The CRA, chaired by Prime Minister Manmohan Singh, had on September 19 directed Karnataka to release 9000 cusecs of water to Tamil Nadu between September 20 and October 15.
When the Central Water Commission - monitoring the flow - reported that only 4000 cusecs was being released, the Water Resources Ministry shot off a letter to the Karnataka Chief Secretary asking him to implement the award.
Highly placed sources in the government told PTI that the letter was sent after monitoring the water flow on September 22, 23 and 24.
Karnataka, meanwhile, has moved a review before the CRA asking it to reconsider its award and stay its implementation till its petition is settled.
After hearing Tamil Nadu and Karnataka, the Prime Minister had ruled that Karnataka release 9000 cusecs of water each day for 25 days after it refused to accept Tamil Nadu's demand for 2 tmc ft water for 24 days or 1 tmc ft for 30 days.
Karnataka Chief Minister Jagadish Shettar had walked out of the CRA meeting as it failed to produce a solution with both states rejecting the Prime Minister's award to save standing crops in the delta region of Tamil Nadu.