Water levels in free fall

Groundwater levels in the state in free fall

GraphsThe quantum of groundwater Andhra Pradesh received earlier from 100,000 borewells is now obtained by drilling 260,000 borewells, said A K Jain, special secretary to the state’s irrigation and command area development department.

B Peddiraji, tehsildar of Butchayyapeta in Visakhapatnam district, added there is tremendous pressure on groundwater, with the level down to 91 metres in most villages. For instance, he cited, “Butchayyapeta mandal depends heavily on borewells as assured irrigation facilities are available only in three of its 32 panchayats.”

The April 2010 groundwater level report also said groundwater levels in the state is falling fast. Compared to last year there was a fall of 23.15 metres in Dhone mandal of Kurnool district. More than 80 villages across the state have seen a fall of more than four metres between 2009 and 2010, the report said.

“The quantum of water that was received by drilling 100,000 borewells is now obtained by drilling 260,000 borewells” — A K JAIN, Special Secretary, Irrigation and Command Area Development

“The fall of groundwater cannot be pegged to one cause (borewells). It is the result of deficit and infrequent rain, reduction in recharge area and lastly, over exploitation,” said Murli Krishna, director of the state’s groundwater department.

The April 2010 report also says that the groundwater level on an average in Andhra Pradesh has fallen 12 metres below ground level in the past year, the lowest since March 2007. Between May 1998 and March 2010 the water level has fallen two metres below average in the state (see graphs).

Despite heavy rains in 2008 the groundwater levels have only margi - nally risen in the state. According to officials the continuing fall is because of uneven rainfall across the state.

“Rainfall is the main source of groundwater recharge and during the last decade this source has become erratic and sometimes very low,” said Krishna. “People resort to groundwater because it is economical and easily available, and it consumes less time to drill a borewell,” he added. This is more so because of the limited surface water resources and their uneven distribution. Thus the strain on groundwater aquifers, mostly in upland areas, is increasing every day, Krishna said.

According to the Bureau of Statistics and Economics in Hyderabad, the total cultivated area in the state in 2008-09 was 6.7 million ha. Of this, 3.3 million ha was under surface irrigation and 3.4 million ha under groundwater irrigation. In 2006-07, the area under groundwater irrigation was 2.8 million ha, surface irrigation was 3.1 million ha.

As per the 2006-07 data of the groundwater department, there are 132 overexploited basins, 89 critical, 175 semi-critical and 833 safe basins (see table).

Andhra Pradesh is divided into 40 drainage basins and 81 sub basins of major and minor rivers. The 81 sub basins are divided into 1,229 groundwater micro basins of 100-300 sq km area based on drainage, geomorphology and hydrogeology. There is an addition of more than 50,000 groundwater extraction structures every year, said Krishna. In the last three decades well population—borewells and dugwells—increased from 0.8 million to 2.5 million.

But there is no record of the borewells that are dug illegally, admits C Suvarna, special commissioner at the state rural development department. The reason, she said, was the district water management authority under the groundwater department does not send them regular data. “When we question them they say the line departments, which include the mandal revenue office and the power department, do not submit any information to them,” she added.

They can just count the number of transformers in villages to find out the number of borewells, said Narshimha Reddy, a farmer from Velgonda village in Mahabubnagar. A 100 KW transformer supports 20 borewells.

Officials of the groundwater department say they collect and collate data in the state and have no policy-making or law-enforcing powers. “We are a technical department and can only assist other implementing agencies like the irrigation department and the rural development department in water conservation or regulation projects,” said Krishna.

Source: Down To Earth