Polecat Creek Channel Relocation and Restoration Project
During their annual inspection of their facilities Oklahoma Transportation Authority (OTA) discovered that erosion caused by Polecat Creek has significantly degraded the east Creek Turnpike bridge abutment to a dangerous stage. Several rehabilitation options were presented to OTA providing design and construction plans to ensure the best options for rehabilitation were implemented.
Due to the lateral movement of Polecat Creek toward the roadway alignment, protection of the Turnpike alignment became crucial.
The goal of the mitigation was to ensure the structural stability of the bridge serving the traveling public on Creek Turnpike spanning Coal Creek and Elwood Avenue using natural means to stabilize the Polecat Creek channel and over banks. The project replaced the existing unstable channel section with a stable section. The design eliminated the channel entrenchment and re-connect the channel with its floodplain area.
The self-mitigating project allows the main creek channel to naturally re-establish a stable section, while not disturbing the wetland area behind a natural levee located on the north side of the creek. All disturbed areas were re-vegetated in the floodplain areas with local plants. This involved 850 trees planted on site and 150 trees planted at an off-site location. The channel section included the construction of two J-Hook structures and one Cross-Vane structure to help the direction of flow in low flow conditions. An individual 404 Permit from USACE was obtained prior to the start of the construction of structural features. In addition to design, plan production and permitting, the provided services included construction oversite and project performance monitoring.
Levee Widening and Repair
The North Levee, which was breached after the restoration effort due to historic rain events, was repaired as a part of maintenance of the restoration project to continue its protection of the protected wetland area.
This project was awarded Oklahoma Floodplain Managers Association Ronald D. Flanagan Platinum Project Award in 2018.