Cost of early snowmelt in terms of reduced irrigation deliveries

Climate change and windborne dust are expected to change snowmelt timing. Dust from agricultural activities is estimated to cause snow to melt two to four weeks earlier in some regions. Early snowmelt may decrease deliveries of irrigation water when reservoirs provide flood protection and irrigation water. To date, the quantity decrease has not been determined. We identify when early snowmelt causes earlier water release, and calculate the quantity decrease in water deliveries downstream. Irrigation reductions are negligible unless the dam capacity is less than twice the quantity of annual runoff, and unless snowmelt occurs more than four weeks early.