AWWA ACE93065

The dependable (safe) yield of surface water supplies has been calculated by several methodologies. These include the use of a mass curve, simulation models based on historical records of flow and simulation models operating on statistically extended records of flow. This paper will discuss the basic principles utilized in developing a daily flow simulation model for a surface reservoir system. The daily flow model operates on a database that is larger than those associated with the other methodologies that normally use monthly cumulative data. The more detailed data set does, however, lend greater flexibility to the approach. The process itself can be very complex and is studied in this paper by considering a series of typical surface water supply systems of increasing complexity.