FORECAST UNCERTAINTY IN WATER-SUPPLY RESERVOIR OPERATION

Questions relating operational losses to forecast period and accuracy are addressed. These issues are addressed through the use of a simulation model of the Cedar and South Fork Tolt Rivers. The following conclusions were made for this system: (1) reservoir operation deteriorates markedly with the loss of forecast accuracy; (2) the optimal length of forecasting period is five months; (3) reservoir operation may be improved by as much as 88 percent if perfect predictive abilities are available; (4) the mean of the historic data is not recommended to predict future flows because Markov methods are always superior; and (5) lagone autoregressive Markov schemes exhibit about a 9 percent improvement in operation over no forecasting.