The Truckee Carson Irrigation District is increasing the flow out of Lahontan Reservoir because of heavy rain and wind predicted in the Sierra Nevada mountain range and western part of the state.
Rusty Jardine, TCID’s district manager general counsel, advised Churchill County Commissioners at their Thursday meeting that the Bureau of Reclamation notified the irrigation district to release more water into the Carson River to alleviate the reservoir’s capacity. The National Weather Service in Reno issued a special weather statement Thursday morning calling for significant rain to the Sierra and western Nevada beginning Friday and continuing through Saturday. The NWS said the main concern associated with this latest atmospheric river is flooding potential along creeks, streams, rivers and in urban areas.
“They’re concerned with torrential downpour upstream,” Jardine said.
Jardine told commissioners he didn’t expect TCID to release water this spring, but he said it’s prudent to heed the current forecast and be proactive.
According to the NWS, “rainfall totals between 2 to 4 inches are expected along the Sierra crest, with 2 to 2.5 inches in the Tahoe Basin, and 1 to 1.5 inches in the Sierra foothills and some valleys along the Sierra Front. Up to an inch of rain is possible in western Nevada valleys.”
The NWS said Churchill County could receive up to an inch of rain during the two days. The forecast is also calling for wind gusts of 40 to 60 mph, with gusts up to 90 mph on the Sierra ridges. Gusts over the Sierra ridges may likely exceed 90 mph.
Naval Air Station Fallon spokesman Zip Upham said the base could readjust any flying schedules on Friday depending on the storm’s severity.
Jardine said Lahontan is at 277,145 acre-feet with normal capacity at 295,500 acre-feet. An acre-foot of water equals 325,000 gallons. Since last week, the Carson River below the dam was running at 350 cubic feet per second, and now the flow has been increased to 1,000 cfs or volume flow rate of 7,480.52 gallons per second. Commission Chairman Pete Olsen said the river should be able to handle 1,000 cfs.
Jardine said the river is in good shape after crews cleaned the channel last year in anticipation of increase water releases.
“You’ll see some reduction in the regulatory reservoirs (such as Harmon and Sheckler) and also see water sent out to Indian Lakes,” Jardine said. “We’re not anticipating any breach at the Bafford Lane Bridge.”
During the 2017 flood mitigation, the Nevada Department of Transportation remove a section of the Bafford bridge to allow the Carson River to flow more freely.
“We’ll have a lot of water in the river channel, so residents need to take care of their personal property.”
Jardine, though, said he doesn’t anticipate TCID charging the V-line canal and releasing water at the emergency weir.
Eric Olsen, a member of the TCID Board of Directors, said the storm is larger than anyone thought. He said the balanced drawdown of water is also for the safety of Fallon and low-lying areas.
“Another storm is coming Tuesday, so we’re getting ahead of it, so the water doesn’t hit the boards,” he said.
Lahontan Reservoir can increase its capacity to 312,000 acre-feet with water reaching holding boards if conditions warrant it.
What makes this storm dangerous, said the NWS, is that it any runoff will cause urban flooding and moderate impact to areas usually affected by excessive rain.
“Areas that experienced enhanced runoff or flooding during the last storm a couple of weeks ago should see similar or greater impacts due to the heavy rain and the expected contribution of the melting snow pack,” the weather service warned in its statement.