------------------------------------------------------------------------------------------------------------------
In a special series, The Goan Everyday examines if Goa’s case against diversion of water from the Mhadei to Karnataka and Maharashtra is weak or not, as claimed by a senior bureaucrat
-----------------------------------------------------------------------------------------------------------------
------------------
WATER WAR
------------------
PANAJI: The quantum of water flowing in the Mhadei is at the heart of the inter-state dispute. And Goa has been avoiding this aspect since 1995.
For over 20 years the State dodged and weaved attempts by Karnataka to pin it down on the quantum of water. When push came to shove, Goa preferred to file a case in the Supreme Court instead of undertaking a study to determine the quantum of water in the river.
While studies in the past have estimated the yield to be 220 TMC, a recent study undertaken by the Indian Institute of Technology, Mumbai has put the yield at 145 TMC. When this study is submitted before the Mhadei Water Disputes Tribunal, it will be the first such report from the Goa side.
After years of rejecting the initial NEERI environment impact assessment plan from 1995 and subsequent objections to studies conducted to estimate the yield of the basin, Goa finally undertook a study of its own in 2014 under pressure from Karnataka and Maharashtra.
Goa had turned down NEERI EIA study because it justified diversion of water saying it would leave most of the navigability of the river unaffected. It study also said, “the prediction of water salinity changes indicate a lowering of salinity in the Mandovi estuary which is beneficial to Khazan paddy cultivation.”
According to information obtained, Karnataka, quoting the NEERI study had said diverting 24.15 TMC of water instead of its initially estimated 9 TMC from Mahadei would not change any of the findings and would not affect the basin.
Goa had however turned down the study saying it seemed to be based on the use of unreliable hydrological data and that the EIA for Goa was not considered. They had suggested involving NIO, Goa in the NEERI study. The tribunal has taken a decision for Goa to present a report of their own, estimating how much water the basin actually contained. Goa on its part had said it would require three months but kept delaying the date.
It was only in 2014 that the IIT report emerged, incidentally using the same rainfall data used in other reports between the years 1964 to 2005.
--------------------------------------------------
GOA HAS TO PROVE HOW
A CUT WILL HIT STATE
* The Indian Institute of Technology (IIT), Bombay based study has now put the number at 145 TMC with a new concept of safe yield at a mere 70.10 TMC
* CWC study in 2003 estimated a yield of 220 TMC, suggesting diversion of 24.15 TMC to Karnataka and 6.36 TMC to Maharashtra
* Goa had in its defence cited damage to the rich biodiversity and salinity ingress as reasons for rejecting the diversion
* The hard part for Goa is to prove how a reduction of 30 TMC (20 pc) of 145 TMC will affect the State
-------------------------------------------
BOX
Yet another attempt at estimating yield
A reported prepared by the Indian Institute of Technology, Bombay (IIT) has pointed flaws at the estimated values of water contained the disputed Mahadei water basin
According to Professor V Jothiprakash and Professor MC Deo, there was a major flaw in the terminology used in previous studies, estimating that the annual runoff was actually 145.05 Thousand Million Cubic Feet (TMC).
Studies in the past have estimated values ranging from 190 TMC to 220 TMC. The first study submitted in May 1982 submitted a report on Water Conservation and Utilization where they assessed the average annual yield of the entire Mahadei River Basin as 126 TMC. The National Water Development Agency (NWDA) in 1989 assessed the yield as being 112 TMC.
A later study conducted by the Central Water Commission (CWC) in 2001 estimated the annual runoff to be between 194 TMC and 209 TMC. The same commission in 2003 then estimated a figure of 220 TMC. The Indian Institute of Science (IISc) in 2011 estimated figures between 189.85 TMC and 253 TMC.
According to the Jothiprakash report however, the past reports make no difference between runoff and yield. “All the studies have failed to make the distinction between the runoff and the yield, and all have estimated runoff while calling it yield,” said the report.
All reports are prepared based on analysis of data collected from Ganjim, that has a catchment area of 880 km2 and Collem that covers 117 km2 of catchment area. While most rely on values from 1964 to 2005, the IIT report too limits itself to this time frame citing errors in measurements post 2006.
Based on calculations and estimations, the report has said the annual runoff in the entire Mandovi River Basin was 145.05 TMC, total runoff or yield was 108.72 TMC and safe yield was a mere 70.10 TMC.
