The sustainable development and management of the resource requires precise quantitative assessment based on valid scientific principles. The updated Groundwater Estimation Committee methodology – 1997 has been used and detailed guidelines were formulated through discussions and deliberations in the State Level Groundwater Estimation Committee.
Andhra Pradesh is the second State to complete the assessment as per the new methodology and is the only state in the entire country, which has extended the assessment up to the village level. The State of Andhra Pradesh has been divided into 119 assessment units, which includes basins with defined hydrological boundaries in hard rock areas of extent ranging between 50 to 450 sq km and mandals in alluvial areas including 36 saline mandals. The parameters measured include –
- Recharge
- Recharge from rainfall
- Recharge from canals
- Return flow from applied water for irrigation from surface water
- Return flow from applied water for irrigation from groundwater
- Recharge from surface bodies like tanks, ponds etc
- Recharge from artificial recharge structures like percolation tanks, check dams, nalla bunds etc.
- Current gross groundwater draft
- Groundwater allocation for domestic and industrial use
- Water table trend
- Current stage of groundwater development
- Net annual groundwater availability for future use
- Categorisation for further groundwater development
The report is the final outcome of the assessment and contains the details of basin wise annual availability of groundwater, current draft, allocation for domestic and industrial needs, availability for future irrigation use and categorisation based on stage of development and long term trend of water levels.
The report also lists out the overexploited areas and poor groundwater quality areas. The district and basin reports up to village level are also generated for use at micro level for development and management of groundwater resources.
The estimates indicate availability of large quantum of unutilized groundwater potential in surface water commands and detailed feasibility studies need to be taken up for developing the available resource in ayacut areas. Even for achieving this potential, conjunctive utilization of surface and groundwater resources are to be planned in a large scale.
The estimates indicate -
- 118 basins as over-exploited covering an area of 20,848 square kilometers (9 per cent of the area considered for recharge)
- 79 basins of total extent 13,569 square kilometer (6 per cent of the area considered for recharge) are critical, which require highest priority for augmentation measures through Neeru-Meeru and other watershed programmes
- 188 semi-critical basins of total extent 34,732 square kilometers (15 per cent of the area considered for recharge)
The report also indicates that the development of groundwater is not uniform throughout the groundwater basins. The village level estimates indicate that there are micro-basins of very high recharge and relatively low draft even in the over-exploited basins. Exploitation of groundwater may be restricted in such villages of overexploited basins in the first instance, where the draft far exceeds the annual recharge.
However, these areas require detailed studies to verify the data and results of data in relation to actual field conditions. Accordingly it is proposed to take up detailed micro-level studies in all the over-exploited basins followed by critical basins.
It is hoped that the results of assessment would be of help in formulating the resource augmentation and regulatory measures for sustainability of groundwater resources in the State.
We thank the State Groundwater Department of Andhra Pradesh, for providing us the printed version of the report and permitting us to place it in the public domain for wider use, and also acknowledge the support of WASSAN in helping us source the report from the Department.
Download the report:
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