Buildings choking 50 pc of SWDs: Palike

Buildings choking 50 pc of SWDs: Palike

The Bruhat Bangalore Mahanagara Palike’s (BBMP) Herculean task of recording micro details of the stormwater drains (SWDs) has thrown up some staggering facts.

Nearly 40 to 50 per cent of the SWDs have been encroached upon. The rampant urbanisation coupled with the mushrooming of illegal layouts, has taken a toll on the SWDs, so much so that this has led to flooding of some areas during the monsoon. For instance, Gali Anjaneya Temple gets flooded every monsoon because of the reduced width of the SWD.

The SWDs, once the lifeline of the City, are in a shambles now, compelling the High Court of Karnataka to crack the whip for their conservation. Subsequently, the Palike swung into action and started surveying all the primary and secondary SWDs. The survey would serve as a guide for the maintenance of SWDs in the long run.

The Palike which has to measure a staggering 856.74 km length of SWDs has literally miles to go. It has so far surveyed around 100 km to 105 km of SWDs.

The survey gives minute details of the SWDs. The record keeping starts with a definite identification number for the low-lying areas, their locations and the names of the watershed clusters.The survey also details the water stagnation depth of the SWD to help understand the percolation capacity.

The civic body is also giving identification numbers to the drains, their chainages, existing chain-beds or invert levels, existing average ground level, existing drain depth, flood water levels, required drain depth and building plinth area from existing ground level.

The most important aspect of the survey is that it also details the nearest tank bed levels and the Great Trigonometric Benchmark (GTB), accepted world-wide.

Seeking anonymity, a senior rank Palike officer engaged in the survey work, said: “The voluminous works we have undertaken is certainly something which people had never thought of before. Our pace may be a bit slow but the work will remain the best source for reference.”

The survey work began with only eight surveyors, but realising the need, the district administration engaged 40 more surveyors. With the existing strength of workforce, the Palike believes that the work will be finished in six months’ time. Once the survey is completed the entire data will be digitised and it will be put in the public domain.

“We do not want to start any controversy, but we did come across some stunning facts that the SWDs changed their course due to encroachment of their catchment areas. It has, of course, affected the water storage system and water percolation capacity. There’s an urgency to free the SWDs and lakes from encroachment. Also there is a necessity to deal with the land sharks with an iron hand,” said the officer.

It came to our knowledge that the flow of rainwater has doubled leading to flooding in Bangalore, which was alien to this City till a decade ago. Also the catchment areas, which are basically lakes, are in danger,” the officer added.