Buck brush group hears update
The announcement that the 1994 and 1997 Buckbrush wash floods were probably the worst case scenarios provided relief to the audience at the Buckbrush Flood Safety Coalition meeting at the Johnson Lane fire station Thursday night.
“However, the Johnson Lane Wash is more dynamic and complex,” warned Dr. Kyle House, research geologist from University of Nevada, Reno’s Bureau of Mines and Geology. “The bottom line is that it is a very complicated system.”
House’s research capped a 5-year study by the coalition into the problems and possible solutions to Buckbrush Wash flooding. Steve Lewis, extension educator for Nevada Cooperative Extension, praised the handful of people who diligently pursued information to determine the floods’ dangers.
“Were they a small warning of something big or quite large in comparison to other floods? That is what we tried to find out,” said Lewis.
Through a grant obtained by the coalition, House is studying aerial photography, coupled with fieldwork, to determine the impact of several washes originating from the Pine Nut Mountains. In addition to the Buckbrush Wash, the study will include the Johnson Lane, Sunrise, Airport and Buckeye Creek washes.
“Other agencies take a more simplistic, cookbook approach to floods,” said House, stating that examining the topography of an area without delving into the underlying geology that creates an alluvial fan can be misleading.
“I am more complex. Aerial photography is indispensable for determining the quaternary geology, and photographs indicate features buried by wind-blown sand that obscures topography,” he said.
Now that the Buckbrush wash study is complete, House has moved onto the Johnson Lane wash.
“I’m more into the Johnson Lane wash because it has many variables that didn’t exist in the Buckbrush wash,” said House.
House explained that the Johnson Lane wash shows evidence for fan apex and trunk channel shifting as well as recent and ancient earthquake-induced surface ruptures, which impact the position of the fan.
“Plus, it has been significantly altered by people,” said House, citing drainage alignments and erosion. “This leads to different uncertainties.”
Field research of the Johnson Lane wash provided more than 800 years of information for House’s study.
“There are four deposits representing large floods over the past 800 years, and two of them were in the past 10 years,” said House. “It is a significant system that requires a lot more study.”
Glenn Hess, geologist for the U.S. Geological Survey, informed the audience that his agency has been gathering topography data for FEMA flood maps, which can affect homeowner’s insurance.
“The 1984 maps have blank areas in them, because that’s as far as FEMA had us go,” Hess said. “Now FEMA has charged us with the responsibility of going as far as U.S. 395, even though we know the water dissipates before reaching the highway.”
Hess said that public comment on the new rate maps would be part of the process.
“I think there will be some surprises on the new FEMA maps as zonings will change,” said Hess.
When asked when the maps will be completed, Hess said, “There is standard time, geological time and FEMA time. Hopefully in the next six months, but it could be two to three years.”
Coalition members Alice Rogers and Gordon Allen outlined the safety coalition’s accomplishments, mentioning education of the community and elected officials as an ongoing concern.
“When we learned that Buckbrush wasn’t in a bad position, many of our members lost interest. But now it’s urgent that Johnson Lane wash people join us. We need to educate the whole Valley about flooding, not an easy task,” said Rogers.
House underscored the frustrations of many coalition members.
“The bottom line is that I can’t stress enough that someone in charge needs to take at look a these washes before future development is approved, especially at the Airport wash,” said House, stating that the Airport wash was probably the most significant during the flooding.
“I’m steamed about some of this stuff. A lot of the information out there is counter-informational. The USGA and FEMA aren’t taking the in-depth studies into consideration. People shouldn’t have to be subjected to bad information or flooding,” he said.