TR(BR)-8/98-99 : Flood control regulation of a multi-reservoir system

Abstract

The purposes which a reservoir is intended to serve is an important consideration in planning and operation of the reservoir. Since the functional, infrastructural and operating requirements of a conservation storage reservoir are quite different from a flood control reservoir, the analysis tools are also different. Moreover, the computational algorithm and data requirements are also different. In view of this, usually different computer models are employed for analysis of flood control and conservation storages although in some models, both capabilities are combined.

A key consideration while operating a flood control reservoir is that the releases from the reservoir should not contribute to flood at important locations downstream, to the extent possible. The reservoirs which exclusively serve for flood control must be emptied as soon as possible so that the next flood, if any, can be moderated to the maximum possible extent.

In India, the emphasis has been on construction of multipurpose projects due to economy of construction cost. In the monsoon climate, these projects have to serve two different objectives. They are required to moderate the incoming floods to the maximum possible extent as well as store enough water during the monsoon period so that the conservation purposes are best served during the remaining period of the water year.

In the present report a software which has been developed for flood control regulation of a system of reservoirs is described. The reservoirs can be gated or ungated and the system can have any combination including weirs and diversions. For operation of reservoirs, the scenario has been divided into two categories depending on the reservoir level and inflows. These categories are normal operation and emergency operation. The input data requirements of the software are modest. This software along with a previously developed software for conservation operation would provide a complete set of tools to analyze any system configuration for the range of purposes for which the reservoirs are commonly built in India.