Cross Reiter was engaged by a private developer to conduct a detailed assessment during the due diligence phase of a property acquisition on Vashon Island. Our task was to evaluate the feasibility and cost implications of constructing a secure access road up a densely forested, exceptionally steep slope. We completed a comprehensive geologic hazard assessment and site investigation to analyze soil and groundwater conditions, as well as assess the extent and severity of potential geologic hazards, including steep slopes, landslides, and erosion risks.

Cross Reiter provided recommendations to facilitate construction of a safe, functional access road that could be permitted by King County despite the challenges and limitations associated with very steep slopes and real landslide risks. Cross Reiter identified several feasible earth retention systems, including modular block gravity walls and mechanically stabilized earth (MSE), and provided construction cost estimates to aid in project planning. We provided recommendations to ensure emergency services access and low maintenance on an engineered access road with maximum grades approaching 15%, including high-traction surfacing utilizing geosynthetic elements, robust stormwater conveyance and management, and thoughtful grading that included retaining walls and permanent cut and fill slopes designed for long-term stability.

This client greatly benefited from Cross Reiter's comprehensive expertise in both civil and geotechnical engineering. Our assessment of site conditions and consideration of permitting constraints enabled us to present this client with a range of viable and cost-effective strategies to achieve their objectives. Cross Reiter is dedicated to delivering outstanding value by providing innovative solutions tailored to our clients' specific needs and ensuring the success of their projects.