Concretisation of stormwater drains, built primarily to drain out excess water during rains, is causing massive flooding every time the Capital gets a smart shower.
Experts say, drains that are lined with bricks are a much better option as they ensure replenishment of groundwater as the bricks soak water. Also, the cracks in the bricks allow water to seep into the ground.
But these days, drains are made of concrete. They are narrower and clogged at different places. Rajiv Kakaria of Greater Kailash-1 RWA said, "Four-inch concrete layers in storm water drains defy engineering principles as well as conventional wisdom and construction methods."
Green building consultant Neeraj Kapoor said, "Even though a lot of money is spent on drainage, much of the benefit is lost. Concretisation of storm water drains and hard-paving of most of what's left of open areas is one of the main reasons for the flooding."
Environment activist Padmavati Dwivedi said, "How can rain beating down on 20x10 feet of cemented car ramp go through a mere two-inch clogged pipe? Illegal encroachments should have been dealt with long back by civic bodies. New constructions must at least keep drains bricklined with porous material on the sidewalks to allow rain water to seep in."
"Brick-lined rainwater drains are now being plastered by the public works department in our locality. I asked the officers to at least remove cement from the base, but they don't listen," said a resident of Sarvodaya Enclave.
Justifying the move, a PWD official said, "Some residents allow sewage to flow into rainwater drains, which makes it difficult for our workers to clean them. Cementing the drains will make our lives easier."
But residents disagree. "Concrete base leads to silting and stagnation of water," said Kakaria.
Government installations are no exception either. Drains in many government offices are being covered for commercial purposes in violation of guidelines of the apex planning body UTTIPEC.