Flash flooding can happen any time
June 29, 2016
In 2014 Carson Valley residents referred to it as a 100-year flood when four separate floods, actually, damaged property and roads from Topaz Ranch Estates to Stephanie Lane between July 17 and Aug. 20.
Then, just a year later, it all happened again during the week of July 8 when $2.2 million in damage to public infrastructure occurred.
So, can yet another repeat be expected this summer? And are you prepared to deal with it?
Tod F. Carlini, who wears dual hats as East Fork Fire Protection District Chief and director of Douglas County Emergency Management, has a simple warning: Anything is possible at anytime.
"Quite honestly, I'm really, really concerned about flash flooding in the same places: Fish Springs, Johnson Lane, Ruhenstroth, Stephanie and Foothill," Carlini said during a recent interview.
Flash flooding is not new to Douglas County, by any means. The University of Nevada Cooperative Extension produced "Flood Hazards and Planning in Douglas County," a 12-page publication after the summer of 1992 after the third flash flood in two years hit the Johnson Lane area. An overflow crowd packed the county commissioner chambers for a public meeting to address public flood concerns and the Citizens Task Force for Flood Control was organized and recommended a flood control element be included in the Douglas County Master Plan, which didn't happen when the plan was approved in 1996.
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Anyone watching what happened after the 2014-15 floods could be forgiven for thinking history was repeating itself. In June, two-dozen Johnson Lane residents sued the county over the flooding.
BACK TO 2014-15
Moving forward two decades, cleaning up damage from the 2014 and '15 floods was no small undertaking.
Carlini noted that one of the contributing factors that led to flooding in Fish Springs on Aug. 6, 2014, was the previous year's 24,000-acre Bison Fire.
"If you look at the Fish Springs flood, it was all the debris that came off of the Bison Fire," Carlini said. "Literally, it was like wet cement. It was water, but it was full of debris and mud."
In 2015, 162 properties were damaged and, based on federal criteria, Carlini reported major damage to four homes and minor damage to seven homes.
Landscaping and yard damage are not eligible under FEMA programs or the state's Disaster Relief Account, which normally will not pay for debris removal from private land unless life or safety is an issue.
"We are so fortunate that we have not, thank gosh, had someone get hurt or worse," Carlini said. "People need to understand and respect the flash flood issues."
John Cobourn, water resources specialist for the University of Nevada Cooperative Extension, watched the impact of flooding in the East Valley from his own home in 2015.
Cobourn founded the Lake Tahoe Environmental Education Coalition to increase collaboration between water quality outreach education agencies.
Along with University of Nevada Extension Educator Steve Lewis, Cobourn co-produced the "Flood Hazards and Planning" publication more than 20 years ago.
First of all, Cobourn spoke about the importance of understanding flash flooding.
"I think people need to be aware that they live in the desert and we're subject to these potential thunderstorms," he said. "They don't come all the time. Most years we'll have a week or sometimes two weeks when we'll get thunderstorms almost every day. Some of them are small and some are big. You don't know when they're going to hit or what direction."
Flash floods are difficult to anticipate, Cobourn went on to explain.
"After the neighborhood is there, it's difficult to deal with a much larger than average thunderstorm," he said. "Usually it's in the summer, it's very intense rainfall and often doesn't even last an hour. But the water comes down from the relatively small subwatersheds and if it's steep at all, it comes down with some force and velocity."
Protection of personal life is not to be taken for granted in any flash flood and that includes precautions that need to be taken when driving. Cobourn pointed out that what a driver might not see when water comes over the top of a road is whether it has caved in underneath.
"Some of the roads around the county have a dip section through a wash," he said. "The advantage to that is it can't plug up like a culvert can. The disadvantage is if somebody decides to drive through that, nine times out of 10 they might get through it. But that 10th time, they could get swept away and die because it's could be 4-feet deep instead of four inches deep."
One point of interest came when the boundaries of the 1997 Carson River flood were laid over the top of an aerial view of what the southern end of Carson Valley looks like nearly 20 years later.
"It's interesting because if you lay out those boundaries, you can see potentially where that water will be," Carlini said. "We have much more development, including a Walmart, an expanded hospital and long-term care facilities … people places that become really problematic if you have to go in and try to evacuate 70, 80 people out of a long-term care facility that wasn't there in '97 … or a Walmart, or additional housing."
In the Carson River Flood Event Planning Project summary prepared in December, Carlini also pointed out that consideration must be made for a debris/mud flow type event due to the impacts of the Washington Fire in Alpine County last summer.
"Anywhere that has seen extensive fire damage due to a wildland fire can contribute to that effect," he noted. "Obviously as time passes and grass return to the area, the chances become less, This is probably the case in the Washington scar area."
Staying informed during a rainstorm is important, Cobourn acknowledged.
"Usually, if people have like a NOAA Weather Radio or they're on social media with the National Weather Service, they can get alerts for flash flood warnings," he said. "There were flash flood warnings issued by the National Weather Service before each of the large floods in both of the last two years."
Needless to say, the impact of flash flooding is a costly proposition.
"We go out there, the county government, after those events and what do we do? We dig it all out repetitively. We've done it three times now and hauled it all away," Carlini said. "And that can't continue to be the solution. Every time it does that out there, it costs the county a million bucks to fix it, on an average."
And that's just the county's cost in cleaning up the public infrastructure. What is the cost of damage to homes in terms of landscaping?
"Between the two floods that were back-to-back, 53 percent of the homes were hit twice," Carlini said. "There were people that would say, 'You won't believe I just finished fixing my landscaping since the last one, and now again.' You know, there is no 100 percent solution for that. It's still going to happen."