Rafted Reedbeds

Rafted Reedbeds
Our rafted reedbeds are used for water quality treatment, but there are numerous other ecological and landscape amenity values to be gained. Rafted reedbeds achieve water quality treatment using a smaller footprint than a constructed wetland. Furthermore, rafts can be used to retrofit existing wetlands, ponds and sediment basins to enhance treatment.

Water is treated biologically by the biofilm rich root mass (that support algal grazers and bacteria that break down pollutants) and physically by the settling of fine pollutant bound particles. The raft also reduces water temperature and sunlight, thereby reducing the optimum conditions for algal blooms.

Our standard raft module is 1.8m x 2m (3.6m2) and made of UV and chemical resistant materials. Raft modules are joined to form a larger rectangle raft and anchored to submerged or shoreline anchor points. Pre-planted coir mats are placed on the rafts (4 per module) to shorten the time it takes to establish reeds and reducing the risk of bird predation.

Floating treatment wetland systems capacity for water treatment has been documented in four key international studies, which show these systems have the capacity to remove between 0.0027 and 0.0058 kg per m2 of TN and 0.0004 and 0.0046 kg m2 of TP per day. There are many variables that need to be considered when using this data, so for simplicity, we assume the HEC rafted reedbed system is likely to achieve an average of this range (0.01kg/day TN & 0.0025kg/day TP). On this basis, a 25m2 Rafted Reedbed has the capacity to remove 0.32 kg of TN and 0.063kg of TP per m2 day, which equals 117kg TN and 23kg TP per annum.

Floating Island

Floating Island
We designed the 25m2 Floating Island to appear more natural than the standard rectangle Rafted Reedbed. The attractive hexagon shape of the Floating Island is well suited for areas of high visual amenity such as ponds in public areas or golf courses. The Floating Islands can be installed using our Established Reed Mats, or a specific mix can be grown and installed by arrangement.

Floating Streambank Edges

Floating Streambank Edges
We designed the Floating Streambank Edges (FSE) to restore riparian streambank vegetation in situations where plants are difficult to establish due to fluctuating water depth, steep eroded banks or an unsuitable substrate to establish plants. The FSE can either float with water levels or root into the underlying substrate if water depth is less than 500mm.

Our Floating Streambank Edges are available as 600mm x 2.4m, 600mm x 1.2m and 600mm x 600mm, so it is possible to work with the natural shape of the streambank.

Established Reed Mats

Established Reed Mats
Established reed mats allow instant revegetation of wetland plants in situations where it may be difficult to establish wetland plants along streambank edges, rivers and reservoirs due to:

• the risk of bird predation
• eroded riparian edges
• limited organic substrate to sustain plants;

They also allow a marginal habitat to be established around artificially lined ponds or as an alternative to hard revetments.

Species we use include:

• Shoenoplecus validus
• Baumea articulata
• Cyperus appressa
• Carex appressa
• Phragmites australis
• Philydrum lanuginosum
• Triglochin procera
• Eleocharis sphacelata
• Juncus sp

Waterfowl and Carp Protection

Waterfowl and Carp Protection
To overcome grazing and damage by European Carp and Waterfowl, we supply and install nets or cages above and/or below water level to keep these predators out. Our cages are recommended as a permanent solution where there is a permanent population of these ‘predators’ Painted black and hidden by the plants, these cages are hidden from view.