Will help collect accurate data on groundwater level and quality

As part of measures to obtain accurate data on groundwater level and quality, the State Ground and Surface Water Resources Data Centre of the water resources department (WRD) is proposing to add more observation wells in and around the city.

The centre, which collates data and analyses the water table across the State, disseminates details to other government departments and research scholars.

WRD’s centre has a network of about 4,100 observation wells across the State. Of these, nearly 500 wells are located in the city and two neighbouring districts.

The centre recently submitted a proposal to the Union Planning Commission to add another 17,000 wells across the State at a cost of Rs. 160 crore.

About 500 additional borewells will be sunk in Chennai, Kancheepuram and Tiruvallur districts under the project.

Officials of WRD said, earlier, observation wells had been provided at block level to collect monthly data on water table, quality and rainfall in a particular region. At present, data from observation wells located at firkas, comprising a group of 2-18 villages, across the State is collated by the department.

“We plan to further narrow it down to revenue village-level to get better data. This time, more borewells will be added as they are easier to maintain than the open wells that dry up. The borewells will be sunk at a depth ranging between 50 metres and 200 metres, depending on the region,” said an official.

Some of the reasons cited for preferring more borewells over open wells are space constraint and the time required to dig the well.

Additional observation wells will help the centre document data and analyse the groundwater potential of various regions across the State. From 2009, the centre has begun a survey to assess over-exploited, critical, and saline groundwater regions, once in two years.

“Earlier, we carried out the survey once in five years. Sinking wells at the village level will help achieve better accuracy,” the official said. The project is expected to be completed in two years.