Water inflow into major reservoirs, if predicted early, can save water and help farmers who depend on dam ayacuts for cultivation.
The case in point relates to the Somasila project formed across the Pennar in Nellore district of Andhra Pradesh in the late 1980s. The reservoir, which has the capacity to impound about 78 tmcft of water, receives water from Pennar and Srisailam reservoirs.
The water received in the July monsoon at Srisailam from Almatti dam could have been anticipated and then released into Somasila; thousands of farmers who depend on wet ayacut could have taken up their first crop. The State Government could have helped farmers in the water-scarce Rayalaseema region to take up cultivation of their first crop this monsoon by diverting the flood water which had hit a whopping four lakh cusecs a day. For nearly two weeks, Srisailam received very heavy inflow, which has now helped the dam hit the full reservoir level.
Srisailam in turn let out water and helped Nagarjunasagar dam attain near-full reservoir level within days.
An automated technology-based solution that helps predict water flow would have helped take early decisions and save water flowing into the sea untapped.
A senior Irrigation Engineer told Business Line that the release of water from Srisailam dam is governed by an order passed by the Government, keeping in mind the requirement of various regions.
The irrigation authorities depend on flood predictions and accordingly take decision on impounding water and also the release. Knowing the unpredictability of monsoons, it is not possible to predict how much water the reservoir will get .
This makes the task difficult. Therefore, after studying the patterns of water inflows for several seasons, reservoir storage capability and need for providing water for drinking and irrigation, it has been decided to release water after the dam attains a certain level.
Smart water grids are based on sensors set up is various places along the water course. They transmit data to the centralised control systems.
This in turn helps assess the potential water flow to take better decisions. Just as smart power grids help switch on and switch off power supply, such smart water systems can assist irrigation experts to judiciously manage water resources.
A senior Government official said that Srisailam, which has become a multi-purpose dam, turns a key generator of power during monsoons and this helps back down thermal plants for maintenance.
Therefore, the minimum draw down level has been placed at 854 feet.
Another engineer cited the example of those in the East and West Godavari districts of the State which were forced to declare crop holidays in two seasons due to lack of water from the reservoir.
In 2012, the High Court directed irrigation officials not to release water for irrigation from Srisailam if the level is below the draw down level.
There are also regional considerations in water resource management, another official said.
Probably, it is time to revisit the way water management is handled in Andhra Pradesh.