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Aquaponics Home Systems
Floating Reedbeds and Wetlands
Floating Biofiltration

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Aqua Biofilter™

Central Victorian Floating Wetlands
Client dams overflow into local waterways carrying sediment and nutrients, affecting river water quality. Land owners wanted to improve their dam's environmental performance, improve the water quality in the dam, and provide habitat for birds and amphibians that was aesthetically pleasing. TheAqua Biofilter™ team visited the site and proposed a design that would capture as much nutrient and seidment as possible before water overflowed into the local environment. Natural materials were used, giving the floating reedbed a natural island aesthetic that would suit any dam, lake or wetland.

Sydney Olympic Park Authority
Water bird refuge in marine estuary - habitat floating islands

Sydney Olympics in year 2000 set the world benchmark for a Green Olympics that still sets the standard for excellence. Extremely rare, threatend and endangered marine estuary ecosystems exist within the Sydney Olympic Park Authority area over 1000 hectares within Sydney City, New South Wales (NSW), Australia. The Badu mangroves estuary has black swiflet water birds and also migratory birds that travel from Australia up to Korea and Siberia every year. The tidal water level variation is approximately 1 metre twice per day, and the floating islands were designed to rise and fall one metre per day, and provide an island habitat for the water birds.

The existing earth mound island was being inundated in high tide which destoys the rare and endangered bird nests and consequently their eggs which is keeping the marine estuary water bird population low. Due to very rare saltmarsh ecosystems on site, the sensitive ecosystem could not be subject to the impacts of earthworks machinery. Aqua Biofilter™ and the Ecoplan Consulting Pty Ltd team of environmental scientists, planners and engineers surveyed the site with Sydney Olympic Park Authority (SOPA), identifying suitable sites for floating islands installation and appropriate materials for migratory and local water birds for nesting. Coconut fibre beds were combined with long lasting food grade plastic floatation frame covered to prevent UV degradation. Marine grade materials were utilised to ensure long term integrity of the floating islands. Sydney Olympic Park Authority rangers collected salt marsh bush seeds from on site, which the Aqua Biofilter™ and the Ecoplan team sowed into the floating islands before launching the islands into the marine estuary. This is a world first that marine species have been integrated into marine floating islands. The primary purpose is habitat, but over time there marine plants will add to biofiltration benefits for the water quality. Installation of 120m2 in total was completed June 2012, made up of two islands, both 60m2 each. It is expected that bird watching enthusiasts will be able to utilise the bird hides located on site to view the rare water birds nesting, also alongside black swans which are a popular favourite with the locals.

Gold Coast City Council
Urban Stormwater Wetlands Case Study

Gold Coast City Council has significant stormwater treatment challenges with a constraint on land availability for conventional stormwater treatment wetlands so decided instead to install floating reedbeds into existing stormwater and sediment ponds, with the reduced costs of not having to excavate new land and deal with issues of long lead times and three times the expense. It was deciced to install 520m2 (520 square metres) into two sites in June 2011. After 12 months performance the plants have grown to maturity with leaves reaching 1 metre height and roots down to nearly 2 metres. Previous years algal blooms and azolla blooms have occured, but after installation of the floating reedbeds, there have been no blooms. This indicates anecdotally that the floating reedbeds have performed well and reduced nutrients to levels that prevent algal and azolla outbreak.

After three months growth.

After three months growth.

After five months growth.

After five months growth

After seven months growth

After seven months growth

Bega Urban Stormwater Wetland Trial

Installation was completed Bega urban wetlands receive the majority of the town's stormwater with a catchment over 60 hectares in size. The urban wetland also becomes a flood plain flow path annabranch rising up 7 metres in height. The Aqua Biofilter™ demonstrated it's high quality construction, rising and falling with the 7m flood, with it's anchor performing well, and plants growing vigourously with the high pollutant loads being delivered to the wetland.

The Bega Urban Wetlands case study can be downloaded as a pdf document, that was published at the National Australian Stormwater Conference 2009 uptakes of iron metals readily at 42,000 mg/kg. Uptake of manganese readily at 7,700 mg/kg, by some carex varieties that readily take up metals via phytoremediation process into rootzone. Total Nitrogen removal of approx. 40kg of in just 200m2 of treatment area.

Bega floating reedbed rootzone of carex fascicularis is considerable

Bega floating reedbed rootzone of carex fascicularis is considerable. Note the lateral root growth and joining of root zones of adjacent plants. This strengthens the overall floating reedbed and provides better water quality improvement performance than compared to plants that send roots straight down, such as Carex appressa which in the same trial proved to grow only vertically, not laterally. This makes species selection important to attain lateral root growth for performance.

China Urban Stormwater and Wastewater Case Study

Professor Li hosted the Australian Aqua Biofilter™ team for involvement in the floating reedbeds and floating island projects in China, April 2007 and also in 2004. The images below give an indication of the scale of some of the trial sites. The floating reedbeds and floating islands are part of On Site Sewage Management (OSSM) approach, intregrating stormwater treatment additionally. Large constructed wetland with weirs separates the floating reedbeds and floating islands, treating all sewage and stormwater before discharge to river, whereby water is accessed for re-use.

The floating reedbeds are actually Chinese characters when seen from above in the adjacent apartment buildings that relate to clean water with the aim of building public awareness about river water quality issues.

Large urban development in China utilising floating reedbed and floating island treatment biomass for a biodigestor that improves overall waterwater treatment performance, whilst providing city precinct district energy & heat production, integrated with sewerage system.

Pictured above is Prof Li left, ZERI Scientist www.zeri.org and IOBB China Representative. Tom Duncan on the right.

Advanced Biofiltration Research and Technology development has been an emerging science in China for many years with scientists from the Chinese Academy of Sciences and UNFAO affiliated FFC. Prof Li, Prof Song, Prof Pu and Prof Ou have all contributed to the science underpinning the development of the Aqua BioFilter™

The Floating Treatment Wetlands in China provided an opportunity for innovation, recyling nutrients and biomass energy. A biodigester was designed and built by Prof Ou. The biomass harvested regulary from the FTWs is inputtted to the biodigestor, where biogas fuel is produced for energy applications. Local organic wastes are also inputted to the biodigestor, genertaing additional biogas for energy applications. The cycling of nutrient dense waste water, and stormwater, with the addition of local organic wastes for biogas energy applications, demonstrates the effectiveness of the zero emissions approach.

Sewerage Treatment Trial in 2007 in Australia

Aqua BioFilterTM

Aqua Biofilter™ Sewerage Trial to prevent Algae Bloom in 2007 improve water quality, reducing nutrients and correspondingly reduce algal blooms.

Aqua BioFilterTM

Algal bloom can kill aquatic life & also block irrigation. Floating reedbeds and islands can biofilter nutrients reducing available nutrients for algal blooms.


China Lake Trial in 2004 of Floating Reedbeds and Islands.
Improved water quality to Class 1 Lake Classification, up from Class 5 subject to complete algal bloom consistently.
The Floating Reedbeds and Islands in China 2004 trial provided excellent results, reducing Ammonia by 55% and increasing Transparency by over 200%. Habitat was provided for turtles, water birds and fish also underneath. Floating curtain booms were installed to create an internal maze to treat the waste water and stormwater as it entered the lake. This increased efficacy of treatment and also large floating curtain booms were installed to delinate between trial and control areas.

Root Development

Large root & shoot Development - China 2004 Trials. Materials included using polyethylene closed cell foam and polystyrene floatation, polyester fibres, recycled plastics, polyurethane open and closed cell foams, peat, coconut fibres and coir peat for planting media

Floating Treatment Wetlands

Floating Treatment Wetlands, Floating Islands and Floating Reedbeds China 2004 Trials - Class I Results for Lake Water Quality. Materials included using polyethylene closed cell foam and polystyrene floatation, polyester fibres, recycled plastics, polyurethane open and closed cell foams, peat, coconut fibres and coir peat for planting media

Algae affected water clears- Floating Treat Wetlands China in 2004 resulting in Class 1 Water Quality improvement. Materials included using polyurethane floating booms to create internal maze effect for water treatment, polyethylene closed cell foam and polystyrene floatation, polyester fibres, recycled plastics, polyurethane open and closed cell foams, peat, coconut fibres and coir peat for planting media

Floating Wetland Treatment

Floating Treatment Wetlands (FTWs) China in 2004. Materials included using polyurethane floating booms to create internal maze effect for water treatment, polyethylene closed cell foam and polystyrene floatation, polyester fibres, recycled plastics, polyurethane open and closed cell foams, peat, coconut fibres and coir peat for planting media






Sydney Olympic Park Authority floating islands habitat for migratory birds
World first marine specie saltmarsh floating islands for migratory water bird habitat. Tidal estuary height differential of 1m. Installed 2 islands at 60m2, total of 120m2 June 2012. Black swiftlets, black swans and migratory birds will use the floating islands for habitat.

Gold Coast City Council Urban Stormwater Wetlands
June 2011 520m installed in two stormwater and sediment ponds. No algal or azolla bloom compared to previous years, good results.

Bega Urban Wetlands
Results indicate strong root and shoot growth of Carex, doubling in size over 3 months, from 30cm at plant out to 2.2 metres length in 14 months.

Wagga Wagga Wetlands and Aquaculture Wastewater
Bolboschoenus & Vetiver excellent performers with root growth down to 50cm in just 3 months. Wastewater column high nutrient loads, large volume of salts uptake

Sewerage pond trial
Aqua Biofilter™ plants developed early with root and shoot growth, effectively reduced nutrient levels to prevent algal blooms

Salinity trial
Aqua Biofilter™ trial to extract salt with a Halophyte forage crop, indicates brackish water can be treated.

China Australia R &D
Aqua Biofilter™ founder Tom Duncan invovled in trials in China and Australia published results at the National Stormwater Conference Australia, 2009. Download here
 email: info@aquabiofilter.com

Copyright 2004 - 2014 Tom Duncan. All rights reserved.