The Overton Road project is located at the old Pinon Road bridge, where the 1999 flood of 18,900 cfs caused the bridge to collapse. While a new bridge was later constructed a few miles downstream, most of the old road remained, which caused a constriction in the floodplain that contributed to erosion problems in subsequent floods. In 2013 and 2015, flood waters removed a portion of Overton Road to the east, requiring realignment of the road. The analysis done of the WARSSS study found that the eroding east bank contributed an estimated 16,000 tons of sediment per year, resulting in the reach receiving a priority designation for stabilization and restoration.
The project implemented a minor realignment for the reach that moved the creek away from the eroding east bank and established channel and planform geometry informed by reference reach data and sediment modeling. Additionally, the project removed about 700 feet of the old road to open up more floodplain. Using 2D hydraulic modeling, Matric Engineering found significant reductions in velocities during large floods due to increased floodplain capacity- the estimated maximum velocity for the 100 year event was reduced from 23 feet per second to 15 feet per second. Other design elements included riprap protection in the outer bends and revegetation of all the disturbed area including 34,000 willow stakes, 340 cottonwood poles, and 3.8 acres of riparian and upland seed. Tezak Heavy Equipment completed construction of the project in May 2020.
View this project on our map!