Building Climate Resiliency in the Lower Willamette Region of Western Oregon

Jessi Kershner Steve Adams
Posted on: 5/21/2011 - Updated on: 3/02/2020

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Steve Adams

Project Summary

The Lower Willamette region is located in northwestern Oregon and is predicted to experience climate changes including increases in temperature, extreme weather events, and reduced snowpack. To address these challenges, the Climate Leadership Initiative (CLI) conducted a series of workshops and published a report entitled “Building Climate Resiliency in the Lower Willamette Region of Western Oregon.” The report provides 40 multi-sector adaptation recommendations to prepare the Portland area for a changing climate.


Modeling provided by the Oregon Climate Change Research Institute projects that under a BAU (business as usual) scenario, the Lower Willamette region of western Oregon may experience:

  • An overall warming trend, with an increase of 10-15° F in summer;
  • Wetter winters and drier summers, and more rain in a shorter period of time;
  • Snowpack loss in the Cascades of about 80% compared to current conditions; and
  • Higher stream runoff in winter and early spring (due to more precipitation falling as rain and in shorter periods), and decreased flows in summer for some locations.

While these climate impacts will have significant regional effects on the local economy, social welfare, environment and quality-of-life, more than 200 local stakeholders found ample opportunity for government, private businesses, and individuals to reduce harm by preparing now. Stakeholders provided 40 recommendations including hardening infrastructure, reducing energy use, encouraging preventative health, diversifying the local businesses and restoring floodplains and wetlands.

Geographic Scope:  The Lower Willamette Region includes Benton, Clackamas, Linn, Marion, Multnomah, Polk, Washington and Yamhill Counties in Northwest Oregon.


CLI engaged over 200 participants with expertise in natural, built, economic, human and cultural systems to:

  • Assess local climate projections provided by the Oregon Climate Change Research Institute and Portland State University;
  • Identify impacts across systems and sectors;
  • Propose strategies to prepare for the projected changes; and
  • Provide a vision of what the Lower Willamette would look like by mid-century should the recommendations be implemented.

The participants identified a number of impacts that may result from regional climate projections, including:

  • Reduced water quality and shifts in water availability (more in winter, less in summer);
  • Mismatch in life history timing of many species, possibly leading to population decline due to diminishing availability of essential resources when needed by each species;
  • Decline in efficiency of, and potentially significant damage to, public works, transportation, and communication infrastructure;
  • Extended duration and shifts in timing of seasonal peak water demands;
  • Diminished productivity or total loss of some agricultural commodities, but potential opportunities for new crops and longer growing seasons;
  • Increased numbers of invasive, non-native plant and animal species, and expansion of ranges for others;
  • Increased instances of heat illness, vector- and water-borne disease, mental health illness, respiratory distress; and
  • Loss of cultural resources (e.g. salmon) and historical landmarks (e.g. covered bridges, century old barns and iconic natural features).

Outcomes and Conclusions

To address these impacts, the participants provided recommendations to prepare and build resilience, including:

  • Protect floodplains, wetlands, and groundwater recharge areas;
  • Further assess anticipated habitat changes in order to preserve existing high-quality habitat and promote restoration where feasible;
  • Preserve, expand, and connect existing high-quality habitat and restore habitat of lesser quality that is crucial to species’ survival;
  • Update infrastructure with projections for future population growth and climate change;
  • Anticipate increased energy needs and provide incentives for efficiency and conservation;
  • Diversify businesses, as well as agricultural and timber crops;
  • Increase preventative health initiatives, notification and warning systems, and diversify health and emergency management partnerships; and
  • Protect key cultural resources and improve historical architecture resiliency to extreme events.

While the climate impacts to the Lower Willamette region are likely to be significant, it may also prove to be one of the more resilient areas of the state due to its physical location, geography, and existing efforts to improve regional sustainability. Due to the region's likely resilience, a possible, unintended consequence is that climate refugees from other places may relocate to the region. Thus, preparing for population growth and development may be just as important as managing for the physical impacts of climate change.


Kershner, J. & Adams, S. (2011). Building Climate Resiliency in the Lower Willamette Region of Western Oregon [Case study on a project of The Resource Innovation Group's Climate Leadership Initiative]. Retrieved from CAKE:… (Last updated May 2011).

Project Contacts

Affiliated Organizations

The Resource Innovation Group (TRIG) is a 501(c)(3) that provides innovative solutions to the challenges of sustainability, climate change and other social, economic and ecological concerns. TRIG was founded in 1996, as an affiliate of the Portland State University Hatfield School of Government. In 2005, TRIG established the Climate Leadership Initiative (CLI) with a specific mission of fostering the development and application of innovative thinking and approaches to the complex causes and solutions to climate change.

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