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Estimation Committee, upgrade the data base from time to time. The National
Water Policy also recommended utilization of only dynamic groundwater
resource (annually replenishable) as against static groundwater resource stored
in alluvial groundwater basins through centuries. Salient features of the
Committees recommendation :-
1.
Groundwater assessment are made on "block" basis ("Mondal" basis in
Andhra Pradesh). "Block" is an administrative unit and as such,
scientifically not correct. However, this system helps the planner for
allocation of fund etc.
2.
Detail guidelines are given for calculation of groundwater recharge and
draft i.e. Rainfall method when data are not available, water table
fluctuation method, rainfall characteristic and normalization factor,
recharge from canals, floods etc. Groundwater draft from various ground
water structures, like tubewells, dugwells etc. are mentioned.
3.
15% of gross groundwater recharge is kept reserved for industry and
domestic use.
4.
Based on stage of utilization of groundwater, blocks are classified as
"over-exploited", "critical" and "safe". Over-exploited blocks are those
which have already utilized 85% utilizable groundwater recharge.
"critical" blocks where utilization is between 70% to 85% - "safe" blocks
are those where utilization is less than 70%.
5.
No fund allocation are made, where the block is declared as
"over-exploited" for construction of any groundwater structures.
Quality of Groundwater
Quality of groundwater is to be ascertained by chemical, physical and
bacteriological analysis of the groundwater samples. The quality required of a
groundwater supply depends upon its purpose, thus the needs for drinking
water, industrial water and irrigation water vary widely. Accordingly prescribed
quality of groundwater for irrigation, drinking water and industry are different.
