FE Editorial : Hydro logical

Written by The Financial Express | Updated: Jun 30 2009, 03:42am hrs
Deficient rainfall in the first month of the south west monsoons has raised the issue of a possible impact on hydro power, which accounts for one fifth of the total electricity generated in the country. There will obviously be an impact. During the last major drought in 2002-03, when rainfall was 19% below normal, hydro electric power generation declined by around 12.9%. But the scenario this year is not as alarming. The most recent data from the 32 major reservoirs till June 22 shows that water levels are just around one percent lower than in the same period of the previous year. In fact, detailed statistical evidence shows that the water level in 10 reservoirs remains higher than in the previous year while in another 8 the water levels are less than 1% lower than in the previous year. The reservoirs where the water levels continue to exceed the previous years levels include major reservoirs like Gandhi Sagar (3.7%) and Indira Sagar (0.5%) in Madhya Pradesh, Koyna (3.4%) in Maharashtra, Idukki (0.3%) and Sabrigiri (0.6%) reservoirs in Kerala and Bali Mela (4.4%), Hirakud (0.1%) and Rengali (9%) in Orissa.

The major reason for the marginal decline in the total water levels in the current year is lower inflows in 14 reservoirs. While water levels fell in the 1-5% range in 10 of them the shortage exceeded 5% in about four. Large reservoirs where water levels are less than in the previous year are mainly in the northern region and include Bhakra (-5.6%), Pong (-2.6%) and Ranjith Sagar (-2.3%) in Punjab, RP Sagar (-1.4%) in Rajasthan, Ram Ganga (-1.8%) and Tehri (-1.8%) in Uttarakhand, Sardar Sarovar (-1.6%) in Gujarat and Sri Salam (-0.7%) in Andhra Pradesh. But with shortfall levels being so minimal, it is not unreasonable to expect a partial if not full restoration of water levels if adequate rains prevail near the reservoirs in the next two months. And more important, irrigation and drinking water, rather than power will be the bigger casualty from any shortfall in rains. For instance in the last drought when hydro power generation declined by more than a tenth, overall electricity generation picked up by 3% as higher power generation by thermal plants more than made up for shortfalls. There are no substitutes for irrigation and potable water sources.