Al Helenberg Memorial Boat Launch Safety Improvements

Client—City of Castle Rock, Washington

The Al Helenberg Memorial Boat Launch was constructed in 2010 and provides boaters access to the Cowlitz River. The boat launch is located 1,300 feet upstream of the SR 411 Bridge. Boaters have reported the ramps are frequently difficult and even dangerous to use during high streamflow velocities. To address these concerns and improve both safety and access for boaters, the City of Castle Rock hired Gibbs & Olson to prepare a bathymetric survey and hydraulic analysis to evaluate flow deflection alternatives that reduce streamflow velocities while maintaining sufficient velocity to minimize sediment deposition at the boat launch. The final analysis recommended the construction of pilings and reinforced precast concrete walls along with rip rap reinforcement of the riverbank. The project design has been submitted to permit agencies and is awaiting permit approval.