It was created specifically to treat storm waters located at Marina Garden Estate in Delta, adjacent to Deas Slough on the Fraser River. The stormwater catchments include a residential development and a golf course.
The first wetland compartment is the primary sedimentation component of the system. It consists of the water ‘traps’ or ponds within the golf course. Stormwater from the residential development discharges into the golf course ponds. Fountains within the large ponds enhance photochemical oxidation of pollutants. The pond system within the golf course encounters the most serious toxins from the residential development as well as the golf course itself (e.g. pesticides).
The second compartment of wetlands is located downstream of the golf course and residential development area and consists of three sequential pools divided by two imperious berms. The top of the berms and the perimeter of the pools are planted with cattalo. The berms force the waters to pass through the cattails, enhancing chemical decomposition, biological assimilation, microbial decomposition and filtration. This second compartment is designed specifically for stormwater treatment. Ancillary fish and wildlife habitat values sustained within this compartment are an additional benefit.
During the specific rainfall events, the pump station located at the most downstream pool is activated and transports waters from the second compartment across a dyke road (i.e. Ferry Road) into two intertidal compartments. These compartments, consisting partially tidal sloughs and intertidal marshes, function as a ‘polishing’ compartment for any residues that may persist after treatment within the upstream compartments. As water is these intertidal compartments is expected to be such quality as not to be deleterious to fish and wildlife, the environmental value of this compartment has been maximized by incorporating habitat features important to critical life history stages of both fish and wildlife.
The Marina Gardens Stormwater Treatment Systems incorporates a management plan within the development area to mitigate impacts on stormwater quality. Firstly, owners of property within the residential development have been and will continue to be informed that the subdivision participates in the B.C. Ministry Environment, Lands & Parks Storms Drain Marking Program. Accordingly, the owners, as part of the sales agreement, agree not to discharged or cause to be discharged the following materials:
a) automotive products, including but not limited to motor oil, brake fluid carburetor cleaner, gasoline, gasoline additives, transmission fluid, degreasers, and sealers.
b) paints and solvents, including but not limited to paints, shellacs, lacquers, varnishes, enamels, paint thinners, paint & varnish strippers, and rustproof coatings.
c) recreational products, including but not limited to swimming pool contents (chlorine), and outboard motor products (gas, oil, etc.).
d) pesticides including but not limited to disinfectants (bathroom, kitchen, etc.), insecticides (garden products, flea collard, etc.), fungicides (mold & mildew control), rodenticides (rat and mouse), herbicides (weed killers), molluscicides (slug baits), and wood preservatives (creosote, pentachlorophenol’s).
e) cleaning products, including but not limited to detergents, drain and toilet cleaners, rug and upholstery cleaners, leather preservers, dry cleaning agents, car wash detergent, and polishing agents.
f) any substances deemed to be hazardous substances under and/all environmental protection legislation by the provincial or Canadian government statutes and regulations.
Those wetlands within the stormwater treatment system designed to sustain plant communities (i.e. downstream of the golf course) were constructed first to ensure that harmony between the specific water regimes and the wetland plant communities was established within each compartment prior to being subject to maximum stormwater loading. This allows either modification of the water regime or a change in the species composition of the wetland plant community the treatment process as would likely otherwise occur if done subsequent to the completion of all upland development.
The Marina Gardens Estates development has completed the first 6 phases of its residential component and the golf course. Prior to the construction of these components of the project, stormwater from the residential development was discharged into a large (1 ha) sediment basin upstream of the ‘design’ second wetland compartment.
Baseline water quality data was collected in 1993 within those compartments downstream of the proposed golf course. Samples were analyzed for metal, non-metal inorganic, and physical parameters. The sampling methodology was by environmental agency personnel.
The Marina Garden Estates Project has the full support of the Fraser River Estuary Management Program, Environmental Review committee and the corporation of Delta represented by Mr. Adrian Duncan and Mr. Dale McTarggart, P. Eng. whose approach to this relatively new, yet proven technology permitted the Marina Garden estates wetland development project to price. Support was also provided by the B.C. Ministry of Environment, Land & Park and Canadian Wildlife Service who own the land occupied by the downstream ponds and channels.
As a result of this project, Marina Garden Estates received an award from the Fraser River Estuary Management Program from recognition of exemplary effort in designing and constructing the project to minimize environmental damage in the estuary. This award was presented the president of Captain’s Cove Marina to acknowledge his personal leadership and commitment during the approval process for the projects.