A study to identify adequate water source to increase the capacity of Medagama water supply scheme.

Abstract

This study covers 31 numbers of Grama Niladari Divisions (GND) of Medagama Divisional Secretariat Division (DSD). The vast majority of the population in rural areas depends on both groundwater and surface water sources for domestic water needs. The objective of this study is to identify the water source alternatives to increase the capacity of Medagama Water Supply Scheme(WSS). The primary data was collected from National Water Supply and Drainage Board (NWSDB), Divisional Medical Officer of Health (MOH), Divisional Secretariat Division (DSD) office and GNs of the relevant GND’s, interviews, field surveys, site inspections and Questionnaire Surveys. The published data in DSD annual reports and report of Census Department were used as secondary data. The elevations were obtained by using Google Earth software and calibrated by Global Positioning System (GPS). The most suitable coverage area of proposed WSS was selected based on considerations of elevation, cost economic and operation and maintenance cost. The existing Medagama water supply schemes cannot cater to the total demand of Medagama WSS, since the limited capacity of the scheme and lack available of raw water. Thus people in the Medagama suburbs have been facing severe difficulties in satisfying their potable drinking water requirement. The Water Demand Requirement per day was estimated which is 4,471 m3/day by the year 2040. To cater to this demand, it has been identified that the most possible surface water sources in the vicinity are the Mallipotha reservoir and Nagahaella stream. These water sources would be the adequate water source to increase the capacity of Medagama water WSS. The water supply can be improved up to 37 % of the demand soon after the capacity improvement of the existing scheme and also can be supplied 55 % of demand by the year 2040 by used this identified water sources.