Development of low-cost rainwater harvesting to support on-site water supply in rural Tajikistan

Abstract

Farmers in remote, arid areas, far from available water sources, need affordable water solutions for household and livestock use. In this study, the water needs and potential for rainwater harvesting (RWH) in the Kysylsu River Basin are estimated at different altitudes. The mean annual net rainfall depth varied from 545 to 900 mm. With an average roof area of 550 m2, 211 m3 to 344 m3 rainwater can be harvested for dry and wet years respectively. Based on the estimated water demand and rainfall deficit, the average household need was estimated to be 100 m3. For a low-cost water storage solution, we tested different types of waterproof materials to replace smaller 12-18 m3 concrete tanks commonly used in the region. Soil pits lined with 0.3 mm double layer polyethene (0.6 mm in total) was the best solution for 5 m3 volume tanks in terms of the costs and durability and 0.8 mm double layer polyethene (1.6 mm in total) was ideal for sealing 10 m3 volume tanks. This study demonstrates the efficiency of the system for improved livelihood of the families through rain harvesting.