356 students and the teachers of Government Middle School in Sukhpuri village of Mewat district, Haryana are a happy lot now that they have access to potable water right within their school premises. The groundwater in the area was saline making it unfit for consumption. The school children had to depend on tankers to meet their water needs. This was not only expensive--Rs.1,200 per month--but also the quality of the water was often questionable, but the school had no other alternative. At times, even this tanker water was unavailable and the school had to borrow water from neighbouring households or, in extreme cases, children had to leave school and return home to drink water. 

All this changed when rainwater harvesting came to the rescue. 

High pressure recharge well as an answer

The solution came in the form of an innovative rainwater harvesting structure called a ‘high pressure recharge well’ (HPRW). This well stores sweet rainwater below the ground as a freshwater pocket within a saline aquifer (groundwater zone). This was achieved by recharging collected rooftop rainwater below the water table with gravity-induced hydrostatic pressure. For this, the recharge well was sunk to a depth lower than that of the existing groundwater level and then raised to a height more than the height of the ground to gain additional hydrostatic pressure.

As rainwater enters this well, hydrostatic pressure pushes the existing saline water aside and forms a pocket of freshwater within the saline aquifer. Later, this sweet water is extracted using a hand pump. The water is then passed through a biosand filter that removes physical, suspended, and biological contaminants, and is accessed through taps at the school. The model is environment friendly as the system requires no use of chemicals or energy. The same model has now been replicated in Jargali village, 20km away from the school at Sukhpuri, which has ended years of misery due to water shortage in that school as well. It could be argued that the effective functioning of these models can provide a basis for the government to consider further replication of the HPRW model in other places.

The HPRW solution came from the efforts made by Sehgal Foundation, a public charitable trust in Gurgaon. Please download a copy of the detailed article below.