The Greater Chennai Corporation has begun a 1,100-crore storm-water drainage programme, the fourth since the floods of 2015 and the first to state, in its own tender documents, the conditions under which it should be judged a failure.
What is different
Previous programmes measured themselves in kilometres of drain laid. This one commits to a discharge time (how long standing water takes to clear from a set of named intersections after a given rainfall) and publishes the baseline.
That is a meaningfully harder promise. A drain can be laid correctly and still not drain, if what it connects to is full.
The catch
The programme covers the corporation area. Roughly a third of the catchment that drains into it does not lie inside that area, and no equivalent commitment exists there.
"You can build a perfect drain and connect it to somebody else’s problem," said one engineer who asked not to be named because the tender is live.