The importance of meteorological knowledge to Southern California Edison operators of the Big Creek hydroelectric program at the upper San Joaquin River watershed cannot be understated. Knowing when to release, store, or divert water to hydroelectric turbines can be the only difference between having power and being without it. For years, program managers relied more on experience than on the limited meteorological and streamflow data available. This caused a vast information backup between system operators.

While years of experience had taught operators when certain operational decisions needed to be made, this institutional knowledge was difficult to transfer. We developed a real-time simulation (RTS) program to simulate the hydrology and hydraulics of the watershed.