ReCode Portland includes an effort to holistically integrate climate resilience into the land use code. The goal of this effort is to add requirements and guidelines to the code to ensure that Portland is resilient in the face of increasing coastal flooding, stormwater flooding, and high heat. This work involves taking stock of the existing patterns and projections for each of these risk factors, developing a shared understanding of how they map onto the city, and then establishing adaptation standards that will help to limit damage and disruption in the future.

what does past planning say about resilience?

Portland’s Plan

This effort touches on all six themes at the heart of Portland’s Plan, but it is most directly tied to Portland’s sustainability goals. Portland’s Plan identified that environmental, economic, and social sustainability are crucial to the long-term health of the city, both in terms of mitigation (preventing or reducing greenhouse gas emissions that are worsening climate change), and in terms of adaptation (adjusting to the current and future effects of climate change).

Maine won’t Wait

Maine Won’t Wait is Maine's four-year climate action plan to reduce greenhouse gas emissions, produce energy from renewable sources, and protect the state’s natural resources, communities, and people from the effects of climate change. Maine Won’t Wait involved the development of sea-level rise projections for Maine’s coastal areas based on the National Oceanic and Atmospheric Administration (NOAA) sea level rise scenarios. As a result of those projections, the Maine Climate Council recommended that the state commit to manage 1.5 feet of sea-level rise by 2050 and 3.9 feet by 2100 (representing the NOAA intermediate scenario). These recommendations formed the basis for the development of a local hydrodynamic model to project Portland’s coastal flood risk.

One Climate Future

One Climate Future established an adaptation goal, stating that the city will build the resilience of its neighborhoods, infrastructure, and ecosystems to prepare for the impacts of climate change.  As with issues of mitigation, adaptation is closely tied to land use - how and where people build homes, workplaces, institutions, and green spaces. One Climate Future suggested an approach to resilience zoning to prepare the City for the impacts of sea level rise, increased precipitation and storms, and hotter air temperatures. This effort builds on that approach.

what do we mean, resilience?

The climate resilience work embedded within ReCode is focused on three major risk factors associated with climate change:

COASTAL Flooding

Coastal flooding is a product of five distinct factors that affect different areas and require different adaptations, but that often converge in coastal areas to have a combined impact. For this effort, we are focused on the impacts of projected sea level rise and tidal flooding combined with coastal storm surge flooding. At this point, this effort does not account for the impacts of two additional factors: local precipitation and riverine flooding.

STORMWATER

Inland stormwater flooding and combined sewer overflows happen as a result of localized precipitation that exceeds the capacity of green and gray infrastructure. In the future, increasingly intense and more frequent precipitation is projected.

High Heat

As climate change and global warming result in more frequent high heat events that last longer, it is important to plan for ways to increase cooling capacity so that residents can remain safe and comfortable in times of high heat.

so how can our zoning address resilience?

Over the past six months, we’ve been working across city staff and local stakeholders to develop an approach to resilience within the City’s land use code that addresses the risk factors above.  The proposed approach is based on available data and scientific models.  You can read about the approach to resilience zoning here. And check out the associated map, which would form the basis for coastal resiliency requirements in the land use code, in full screen or here:

Questions or feedback? Email recodeportland@portlandmaine.gov.