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Water and Climate Change: Learning to Think and Plan Adaptively

Blog post

How our Supply System Master Plan leans into uncertainty to prepare for different events that could impact our water system.

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The Portland Water Bureau takes seriously the task of preparing and adapting to a warming climate to provide water that is safe and abundant for years to come. The Supply System Master Plan looks ahead decades into the future, making sure that we have enough water supply, resources, and infrastructure to flexibly meet the demands of our system over a planning period.

Graphic depicting the supply decisions for water types
Adaptive planning: the Water Bureau assesses water demand, supply availability, and economic constraints every five years [GW = groundwater].

“Twenty to fifty years means that the uncertainty is exponential,” said Cindi Lombard, the Project Manager on the Supply System Master Plan. “It’s really important to start planning early to see where potential gaps in the water supply could be; it requires multiple years of lead time, which is why we look so far ahead.”

The project team defined a range of plausible future conditions to represent how demand, climate, the economy, and other factors might influence our trajectory.

Climate change will impact the Bull Run Watershed. Drought conditions could be more common and water availability from Bull Run could change. These changes highlight the importance of groundwater and the role groundwater will play in our future water supply portfolio, including after the Bull Run filtration plant is operational. The bureau’s groundwater aquifers are relatively resilient to changes in climate.

Climate change is also expected to impact the severity of flooding and rainstorms. The increased potential for intense storms affects how we assess the size of road culverts and the vulnerability of bridges and conduits.

The Supply System Master Plan provides a toolbox to help us adapt to future conditions, including the effects of climate change. As the COVID-19 pandemic has shown, change is around every corner. Planning for various outcomes doesn’t just make your plans better, it also improves your team’s problem-solving skills.

“This adaptive planning approach is so important because we cannot anticipate the full range of climate impacts to our water system,” said Kavita Heyn, Climate Science and Adaptation Program Manager. “Planning in a way that anticipates change and having a toolbox of good solutions will make our utility more robust and resilient in the coming decades.”