Integrated Operation of Water Infrastructure including Dams

Several multipurpose, multi-reservoir systems have been assessed in terms of optimizing reservoir operation, assessing impacts on different sectors and on the hydrological regime downstream at river basin level. The objective was to find optimal operating rules and to bring them into operation to achieve practical, long-term and sustainable solutions. The solutions have to meet constraints regarding the natural hydrological regime downstream the dams. The assessments involved river basin modelling and had to cope with diametrically opposed purposes like water supply, flood protection, hydropower, low flow augmentation, environmental flows. The rules are site-specific and balance short-term benefits and safeguard long-term supply safety with environmental requirements. Assessments of the changes in the hydrological regime and their impact on ecology, other water users downstream, erosion/sedimentation/colmation, flooding and minimal flow are always part of the investigations. Cumulative effects need to be considered in terms of intensity, frequency and duration of impacts along the time axis. Impacts are considered as alterations of the natural flow regime like number of sharp rising/falling water levels, relationship between peak and flood volumes as well as the water temperature regime affecting the ecological system and utilization of the water for other downstream users.

The principles of operation policies and release strategies take the monitoring facilities and operational skills of the operator into account. The states used to derive the water management strategies range from forecasts from weather services to hydro-meteorological and reservoir related states, surface or subsurface flow components. Each project resulted in the implementation of the rules at the reservoirs for the day-to-day business.