The water quality in lakes is an essential factor for ecosystem sustainability and quality of life in highly urbanized countries, where lakes play significant roles as potable water sources, flood control measures, and recreational spots. This research assesses the water quality of nine key lakes in Hyderabad, Telangana, India: Himayat Sagar, Hussain Sagar, Saroornagar, Alwal, Miralam, Safilguda, Kapra, Jeedimetla, and Nacharam, for a five-year period of 2018–2022. The Water Quality Index (WQI) was determined using six key parameters: temperature, pH, dissolved oxygen (DO), electrical conductivity (EC), biochemical oxygen demand (BOD), and nitrates. Data was collected from the Central Pollution Control Board (CPCB), and WQI calculations were made using index formulae recommended by the World Health Organization (WHO) and the Bureau of Indian Standards (BIS). Each lake is characterized by spatial and temporal discrepancies of water quality, and several of them have displayed significant deterioration, presumably due to anthropogenic activities such as effluent discharge and urban run-off. This study highlights the necessity of ongoing monitoring and adoption of effective water management practices to combat pollution and protect these essential water resources. Results showed that most lakes exhibited poor to very-poor water quality (WQI 158–270), driven by elevated conductivity and BOD. Himayat Sagar remained comparatively stable near the good-poor boundary, while Kapra showed slight post-lockdown improvement. Several lakes recorded critically low dissolved oxygen, indicating sustained anthropogenic pollution stress.
Yeshaswini et al. (2026) studied this question.