CHENNAI: In a bid to enhance groundwater recharge, the Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) will soon inspect all rainwater harvesting (RWH) structures across the city. Metro water officials said they will check if buildings have RWH structures at all, or if the building has space to install more structures to ensure maximum recharge of groundwater.
Apart from this, the team will also check the quality of water (residual chlorine levels) in buildings. Though the inspection is carried out every year, the measure didn’t take place last year due to the pandemic. In 2019, it was found that as many as 1,36,631 houses had RWH structures in good condition, structures in over 37,000 houses needed improvement and about 65,000 houses did not have RWH structures at all.
“Firstly, the mindset of the public must change. Instead of looking at installing RWH structures as a mandate by the government, they must realise the importance of it. The situation has improved since 2019,” said Pritham Shankar, a rainwater harvesting consultant.
He pointed out that while most people opt for percolation pits, it is better to install recharge wells. “Percolation pit, a hole dug into the ground, allows water inflow through a pipe. The problem here is, the percolation pits only work for a year or two. As soil gets accumulated, which is natural with rainwater, the pipes get clogged and stop working. It is not possible to clean these pits regularly,” he said.
Meanwhile, the storage levels at Chembarambakkam, Red Hills, Cholavaram and Poondi, the four reservoirs that supply drinking water to the city, are substantially higher than what they were during the same period in 2020. Groundwater levels too have increased due to copious amounts of rainfall this year.