Which Mumbai areas get water from which lakes? A complete guide to the city’s water supply network

Mumbairsquos sprawling population depends on a vast and interconnected water network of seven major lakes and reservoirs that collectively supply around 3850 million litres of water per day MLD to the cityManaged by the Brihanmumbai Municipal Corporation BMC these water sources form the backbone of Mumbairsquos daily water supply Interestingly only two of the seven lakes Vihar and Tulsi are located within Mumbairsquos boundaries while the remaining five are situated in the neighbouring districts of Thane Palghar and Nashik regionsTwo lakes within Mumbai five outside city limitsLocated inside the Sanjay Gandhi National Park SGNP Vihar and Tulsi lakes are among Mumbairsquos oldest water sourcesVihar Lake built in 1860 on the Mithi River was Mumbairsquos first piped water source and continues to support parts of the suburban region Tulsi Lake constructed in 1879 as a backup reservoir is the smallest among the seven lakes and is known for overflowing quickly during intense monsoon spells due to its limited catchment areaTulsi Lake only supplies water to the Goregaon area of the Western suburbs of MumbaiHowever the majority of Mumbairsquos water comes from massive reservoirs located outside the cityBhatsa Mumbairsquos biggest water sourceLocated in Shahapur Thane district the Bhatsa Dam is the largest contributor to Mumbairsquos water supply meeting nearly half of the cityrsquos daily requirement Apart from supplying drinking water the reservoir also supports hydroelectric power generationOther major external sources includeUpper Vaitarna One of Mumbairsquos largest storage reservoirs located in the NashikThane regionMiddle Vaitarna Commissioned in 2012 to bridge the cityrsquos growing water demandModak Sagar Lower Vaitarna Built on the Vaitarna River in the 1950s and serves as a major water storage and settling pointTansa Lake Commissioned in 1892 in Thane district known for its massive dam structure and overflow gates during the monsoonHow Mumbairsquos water reaches different areasContrary to popular belief there is no direct pipeline connecting a single lake to a particular neighbourhood Instead water from the seven sources is channelled through two major distribution networks after treatmentVaitarna and Tansa systemSource lakes Upper Vaitarna Middle Vaitarna Modak Sagar and TansaTreatment hub Bhandup Water Treatment PlantThis network mainly supplies the Western Suburbs and parts of South MumbaiAreas served includeDahisarBorivaliKandivaliMaladGoregaonJogeshwariAndheriVile ParleSantacruzKharBandraBhatsa systemSource lakes Bhatsa Reservoir along with support from Vihar and Tulsi lakesTreatment hub PanjarpurPise Treatment PlantThis network primarily supplies the Eastern Suburbs and central parts of MumbaiAreas served includeMulundBhandupKanjurmargVikhroliGhatkoparVidyaviharKurlaParts of Central MumbaiSouth Mumbai gets a mixed water supplyThe Island City receives water from a combination of the Bhatsa system and the VaitarnaTansa networkAreas includingSionMatungaDadarWadalaMahimBycullaMazgaonMalabar HillGirgaonFortColabareceive water through interconnected transmission networksWhile Tulsi Lake has a much smaller capacity compared to reservoirs like Bhatsa and Vaitarna it continues to play a crucial role by supplying select highelevation areas and institutional zonesMumbairsquos water security depends on monsoon bountyWith millions of residents relying on these seven reservoirs the cityrsquos water availability is closely linked to monsoon rainfall Every year the rise in lake levels becomes a key indicator of Mumbairsquos water security while delayed rains can raise concerns over future supply cutsFrom the hills of Thane and Palghar to the heart of Mumbai these seven lakes remain the cityrsquos hidden lifeline