Abstract:
The Rongai Valley Irrigation Scheme of Meghalaya envisages construction of a barrage founded on firm rock. For design of this barrage, a 50-yr return period flood peak is required. To analyse incremental cost and additional risk covered, floods of various return periods are needed. Probable Maximum Flood (PMF) peak is required to visualise potential flood hazard downstream.
Design flood peaks of various return periods, SPF and PMF assessed are presented in the paper. The approach adopted is based on the practical view point that : since water use projects cannot be delayed till data of adequate quality and quantity are available,recourse is to be taken to arrive at the best judgement assessments after analysing whatever information is readily available.