The groundwater level has depleted to a record low

Despite receiving excess rainfall during the monsoon, coastal Karnataka — where water scarcity was unheard of till recently — is facing severe water scarcity for the past two months with surface water bodies running dry and groundwater depleting to record-low levels.

Dakshina Kannada and Udupi districts had received above normal rain in the last monsoon, while Uttara Kannada had faced a shortfall of 586.1 mm from the normal.

The coastal region received below normal rainfall post-monsoon (180.4 mm as against 263 mm) and during January-May (36.6 mm as against 50.3 mm).

Fresh water flow has stopped in all major rivers in the coast, including Netravathi, Phalguni, Swarna, Chakra, Varahi, Sharavathi, Aghanashini and Kali at present.

Groundwater level is 30-40 m deep in Mangaluru taluk and 20-30 m in Belthangady taluk while it is between 10-20 m in other taluks of the region as of March. In fact, Belthangady taluk on the foothills of the Western Ghats from where Netravathi flows down, used to be rich in groundwater.

With water level reaching the dead-storage level at Baje dam across the Swarna, the main source of water for Udupi, the city municipality has decided to provide water once a week to residents by dividing the city into six zones.

With storage enough for about a fortnight at Thumbe vented dam across Netravathi, Mangaluru City Corporation has resorted to water rationing. The problem has worsened owing to the near absence of summer showers.

Forest cover

Multiple reasons, including depleted forest cover, particularly in the Western Ghats, and a very high temporal variation in rainfall are the reasons for the situation, said S.G. Maiya, hydrologist and retired professor from NITK, Surathkal.

Though the total quantum of rainfall was very high, there was a skew in the initial period and later there was drastic reduction with almost no rains in August and September 2018.

Prof. Maiya said Western Ghats play a crucial role in bringing rains and facilitating gradual percolation of rainwater into the ground. However, drastic depletion of forest cover by different projects has affected rainfall pattern and percolation.

The rainwater immediately gushed into the Arabian Sea instead of gradually percolating into the gerund and getting released to the river system slowly.

(With inputs from

Ganesh Prabhu in Udupi)