The banks of Cottonwood Creek, a narrow waterway in north central Colorado Springs, have been carved into 20-foot walls near main power lines, Woodmen Road and a bus barn, a problem that has caught the city of Colorado Springs’ attention.
The eroded, nearly vertical banks near east Woodmen Road and north Powers Boulevard are about 20 feet from the foundation of poles supporting main power lines and about 50 feet from Woodmen Road, said Timothy Biolchini, Colorado Springs’ stormwater capital projects program manager.
“That section has just become a canyon,” Biolchini said.
Storms erode the sandy soil along the creek banks a few feet each year and in a big flood it could erode as much as 10 feet, he said. The city has been concerned about the erosion for years, but it hasn't had the funding to mitigate the risk until recently.
City officials announced last week it received a $2.9 million grant from the Federal Emergency Management Agency for stabilization work along 9,000 feet of Cottonwood Creek, Biolchini said. The city plans to match the grant with $993,924 from funds intended to improve its stormwater management.
The work will also keep thousands of cubic yards of sediment from washing into Fountain Creek and flowing south to Pueblo, Biolchini said. The project is among 71 Colorado Springs must complete as part of an agreement with Pueblo County to better control the volume and quality of water flowing south in Fountain Creek.
Colorado Springs officials expect to spend $16 million in 2020 on stormwater improvements using fees paid by homeowners and nonresidential property owners, according to the city’s website. Officials must spend $100 million on stormwater projects, operations and maintenance from 2016 through 2020 to comply with the Pueblo agreement. Projects are on track to hit that goal, Biolchini said. The five-year benchmark is part of the requirement to spend $460 million over 20 years on stormwater improvement.
Construction to help prevent erosion of Cottonwood Creek is expected to be designed this year and completed in 2021, he said.
The construction will likely include reshaping the banks so they have gradual slopes and burying hardened structures to keep the creek from changing course, he said.
If a bank collapsed, it could block the stream and force the water to change direction, which could cause more erosion, Biolchini said.
“If you get one failure, it could drive the creek to move in another direction that could point it right at Woodmen,” he said.