The redevelopment of the waterfront in West Palm Beach Florida, a 12.5-acre project featuring a new park, water gardens, boat piers, and new paths, also includes a new "living" dock that doubles as a water-filtration system, writes GreenSource magazine. The dock is designed to support natural systems — mangroves, grasses, and oysters that create habitat and provide water-filtration services.  

According to GreenSource, the living dock system is multi-layered and includes geotextiles: "Measuring approximately three times wider than a normal dock, the living dock is made of concrete over a foam core and its public surface is clad in sustainably harvested Ipe planks. A series of indentations of varying sizes runs down the center of the 400-foot-long living dock; each is surrounded by an aluminum safety railing as well as seating for visitors. For the floating mangroves and spartina, a special soil mix is sandwiched between layers of geotextiles."

The geotextiles help create a growing substrate for the oysters. Embedded within these geotextile layers are oyster shells from restaurants, which were brought it to help spur natural oyster growth. "The volume containing the oysters is more perforated to boost water flow. Oyster shells discarded from restaurants fill the bottom, since those shells are ideal for prompting subsequent oyster colonization."

Each oyster can filter 40 gallons of water per day. From the photos, it also looks like the oyster water-filtration area is clearly visible to users of the floating dock. The green infrastructure component is open, adding an educational component to the project.

However, GreenSource notes there are some limitations to the geotextile substrate – they are almost impermeable, meaning they may limit the erosion-control capabilities of the mangroves. "Because the geotextiles cradling the spartina and mangroves are almost impermeable (and these root balls are becoming more sealed as barnacles accrete to their planting substrates), they aren't necessarily controlling erosion as they would in a natural setting."

Even more ambitious plans are in development. More than $2 million has been raised to rehabilitate another portion of the area's Intracoastal Waterway. "When completed, this undertaking will feature entire oyster reefs and, one-upping even the innovative living dock, it will include stepped tidal gardens whose mangroves and spartina will filter stormwater, build underwater habitat, and provide safe haven for birds."

The waterfront's park includes Lake Pavilion, a LEED certified municipal building featuring a 17-KW photovoltaic roof system. The waterfront's development was led by Michael Singer Studio, and the landscape architecture was designed by Carolyn Pendleton Parker, ASLA, at Sanchez & Maddux and Connie Roy-Fisher, ASLA, Roy-Fisher Associates.

Read the article and see a slideshow.

Image credit: Michael Singer Studio / GreenSource