Last updated: June 2024
Wetlands provide a varying degree of treatment of discharged water and are ideally suited for the containment and treatment of polluted water runoff, being a holistic example of Sustainable Drainage Systems (SuDS). The Dublin Local Authority installed an Integrated Constructed Wetland to treat polluted water discharged from the urban area, with the aim of cleaning urban runoff and drainage water. It was meant to purify water that discharges into a pond, and later on into the Tolka river. The project has been very successful in treating polluted water effectively, according to studies. (Ref. 1; Ref. 3)
Overview
Nature-based solution
- Blue infrastructure
- In-land wetlands, peatlands, swamps, and moors
- Green areas for water management
- Swales and filter strips
- Sustainable urban drainage systems
- Grey infrastructure featuring greens
- Riverbank/Lakeside greens
Key challenges
- Green space, habitats and biodiversity (SDG 15)
- Habitat and biodiversity restoration
- Green space creation and/or management
- Water management (SDG 6)
- Stormwater and rainfall management and storage
- Improvements to water quality
- Inclusive and effective governance (SDG 16)
- Inclusive governance
Focus
Management and improved protection of rivers and other blue areas, Ecological restoration of ecosystems, Protection of natural ecosystems, Monitoring and maintenance of habitats and/or biodiversity
Project objectives
1. Clean polluted urban runoff and sewage water;
2. Preserve the Tolka Valley ecosystem by preventing damage caused by pollutants in the water (Ref. 1; Ref. 3).
3. The wetland was designed so that it would blend in with the natural surroundings and thereby retain the aesthetic appearance of the place (Ref. 1).
4. The plants included in the wetland needed to be pollution tolerant and able to establish themselves quickly, and the project aimed at planting a wide variety of plants both native and introduced and known invasive species would be avoided. (Ref. 1)
Implementation activities
- An Integrated Constructed Wetland that mimics natural wetlands was created so that polluted water that ran through it could be filtered and thus become purified before reaching a retention pond. As a result, the water in the pond would become cleaner and also reduce pollution in the river into which it would flow (Ref. 1; Ref. 3).
- The wetland creation "consisted of the installation of a primary and secondary cell, planting of various plants and the diversion of the Finglaswood Stream into the wetland with major storm events by-passing the wetland. The plants in the wetland needed to be pollution tolerant and able to establish themselves quickly. Planting consisted of a wide variety of plants both native and introduced - known invasive species were avoided." (Ref. 1)
Biodiversity conservation or restoration-focused activities
Biodiversity restoration:
- Rehabilitate and restore damaged or destroyed ecosystems
- Restore species (native, endangered, or unspecified)
- Restore valued species
- Restore endangered species
- Clear and control invasive alien species
Main beneficiaries
- Local government/Municipality
- Citizens or community groups
Governance
Management set-up
- Government-led
Type of initiating organisation
- National government
- Local government/municipality
Participatory approaches/ community involvement
- Unknown
Details on the roles of the organisations involved in the project
The project was jointly initiated by Dublin City Council Parks and Landscape Services Division, Drainage Division and National Parks and Wildlife Service (Ref. 4). The wetland was a joint design by Dr. Rory Harrington of National Parks and Wildlife Service in co-operation with Dublin City Council (Ref. 1). The Integrated Constructed Wetland site’s manager is Mr. Martin Ryan, Senior Engineer in the Drainage Division of the Council (Ref. 3).
Project implemented in response to ...
... an EU policy or strategy?
Yes
(The wetland was constructed in order to comply with the EU Water Framework Directive and the Nitrates Directive (Ref. 1).)
... a national policy or strategy?
Yes
(The wetland was constructed in order to comply with the national Phosphorus Regulations (Ref. 1).)
... a local policy or strategy?
Unknown
Financing
Total cost
More than €4,000,000
Source(s) of funding
- Public national budget
Type of funding
- Direct funding (grants, subsidies, or self-financed projects by private entities)
Non-financial contribution
Unknown
Impacts and Monitoring
Environmental impacts
- Environmental quality
- Improved soil quality
- Water management and blue areas
- Improved water quality
- Enhanced protection and restoration of freshwater ecosystems
- Green space and habitat
- Increased conservation or restoration of ecosystems
- Reduced biodiversity loss
- Increased number of species present
- Increased protection of threatened species
- Improved prevention or control of invasive alien species
Economic impacts
- Unknown
Socio-cultural impacts
- Health and wellbeing
- Improved physical health
- Gain in activities for recreation and exercise
- Education
- Increased support for education and scientific research
- Safety
- Increased perception of safety
- Decreased crime rates
Type of reported impacts
Achieved impacts
Presence of formal monitoring system
Yes
Presence of indicators used in reporting
Yes
Presence of monitoring/ evaluation reports
Yes
Availability of a web-based monitoring tool
No evidence in public records
References
Ref. 1. Collins, & J., McEntee, D. (2009). A Constructed Wetland for the Removal of Urban Pollution in the Finglaswood Stream, Tolka Valley Park, Dublin [pdf]. Dublin City Council. available at: Source link (accessed 10th September 2020).
Ref. 2. Ecofys by order of: the European Commission (2016). Assessing Adaptation Knowledge in Europe: Ecosystem-Based Adaptation. [online] available at: Source link (accessed 10th September 2020).
Ref. 3. Laffiteau, C. (2011). The Tolka Valley Park Integrated Constructed Wetlands. [online] available at: Source link (accessed 10th September 2020).
Ref. 4. Dublin City Council (2017). Tolka Valley Park. [online] available at: Source link (accessed 10th September 2020).
Ref. 5. OPENFIELD Ecological Services (2008). Biodiversity Survey of the Integrated Constructed Wetland at Tolka Valley Park, Finglas, Co. Dublin. [pdf] available at: Source link (accessed 10th September 2020).
Ref. 6. Dublin City Parks (2017). Tolka Valley Greenway. [pdf] available at: Source link (accessed 10th September 2020).
Ref. 7. Natural Water Retention Measures (NWRM) (2015) River Tolka constructed wetland and enhancements, Ireland. Available at: Source link. Accessed on 10th September, 2020.
Ref. 2. Ecofys by order of: the European Commission (2016). Assessing Adaptation Knowledge in Europe: Ecosystem-Based Adaptation. [online] available at: Source link (accessed 10th September 2020).
Ref. 3. Laffiteau, C. (2011). The Tolka Valley Park Integrated Constructed Wetlands. [online] available at: Source link (accessed 10th September 2020).
Ref. 4. Dublin City Council (2017). Tolka Valley Park. [online] available at: Source link (accessed 10th September 2020).
Ref. 5. OPENFIELD Ecological Services (2008). Biodiversity Survey of the Integrated Constructed Wetland at Tolka Valley Park, Finglas, Co. Dublin. [pdf] available at: Source link (accessed 10th September 2020).
Ref. 6. Dublin City Parks (2017). Tolka Valley Greenway. [pdf] available at: Source link (accessed 10th September 2020).
Ref. 7. Natural Water Retention Measures (NWRM) (2015) River Tolka constructed wetland and enhancements, Ireland. Available at: Source link. Accessed on 10th September, 2020.