Urban flooding (stormwater)

The Ringsend Open-Air Laboratory project in Dublin, Ireland, is part of a broader effort to adapt urban areas to increasing climate change risks. This initiative focuses on installing green roofs and deploying a network of environmental sensors to enhance urban resilience. Launched in 2018 under the Horizon 2020 OPERANDUM project, the effort seeks to find nature-based solutions for climate change impacts worldwide. Led by the University of Bologna, OPERANDUM involves over 20 partners, primarily in Europe, working together to address environmental challenges like flooding, drought, and coastal erosion through the establishment of ten "Open Air Laboratories" globally.
In Dublin, the project aims to bolster flood resilience in Ringsend, a critical economic area near the city’s tech district, which faces substantial flood risks due to its low elevation and proximity to the Dodder River. This river, which flows through both rural and urban areas before meeting the River Liffey near Ringsend, has caused property and infrastructure damage from extreme rainfall and combined river and tidal flooding.
Green roofs play a key role in mitigating urban flood risks in this project. These rooftop gardens absorb large volumes of rainfall before it reaches the streets, easing the load on existing flood prevention systems like storm drains and gullies and reducing the need for additional "grey" infrastructure. Based on community insights and recommendations, construction has begun on a green roof on top of the CHQ building in Dublin’s Docklands, in partnership with Dogpatch Labs.Complementing this, over 100 sensors have been deployed in recent research trials across Dublin. OPERANDUM researchers are now building on this foundation to create a denser, more reliable, and cost-effective sensor network, with data from earlier low-cost sensor trials made publicly accessible via Dublinked, Dublin’s open data platform, and exploring the use of LPWAN for environmental sensing. (1-5, 7)

Torslanda School is a newly built elementary school (years 0-6) where the schoolyard includes innovative ways to manage rainwater. The school was initially part of the Rain Gothenburg project, which aims to make the city, and this school, the best in the world when it rains. It was also a pilot project within the city's "equal building" initiative, aiming to make indoor and outdoor environments accessible and attractive to everyone regardless of gender identity, functional diversity or age [Ref. 1]. The main element of the schoolyard is a "river" to which water will be led when it rains, combining stormwater management with opportunities for play and education. The system will retain about 310 m3 of water and treat it before releasing it to a recipient. The river will be used to teach the children about climate, ecology, biodiversity and the water cycle. The river and schoolyard are connected to a natural wetland [Ref. 3, 4]. The school is run by the City of Gothenburg, who initiated the project, employing an architecture firm and a construction company to design and build the school and schoolyard [Ref. 3-5].

The Alexandria Governorate is especially susceptible to the impacts of climate change, a vulnerability exacerbated by its dense coastal communities and rapidly growing population (2). Both demographic shifts and urban development intensify how climate phenomena affect the people and infrastructure of Alexandria (1). Buildings, roads, and other concrete structures absorb and release solar heat, significantly contributing to the urban heat island effect, which is causing temperatures in the city to rise faster than in less developed areas (1). Despite Alexandria’s growing need for cooling green spaces, they currently make up only 0.25 percent of the total area within the Governorate, highlighting an urgent need for environmental interventions (3-6).
In response, Ahmed Gaber, chairman of the Alexandria Water Company, initiated a public awareness campaign in 2023 focused on the numerous benefits of planting green roofs (3-6). Green roofs serve multiple purposes: they extend the longevity of buildings, lower energy consumption, improve air quality, increase biodiversity, manage rainwater runoff, and mitigate the urban heat island effect (3). Furthermore, Gaber has emphasized the visual appeal of eco-friendly roofs, noting that green roofs offer an aesthetically pleasing option that enhances the urban landscape while serving critical environmental functions (4).
This initiative by the Alexandria Water Company marks a pioneering step among governmental organizations in the region, as they lead efforts to address climate and environmental challenges actively. The company has begun planting green roofs across its facilities, including the new Al-Mashishya water station, where green spaces atop buildings are set to bring lasting environmental benefits to Alexandria. Through these efforts, the Alexandria Water Company is working to set an example for public and private sectors alike (3-6).

The City of Mobile has developed and implemented a Storm Water Management Program (SWMP) as required by the regulations of the Environmental Protection Agency (Ref 1). Flooding is a significant issue in Mobile, occurring frequently throughout the town (Ref 3). The SWMP aims to protect water quality and prevent harmful pollutants in stormwater runoff from entering the Municipal Separate Storm Sewer System (MS4) area (Ref 1). Stormwater runoff refers to rainfall that does not seep into the ground but instead flows over yards, streets, parking lots, and buildings, eventually entering the storm sewer system, which directs it into creeks, rivers, bays, and the Gulf of Mexico (Ref 1). Stormwater can collect pollutants such as trash, debris, sediment, heavy metals, oils, and hazardous household materials. Additionally, development increases impervious surfaces, leading to more stormwater runoff (Ref 2).

Chickasabogue Park, a 1,100-acre outdoor recreation facility and wildlife refuge in Eight Mile, Alabama, is the largest park in Mobile County (Ref 3). Since 2022, the park has undergone extensive renovations aimed at increasing public access to green spaces and shoreline recreational areas, particularly along Chickasabogue Creek, while offering a variety of outdoor activities in a natural setting and preserving local biodiversity (Ref. 3).
The improvements focus on enhancing the day-use area, including upgrades to the playground, a splash pad, basketball courts (adapted to heavy rains with water-permeable materials), and a ball field (Ref 1, Ref 2). Additionally, a new pavilion site and an events and interpretive centre are being developed (Ref 1, Ref 2). Sidewalks and family-friendly walking trails are being built, and improvements are also being made to the park's mountain bike trail and disc golf course (Ref 2), providing more opportunities for outdoor physical activities in nature. Other significant upgrades include the creation of a restroom and a new parking lot with permeable pavers to prevent flooding (Ref 2). Critical infrastructure work is underway, including the installation of underground utilities, water, sewer systems, and roadwork (Ref 2). Furthermore, a new Recreational Vehicles (RV) campground with 38 spaces is in the works (Ref 2).
These upgrades are part of a broader initiative aimed at ensuring the public can quickly access and enjoy natural resources (Ref 2). The renovation also emphasises the cultural heritage and historical significance of the park, with plans to use architecture, design, and artefacts to honour the different cultures that once lived in the area (Ref 2). The next phase includes seeking funding to renovate the beach area and construct a new boat ramp (Ref 1).

The PARC Rain Garden project in Plymouth, Michigan, is an innovative initiative led by the Plymouth Arts and Recreation Complex (PARC) and Friends of the Rouge, aimed at addressing stormwater management and enhancing local environmental quality. Supported by a $400,000 grant from Michigan’s Department of Environment, Great Lakes, and Energy (EGLE) through its Nonpoint Source Program, this project will involve the construction of over 31,500 square feet of rain gardens located on the property of Plymouth Arts and Recreation Complex (PARC). These gardens are designed to filter up to 240,000 gallons of stormwater per rainfall event, preventing runoff from entering local waterways like the Tonquish Creek. The rain gardens will also mitigate flooding, reduce pollution, and create a more stable water flow in the Rouge River watershed, which is heavily impacted by urban development.
In addition to their environmental benefits, the rain gardens will provide aesthetic and ecological value to the PARC campus. The plantings, featuring native Michigan species, will create habitats for pollinators such as bees, butterflies, and birds, complementing the existing beehives on the PARC rooftop. The project aims to showcase the feasibility of integrating green infrastructure into routine construction, encouraging its adoption in other urban areas and residential spaces.
Ultimately, the PARC Rain Garden project will not only improve stormwater management but also serve as a model for sustainable urban development, enhancing the landscape while fostering environmental stewardship in the Plymouth community.
(Ref.1,2)

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)

A new landscape plan for the Santry River, developed since 2019, envisions it as “the backbone of a green infrastructure project,” designed to support nature, pedestrians, and cyclists. The project will create a continuous route from the Dublin Bay Biosphere at St Anne’s Park to the wider hinterlands of Dublin at Sillogue.
The plan proposes transforming the Santry River into an “integrated green-blue landscape for ecology and recreation,” incorporating a variety of sports, cultural, and leisure activities. Through an agreement with Fingal County Council and the National Transport Authority, Dublin City Council has commissioned studies to address the existing flood risks along the river.
The council’s goals for the Santry River include river restoration, flood mitigation, greenway development, and environmental protection, extending from the river’s origin in Harristown within Fingal County to its outlet at James Larkin Road. The project framework will span four years, with annual reviews and budget assessments.
The project team has engaged the public in early autumn of 2022 to gather input on these plans, as the Santry River project aims to create a vibrant River Park that integrates natural and recreational elements. Running through North Dublin, this new green-blue infrastructure will serve both ecological and community needs, offering opportunities for sports, culture, and relaxation. Ultimately, it will form a natural corridor linking the Dublin Bay Biosphere at St Anne’s Park with Sillogue, promoting biodiversity while enhancing accessibility for pedestrians and cyclists (2).

Perch Creek is one of the many meanders that drain into Dog River (Ref 2), located just west of Mobile Bay (Ref 3). These areas include sensitive, tidally influenced marshes and flats where the brackish water of the Bay meets fresh waters (Ref 1). The Perch Creek Nature Trail & Preserve project aims to protect 96 acres on Perch Creek (Ref 3). It is part of efforts to revitalise Mobile’s coastal community and improve the water quality of the city's urban river (Ref 2), following the devastation of the BP oil disaster in 2010.
The project focuses on two main aspects: creating a low-impact recreational destination to spark economic redevelopment, and preserving Mobile’s coastal wetlands (Ref 1).
The conservation aspect involves wetland acquisition, marsh restoration, and invasive species management, improving water quality in both waterbodies (Ref 1). The area, rich in wildlife, requires habitat protection, including for migrating birds, foxes, alligators, manatees, and bald eagles (Ref 1). Brackish marshes on the property serve as nurseries for fish, while forested areas provide natural corridors for wildlife (Ref 3). The wetlands also play a role in flood control, acting as natural sponges to absorb rising tides and cleanse stormwater runoff before it reaches Mobile Bay (Ref 1). Additionally, they store stormwater, helping mitigate flooding as storms intensify (Ref 3).
The recreational aspect includes developing nature-based recreation, such as nature trails and kayak launches, as well as expanding public access to natural resources (Ref 3). In 2018, the Perch Creek section was added to the Alabama Coastal Birding Trail, with educational signage for kayakers (Ref 1).
This comprehensive project preserves vital habitats and flood-absorbing wetlands, while providing outdoor recreation opportunities and supporting the coastal community's recovery (Ref 2). It combines high-quality water resources, wildlife connectivity, scenic beauty, and outdoor recreation (Ref 3).

In 2015, The Greening of Detroit and the Joy-Southfield Community Development Corporation collaboratively installed a bioswale in Stein Park, Detroit, as part of a broader effort to mitigate flooding in the Cody Rouge neighborhood. The area, particularly affected by heavy rains and flooding due to its proximity to the Rouge River, suffered significantly during the 2014 Great Flood, highlighting the need for improved stormwater management. The bioswale, a Green Stormwater Infrastructure (GSI) feature, was designed to capture and infiltrate up to 6,000 gallons of stormwater, diverting it from the city’s aging combined sewer system. By reducing the risk of sewer overflows, this installation also decreases the flow of untreated water into local waterways.

Funded by an $83,000 Kresge Foundation grant, the bioswale incorporates a mixture of native plants, prairie wildflowers, and ornamental grasses to filter sediment and pollutants. In addition to stormwater management, the project aims to enhance community engagement and economic revitalization. Students from Cody DIT High School's Green Team participated in the planting and design process, learning valuable skills in landscape architecture and green infrastructure. The project also ties into the Joy-Southfield CDC's vision of establishing a "green zone" to promote community safety, economic growth, and environmental stewardship.

Future plans include further green infrastructure development, such as additional bioswales and a parking lot with pervious pavers, contributing to Cody Rouge’s transformation into a model neighborhood for green development. This project not only addresses urgent environmental concerns but also fosters community pride, safety, and economic opportunities, positioning the neighborhood as a leader in Detroit’s green infrastructure movement.
(Ref.1-4)