Application of Safety Plans for Rainwater Harvesting Systems in Sri Lanka

Abstract

Water is often considered the most basic need for sustaining life. As the world population increases, the demand for quality drinking water increases. Dug wells and tube wells are considered as the main water source among the rural community in the dry zone. Rainwater harvesting is receiving increased attention in the dry zone as an alternative source of drinking water. While rooftop rainwater harvesting is being promoted, little attention has been paid to the quality of collected rainwater until recently. It becomes nationally important to look for low cost options which could be managed and afforded by the communities themselves. Rain water systems are categorized as individual systems and there are no proper regulations for maintaining the rain water harvesting systems. Therefore, it is vital to develop a proper guideline for rain water harvesting systems. Kebethigollewa was selected as the sample location due to the high number of rain water harvesting systems available. A questionnaire survey and focus group discussions with the beneficiaries were conducted to collect data on different rain water harvesting systems, rain water usage pattern and health concerns due to consumption of rain water. Based on the outcome of the data from observations, questionnaire survey and sample analysis, cost effective and community manageable rain water harvesting safety plan were introduced. Rain water was mainly used for the drinking and cooking purposes and dug well water was used for other activities like bathing and washing. Over hanging vegetation was identified above the roof catchment which may attract animals. Fallen foliage which blocked the gutters were identified in most of the guttering channels. According to the analysis, samples shows slight acidity. Turbidity ranged from 0.22 to 2.80 and TDS varied from 5 to 120 mg/l. All the water samples have TDS, Nitrate, Sulphate and hardness concentration below the prescribed limit.