This deterministic model modifies the original Mono Lake water balance model by starting with measured volume and elevation values in 1994 and assuming that new diversion rules go into effect starting that year. The rules are as follows:
If Mono Lake elevation falls below 6377 feet, then no water shall be diverted.
If Mono Lake elevation lies between 6377 and 6380 feet, 4500 acre-feet/year shall be diverted.
If Mono Lake elevation rises above 6380 feet, then 16000 acre-feet/year shall be diverted.
Evaporation and precipitation rates, as well as gauged and engaged stream flows, are fixed at the 1937-1983 mean values.
These modeled values are plotted against historical elevation data from 1994 to 2020. The fit is not perfect, implying the need for a stochastic model to determine the range of probable values to see whether our observed data falls within the range of expected outcomes given our modeling assumptions.