ENVIRONMENTAL CONSEQUENCES OF MORAGAHAKA,NDA DEVELOPMENT PROJECT

Abstract

The Moragahakanda Development Project is an integral component of the 30-year Master planfor the Mahaweli Development Programme and is the last of the reservoirs to be developed.

The project comprise of many components; a 63 m high dam and two smaller saddle dams atMoragahakanda forming a reservoir with full supply level (FSL) of 185 m msl and area of 29.5km2, a 20 MW base power plant incorporated in the dam with a 132 KV transmission line toHabarana, a second diversion tunnel from Bowatenna to Lenadora with 25 m3/s capacityaccompanied by improvement of the Huruluwewa Feeder Canal, a branch extension of theUpper Left Bank Canal of the Kariudulla Irrigation Scheme in System Dl to accommodatearound 1000 families who would be displaced by the Project.

This paper attempts to review the principle environmental impacts of the proposed project,especially in upstream catchment, reservoir area and the dam, power plant, downstream riverand irrigation and settlements. Effects on the environment in the construction phase andoperational phase also were taker. separately. An environmental management plan had beendesigned covering all the project components and mitigation measures in the upstream riverbasin, reservoir area and dam site, downstream river and irrigation areas.