What is a dependable year?
Water availability will be computed using 10 daily flows. While planning Hydro Power Projects, discharge data of the river for about 20 continuous years is taken into consideration. Unrestricted energy generation of these hydrological years is arranged in descending order and exceedance probability computed. Based on the exceedance probability, 90% & 50% dependable years are identified. If discharge data for ‘N’ years is available, the 90% dependable year is defined as (N+1) x 0.9 year in the Table arranged in descending order. Power planning of the project is done on the basis of annual generation of 90% and 50% dependable years.
