NEW DELHI, Aug 24 ? A long-term analysis of ground water levels by Central Ground Water Board has revealed ground water depletion of over four meters in 306 district including Jorhat, Karbi Anglong and Morigaon districts. In a RS reply, Water Resources Minister Priya Ranjan Das Munshi informed that the Government of Assam has initiated actions for preparing legislation for regulation of ground water development. The Nagaland Government has taken measures to promote water harvesting. East Siang district in Arunachal Pradesh and W Garo Hills in Meghalaya are the two other NE districts where ground water level has depleted. Meanwhile, the average annual water availability in Brahmaputra and Barak sub-basins is the highest in the country at 585.60 billion cubic meters. The lowest average annual water availability is Sabarmati river, which has 3.81 BCM of water availability round the year.