<p>Bengaluru: Water levels at Sankey Tank have dropped sharply this summer, triggering concern among local residents and experts.</p>.<p>While seasonal dips are not unusual, residents say the decline this year is far steeper than in recent years.</p>.<p>"We have not seen water levels fall this low before. It looks unnatural, and we have written to the Bengaluru West City Corporation (BWCC) seeking a study. We are also reaching out to experts to assess the situation,” said Preeti Sunderajan, a member of the Citizens for Sankey collective.</p>.<p>Veena Srinivasan of WELL Labs, who analysed Google Earth images of the lake over the past two decades along with rainfall and groundwater data, said the tank has historically been sustained by groundwater.</p>.<p>“Groundwater levels in the Malleswaram monitoring well have remained relatively shallow, at about 2–6 metres below ground level. This suggests groundwater likely contributed to sustaining the tank during the dry season,” she said.</p>.Bengaluru's Ulsoor Lake to get Rs 100-cr facelift, to model Sankey Tank.<p>She added that the lack of pre-monsoon showers and higher-than-average temperatures in March and April are unlikely to be the primary cause of the drop.</p>.<p>Instead, she pointed to three possible reasons: a crack in the outlet weir may be causing leakage into the downstream channel; a diversion in a stormwater drain upstream may have reduced inflow during the last monsoon; or a fall in groundwater levels this summer may have reduced the base flow into the lake.</p>.<p>Veena recommended inspecting the outlet weir and downstream channel for leaks, and mapping and monitoring open wells around Sankey Tank to track groundwater levels.</p>.<p>BWCC officials are yet to determine the exact cause or outline corrective measures.</p>.<p>“We will assess the situation soon. We have also sought assistance from the Indian Institute of Science (IISc), and private researchers and residents have offered support,” said BWCC Commissioner Rajendra KV.</p>
<p>Bengaluru: Water levels at Sankey Tank have dropped sharply this summer, triggering concern among local residents and experts.</p>.<p>While seasonal dips are not unusual, residents say the decline this year is far steeper than in recent years.</p>.<p>"We have not seen water levels fall this low before. It looks unnatural, and we have written to the Bengaluru West City Corporation (BWCC) seeking a study. We are also reaching out to experts to assess the situation,” said Preeti Sunderajan, a member of the Citizens for Sankey collective.</p>.<p>Veena Srinivasan of WELL Labs, who analysed Google Earth images of the lake over the past two decades along with rainfall and groundwater data, said the tank has historically been sustained by groundwater.</p>.<p>“Groundwater levels in the Malleswaram monitoring well have remained relatively shallow, at about 2–6 metres below ground level. This suggests groundwater likely contributed to sustaining the tank during the dry season,” she said.</p>.Bengaluru's Ulsoor Lake to get Rs 100-cr facelift, to model Sankey Tank.<p>She added that the lack of pre-monsoon showers and higher-than-average temperatures in March and April are unlikely to be the primary cause of the drop.</p>.<p>Instead, she pointed to three possible reasons: a crack in the outlet weir may be causing leakage into the downstream channel; a diversion in a stormwater drain upstream may have reduced inflow during the last monsoon; or a fall in groundwater levels this summer may have reduced the base flow into the lake.</p>.<p>Veena recommended inspecting the outlet weir and downstream channel for leaks, and mapping and monitoring open wells around Sankey Tank to track groundwater levels.</p>.<p>BWCC officials are yet to determine the exact cause or outline corrective measures.</p>.<p>“We will assess the situation soon. We have also sought assistance from the Indian Institute of Science (IISc), and private researchers and residents have offered support,” said BWCC Commissioner Rajendra KV.</p>