GUEST COLUMN: Cimarron/I-25 project's environmental/aesthetic elementsBy Scott Schnake
One of the goals of the I-25 & Cimarron (US 24) Interchange Design-Build Project involves making the area aesthetically pleasing and compatible with the current and future amenities and enhancements in and around the interchange.
That goal also includes expanding Upper Fountain Creek to convey 100-year Federal Emergency Management Agency (FEMA) flow rates. This project provides for new and enhanced trails, pedestrian creek-crossing bridges, and increased visibility of the creeks from roadways and paths, along with other planned elements that expand and conserve riparian buffer zones.
The Upper Fountain Creek restoration is being closely coordinated with the U.S. Army Corps of Engineers, the El Paso County floodplain administrator and other
The I-25/ Cimarron creek and trail work aligns with the Fountain Creek Corridor Restoration Master Plan (2011), providing greater recreation opportunities by creating a community and regional amenity in Fountain Creek.
In support of the goal of connecting America the Beautiful Park with Fountain Creek, the City of Colorado Springs recently constructed a playground with all-natural elements on the east bank of the creek, immediately adjacent to the Cimarron/I-25 interchange project site.
Many challenges are inherent in the interchange reconstruction project, due to the three creeks running through the project site. Water flows must occasionally be temporarily diverted to allow for bridge and creek work to be performed.
To minimize environmental impact during construction, the project team carefully plans and performs work to comply with state and CDOT construction stormwater discharge permits, groundwater dewatering permits, 404 permits administered by
Other regulations address relocation of the Midland Trail, consultation with Colorado Parks and Wildlife regarding fish movements that must be maintained in Upper Fountain Creek and preventing fish movements in Bear Creek to protect the greenback cutthroat trout upstream.
Creeks are temporarily diverted, when necessary to perform construction, in a manner that minimizes impacts to water quality and the surrounding creek channel. These diversions and required dewatering are permitted by the U.S. Army Corps of Engineers and the Colorado Department of Public Health and Environment.
The anticipated restoration of Upper Fountain Creek between Eighth Street and the confluence of Fountain Creek with Monument Creek is part of the I- 25/Cimarron Project plan. The US 24 bridge over Upper Fountain Creek has already been replaced, providing adequate channel height of Upper Fountain Creek under US 24 to minimize flooding potential. Several drop structures between 8th Street and US 24 will be installed, as well as construction of a natural channel design of Upper Fountain Creek.
The design includes a low-flow channel with increased sinuosity, bank sloping, willow plantings and healthy riparian areas, in line with the Upper Fountain Creek and Cheyenne Creek Flood Restoration Master Plan (2015), while conveying the 100-year flood condition within a stable natural channel. The riparian areas function as an improved buffer between the creek channel and the adjacent dense urban areas and roadways.
The City of Colorado Springs and El Paso County are collaborative partners on the Cimarron/I-25 project. CDOT, the city and the county have held numerous meetings with local community representatives and groups discussing aesthetic and functional features of the project. Pre-project coordination with the Army Corps of Engineers, Colorado Parks and Wildlife and the Colorado Department of Public Health and Environment have also been critical to project success, with ongoing discussions to ensure that creek improvements are performed in ways most beneficial to the environment, the habitat and the community.
Editor's note: Schnake is a CDOT engineer. The article originally appeared in a project newsletter prepared by Bachman PR, a CDOT communications contractor.
(Posted 2/20/17; Opinion: Guest Columns)