Walker Lake is the destination for all surface water and ground water flow in the Walker River water basin not consumed by agricultural and domestic users or lost to evaporation and other natural causes.
Most terminal lakes in the Great Basin are too saline to support fish. In Nevada, the only terminal lakes that do are Pyramid, Ruby and Walker.
As a terminal sink, with no documented surface or ground water outflow, dissolved solids that enter Walker accumulate as the lake water evaporates. It is estimated that an average of 66,000 tons of dissolved solids have been added to the lake annually between 1882 and 1994.
Walker Lake is sampled for total dissolved solid levels on a regular basis.
According to Nevada Division of Wildlife Western Region Supervising Fisheries biologist Mike Sevon, samples are taken from different depths by a hydro-lab unit. The results are then averaged.
"We take our samples from a fairly deep area near the cliffs on the west side of the lake. The dissolved solid content is pretty well uniform from one end of the lake to the other, so one sample can pretty much tell what the TDS (total dissolved solid level) is," Sevon said.
Sevon said there is not always a linear relationship between the elevation of the lake and the total dissolved solids count. A buffering factor with calcium and other minerals leaves room for some variability.
"In setting 10,000 mg/L at an elevation of 3970 (feet) as our goal, we wanted to be able to take the hit of another drought," he explained.
From past records, the total dissolved solids levels in Walker Lake:
Year TDS (mg/L) Lake Elevation (feet)
1882 2,500 4080
1986 12,000 3970
1994 (July) 13,300 3944
1999 (end) 10,300 3953.4