County installs more flood walls in Lemmon Valley

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LEMMON VALLEY, Nev. (KOLO) Last winter's storms filled Lemmon Valley's Swan Lake, flooding some homes and overwhelming the county's response. Monday, with months of winter weather ahead, the lake is still high and the county is bracing for what might be ahead. That means more temporary flood walls.

They're called Hesco walls. wire and felt frames filled with sand. Many were employed last winter. The county just bought $300,000 more.

"If we get a normal precipitation and it reacts the same way it did in November we'll be a little bit higher than we were last year, which might impact more homes," says Assistant County Manager Dave Solero.

Everyone admits this is a temporary solution and accepting the reality of climate change, it's possible, maybe likely, this will happen again.

The options moving forward include keeping these walls in reserve and deploying them if and when needed in the future, or building a permanent berm, perhaps by dredging the lake.

"With building and taking material out of the bottom of the lake, that's very expensive," says Solero. "We're going to have to figure out how to pay for that."

Those options have to be measured against another permanent solution--buying up homes which are now or could be in jeopardy. An initial offer to those most at risk has drawn some applications--and at least one refusal.

All of this leads to a question. Why were developers allowed to build on ground that might flood?

"A normal logical person would say, 'Yeah why did they allow those houses to go in at that elevation?" asks hydrologist Jay Aldean.

Aldean is the Executive Director of the Truckee River Flood Control Project. Lemmon Valley is outside his organization's scope of responsibility, but he's an experienced hydrologist familiar with the studies that led to that decision.

He says the county based its research on a 100-year storm, adding another 25-year event on top of that when determining how high Swan Lake could rise. Development was allowed above that level. No one anticipated the series of storms we saw last winter.

"We had 11 of those things this year, so that means we had more water than anyone ever anticipated and I doubt seriously that any government would have gone any more conservatively than what was originally proposed."

Solero agrees that would be a much different discussion today. Measures like the Hesco barriers are a stopgap to get the county to that new conversation.

"To get us past the point where this water evaporates out, and we've been able to do the proper planning to really understand what we should be doing in the future to prevent this from happening, or whether this is the type of system that should be employed when the water starts coming up."

Click for earlier stories about Lemmon Valley flooding.