanka results in high post-ITCZ rainfall in the Maha season and low rainfall in the Yala season. During Yala, however there is high rainfall due to orographic influence in the South-West quadrant of the island in Yala. Hence rivers such as Mahaweli and Walawe which originate in the South-West and traverse elsewhere are important sources of irrigation during Yala. An elaborate system of water management is in place within the Mahaweli river basin. Water management is based on consultation at various geographic scales: that of the field, block, system, basin and the island-wide. The downstream regions of the Mahaweli Basin and adjacent basins fed by the Mahaweli has been broken up into 16 irrigation areas called Systems. Each of the Systems is again broken up into Blocks, which share the water from an irrigation control point. A field may refer to a stretch of paddy lands that is shared among several farmers. Seasonal Water BudgetingTwo Kanna (or seasonal meetings) are held in March and September to budget for the water allocation in the subsequent season. This meeting is attended to by representatives from local government agencies, central government officials functioning in the agricultural regions such as Government Agents, Members of Parliament and Provincial Governments, officials of various agricultural agencies such as the Paddy Marketing Board, the Agrarian Services Department, the Agriculture department, the Irrigation Department, System Managers within the Mahaweli Authority, Farmer organization representatives and the Ceylon Electricity Board and Water Supply and Drainage Board. At this meeting overall allocation of water for the different systems is decided upon. The decisions are based upon experiences in the past seasons, the demands from the different irrigated regions and the available storage in the reservoirs and an outlook for rainfall. Usually in the Maha season, water for cultivation of 100% of the irrigated land with rice is planned for. However, the releases for Yala is limited to perhaps 50% and the water allocation for Yala is thus more critical and contentious. The Water Management Secretariat of the Mahaweli prepares alternative scenarios based on the simulations using the Acres Reservoir Simulation Model for water use based on the current storage and likely rainfall. It also continuously monitors the larger reservoirs and releases. In the Mahaweli regions, the water demands for the forthcoming season are decided first at the Block level based upoun a meeting held in each area with farmers and irrigation officials. Thereafter the block-level demands are carried to a system-wide meeting where these demands are consolidated. These meetings are attended by the relevant government officials in the region such as Agricultural officers, Paddy marketing Board officials, Farmer Organizations and Irrigation Department officials. The water demands identified at each block are then taken to the Kanna meeting. Implementation of Water ReleasesOnce the seasonal allocation of water is decided upon based on this wide-ranging consultation, the implementation for the larger upstream reservoirs, barrages and diversion points is in the hands of the Ceylon Electricity Board, the Headwork’s Division of the Mahaweli Authority. The Ceylon Electricity Board has to operate the hydroelectric generators in accordance with the budgets and the Headwork’s division operates the sluices on the Dams and Barrages. The downstream management is in the hands of the downstream Units of the Mahaweli Authority and the Irrigation Department.
Weekly Inter-Agency MeetingEvery Friday morning, engineers from the Irrigation Department, Headwork’s Division, the Ceylon Electricity Board and the Water Management Secretariat meet in the WMS office under the chair of the Director of the WMS to review the operation in the previous week and to decide on operations for the coming week. I attended one of these meetings on August 18th. At these meetings, there are some recriminations between agencies regarding unplanned releases, demands regarding the timing and quantum of water releases. Further Investigations on Water ManagementThis system of water management needs further investigation and I hope to do so in terms of carrying out a survey in the semi-structure interview format suggested by Steve Rayner. During this visit, I could not get started on with the interviewing as my time was taken up with arrangements for starting up of the project, such as obtaining a research assistant, data and establishing relationships and further defining the scope of the project. However, it is clear that we need to survey a wide range of officials and water users to obtain a comprehensive picture of water management. They would include officials from the Water Management Secretariat, the Headwork Divisions, the System Managers, the Environment and Forest Conservation Division, Block managers and a sample of farmers and farmer organizations within the MASL and representatives from the Ceylon Electricity Board, the Irrigation Department, Health officials such as the Anti-Malaria Campaign, domestic water supply agencies such as Water Supply and Drainage Board and Flood related agencies such as the Land Reclamation Board and the environmental and wildlife conservation agencies. Current Reforms to Water ManagementWater management has been under sustained criticism on account of it being driven by a hydraulic engineering perceptions rather than environmental or farmer perspectives or considerations such as health and wetlands.The government has agreed to programs to reform all this. To this end, already a Water Resources Council has been established and is gearing up to take over some of decision-making in Water management. Since the new water management architecture is slowly coming into place it is an interesting time to study how it all works out. Seasonal Forecast Needs for Water ManagementFrom these limited discussions, it is clear that climate forecasts at all time scales are useful for water management. On a seasonal (3-6 months) scale there are clear needs for Maha forecasts in September, Yala forecasts in March and 3-5 months forecasts for electricity management, domestic and industrial water supply and health in December and June Informants:
References on Water Management in the Mahaweli
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