Opportunity
One of many public parks in the area, Don Morse Memorial Park has 2,000 feet (609 meters) of waterfront on the lake. Its 40 acres (16 hectares) offer an 18-hole putting course, a skate park, playground and barbecue areas, picnic shelters, and courts for tennis, volleyball, and basketball.
Over time, the park’s beach was diminished by erosion. Longshore sand transport caused sand to be deposited at the city marina.
Solution
The City of Chelan retained Mott MacDonald to address the problem. We were responsible for soft shore stabilization, design of beach groins, wave protection for the marina, and restoration of the recreational beach.
To restore the beach and shoreline, we coordinated with the client regarding design life, design storms, beach configuration, maintenance cycles, size criteria for beach surface material, and preferences for beach retention structures and other infrastructure. Modeling was used to calculate loss rates for beach sand for each alternative.
To protect and optimize the marina, Mott MacDonald identified an optimal entrance configuration by modeling wave interactions with the marina’s breakwater and entrance. We simulated wave heights inside the marine at the entrance for alternative layouts.
We finalized beach design drawings through the 60%, 90%, and 100% levels, prepared the cost estimate, and specified the type and placement of beach materials. We answered technical questions, reviewed submittals, attended on-site meetings, inspected construction, developed a punch list, and participated in a final review meeting.
Outcome
The project has halted beach erosion, provided additional protection for the marina, and upgraded the recreational beach, replacing a retaining wall with a sloping pebble beach.
The beach is safer and more convenient for swimming, boating, and other activities, and the number of visitors has increased.