Creation of artificial wetlands

The environmental impact of golf has led to growing calls to make the sport more sustainable (1). Golf course maintenance often involves carbon-intensive fertilizers, frequent mowing, and, in some cases, the clearing of forests or trees that naturally absorb carbon dioxide to make room for expansive fairways (1). However, the Tournament Players Club (TPC) Michigan is working to create courses that benefit both golfers and the environment (2).
Fifteen years ago, the site was a neglected floodplain along the Rouge River, initially purchased by Henry Ford in 1915 and once littered with community waste and old motor parts from the Ford Motor Company (2-3). Today, it has been transformed into an 85.8-hectare course that supports a diverse range of wildlife, including birds, fish, foxes, and coyotes (2). Led by Jack Nicklaus, the restoration aimed to turn this former waste site into an eco-friendly course (2). With guidance from Audubon International, the course was converted into a wildlife sanctuary, becoming the world’s first golf course to receive the prestigious John James Audubon Environmental Steward Award for ecological restoration (2).
TPC Michigan features native Michigan plants, such as viburnums, which produce berries for wildlife, along with various native grasses (2). To prioritize environmental stewardship, the course managers have created buffer zones to protect natural habitats and conserve water by using coring methods to monitor soil moisture (2). Pesticide use is minimized; instead, staff monitor for signs of disease or pests and test the soil to determine the specific nutrients needed for the turf (2). The course’s links-style layout includes rolling fairways, tiered greens, and natural wetlands, with tee options ranging from 5.5 to 6.4 meters (4). By establishing a wildlife sanctuary, TPC Michigan offers golfers a unique experience that fosters a connection with nature (3).

The former Kulturpark Plänterwald, once the only permanent amusement park in the GDR, closed in 2001 due to declining visitor numbers. Over time, the 23-hectare site became a ‘lost place,’ falling into disrepair. In 2014, the state of Berlin reacquired the area, and two years later, Grün Berlin initiated its redevelopment with a sustainable development concept that places significant emphasis on rainwater management.
The project’s goal is to avoid discharging rainwater into the sewer system and instead manage all precipitation on-site. This approach addresses both heavy rainfall events and extreme drought conditions, creating a sustainable rainwater management system. A central element of this concept is the historic but dried-up water basin located near the iconic Ferris wheel. Plans include redesigning and reactivating the basin, incorporating terraces and a shallow water zone, transforming it into a key part of the rainwater cycle while providing an attractive recreational and adventure area. (Ref. 1; Ref. 2)
In the future, the water basin will no longer be purely decorative but will serve as a critical artificial water reservoir. To support this function, it will be equipped with a natural horizontal filter system featuring reeds for rainwater purification. Pre-treated water will flow into the newly designed 3,000-square-metre basin near the Ferris wheel. Rainwater collected in the basin, along with water stored in cisterns throughout the park, will irrigate the site’s vegetation. This innovative approach ensures sustainable water use and contributes to the ecological revitalization of the park. (Ref. 1; Ref. 3)
By integrating sustainable rainwater management into its redevelopment, the former Kulturpark Plänterwald is being transformed into a resilient and environmentally conscious space, combining historical preservation with modern ecological practices.

The Far West Detroit neighborhood faces significant challenges with its aging infrastructure. The neighborhood’s stormwater and sewer systems are combined into a single system that is only capable of handling a limited volume. During heavy rain events, the system's capacity is exceeded, causing excess stormwater and untreated sewage to overflow into the Rouge River, which negatively impacts the environment (Ref. 1).
Detroit is investing $40 million in a transformative stormwater management system in the Far West neighborhood near Rouge Park. Described by the Detroit Water and Sewerage Department as the largest project of its kind, it will redirect 98 million gallons of rainwater and snowmelt into two new detention basins and a renovated sewer system. The new wastewater system is expected to significantly reduce water volumes in Detroit’s combined sewer system during heavy rainfall and to provide flood relief for approximately 1,200 homes that have experienced flooding in recent years. This expansion, informed by community feedback, marks one of the city's most notable investments in green infrastructure to improve its overextended wastewater management system.
The project has been planned through extensive studies and community coordination since 2016, with construction set to occur in three phases, extending through 2026. Crews broke ground on the South Basin, North Basin, and sewer overhaul in July 2022, and progress is reportedly on track. In addition to the basins, the stormwater management initiative includes neighborhood improvements to enhance recreational opportunities for residents and visitors alike. Planned enhancements in Rouge Park will introduce wetland spaces with native flora, creating greener, more inviting areas in the community for residents to enjoy (Ref. 2).

Chandler Park, a historic park in Detroit constructed in the 1800s, underwent multiple expansions from 1922 to 1950 to include amenities such as a pool (later converted into a water park), a golf course, and public green spaces. In 2013, an expert panel recommended constructing a 2.5-million-gallon marshland within the park to provide a unique recreational and educational feature and incorporate green infrastructure principles for improved stormwater management. Completed in December 2019, the Chandler Park marshland was a collaborative project between The Greening of Detroit and the Chandler Park Conservancy, designed to enhance Green Stormwater Infrastructure (GSI) across 200 acres.
The marshland manages 2.5 million gallons of stormwater, substantially reducing the load on Detroit’s combined sewer system and minimizing basement flooding during heavy rains. Engineered with rain gardens, bioswales, and a pump system circulating up to 4 feet of water, the marshland fosters a balanced ecosystem with higher oxygen levels, benefiting local flora and fauna.
With 4,500 native plants, the marshland supports diverse wildlife, including migrating birds, turtles, frogs, pollinators like bees and butterflies, and natural mosquito predators. This project not only contributes to flood mitigation but also improves water quality by capturing stormwater and allowing pollutants to settle.
Additionally, the marshland provides a foundation for future environmental education, with plans to add an outdoor classroom and public learning spaces. The use of native plants ensures low maintenance and sustainability, requiring minimal water and fertilizers. By creating new habitats and recreational areas, the Chandler Park Marshland promotes biodiversity, environmental education, and community engagement, while alleviating urban runoff’s impact on Detroit’s sewer system.
(Ref.1-3)

Ballymun is a suburban area on the north side of Dublin, Ireland. Originally developed in the 1960s, Ballymun was built to address Dublin’s post-war housing shortages, with iconic high-rise towers and flat complexes. However, over the years, the area faced social and economic challenges, leading to a reputation for issues such as poverty, unemployment, and lack of services.
In response, the Irish government launched the Ballymun Regeneration Project in the late 1990s. As part of the Ballymun Regeneration, Poppintree Park has been transformed into a 45-acre public space at the heart of Ireland’s celebrated urban renewal project in Ballymun Town Centre. This redevelopment followed an extensive public consultation process, incorporating input from local residents, sports clubs, community groups, and youth organizations.
Poppintree Park now offers a range of upgraded amenities, including a Tree Trail featuring 15 native tree species, enhanced biodiversity, extensive wetlands, sustainable drainage systems, and spaces for passive and active recreation. The park also features a 1.25-acre playground for children aged 0-12, an amphitheater with a permanent pond, and a fully accessible pathway network with abundant seating and viewing areas. Over 50,000 plants have been added to enhance the park’s natural beauty.
The park’s transformation, led by Ballymun Regeneration Ltd., involved significant engineering and landscaping efforts. Mitchell + Associates provided the detailed landscape design, construction drawings, and supervised the landscape works.
Completed in 2010, Phase 1 of Poppintree Park’s redevelopment represents an investment exceeding €6 million. The project includes substantial earthworks, drainage systems, gabion walls, three limestone-paved entrance plazas, structural retaining walls, a cantilevered pond walkway, diverse path surfaces, and high-quality playground construction. (1-7, 10)

The Filter Ecosystem project, completed in 2007, aims to improve water quality and enhance the ecological health of the Molentargius wetland area in Sardinia, Italy, also known as the Molentargius Saline Regional Nature Park. This diverse territory includes freshwater basins such as Bellarosa Minore and Perdalonga, saline water basins like Bellarosa Maggiore and Stagno di Quartu, and the predominantly dry area known as Is Arenas.
The Molentargius ecosystem is a crucial European site for various aquatic birds and features diverse flora, including endemic species and endangered plants on the "Red List." It is one of the few globally recognized wetlands of international importance for aquatic birds located entirely within a large urban center, protected as a biotope by the RAMSAR Convention in Sardinia's major urban area. Since the 1980s, it has suffered environmental degradation due to inadequate infrastructure for wastewater management and human pressures.
Implemented by the city of Cagliari, the project employs a phytoremediation technique to supply water to the ponds. This involved constructing a phytoremediation system between the Bellarosa Maggiore and Bellarosa Minore ponds, functioning as a surface flow filter ecosystem resembling a marsh or wetland.
The system enhances natural self-purification processes, promoting prolonged contact between water, organic matter, and plants. This setup creates microhabitats that support microbial flora crucial for purification. The project's primary goal is to treat wastewater from the Is Arenas treatment plant, ensuring that the treated water meets optimal conditions for sustaining the wetlands' biodiversity. Additionally, the project will expand reed bed areas, vital habitats for avian species, and is designed to purify up to 300 liters of water per second to meet the area's needs (Refs. 1, 2, 3).

Two new wetlands were established in Dodder Valley Park as part of the Dublin Urban Rivers Life Project (DURL). This project aimed to create integrated constructed wetlands (ICWs) at strategic locations in South Dublin County to purify wastewater and storm-water before it discharged into rivers.
The ICWs consisted of a series of cells resembling shallow ponds, typically 200 to 300 mm deep. Heavily planted with specific vegetation, these cells treated water by removing nutrients and harmful impurities, resulting in cleaner, purer water being discharged. The water flowing into the wetlands came from wastewater of misconnected appliances and storm-water pipes located under public roads, which collected rainwater from roads, footpaths, and the roofs and patios of houses.
These wetlands also provided important benefits, including flood alleviation, bioretention of particulates and nutrients, improved habitat conditions, and enhanced biodiversity. The project aimed to promote the relationship between green infrastructure and public well-being, creating a complex biological system that supports a diverse range of plants, animals, microorganisms, and hopefully attracts frogs, newts, and birds.
To increase native biodiversity, the wetlands were designed with pollinator-friendly plants and trees, making them visually appealing for park users and the public. A Wetland Planting Day took place on September 9, 2022, with over 40 participants, including residents and representatives from local organizations. This phase of the project fulfilled not only the objectives of the LIFE project but also those of the River Basin Masin Management Plan 2022–2027, the Water Framework Directive, the Climate Change Action Plan, the Floods Directive. (1, 2, 5)

The Upper Detroit Riverfront Habitat and Parks Restoration Project aims to restore and enhance vital fish and wildlife habitats along the Detroit River. This initiative seeks to rehabilitate approximately 30 acres of upland and shoreline habitats within Riverfront-Lakewood East Park, A.B. Ford Park, and Mariners Park (all located alongside the river), covering nearly one mile of the Detroit River and its shorelines.
Key outcomes include improving approximately 1,000 linear feet of existing shoreline along the Detroit River by incorporating native wetland edges and fish spawning shelves into the restoration efforts. The project also plans to enhance around 2,000 linear feet of canal shoreline and 800 linear feet along Fox Creek to create or improve habitats for fish and herpetological species. In Riverfront-Lakewood East Park, 28 acres are targeted for the establishment or enhancement of native vegetation to support birds, mammals, and pollinators. If feasible, the creation of about 7 acres of wetlands, along with shallow and deep-water habitats, is also part of the vision.
The project is guided by the City of Detroit's 2017 Parks and Recreation Improvement Plan and represents part of a broader strategy to revitalize the city’s green spaces after years of underfunding. With renewed commitment, the city has allocated nearly $12 million to enhance neighborhood parks, particularly in areas that have lacked investment over the past decade.
However, the project was temporarily halted in 2020 due to high water levels causing flooding in the adjacent neighborhood. As of 2024, it remains on hold while the City of Detroit conducts a flood mitigation study. Despite this delay, the project remains a critical step toward fostering community stewardship and creating sustainable green spaces that improve the quality of life for all Detroit residents.
(Ref. 1, 4, 5)

The Tres Rios Ecosystem Restoration Project is an ambitious initiative aimed at revitalizing a seven-mile stretch of the Salt and Gila Rivers in Phoenix, Arizona. The Tres Rios Environmental Restoration project involves the rehabilitation of nearly 700 acres in and around the Salt River, restoring a vital wetland and riparian habitat. Initially conceived in 1993 to tackle water quality issues and improve flood control, the project gained significant traction in the 2000s through a partnership between the City of Phoenix and the U.S. Army Corps of Engineers (USACE). Funding was structured with 65 percent from the USACE and 35 percent from the City of Phoenix and the Sub-Regional Operating Group Members, including Scottsdale, Tempe, Glendale, and Mesa.
The Tres Rios project encompasses habitat restoration, flood control, and recreational development, with the primary objectives being to restore a degraded ecosystem, enhance water quality, and provide new recreational spaces. Construction involved relocating 1.6 million cubic yards of earth to shape three large wetland zones and two deep-water retention basins. Additionally, 18,000 feet of underground water lines and 600 feet of 84-inch fiberglass effluent pipelines were installed. To establish a thriving wetland habitat, the project coordinated the planting of over 300,000 aquatic and terrestrial plants.
Habitat restoration efforts re-establish native vegetation and create wetland areas that support local biodiversity. The lush and scenic Tres Rios is now home to more than 150 different species of birds and animals like muskrats, raccoons, skunks, coyotes, bobcats, and beavers. By using treated wastewater to sustain the ecosystem, the project reduces dependency on natural water sources, thereby helping to mitigate water scarcity. The Tres Rios Ecosystem Restoration Project serves as a model for sustainable urban ecological initiatives, combining environmental health with community benefits. (1-8, 10-13)

The Dublin Urban Rivers LIFE (DURL) project incorporates two interconnected wetlands in Griffeen Park as part of its broader initiative to improve water quality, natural water management and aquatic biodiversity in urban areas. These wetlands were specifically designed as a natural sewage system to treat wastewater from the surrounding areas, addressing a significant environmental issue known as "domestic misconnection." Domestic misconnection occurs when household appliances, such as washing machines, dishwashers, and kitchen sinks, are incorrectly linked to surface water drains rather than the sewage system. This leads to untreated wastewater being directly discharged into local waterways, contributing to contamination.
In the River Griffeen catchment, which includes approximately 12,000 dwellings and associated infrastructure, domestic misconnections are a considerable threat to water quality. The DURL project focuses on identifying and rectifying these misconnected appliances to ensure that wastewater is properly treated before entering the river. This process will not only improve water quality but will also provide flood alleviation and support healthier aquatic ecosystems in the area.
The project is aligned with broader environmental policies, including the River Basin Management Plan 2022-2027, the Water Framework Directive, the Climate Change Action Plan, the Floods Directive, and the draft Biodiversity Plan. One of the key strategies is to use a Geographic Information System (GIS) to streamline inspections for domestic misconnections, making the process faster and more cost-effective.
The constructed wetlands in Griffeen Park, with a standing water depth of approximately 30 cm, are planted with a variety of native Irish species. These wetlands offer a natural, sustainable solution to wastewater treatment, with the potential for similar applications across Europe. (Ref. 2, 4)