Farmers and ranchers create stock dams to hold water in dry areas. Salt from the soil washes into the dams during wet periods. The water evaporates during drought and the salt is left behind which can be toxic for livestock and wildlife.
Patrick Kozak who is a Ph.D. student at South Dakota Mines in Rapid City who is studying stock dams. He said salinity is measured in micro siemens per centimeter. Water becomes lethal at the 15,000 level.
“We found in 2019, none of them were over 4,000,” Kozak said. “This year, we had 6 percent over 15,000 and as we’ve gone out every month, we’ve seen an increase in those as those impounds … there’s no freshwater recharge to dilute so they keep concentrating.”
Kozak said some stock dams are completely dried up.
“As they recede down you still have water in that pure shale, and it becomes a very thick, quick clay almost and small lambs and sheep will get in there and they’ll get mired,” he said. “They’ll go down to their chest and not be able to get out.”
“I have had that experience personally and gone down past my knee while I’m walking out trying to get measurements even though I’m being safe.”
Kozak said some ranchers with dried-up dams are bringing in water by truck.
This story comes from a recent interview on SDPB's weekday radio program, "In the Moment." Listen to the full interview below.