IRI Home

Sri Lanka Projects -> River Basin, Mahaweli -> Project Description

Project Description

  > Project Summary
    Timeline
    NRMS
    Project Slides
    Maproom
    Reports/Links

Project Summary

  Overview
  Current IRI project, progress, anticipated output
  Project in development

Also see Visual Introduction

Overview of the Mahaweli River and the Mahaweli Project

The 207 mile long Mahaweli river traverses from the so-called "Wet Zone" of the island to the "Dry Zone" - a process which has been augmented with dams, canals and tunnels starting over 2000 years ago. Of the annual precipitation in the basin of 28,000 MCM, 9,000 MCM is discharged to the sea. The Accelerated Mahaweli project, which was carried out in the last two decades, was the largest development project in Sri Lanka involving the generation of hydroelectricity, irrigation of the "Dry Zone", land settlement, employment generation and infrastructure development. This project led to hydropower generation capacity of 470 MW and irrigation of an additional 365,000 ha of land in the Dry Zone. Its catchment spans 10,448 square km and it feeds 1003 tanks. Subsequent to construction, attention has shifted to watershed management, water management, crop diversification, participatory management and enterprise development. There have been concerted efforts to manage the watershed in the upper reaches of the Mahaweli.

The Mahaweli Authority also manages the Walawe basin whose headstream and downstream climatology and geography are similar to that of the Mahaweli. The Walawe basin is a simpler basin and serve as a pilot basin for research.

Back   Top  

Current IRI Project

Following sustained interaction with the Directors of Environment and Monitoring and Plan Implementation Units of the Mahaweli Authority in early 2000,  a proposal was formulated and  letters of understanding on this proposal were exchanged between the Director-Generals of the Mahaweli Authority of Sri Lanka and the IRI. Broadly, the project team seeks to develop tools for the use of climate information for river basin system management, to generate indices for droughts, floods and hazards and to study various environmental impacts (floods, droughts, malaria) and societal impacts (equity, communication of forecasts) of climate.   The project has been funded by the IRI  and the Mahaweli Authority (Office Support and Local Travel).

Progress of the Current Project

In the seven months since the project proposal was accepted, we have developed our partnership with the Mahaweli authorities, collected data and literature, studied the ENSO sensitivity of climate and rice production in Sri Lanka and are progressing towards a comprehensive forecasting system. The coverage of Sri Lanka by the IRI forecasting system and its skill is relatively good. Lareef Zubair visited the river basin in August 2000 to initiate the project.  The local authorities were found to be quite helpful and to have adequate infrastructure to support our work.

Anticipated Output by the End of 2001

Towards the end of this year, our output should  include ˇ Tailored climate and stream flow forecasts for Mahaweli and Walawe ˇ Forecasts for water availability in the Upper Mahaweli and Walawe Basins ˇ Studies on Climate Variability and Impacts in Mahaweli and Walawe (on Rice and Tea production and Malaria)

Back   Top  

>Related Project in Development - March 2001

The climatological and hydrological work done in the Mahaweli project is being used to to collaborate on a proposal to study the “Impacts of Climate Variability on the Transmission of Malaria Transmission and the Development of an Early Warning System” with the Lamont Doherty Climate Group and partners in Sri Lanka, namely,  the International Water Management Institute, University of Sri Jayawardhenepura, Department of Meteorology and the Anti-Malaria Campaign of the Ministry of Health. This proposal is under review by funders.

Project Coordinator

  Dr Lareef Zubair
  Email:

Back   Top