The Brihanmumbai Municipal Corporation (BMC) has stepped up efforts to restore Mumbai’s groundwater resources as Maharashtra faces growing water-supply concerns. The move comes after the state government declared drought in 265 of its 358 tehsils, covering nearly three-fourths of the state.
Mumbai currently depends largely on seven lakes for its potable and industrial water requirements. However, before the development of major dam and water-supply schemes from the late 19th century, wells and borewells were important sources of water. Many of these groundwater structures have since fallen into disuse because of pollution, silt accumulation and seawater intrusion.
The BMC is now working to revive around 3,000 wells across the island city and suburbs. The programme, being implemented at ward level through the hydraulic department, includes desilting wells and reopening natural underground water channels to improve their storage and flow.
“Since most wells have fallen out of use over the past decades, the natural sources of streams inside the wells have closed up. Furthermore, the stagnant water in several wells have become laden with silt which further obstructs the flow of water and reduces the carrying capacity of the structures,” a senior official told The Indian Express.
The civic body is also planning to construct around 10,000 groundwater recharge structures to strengthen replenishment. “While efforts to revive the existing wells are fast unfolding, we have also called for construction of new recharge structures so that groundwater can be extracted for potable and industrial consumption. We are eyeing to build approximately 10,000 recharge structures,” a senior official said.
To assess another challenge, the BMC has appointed the All India Institute of Local Self Government to examine groundwater salinisation. Water samples from wells across Mumbai will be tested to determine the extent of seawater intrusion.
“The consultant has been tasked with analysis and submission of a detailed roadmap to curb the salination of groundwater resources, which renders the water inaccessible for human use. Once the plan is submitted, we will be able to assess the extent of seawater intrusion as well as determine the costs and scope of work to regulate the salination levels,” an official told The Indian Express.
Mumbai’s seven lakes currently provide about 3,850 MLD against a daily requirement of 4,200 MLD. Despite lake levels reaching 97%, the BMC has retained its 10% water cut as a precaution.
“While we have retain the water cut to ensure that the lake stock suffices through the year, we are focusing on reviving our groundwater resources which can serve as a supplementary source of water in times of shortage,” an official said.
Source: Indian Express
