Parker is working to restore soils on Cherry Creek after severe
erosion began to threaten the stability of nearby roads and
bridges.
The town’s storm water utility division is halfway through a
$1.3 million project north of the Cottonwood Drive bridge to
stabilize the creek soils.
“We’ve had severe erosion in that area over the last 20 years.
It got to the point that it’s so deep in some areas, that it
threatens the stability of the roadway bridge and pedestrian
bridges and trails over there,” said Tom Williams, storm water
utility manager.
The town is using three to four grade control structures to
mitigate continuing erosion and prevent future erosion. Crews are
constructing drop structures, which are steel walls that are driven
into ground to prevent soil degradation, Williams said.
The steel walls rise just above the creek bottom, causing
sediment to fill in behind the drops and restore the eroded areas.
Construction began in May and is expected to end in September.
The erosion, which has occurred in several areas along Cherry
Creek, is the result of increased water volume caused by heavy
development in the Parker area. Essentially, the rainfall that once
soaked into the ground now lands on hard surfaces, such as
driveways, rooftops and sidewalks, Williams said.
The storm water then drains to Cherry Creek where the increased
volume has eroded the bottom of the creek up to 10 feet in some
areas, he said.
The storm water utility division has planned the project near
Cottonwood Drive for three years, most of which has been dedicated
to a lengthy permitting process.
The erosion did not reach a point where it was an immediate
danger to motorists and pedestrians on the Cottonwood Drive bridge
over Cherry Creek, but it has been a concern for the town for five
years, Williams said.
In the last few years, the town has tackled roughly 10 other
projects to stop soil erosion along the creek and has plans for
three or four similar projects in the next five years, Williams
said.
“If it goes unchecked, it could cause damage to private property
and become a public safety concern,” he said. “We’re targeting the
high hazard areas and will continue to stabilize the creek to
prevent further degradation.”
The division is now moving the Cherry Creek Stream Restoration
Project to Stroh Ranch. The project will cover a longer portion of
the creek, but will cost roughly the same as the work near
Cottonwood Drive. The project near Cottonwood Drive stretches from
the bridge north to a pedestrian bridge about a mile south of the
Douglas-Arapahoe county line.
Approximately three to four feet of soil has eroded north of the
bridge on Stroh Road; the creek area near Cottonwood Drive has lost
seven to eight feet of soil, Williams said.
Dirt will be used to restore the creek bottom to its original
grade near Stroh Road. The project includes a plan to build a
pedestrian water crossing that will connect the Cherry Creek
Regional Trail to the Stroh Ranch soccer park. Work is expected to
begin next January and end in May.
Heavy rainfall in July didn’t help the erosion along the creek
and even washed away an additional foot of soil near Cottonwood
Drive, Williams said. Weather forecasts are predicting above-normal
flow in the coming months, Williams said.
“I’m glad we’re doing the project now because if we would have
left it we would have had more significant problems,” he said,
adding there are more options and the cost is less if erosion is
resolved early.
The project was funded by the storm water utility fund, which
comes from fees paid by commercial and residential developers. The
town spent $900,000 for the drop structure installation, $300,000
for designing and permitting and $100,000 for re-vegetation and
landscaping.
Parker obtained permits from the U.S. Army Corps of Engineers,
Federal Emergency Management Agency and U.S. Fish and Wildlife
Service to work on the creek. Only a portion of the steel drop
structures will be visible to those standing near the creek,
Williams said.
The Cottonwood Drive project includes flood control measures for
Cottonwood Park, which typically gets flooded two or three times
per year. A new channel will be built with culverts running beneath
the trail, diverting water from the park, Williams said.
The Cottonwood Water and Sanitation District is planning to
construct a new sanitary line near Cherry Creek once the
stabilization project is complete.
Contact Chris Michlewicz at
cmichlewicz@ccnewspapers.com