Carson River a surprise to many residents

Not quite a tenth of the residents living in the Carson River Watershed could name the river in a recent survey.

Carson River Subconservancy Watershed Program Manager Brenda Hunt told Douglas County commissioners on Thursday that 62 percent either didn’t know or think they lived in a watershed at all, and that 70 percent thought they didn’t affect the watershed, or only had a slight impact.

But she said, once people were informed about the watershed, three-quarters indicated they did care once they knew about it.

The Carson River springs from the Sierra and is fed by the annual snowpack. It travels through Alpine, Douglas, Carson, Lyon and Churchill counties before ending in the Carson Sink north of Fallon.

Until the Lahontan Reservoir in Churchill County, there is no significant water storage upstream on the Carson, besides the snowpack.

There are a few small reservoirs, including Mud Lake south of Gardnerville and in the upper reaches of Alpine County.

“We have very little storage in the watershed, so really we depend on Mother Nature,” said Subconservancy General Manager Ed James. “We could have a major flood in January and be in a drought in July.”

While people don’t drink water from the Carson, it is one of the key sources of water in Carson Valley’s aquifer. 

“It’s a dynamic system because of the river and agriculture spreading water in the Valley,” James said on Thursday. 

James said that water levels below Carson Valley have not altered much, but the only source for recharge in the Pine Nut foothills are the mountains themselves.

“We don’t get much precipitation that goes across the Valley and into the Pine Nuts,” he said.

Providing major upstream storage on the Carson would be an expensive undertaking, with James estimating a dam would cost somewhere in the neighborhood of $200-$400 million. Even efforts to create off-stream storage, like a proposal to turn the Bing Pit into a big pond, could run to $18 million.

Even expanding Mud Lake would top $11 million.

James warned commissioners that those costs are very rough.

“I wouldn’t bank on anything there,” he said.

Efforts to change how Nevada regulates its rivers at the Nevada Legislature have either died or been significantly altered.

James said he pointed out that while the rules might apply to the rest of the state, they would violate the Alpine Decree, which dictates how the Carson is distributed. He said they wouldn’t have worked on the Truckee, Walker or Humboldt rivers, either.

While the water in the Carson isn’t potable, in good irrigation years ranchers don’t have to pump water from the aquifer to water their fields. That reduces the pressure on the aquifer to provide drinking water to Carson Valley residents.