A STUDY OF DESIGN FLOOD FOR LAKHWAR DAM IN YAMUNA BASIN

Abstract

In planning water resources development projects the knowledge of the peak and magnitude of the flood that have to be adopted in the design of engineering structures is of great importance. If the design flood adopted is low, it may cause overtoping or even failure of the structure when a higher flood than this occurs. As such it will damage life and built of property located in the downstream. On the other hand if the design flood adopted is too high, it will unnecessarily increase the cost of the structure and even economic feasibility of the project may not be possible. Therefore, selection of design flood is based on optimal combination of risk, safety and economy. The dissertation deals with computation of Probable Maximum Flood for Lakhwar Dam on river Yamuna. The study uses the simple concept of unit hydrograph which has been worked out by three different methL-ds namely; Conventional, Nash and -lark's Model to arrive at the average unit hydrograph. The available data of rainfall and runoff for the Lakhwar catchment has been used to develop the unit hydrograph. The severest storm of 28-29 September, 1924 experienced in the region has been utilised to arrive at the Probable maximum Flood Hydroyraph by design unit hydrograph. However, the in-filtration and interception losses have been accounted for by --index and the runofU coefficient approaches.