Constructing artificial wetlands to reduce flood risk
Glasgow and Clyde Valley Green Network Partnership, United Kingdom
Description
The lochs and wetlands within the Gartloch and Gartcosh area are natural heritage sites. The area has a history of flooding, and there are some water quality concerns. These areas are home to a rich assortment of wildlife and habitat, whilst also holding significant housing potential for a growing population. The Seven Lochs Wetland Park was established in July 2016 on 16 square kilometres of this land. It is managed by a unique partnership among Glasgow City Council, North Lanarkshire Council, Forestry and Land Scotland, Scottish Natural Heritage, The Conservation Volunteers Scotland, and two local community development trusts. The partnership started off as a steering group in 2012 and evolved to become The Seven Lochs Partnership in 2016 to consider how best to manage the site. This case study shows how the integration of nature-based solutions into existing local planning, the assimilation of cross-sectoral co-benefits, and a partnership governance structure can pave the way for innovative financing solutions and open the door for a wide range of new opportunities.
Challenges
Surface water is a central feature of the Gartloch and Gartcosh site, which is composed of a complex network of lochs, wetlands, seasonal water bodies, and drainage ditches. The area is in large part low lying and is the headwaters of four catchments draining into four main watercourses, making it prone to flood risks. These watercourses all drain into urban areas and have a history of flooding. The presence of residential developments and fragmented farmland further heightens this risk. Water quality is an additional concern. Whereas the general water quality is good, a couple of downstream sites are affected by diffuse pollution and do not meet good ecological status as per the Water Framework Directive. Other non-water-related challenges include loss of biodiversity and natural habitat, high development pressure, and endangered natural heritage, among others.
©Chris Helzer
Financing
Both the partnership governance structure and the multi-sector approach were essential for securing £6.8 million funding for the project, including a £4.5 million grant from the national Lottery Heritage Fund. Other funding is being provided by the project partners, Scottish government, and charitable trusts. The partnership also continues to nurture an enabling environment by providing a wide range of opportunities for local people to learn about and help manage heritage and nature in the park.
Governance:
Key to the success of this initiative was the incorporation of multiple benefits across multiple policy agendas (flood mitigation, climate adaptation, recreation, heritage, biodiversity, education), with existing local policies for regeneration and development (such as the Glasgow and Clyde Valley Strategic Development Plan, 2012) to develop a shared, long-term vision for the area. The Seven Lochs Vision and Masterplan (2013) has been adopted by both Glasgow and North Lanarkshire Councils, and will inform and support future development and regeneration activity.
This wide spectrum of interests paved the way for the formation of a unique partnership to govern the project. This was further strengthened by the need for co-decision-making between the Glasgow and North Lanarkshire Councils regarding the management of publicly owned land and planning of development within the park boundary. The councils gave the project additional anchoring and legitimacy by committing to include the park vision in their strategic development frameworks for the area. (North Larnarkshire has already done so, and Glasgow will soon follow suit). This means that developers must work with the partnership to identify how new development can contribute to delivering new green infrastructure. The new green infrastructure within the development boundary—such as Sustainable urban drainage (SuDS), walking and cycling routes, and new greenspace—is a requirement for planning permission and will be delivered by developers. Glasgow and North Lanarkshire councils can also request a contribution from developers towards new green infrastructure on adjacent land.
Actions and impacts
A mapping exercise of various flood scenarios was conducted as part of the Seven Lochs Hydrological Study. The study indicated that improvement and better management of natural wetlands, and the creation of wetland habitat linked to planned development, would help mitigate flood risk as well as improve water quality.
As of mid-2019, the project was in its initial implementation phase. The following measures were in place to help reduce flood risk in the surrounding communities as well as in downstream areas: creating new areas of wetland habitat, installing floating islands, restoring peatland, and de-culverting a watercourse. Further actions include the preservation and expansion of reedbeds and marsh, including planting the floating islands with reedbed vegetation to facilitate removal of nutrients and improve water quality. Water quality is regularly monitored to assess these measures, but no conclusions can yet be drawn as to whether water quality has already improved.
References
- AECOM. (2011). Gartloch and Gartcosh Hydrological Study.
- (2011). Gartloch and Gartcosh Surface Water Management Strategy.
- Collective Architecture, AECOM, Brown & Wallace, MCM Associates. (2013). Seven Lochs Wetland Park: vision and masterplan.
©Chris Helzer
