home | profile | services | links | contact us

Breakwater Design

A breakwater is a structure, usually made out of rock, that protects a marina from waves. There are many kinds of breakwaters including rockmound, floating, sheet pile wall, timber pile wall, and A-Frame breakwaters. Rock reefs and natural sloping beaches have also been used as wave protection. Integrated Planning has designed breakwaters world wide for a variety of applications.

Breakwater Designs

Rockmound Breakwater

Rockmound breakwaters are constructed using 4 layers of riprap, or angular rock: armour (large), fiter(medium), core(medium small) and quarry tailings(small). Material size design depends on the wave climate and slope of the breakwater. Typically a rockmound breakwater will be designed to have a 1.5 to 1 slope with rock size to suite and a flange at the toe double the width of the armour layer. Each layer is usually 1.5 to 2 rocks thick, but again varies with each application. Each rock layer is designed to maximum the dissipation of rock energy and still not allowed to be sucked out from the next rock layer. Integrated Planning has constructed rockmound breakwaters in Campbell River, Powell River, Cowichan Bay, Parksville, Hornby Island, and Howe Sound.

Floating Breakwater

Floating breakwaters are used in areas that are too deep to feasibly construct a rockmound breakwater. Floating breakwaters are held in place with sophisitcate rope or chain mooring systems and are constructed from plastic, concrete, steel, or some combination. Floating breakaters are cost-effective when stopping small to moderate size waves. Larger waves require more costly breakwater designs. Integrated Planning has constructed floating breakwaters in Okeover, Fanny Bay, Prince Rupert, Sointula, and Indian Arm.

Piling

Sheet pile, timber pile, and A-frame timber pile breakwaters have traditionally been used to stop waves. However, corrosion and attack from marine organisms reduces the life expectancy of these structures making rockmound breakwater more common for protecting marinas from waves. Piling run from $1,000 and up per pile and will need to be replaced in time. These forms of breakwaters are not recommended.

Breakwater Design Resources

The key to ensuring a properly constructed breakwater is to obtain the services of a professional engineer to generate plans and specifications for the entire job, including rock or material specifications, gathering bids from local contractors, and overseeing construction. Poor management of breakwater construction projects can lead to expensive and unnecessary contracting. For example, bids from contractors can easily range in the hundreds of thousands of dollars on a breakwater construction project.