Impact of unplanned urbanization on surface water quality of the twin cities of Telangana state, India

Abstract

Hyderabad is known as the limnological capital of India. Due to unplanned urbanization, the twin cities, Hyderabad and Secunderabad, have been experiencing a decline in the quantity and quality of water. This work focuses on the comprehensive assessment of the water quality of four important lakes of Hyderabad, viz. Hussainsagar, Himayathsagar, Saroornagar, and Miralam lakes. The water quality of these lakes has been assessed using the weighted arithmetic water quality index (WAWQI) method, irrigation indices, Nemerow's pollution index (NPI) and trend analysis of various water quality parameters (WQPs). The average value the of water quality index (WQI) were calculated as 621.99, 86.93, 310.55 and 206.75 for Hussainsagar, Himayathsagar, Saroornagar, and Miralam lakes respectively. The present study reveals that the water of these lakes is suitable for irrigation but unfit for drinking as per Indian Standards. The results of the present study indicated that conductivity, total dissolved solids (TDS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), sodium, calcium and magnesium are the major contributors to pollution in Hussainsagar lake, whereas BOD and conductivity are high in Himayathsagar, Saroornagar and Miralam lakes. The findings of the study can be beneficial to government organizations, water management authorities and stakeholders to plan strategies for ensuring the availability of good quality surface water for public use.