CONSERVATION AND MANAGEMENT OF LAKES WITH SPECIAL REFERENCE TO ITS APPROACH CHANNEL

摘要

The waste weirs are constructed for any lake system, which generally serves as spillway for allowing the excess flood discharge with arrangement for regulation of gates. The inflow designed for any reservoir is a function of rainfall and runoff parameters and the outflow is a function directly related with the discharging capacity of its spillway. The siltation of lakes is a common activity that results in reduction of the carrying capacity of its approach channel too. However, the attention of the reservoir management authorities are always towards routine flood management, and any obstruction in the approach channel is not given weightage till the consequences are observed while managing the flood threats in the lake boundaries. The insufficient carrying capacity not only causes alarming high afflux at the dam end but breaching of the banks could also take place. Having experienced such flood threats and alarming rise in water level a detailed study was carried out for Approach channel of a 900 years old man made lake called Upper lake (having live storage more than 100 million m~3) situated in Bhopal city, the capital of State of Madhya Pradesh in India, and remodeling of its Approach Channel was considered a must. A detailed log frame matrix was developed with measurable indicators, its means of verification and important assumptions while considering the Deepening and Widening of its Approach Channel. And this work was successfully implemented. (Detailed project report for Deepening and widening of approach channel) Therefore this activity should be given proper attention before developing any reservoir regulation management plan.