Carson City area prepares for possible flooding due to spring runoff

When it comes to spring runoff, Carson City officials are more worried about flooding in surrounding areas than inside city limits.

“The concern is we could be cut off,” said Sean Slamon, fire chief. “It could impact travel coming in if that occurs and be difficult to get things into here.”

In the worst case scenario, flooding in Washoe and Carson valleys could close off Highway 395 and Interstate 580 at the south and north ends of town, and flooding in Lyon County could block access to Highway 50 to the east.

“We have Eastlake Boulevard and Franktown Road so there are alternative routes, but we’d like to not see those put in place. It would be a big disruption to residents there,” said Dave Solaro, director of community services, Washoe County.

About 35,000 cars and trucks travel on I-580 through Washoe Valley every day, according to the Nevada Department of Transportation.

“This spring, NDOT hydraulic engineers have worked closely with federal and local water and ditchmasters to open water control gates, allowing some water out of Washoe Lake and down Steamboat Creek. That has helped stabilize Washoe Lake water levels for now,” said Meg Ragonese, NDOT spokeswoman. “While we are optimistic that lake levels do not pose an immediate threat to the interstate, we will continue to very closely monitor lake levels for any potential impacts to I-580.”

NDOT is also watching U.S. 395 in Douglas County where flood events this winter closed the highway, leading to a miles-long backup on Jacks Valley Road.

“We are also right now evaluating potential projects to review and, if needed, reestablish any riverbed erosion underneath Carson Valley-area state bridges created by winter flooding,” said Ragonese.

Water is also being released as a precaution out of Lake Tahoe and Lahontan Reservoir.

The Truckee Carson Irrigation District began letting water out of Lahontan in February and in March NDOT installed culverts south of Fallon to divert water onto federal land south of Sheckler Reservoir and the Carson Lake area.

The extent of flooding from spring runoff depends on the weather, especially the temperatures for the next few months.

“The current condition is just what we want, sunny and 70s,” said Darren Schulz, Carson City Public Works director. “Every day that goes by with mild weather lessens the risk.”

The risk jumps if and when temperatures spike into the 90s for a prolonged period of time, said Schulz.

But flooding would be different than this winter, when steady rain caused flooding on Curry Street and Kings Canyon Road, flooding the Carson Mall parking lot.

Public Works concerns in Carson City are with Ash Canyon and Kings Canyon creeks.

“We learned that our system is still deficient,” said Robb Fellows, senior project manager, stormwater, Public Works.

Specifically, the Kings Canyon area storm water system is old and only suited for a two-to-three year flood event.

“Once capacity of the pipe was met the water had to go above ground,” said Fellows. “We had about 100 (cubic feet per second) and the system can only handle 50 cfs.”

Fellows said all should be well if both creeks stay below 50 cfs. On Friday, Ash Canyon Creek was at 10 cfs and Kings Canyon Creek just under 1 cfs, according to the U.S. Geological Survey web site.

If problems do arise, many of the same measures will be taken, including making sandbags available for residents.

In the meantime, the city is ramping up its social media and information campaign on emergency planning and working with groups like Triad to inform senior citizens and the Chamber of Commerce to make businesses aware commuting employees may not be able to make it to work.

People with prescriptions should have enough medications on hand and everyone should have gas in their cars and water and food to last a few days or more, said Slamon.

Also, once the weather heats up, kayakers and others may be tempted to take advantage of the increased river flows.

“Water safety is a concern,” said Slamon. “You may see the river doing things that you’ve never seen before.”