Restore wetlands and/or coastal ecosystems to dissipate the effects of flooding and/or storms

This project aimed at the reconstruction of the Lepiku channel that is part of the drainage system, which starts next to the Tallinn Botanic Garden and includes wetlands, detention ponds, ditches and channels and flows into the Pirita river. The aim of the project was to improve the quality of the stormwater that flows into the Pirita river which is a Natura 2000 site and flows into the Baltic Sea. The work included: widening of channel bottom in different segments, creating artificial dykes and rapids and creating suitable conditions for the aquatic plants exhibited in Botanic Garden (ref 1). With the project, 200m of the channel was reconstructed (ref. 5).

Within the territory of the Region of Attica there are more than 100 wetlands including streams and their estuaries, coastal marshes and lagoons, lakes and constructed wetlands. They constitute “biodiversity islands” within a broadly degraded environment and offer the inhabitants of the Attica Region the opportunity to stay in touch with nature. A strategy and an action plan were developed for the conservation and restoration of these ecosystems in fighting climate change within the EU-funded OrientGate transnational co-operation project. (Ref. 1)
Climate Change is expected to put additional pressure on these habitats as, based on future climate projections, Attica’s vulnerability to drought is expected to rise from low to moderate by the year 2100. Drought episodes are expected to last longer and occur more frequently than in the past. This phenomenon is expected to have a serious impact on Attica wetlands as most of them are rain-fed. (Ref. 1)

The scheme was designed to manage surface water runoff from a 1 in 30 year event and to always intercept and treat the, often more polluted, first flush of highway runoff (ref. 1). A total of 21 linear rain gardens (total of 148m2) were constructed within the grass verge, allowing for the constraints of access, below-ground services, street furniture and trees. The rain gardens utilise a combination of clean stone aggregate and proprietary units to create void space beneath a planted topsoil layer. They were designed to capture runoff from 5500 m2 of highway from a total surface area of 7100 m2 (ref. 1).

The Grand Park Garonne urban project aims to rehabilitate and develop the banks of the river Garonne that runs 32 kilometers through the city. From 2015, several development projects was planned to be carried out for a total of 28.7 million euros across 3 areas: the Garonne downstream, Toulouse center and the city's "green lung" Island of Ramier (Ref. 1, 4). Within these are 12 sites that consist of 40 pilot projects for operations. Among these are projects focused on protecting and restoring natural habitats and species in order to create a citywide green corridor (Ref. 8).

In response to floods that had been afflicting the Rhiwbina area of Cardiff, a capital scheme was promoted in order to develop an integrated Rhiwbina Flood Defence Scheme. First, a pond was built in the Caedlyn Park to capture peak flows during extreme rainfall (ref 2; ref 8). The City of Cardiff also built low walls alongside the brook that flows through the neighbourhood to better channel water while also removing debris and reinstating the banks that had eroded over time (ref 1; ref 2). Additionally, by realigning and widening the watercourse, establishing earth bunds and creating a large attenuation pond downstream that aligns with the drainage system (ref 7). Taken together, flood risk decreased for the area overall, assisting local residents.

The renaturalization of streams is a common strategy for improving the ecological quality of water bodies as mandated by the European Water Directive. For that reason, parts of the Aa stream in Münster upstream until its flow into the Aa lake covering 2.6 km were renaturalized from 2012 to 2013. Renaturalization is a means to restore the natural river banks, local ecosystems of the Aa rive and improve the water quality of the Aa lake (Ref. 1 and 3).

The Restoration of degraded wetlands in Wolfschlugen (in the administrative district of Stuttgart) was conducted within the wider regional level of sustainable urban development to enhance resilience, protect the city from flooding, support sustainable development, and safeguard biodiversity. Ditches and craters line the 700 metres long and 50 - 70 metres wide strip of landscape northeast of the development boundary behind the Wolfschlugen forest cemetery. This is formed by the Riederwiesen, which absorb water to protect the place from flooding. The wetland should protect people at least during a so-called hundred-year flood and at the same time offer animals and plants a habitat. (ref 3, 11)

The city of Salford has experienced several floods and is at risk of flooding once every 100 years (Ref1). The majority of properties in the city that lie in a high-risk flood zone are in the floodplain of the Irwell. The UK's Environment Agency and the council, designed a flood prevention scheme which included temporary water storage areas which will store floodwater on the existing Castle Irwell playing fields and public open space, and double as sports area otherwise (Ref 5). It aimed to have its own wetland and wildlife habitat, and will help protect hundreds of homes and businesses (Ref 4).

The Carbon Landscape is a pioneering project in landscape restoration in Wigan, Warrington and Salford. Led by the Lancashire Wildlife Trust, it will revitalize a landscape left devastated by decades of coal-mining and peat extraction (Ref 5). It works to restore key habitats and reconnect local people with their unique natural heritage, preserving it for future generations. The restoration of the peat base to lowland raised bog provided an opportunity for carbon sequestration and storage (Ref 1). There is a strong vision to reconnect local people with their rich natural heritage, creating opportunities and a sense of pride in the local area (Ref 4).

Warwickshire Wildlife Trust has completed an urban river restoration on the Guphill Brook that aims to restore the brook's natural features and enhance the surrounding habitat. "The project [is expected to] bring multiple benefits to diminishing wildlife and deprived local communities but also importantly to flood risk reduction, which is becoming ever more important with the increased negative effects of climate change." (Ref. 1)