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Dharmambudhi, a large tank that once supplied water to the old pete (market town) of Bengaluru, fell into disuse once piped water arrived. It was drained and filled in, and the Kempegowda (Majestic) bus station was built on its bed. Other tanks met the same fate: Sampangi tank largely became Kanteerava stadium, and the flood-prone low points of today's city often sit exactly where these tanks used to be.
Once colonial and post-colonial authorities brought in distant water through reservoirs such as Hesaraghatta and Tippagondanahalli, and later the Cauvery pipeline, the city no longer drank from its tanks. Without that daily dependence, the tanks lost their constituency of users and maintainers. They were reclassified as vacant land ripe for housing, roads and institutions, and their silting, encroachment and sewage pollution followed from that shift in perceived value.
Bengaluru's lakes were not natural ponds but human-built tanks, commemorated in inscriptions from Ganga-era and later rulers. They were sited on a ridge-and-valley terrain so that overflow from one tank fed the next downstream through channels (raja kaluves). Because the system functioned as a chain, breaking one link by filling a tank or blocking a channel shifted flooding and drought to other points in the network.
Urban nature is best understood as a working commons: fishers, washermen, grazers, fodder and firewood collectors, and worshippers at tree shrines all depended on it. When middle-class groups and agencies 'rejuvenate' a lake by fencing it, adding walking paths and charging entry, it becomes an amenity for recreation. The people whose livelihoods kept them tied to it are excluded, so the question of who restoration is for matters as much as the ecology.