Living machines / ecomachines

Baima canal. Photo from Cyclifier.

John Todd, an ecological designer and biologist, pioneered the concept of living machines in the 1970s. ‘Living Machine’™ is trademarked to Ocean Arks International. Todd credits the concept of ecological engineering that inspired living machines to H.T. Odum (Todd, 1991). Living machines (not to be confused with robots and AI) refer to constructed ecosystems that utilise a variety of plants, microbes, and other organisms to treat greay water or blackwater and to remediate polluted water environments. These systems are designed to mimic natural ecological processes and functions, such as purification, nutrient cycling, and habitat creation. Living machines essentially replicate a river system, including the final filter of wetlands. They use natural the abilities of living organisms to break down macromolecules and metabolise organic nutrients found in wastewater and polluted water bodies (Hung et al., 2014), and are a type of bioremediation / phytoremediation of water system.

A series of connected treatment cells / tanks in a living machine house a higher concentration of the plants, animals, and microbes that naturally purify water, ‘in an enriched environment that maximises the efficiency of their work’. Contaminated water is pumped into the first treatment cell, where the living organisms begin the cleansing process, and then flows by gravity through the cells. In each subsequent treatment cell, increasingly higher life forms become involved. Wastes generated by the microorganisms, bacteria, algae, mollusks, fishes, flowers, shrubs, trees and other animals in one cell flow with the water and become food for the inhabitants of the next. Sunlight as the primary source of energy for plant growth in living machines, also helps to break down compounds and purify water through UV treatment. 

In the 1970s and 80s Todd and his colleagues developed the concept of “eco-machines,” which were constructed wetland systems designed to mimic natural ecosystems and purify wastewater. Throughout the 1980s and 90s, Todd and his team implemented eco-machines in various settings, including eco-resorts, botanical gardens, and industrial facilities. These projects demonstrated the effectiveness of living machines for decentralised wastewater treatment and ecological remediation.

In 1996, John and Nancy Jack Todd published the book “From Eco-Machines to Living Machines,” which documented their experiences and insights. The book introduced the term “living machines” to describe constructed ecosystems that exhibit lifelike properties and functions. Since the late 1990s, interest in living machines has grown, leading to further research, innovation, and practical applications. Living machines continue to evolve with advances in technology, biomimicry, and interdisciplinary collaboration. Several case studies of living machines located in the United States are provided by Hung et al. (2014).

Typically living machines are hosted in greenhouses on land, but by the 1990s, were also created on floating rafts to treat ponds, lakes, and canals directly in water sources. These raft living machines are called ‘restorers’ (Yaron et al., 2000). They are designed to support a diversity of microorganisms, algae and higher plants including shrubs and trees, and provide internal habitats for water-cleaning animals, including fresh-water clams. 

The first restorer was designed and installed in a fifteen-acre pond, degraded by landfill leachate near Cape Cod in the United States of America (Todd, 2004). Powered by an electricity generating windmill and an array of solar panels, it was launched in 1992. Up to 380,000 litres per day of water from near the bottom of the pond were circulated through nine separate treatment cells (Todd, 2004). By 1995 sediment depth had been reduced by over two feet and there were large reductions in phosphorus, ammonia and organic nitrogen compounds. The overall health and biodiversity of the pond continued to improve. In 2002, after a decade of operation, the restorer was removed. Other restorers exist in other parts of the United States and China. A restorer was installed along a sewage-laden canal in the southern Chinese city of Fuzhou (the Baima Canal). The canal was contaminated with garbage, raw sewage and a variety of wastes including fats and grease. The restorer built to treat the canal was approximately 0.8km long. Its effect on the canal was dramatic. The smell went, the water cleared, and several species of fish, butterflies, and birds previously missing from the inner city returned over time (Todd, 2004).

Living machines offer an alternative to conventional treatment methods, particularly in resource-constrained and ecologically sensitive regions, so may be of particular interest in Te Moananui Oceania.

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Name of NbS

 Living machines / ecomachines

Type of NbS

Hybrid living/engineered interventions


Living machines can work in rivers, streams and canals or on land in either exterior or interior settings. They suit both urban and rural locations.

Case Study

The Hawai’i Nature Center Green Machine

The Green Machine. Photo by the Hawai’i Nature Center

Relationship to Indigenous knowledge

Living machines are not based on specific Indigenous precedents but many Indigenous cultures have developed sustainable practices for managing water, soil, and biodiversity systems (Watson, 2019; Carter, 2018; Bryant Tokelau, 2018). These practices often involve a deep understanding of local ecosystems and the use of techniques that also mimic natural processes. Similar concepts include constructed wetlands and reed beds for wastewater treatment, which have traditionally been used in various parts of the world by some Indigenous peoples to filter and purify water for drinking and irrigation.

Indigenous cultures often recognise the interconnectedness of all living beings and value biodiversity. This is true in Te Moananui Oceania (Mihaere et al., 2024). Living machines, with their focus on creating ecosystems that support diverse plant and animal life, align with this perspective on ecological health and resilience.

Incorporating Indigenous knowledge and perspectives into the development and implementation of living machines in specific places may enrich these technologies and foster greater cultural sensitivity, environmental justice, and sustainability. Understanding local species, relationships between species, cycles, and traditional calendars may be of value to the development of living machines in Te Moananui Oceania.

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Climate change benefits
  • Increased incidence / distribution of disease
  • Loss of food production
  • Reduced fresh-water quality/availability

With water scarcity a pressing issue in many Te Moananui Oceania islands, exacerbated in some cases by climate change, living machines can conserve water resources by treating wastewater for reuse. They can withstand fluctuations in temperature, precipitation, and nutrient inputs better than conventional treatment systems, making them suitable for diverse climates and climate variability

Traditional wastewater treatment plants often require significant energy inputs for operation. Living machines, however, rely on natural processes such as microbial activity, plant growth, and solar energy, reducing the need for fossil fuel-derived energy, aiding climate change mitigation. Furthermore, the plants within living machines absorb carbon dioxide during photosynthesis, helping to mitigate greenhouse gas emissions. 

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Societal / socio-cultural benefits
  • Food security and quality
  • waste management and hygiene
  • Fresh water security and quality
  • Empowerment/equality

Living machines are typically primarily used for water purification. They can treat wastewater for reuse in irrigation or other non-potable applications, reducing the demand for freshwater resources. In regions facing water scarcity due to climate change, this can be particularly valuable. 

By treating wastewater effectively, living machines reduce the risk of waterborne diseases, improving public health outcomes. Compared to conventional wastewater treatment plants, living machines can be more cost-effective to build and operate (no chemicals are used), especially in rural or remote areas. 

Other documented applications (many co-exisiting in the same living machine system) include: food growing (Hung et al., 2014), heating and cooling buildings, sewage treatment, boat waste treatment, production of fuels (hydrogen gas), and production of materials for use in paper making and building materials (Todd, 1991).

By involving local communities in the design, implementation, and maintenance of these systems, living machines can foster a sense of stewardship and empower individuals to take action against climate change. Their holistic approach aligns with sustainable development goals, offering a scalable, nature-based solution for climate change adaptation.

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Ecological and biodiversity benefits
  • Fixation of solar energy
  • Food production (for humans)
  • Fresh water
  • Production of fuel / energy
  • Genetic resources (diversity)
  • Habitat provision
  • Nutrient cycling
  • Purification (of water, soil, air)

Living machines can enhance biodiversity and ecosystem services in the surrounding area. Living machines can degrade pollutants, assimilate nutrients, sequester heavy metals and break down various toxic organic compounds (Todd, 2004). 

In a water body like a canal or pond, a restorer “jump starts” the aquatic ecology, enabling organisms to metabolise nutrients in the pond. The restorer creates important habitat, adds oxygen, and re-circulates water, while increasing biological diversity (Todd, 2004).

Aquatic plants and microorganisms within living machines serve as food sources for various aquatic organisms, contributing to the food web and providing shelter for fish and invertebrates. 

These systems provide valuable research opportunities for studying ecosystem dynamics, species interactions, and the effectiveness of nature-based solutions in biodiversity conservation

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Typical operational setup and components of the Living Machine: (1) anaerobic reactor, (2) anoxic reactor, (3) closed aerobic reactor, (4) open aerobic reactors, (5) clarifier, and (6) “ecological fluid bed”. Figure by MIT OpenCourseWare.
Operational setup of open aerobic tanks in a greenhouse of the South Burlington living machine. Images from: Hung et al., (2014).

Technical requirements

Living machines typically consist of several interconnected components, including tanks or ponds filled with various plant species, gravel beds, and microbial communities. Todd (1994) provides more details. These components work together in a symbiotic relationship, with each organism playing a specific role in the treatment process. Living machines are often modular and scalable, allowing them to be adapted to different environmental conditions and treatment requirements. They can range in size from small-scale systems for individual households or communities to larger installations for industrial or municipal wastewater treatment.

Customising the design of living machines to accommodate the specific biodiversity goals and ecological characteristics of Te Moananui Oceania, such as selecting native plant species and aquatic habitats that support local flora and fauna is an important technical consideration. So is ensuring optimal water quality within the living machines, including appropriate nutrient levels, oxygenation, and pH balance to support diverse aquatic life. Monitoring and maintenance is key to the success of living machines.

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A schematic diagram of the Findhorn Living Machine system. Image by Organica Ecotechnologies.

Issues and Barriers

While living machines offer promising solutions for sustainable wastewater treatment and ecological restoration, they also pose challenges related to design complexity, maintenance requirements, and regulatory approvals. Additionally, their effectiveness may vary depending on factors such as climate, soil type, and pollutant load.

In Te Moanui Oceania, the implementation of living machines may face several additional barriers. Many people in the region will not be familiar with living machines and their benefits for wastewater treatment. Educating communities and decision-makers about these technologies is crucial for their adoption. The upfront costs of designing and installing living machines can be significant, posing a barrier to adoption, especially for communities with limited financial resources in Te Moanaui Oceania. Building and maintaining living machines requires specialised knowledge about native plant and aquatic animal communities and skills in ecological engineering. The availability of trained personnel to design, construct, and manage these systems may be limited in some areas.

Cultural attitudes, social norms, and perceptions about wastewater treatment technologies may influence community acceptance and participation. Hung et al., (2014) discuss other limitations of living machines.

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Boyne River School Ecology Centre sewage treatment. Image from Todd (1994).


In Te Moananui Oceania, there are several opportunities associated with the implementation of living machines. Living machines offer an opportunity to treat wastewater locally, cheapley, and without imported chemicals, providing a sustainable source of water for irrigation, industrial processes, and non-potable uses.

Living machines can contribute to habitat restoration and conservation efforts by creating artificial wetlands and supporting native flora and fauna.

Implementing living machines presents an opportunity to engage local communities in environmental stewardship and education initiatives. By involving communities in the design, construction, and maintenance of these systems, awareness and ownership of environmental issues can be fostered. 

Te Moananui Oceania’s unique ecosystems offer a valuable research opportunity for studying the effectiveness of living machines in diverse environmental conditions. Other benefits and opportunities to explore with living machine are described in Hung et al., (2014).

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Financial case

While the upfront investment for installing living machines may be high, they can offer long-term cost savings. Reduced energy consumption, lower maintenance requirements, and potential revenue generation from treated wastewater reuse can offset initial capital expenditures.

By remediating pollution and protecting water quality, living machines can help avoid costs associated with pollution and cleanup efforts. This includes mitigating the impact of nutrient runoff on coral reefs, fisheries, and other marine ecosystems in Oceania.

Investing in living machines might stimulate green economic growth in the region by creating job opportunities in ecological engineering, water management, and environmental consulting. Additionally, the development of local expertise in sustainable wastewater treatment technologies can support economic diversification and innovation. Well-designed living machines can enhance the aesthetic appeal of urban areas and provide opportunities for ecotourism and recreational activities such as birdwatching, fishing, and nature walks, thereby contributing to local economies and community well-being.

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The Living Machine, Findhorn Foundation, United Kingdom. Photo by Julian Paren / The Living Machine, Findhorn Foundation
Emmen Zoo living machine. Photo by Inhabitat.
  • Bryant-Tokalau, J. (2018). Indigenous Pacific approaches to climate change: Pacific Island countries. Springer.
  • Carter, L. (2018). Indigenous pacific approaches to climate change: Aotearoa/New Zealand. Springer.
  • Hung, Y. T., Hawumba, J. F., & Wang, L. K. (2014). Living Machines for bioremediation, wastewater treatment, and water conservation. Modern water resources engineering, 681-713.
  • Mihaere, S., Holman-Wharehoka, M. T. O., Mataroa, J., Kiddle, G. L., Pedersen Zari, M., Blaschke, P., & Bloomfield, S. (2024). Centring localised indigenous concepts of wellbeing in urban nature-based solutions for climate change adaptation: case-studies from Aotearoa New Zealand and the Cook Islands. Frontiers in Environmental Science, 12, 1278235.
  • Todd, J. (1991). Ecological engineering, living machines and the visionary landscape. Ecological Engineering for Wastewater Treatment, C. Etnier and B. Guterstam (eds.), BokSkogen, Stensurd Folk College, Trosh, Sweden, 335-343.
  • Todd, J. (1994). Living Machines and Ecological Design: A New Synthesis. Bulletin of Science, Technology & Society, 14(2), 69-74.
  • Todd, J. (2004). Restorer eco-machines for the culture of aquatic animals and the restoration of polluted aquatic environments. BioInspire Magazine, 19.
  • Watson, J., & Davis, W. (2019). Lo-TEK. Taschen.
  • Yaron, P., Walsh, M., Sazama, C., Bozek, R., Burdette, C., Farrand, A., … & Kangas, P. (2000). Design and construction of a floating living machine. In Proceedings of the Twenty-Seventh Annual Conference on Ecosystems Restoration and Creation. Hillsborough Community College, Plant City, FL, pp. 92À101.

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