Importance of Lakes

Beyond rainwater harvesting structures, natural and man-made water bodies such as lakes and ponds deliver environmental benefits that also translate into direct economic and public-health value: they supply drinking water, recharge groundwater levels, and preserve freshwater biodiversity and the habitats that depend on it. As a water-management service, lakes retain nutrients, influence local rainfall patterns, remove pollutants including phosphorus and nitrogen from the water they hold, and contribute to carbon sequestration — functions that make their protection a conservation priority in their own right, not just a water-supply concern. In Tamil Nadu, several man-made lakes illustrate this role concretely. Sholavaram Lake, in Ponneri Taluk of Thiruvallur District, is a British-era, rain-fed reservoir with a full capacity of 65.5 ft that supplies water to Chennai and supports varied flora and fauna alongside water-sports use. Chembarampakkam Lake, about 25 km from Chennai and roughly 500 years old, is another rain-fed reservoir supplying the city and is the source of the Adyar river, spread over about 15 sq km. Maduranthakam Lake, in Kancheepuram district, is a man-made reservoir built by the Chola king Uttama Chola with a full capacity of 23.3 ft, spread over 2,908 acres, with boundaries later strengthened by the British to a storage capacity of 690 million cubic feet, fed in turn by rainwater from Cheyyar, Thiruvannamalai and …