
Drainage Evaluation & Detention Structure Modifications
Client—Lexington Flood Control Zone District, Cowlitz County, Washington

Regional Stormwater Management Plan
Client—Lewis County Flood Control District 1, Washington

Stormwater Management Plan
Client—Pacific County, Washington

Drainage Analysis & Flood Mitigation
Client—City of Oakville, Washington

Tennant Way Stormwater LID Improvements
Client—City of Longview, Washington

16th Street Combined Sewer Overflow Separation Project
Client—City of Astoria, Oregon

Downtown Corridor LID Improvements Pre-Design Report
Client—City of Longview, Washington

SR 503 Intersection Improvements
Client—City of Woodland, Washington

11th Street Combined Sewer Overflow Separation Project
Client—City of Astoria, Oregon

Dilly Twig Creek Basin Drainage Plan
Client—Lewis County Flood Control District 1, Washington

Stormwater Master Plan
Client—City of Kelso, Washington
Contact us to find out how Gibbs & Olson can help you.
- Stormwater Mitigation (treatment, detention & infiltration)
- Erosion Control
- Low-Impact Development (LID)
- Hydrologic and Hydraulic Modeling
- Conveyance System Inventory, Analysis & Design
- Pump Station Evaluation & Design