Powell Ditch & Bridge Improvements

COLUMBUS, OHIO

Powell Ditch & Bridge Improvements

Project Overview

Ribway provided professional engineering services to address significant structural and yard flooding issues along a one-mile stretch of Powell Ditch. The service area, encompassing nearly 1,000 acres, experienced chronic stormwater management challenges.

Study Phase

The study phase focused on evaluating alternatives to manage runoff effectively, including:

Rerouting existing stormwater flow.
Removing and replacing culverts.
Upsizing the channel to increase capacity.

Hydrologic and hydraulic computations were performed using:

SCS TR-55: For hydrologic analysis.
HEC-2 Model: For hydraulic design.

The chosen solution involved widening and deepening the existing channel to manage the estimated runoff volume.

Design Phase

The design phase included the preparation of comprehensive plans and specifications for:

Open Channel Improvements:
- 4,000 linear feet of channel upgrades from Chatford Drive to Scarborough Boulevard.
- Channel bottom widths: 8–12 feet.
- Channel depths: 6–10 feet.
- Cross-sections: Concrete and natural earth bottoms with dumped rock and grassed side slopes (2:1 maximum) to ensure stability and integration with the environment.
Bridges:
- Replacement of three pedestrian bridges and construction of a new three-sided vehicular culvert bridge (30 ft long x 10 ft high).
- All bridges were designed to comply with ADA standards.
Environmental Considerations:
- Efforts were made to minimize tree removal and impact to the environment and aquatic life.
- Erosion control measures were implemented to stabilize side slopes.

Regulatory Compliance

Ribway secured necessary permits, including:

Ohio EPA Section 401 Water Quality Certification.
US Army Corps of Engineers Section 404 Permits.

Challenges and Solutions

Community Impact: Designed improvements to blend with the natural setting of the golf course and residential areas.
Environmental Sensitivity: Preserved existing trees and aquatic life while integrating stormwater management solutions.