Desiltation of Reservoirs of Small Earthen Dams-Technological Options and Lessons of Experience

Abstract

Following the success of watershed development operation research project Sukhomajri in Haryana, large number  of water harvesting dams were constructed in the Shivaliks region of north India. The reservoirs of a number of these earthen dams got silted due to fragile geological strata, inadequate vegetation cover in the catchment areas, continued biotic interference and lack of community participation in building social pressure against grazing and illicit felling. The pre-mature siltation disappointed the poor farmers who enjoyed the benefits of supplemental irrigation for few years. The Haryana Community Forestry Project (HCFP) funded by the European Commission constructed 19 earthen dams during 2001-2007 and made them operational after addressing all possible causes of pre-mature siltation. The HCFP also decided to desilt two reservoirs constructed earlier for the study of technological options.

The paper builds a case infavour of desiltation because of very low cost involved. The study suggest that the silted reservoirs could be revived provided a) the original conveyance system and spillways are fully functional b) there is a strong demand from the community and c) Village Committees are functional and willing to contribute at least Rs. 50,000/- or 10% of the cost.