Last updated: October 2021
Since 2008, the City of Portland, Oregon has used various policies and programming to encourage the use of eco-roofs (vegetated roofs) throughout the city to address stormwater management (Ref. 2,3,4). In addition to stormwater management, eco-roofs have the benefits of: saving energy, reducing pollution and erosion in waterways, preserving fish habitats, creating new habitats for birds and insects, absorbing carbon dioxide, cooling urban heat islands, filtering air pollutants, and providing urban green space (Ref. 1,5). From 2008 to 2012, the City of Portland used the Ecoroof Incentive program to encourage property owners and developers to construct ecoroofs (Ref. 4,5,12). In 2018, the City of Portland adopted a mandate for ecoroofs in new buildings (Ref. 2,3,12). These policies and programs led to a growing interest in the use of ecoroofs, and resulted in the construction of over 130 ecoroofs (Ref. 3,4,11).
Portland Ecoroof
Source: Ref. 1
Overview
Nature-based solution
- Nature on buildings (external)
- Green roofs
- Green areas for water management
- Sustainable urban drainage systems
Key challenges
- Climate action for adaptation, resilience and mitigation (SDG 13)
- Climate change adaptation
- Water management (SDG 6)
- Flood protection
- Stormwater and rainfall management and storage
- Green space, habitats and biodiversity (SDG 15)
- Habitat and biodiversity conservation
- Green space creation and/or management
- Regeneration, land-use and urban development
- Promote natural styles of landscape design for urban development
Focus
Creation of new green areas, Strategy, plan or policy development, Monitoring and maintenance of habitats and/or biodiversity
Project objectives
Portland’s ecoroofs are largely designed to aid with stormwater management (Ref. 2,4,12), in broader efforts to increase the City’s resilience to natural hazards, disasters, and climate change (Ref. 3,9).
Stormwater management principles are used to protect the City against runoffs and flooding, and to maintain the health of the city’s watersheds (Ref. 7,12).
The City prioritizes the use of vegetation and infiltration to meet stormwater requirements because it improves resilience to changes in hydrology anticipated due to climate change (Ref. 7).
Furthermore, ecoroofs are incorporated into green building design to provide a ‘sustainable alternative to conventional roofing’ and ‘reduce the negative impacts from buildings on air, water, energy and the earth’ (Ref. 8).
Implementation activities
- From 2008 to 2012, subsidies of $5 per square foot were provided for projects meeting the following criteria: ‘be in the Portland city limits, be designed to manage stormwater, and be feasible and buildable within two years of receiving funds’. Projects were also evaluated on ‘cost estimates, size, ratio of green roof to total roof area, visibility, innovation, and the opportunity to engage diverse communities’ (Ref. 5).
- From 2018, the following criteria are mandated: ‘new buildings with a net building area of at least 20,000 square feet must have an ecoroof that covers 100% of the building area; at least 50% of the ecoroof vegetation must be an evergreen species; the vegetation should be hardy and achieve 90% coverage within 2 years of planting; the roof must reduce annual runoff volume by 50%; the roof must have at least 4 inches of growing media’ (Ref. 2).
- Energy conservation & avian monitoring studies were conducted on ecoroofs (Ref. 14,15).
- Support from the City has been provided, including providing classes, tours, events, technical assistance, and online resources for DIY ecoroofs and professional ecoroof service providers (Ref. 1,4,12,13).
Climate-focused activities
Climate change adaptation:
- Implement sustainable urban drainage infrastructure (e.g. to make space for water)
Biodiversity conservation or restoration-focused activities
Biodiversity conservation:
- Protect species
- Undertake specific measures to protect species
- Undertake specific measures to protect valued species
- Other
Main beneficiaries
- Local government/Municipality
- Other
Governance
Management set-up
- Government-led
Type of initiating organisation
- Local government/municipality
Participatory approaches/ community involvement
- Dissemination of information and education
Details on the roles of the organisations involved in the project
City Council – primary lead for initiative (Ref. 1-15).
Local Nonprofits – Green Roof information Think Tank (GRiT) – has provided green roof studies, symposia, and stakeholder testimony (Ref. 3); Green Roofs for Healthy Cities and Audubon Society had significant impact on awareness & research of green roofing in Portland (Ref. 3).
Developers & Property Owners – to build/ implement projects (Ref. 1).
Ecoroof Professionals – to build/ implement projects (Ref. 1).
Universities – Portland State University – greatly involved in ecoroof research for Portland (Ref. 3,12,13).
Project implemented in response to ...
... an EU policy or strategy?
No
... a national policy or strategy?
No
... a local policy or strategy?
Yes
(Grey to Green Initiative – launched in 2008, aimed to expand the city’s green stormwater management infrastructure (Ref. 13), Guidance on CC2035 (Central City 2035 Plan) Ecoroof Requirements and the SWMM (Ref. 1), City of Portland Green Building Policy (Ref. 1,4) – passed in 2011, and ‘require[d] ecoroofs for all new city-owned facilities and roof replacements on buildings greater than 500 square feet’ (Ref. 4))
Financing
Total cost
More than €4,000,000
Source(s) of funding
- Public local authority budget
Type of funding
- Earmarked public budget
- Direct funding (grants, subsidies, or self-financed projects by private entities)
Non-financial contribution
Unknown
Impacts and Monitoring
Environmental impacts
- Water management and blue areas
- Improved stormwater management
- Green space and habitat
- Increased green space area
- Increased number of species present
- Enhanced support of pollination
Economic impacts
- Increase of green jobs (e.g. paid employment positions)
Socio-cultural impacts
- Unknown
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
Yes
References
1. Environmental Services. (2021). Portland Ecoroofs. City of Portland. Available at: Source link [Accessed: 19 September 2021].
2. Sabin Center for Climate Change Law. Portland’s EcoRoof Requirements. LPDD. Available at: Source link [Accessed: 19 September 2021].
3. Morris, E.H. (2018). Portland Adopts a Green Roof Requirement in the Central City 2035 Plan. Source link. Available at: Source link [Accessed: 19 September 2021].
4. Georgetown Climate Center. (2017). Case Study: City of Portland, Oregon Ecoroof Incentive. Adaptation Clearinghouse. Available at: Source link [Accessed: 19 September 2021].
5. Environmental Services. (2021). Ecoroof Incentive. City of Portland. Available at: Source link [Accessed: 19 September 2021].
6. City of Portland. (2021). Guidance on CC2035 Ecoroof Requirements and the Stormwater Management Manual. City of Porland. Available at: Source link [Accessed: 19 September 2021].
7. City of Portland. (2020). 2020 Stormwater Management Manual. City of Portland. Available at: Source link [Accessed: 20 September 2021].
8. City of Portland. (2015). 37122 Comprehensive update to the City's Green Building Policy to reflect advances in green building knowledge and practices exhibit. City of Portland. Retrieved from: Source link [Document provided].
9. City of Portland. (2020). As Adopted Plan – Central City 2035. Available at: Source link [Accessed: 20 September].
10. Slothower, C. (2021). Eco-roofs growing into urban role in Portland. DJC Oregon. Available at: Source link [Accessed: 19 September 2021].
11. Portland State University and the City of Portland. Portland Ecoroof Map. Available at: Source link [Accessed: 19 September 2021].
12. Netusil, N.R. and Thomas, B. (2019). Ecoroofs in Portland, Oregon, USA. University of Nottingham Blogs – Blue-Green Futures. Available at: Source link [Accessed: 20 September 2021].
13. Chomowicz, A. (n.d.). 49th International Making Cities Livable Conference: Ecoroofs in Portland, Oregon. City of Portland. Retrieved from: Source link [Document provided].
14. Cunningham, C. and Liebezeit, J. (2015). Portland’s Ecoroof Avian Monitoring Project 2012-14: Final report. City of Portland. Retrieved from: Source link [Document provided].
15. City of Portland. (2013). Vegetated Roofs and Energy Conservation. City of Portland. Retrieved from: Source link [Document provided].
2. Sabin Center for Climate Change Law. Portland’s EcoRoof Requirements. LPDD. Available at: Source link [Accessed: 19 September 2021].
3. Morris, E.H. (2018). Portland Adopts a Green Roof Requirement in the Central City 2035 Plan. Source link. Available at: Source link [Accessed: 19 September 2021].
4. Georgetown Climate Center. (2017). Case Study: City of Portland, Oregon Ecoroof Incentive. Adaptation Clearinghouse. Available at: Source link [Accessed: 19 September 2021].
5. Environmental Services. (2021). Ecoroof Incentive. City of Portland. Available at: Source link [Accessed: 19 September 2021].
6. City of Portland. (2021). Guidance on CC2035 Ecoroof Requirements and the Stormwater Management Manual. City of Porland. Available at: Source link [Accessed: 19 September 2021].
7. City of Portland. (2020). 2020 Stormwater Management Manual. City of Portland. Available at: Source link [Accessed: 20 September 2021].
8. City of Portland. (2015). 37122 Comprehensive update to the City's Green Building Policy to reflect advances in green building knowledge and practices exhibit. City of Portland. Retrieved from: Source link [Document provided].
9. City of Portland. (2020). As Adopted Plan – Central City 2035. Available at: Source link [Accessed: 20 September].
10. Slothower, C. (2021). Eco-roofs growing into urban role in Portland. DJC Oregon. Available at: Source link [Accessed: 19 September 2021].
11. Portland State University and the City of Portland. Portland Ecoroof Map. Available at: Source link [Accessed: 19 September 2021].
12. Netusil, N.R. and Thomas, B. (2019). Ecoroofs in Portland, Oregon, USA. University of Nottingham Blogs – Blue-Green Futures. Available at: Source link [Accessed: 20 September 2021].
13. Chomowicz, A. (n.d.). 49th International Making Cities Livable Conference: Ecoroofs in Portland, Oregon. City of Portland. Retrieved from: Source link [Document provided].
14. Cunningham, C. and Liebezeit, J. (2015). Portland’s Ecoroof Avian Monitoring Project 2012-14: Final report. City of Portland. Retrieved from: Source link [Document provided].
15. City of Portland. (2013). Vegetated Roofs and Energy Conservation. City of Portland. Retrieved from: Source link [Document provided].
Portland Ecoroof
Source: Ref. 1
Source: Ref. 5
Source: Ref. 5, David McLaughlin
Ramona Apartments
Source: Ref. 5
Reed College Ecoroof Terrace
Source: Ref. 5
Ecoroof Incentives Project Map
Source: Ref. 5
Information about this nature-based solution was collected as part of the UNA global extension project funded by the British Academy.