Over the last 12 years, HWA provided geotechnical engineering services for Phases 1-3 of the North Creek Trail. Performing geotechnical feasibility review and presenting recommendations regarding soil conditions and geologic hazards. HWA conducted geotechnical investigations for design that involved extensive cuts and retaining walls, providing recommendations and cost comparisons. Stormwater detention vault and signal poles were evaluated and HWA provided inspection services during construction

HWA provided geotechnical engineering services to support design and construction of a two-mile segment of a mixed-use trail in Maple Valley. The project included retaining walls, stormwater convenience, infiltration facilities, lighting, and design of safe at grade trail crossings at four road crossings. Also, this project included a 150-foot-long pedestrian bridge to cross an active BNSF rail line. HWA has managed three phases of field explorations to support this project.

HWA provided geotechnical engineering services in support of design for a new parking lot to provide access to the East Lake Sammamish Trail. HWA designed a soldier pile wall that was required since the slope exhibited marginal stability and an ADA ramp to connect the newly constructed parking lot to the trail. HWA performed engineering analyses for foundations and slope stability of the walls as well as recommendations for capturing ground water and diverting it away.