Water Quality Characteristics of the Upper Bhopal Lake, M.P., India

The Upper Bhopal Lake in the city of Bhopal in the State of Madhya Pradesh of India is the only source of water for the city of Bhopal. Economic as well as recreational activities of the city of Bhopal is dependent on the water availability in the Upper Bhopal Lake which receives water as surface runoff only during monsoon period of every year. Though, the lake exists for more than 1100 years, neither any data on hydrological characteristics of catchment of the lake was available nor any hydrological model was available for predicting runoff reaching to the lake from its catchment. The Upper Bhopal Lake has a catchment area of 362.35 square kilometer. The land use pattern of about 80% of the catchment is agricultural, where as 5% is of forest and the rest is urban. Since the onset of monsoon in the catchment area by 15 th June every year, the agricultural area starts contributing by the end of August where as the lake starts receiving surface runoff right from the beginning of monsoon season as runoff from the urban area. In this paper temporal and spatial characteristics of water quality of the lake have been established. It is concluded that the lake can be divided into two parts. One part is upstream portion of the lake which behaves like a wetland, the water depth is in the range of 1 to 1.5 feet during pre-monsoon season and 3 to 5 feet during post monsoon season. Still water quality of this portion is not eutrophic and the species survive. The second part is the downstream portion of the lake which behaves like a reservoir and satisfies the drinking water requirement through out the year, the water depth is in the range of 10 to 15 feet during pre-monsoon season and 20 to2 5 feet during post monsoon season. The water of this portion is fit for drinking purpose throughout the year with just disinfection and the water treatment of this lake is not required.