Copeland Detention Basin
The Copeland Detention Basin Project in Flagstaff, AZ is a flood mitigation project facilitated by ADOT, the Federal Highways Administration (FHWA) and Coconino County Flood Control District. The project was built to mitigate the impacts to Highway 89, the Cinder Lake Landfill and downstream neighborhoods resulting from increased storm runoff caused by the 2010 Schultz Wildfire. This area of the highway has been subjected to flooding (which overtops the highway in several locations in this area) in the past and is an essential component of the overall Schultz Flood mitigation efforts.
The project sits on 81-acres in Coconino County five miles north of Flagstaff. The scope of work included constructing a series of three sediment traps and two detention basins which would act as a flood mitigation measure between Copeland Avenue and Kevin’s Way, as well as constructing a new channel between Kevin’s Way and Brandis Way to reduce the potential flooding and closure of US89 in the event of heavy monsoon storms. Three sediment trap basins and two detention basins were constructed with culverts and channels to re-route the water in a controlled manner through the site. Additional land forming earthwork, as well as constructing a new 4-barrel 10’x4’ reinforced box culvert, installation of guardrail, wood and fire fence and other miscellaneous work was also completed. Improvements to an existing ditch within the current ADOT right of way, as well as improvements to the box culvert located at the intersection of US 89 and Kevin’s Way also completed the scope.
The construction team built a 2650 ft access road for residents since the project would shut down a portion of the road to their homes. The detention basins will be hydro-seeded and eventually turned into a park facility for residents.