At a water elevation of 6,391 ft, Mono Lake has a volume of 2,939,000 ac-ft, and a surface area of 48,100 ac. Annual inputs to the lake include 8 in of direct precipitation, runoff from gauged streams of 150,000 ac-ft per year, and ungauged runoff and groundwater inflow of 37,000 ac-ft per year. Evaporation is 45 in per year.

a. Make a water budget showing inputs, in ac-ftper year and outputs in ac-ft per year. Does the input balance the output?
b. Will the average lake level rise or fall from the 6391ft elevation over the long-term?
c. What would be the lake surface area when the inputs blance the outputs? ( Assume that the volume of gauged and ungauged runoff and ground-water inflows remain constant with a change in lake surface area).
d. What is the residence time for water in Mono Lake when the water surface is at 6391ft?


Leave a Comment