It's going to take a lot of water to fix Walker Lake

It will take 2 million acre feet of fresh water to dilute the dissolved solids in Walker Lake to just three times their original amount.

According to a new study prepared by the U.S. Geological Survey, Walker Lake is up to 18,000 milligrams per liter of dissolved solids, increasing the lake's salinity to the point where it threatens survival of native species. In 1882, the lake had 2,500 milligrams per liter of dissolved solids.

"There's a lot of water needed to get the concentrations of solids down and keep them down," study co-author Thomas Lopes said.

The new hydraulic studies will provide information about how the 3,950-square-mile Walker River basin works and its management in the future.

Comments were accepted through Oct. 5 for a $70 million federal program to purchase water rights along the river to send downstream to the lake. The program is being administered by the University of Nevada, Reno, for the U.S. Bureau of Reclamation. The study was begun in 2004 to provide more precise information about the nature of the Walker River basin and how much water goes through it.

Walker Lake is part of old Lake Lahontan, which existed about between 12,000 and 650,000 years ago. Lahontan included Pyramid Lake, Honey Lake and the Carson Sink.

According to the study, Walker Lake has dried up on at least two occasions since it was separated from Lake Lahontan, once for 500 years between 5,300 and 4,800 years ago and again for 600 years between 2,700 and 2,100 years ago. The lake may have dried up during those two periods when the Walker River meandered into the adjoining Carson River basin. Walker Lake is currently at its lowest level during the past two millennia.