Why "climate resilience zoning"?
As climate change drives extreme weather that threatens people, infrastructure and the environment, municipalities can implement strategic land use planning and zoning regulations to responsibly manage future development in areas with high climate-related risks. Adopted in 2020, Appendix C of the City’s climate action plan One Climate Future outlined how South Portland could adopt new zoning codes to guide future development in ways that reduce risks and impacts from key climate hazards identified in the City's Climate Vulnerability Assessment. These recommendations included creating an “overlay zone” in areas of the city at highest risk of flooding that would require future development adapt to risks from sea level rise and storm surge. One Climate Future also proposed city-wide land use standards focused on resilience in the face of higher intensity rainstorms and more frequent and intense heat waves.
Coastal Flooding
Present-day coastal flooding in South Portland is caused by multiple intersecting factors, including tides and storm surge. Due to anticipated sea level rise in the coming decades, increased coastal flooding is projected to impact key areas of South Portland’s waterfront during severe storm events, as well as cause more frequent inundation in certain waterfront areas during high tides. Any future development along the City’s coast will require different adaptation strategies in order to mitigate these risks.
Increased flood risk can be managed through the elevation of ground floors and critical systems in buildings above a set Design Flood Elevation (DFE), along with strategies like “wet” and “dry” floodproofing structural reinforcements, and operational adaptations. The Climate Resilience Zoning project will focus on flood resilience strategies that can be regulated within South Portland’s land use code, including development of one or more Design Flood Elevations.
Learn more about the projected coastal flood risks to South Portland’s waterfront neighborhoods here.
High Heat
As climate change results in longer and more frequent high heat events across the northeast, it is increasingly important to consider the cooling capacity of existing and future development in South Portland to ensure residents can remain safe and comfortable in times of high heat. Developed areas with high concentrations of impervious surfaces like buildings, roads, and parking lots also absorb and retain more heat than rural or undeveloped areas, known as the “heat island effect.”
High heat in cities can be managed through multiple strategies, including increasing urban tree cover and green spaces, increasing the solar reflectivity of surfaces, utilizing building design solutions like “green” or “cool” roofs, and providing cooling centers and water access across the community. The Climate Resilience Zoning effort will assess and update how South Portland’s current zoning code requires property development to increase cooling capacity.
Learn more about the high heat risks facing South Portland via the Trust for Public Land’s Urban Heat Island Severity Viewer.
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