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Case Study: Flamingo Wash (Las Vegas, NV)
Terramesh®Flamingo Wash is one of the primary drainage channels in the greater Las Vegas area. The drainage area begins in the mountains west of Las Vegas, which drain into the Upper Flamingo Detention Basin, located by Russel Road and Durango Drive in the southwestern valley. Flamingo Wash crosses the famous Las Vegas Blvd close to Caesar's Palace.
The channel is underground in much of this heavily populated area. Many have seen pictures of the 1983 flood waters on Flamingo Wash, with cars from Caesar's Palace being pushed aside and destroyed. "Since 1960, this area has experienced at least seven million dollar floods. In that same period, 22 lives were lost in nine separate flash flood events." (Clark County Regional Flood Control District, Annual Report 1993-1994, Pg. 5) The Flamingo Wash crosses Boulder Highway between U.S. 95 (Freeway) and Sahara Ave. At this location the wash is perennial, flowing all year round. Flamingo Wash later joins the Las Vegas Wash and then empties into Lake Mead and the Colorado River.
On the east side of Boulder Highway, next to Flamingo Wash a new suites style hotel was under construction and the concrete retaining wall, planned for the barrier between Flamingo Wash and the parking lot, was found to be unacceptable because of wet foundation conditions. Working with the engineer, Maccaferri Gabions proposed a 1270 foot long mechanically stabilized earth wall (Terramesh) for the south side next to the hotel parking lot and a 600 foot gabion gravity retaining wall for the north side. A sewer line running along the north side did not allow enough room for the Terramesh soil reinforcement panels.
The Terramesh wall is 9 feet high with 3 foot lifts and a total width of 15 feet (using Terramesh TD-3 15' x 6' x 3' units.) The gabion gravity wall is 9 feet high and 4.5 feet wide at its base, with a batter of 6 degrees. Both walls have a 6' x 1' scour apron extending from their base. To prevent head cutting, grade control structures of 3' x 3' gabions extend across the wash at 200 foot intervals. Both walls were designed using Maccaferri software.
Construction began in September 1996 and was completed around the end of 1996. Several weeks after the project's completion Flamingo Wash experienced a flash flood, resulting in very high flows (approximately 7' high). Both walls performed well with no damages. Clark County Regional Flood Control officials visited the site during the flash flood and were pleased with the performance of the Terramesh and gabion walls.
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