| Climate change and water utilities: the time to act is now
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Climate change and water utilities: the time to act is now

Taylor WinchellClimate change is happening now, it is intensifying, and it will continue to have widespread impacts on water utilities.

That’s the message from Taylor Winchell, a climate adaptation specialist at Denver Water, who presented at the Nov. 3 opening session of the American Water Works Association’s OpShow virtual conference for operators and operations. 

“Climate change is water change because the water cycle is directly connected to the climate cycle,” Winchell said. “The water sector is on the front lines of climate change impacts.”  

At Denver Water, Winchell focuses on translating climate change threats to on-the-ground adaptation efforts. His OpShow presentation happened to coincide with the United Nations’ COP26 international climate change conference in Glasgow, Scotland, attended by global leaders.

Climate change defined

Winchell began his presentation by clarifying the definitions of weather and climate. Weather encompasses day-to-day, short-term variations, he said, whereas climate is a 20-to-30 year average pattern of weather for a region.

“Climate change is long-term change in local, regional or global weather,” he said. 

The water sector is on the front lines of climate change, says Taylor Winchell.Winchell presented data from the National Oceanic and Atmospheric Administration showing that since the late 1970s, every single year of annual average global land and ocean temperatures has been warmer than the pre-industrial average, and they are getting increasingly warmer. “Climate change is here, it’s been happening, and it will continue to happen,” he said.

He also presented the following headline statements from the Sixth Assessment Report (AR6) on climate change, released in August 2021 by the United Nations’ Intergovernmental Panel on Climate Change (IPCC): 

  • “It is unequivocal that human influence has warmed the atmosphere, ocean and land. Widespread and rapid changes in the atmosphere, ocean, cryosphere and biosphere have occurred.”    
  • “Continued global warming is projected to further intensify the global water cycle, including its variability, global monsoon precipitation and the severity of wet and dry events.”

Water cycle impacts

Winchell explained that climate change and warming temperatures increasingly impact the water cycle because of the following principles:

  • Warm air holds more moisture than cold air, which means that as the atmosphere warms, it gains greater capacity to hold more water that evaporates from the land surface. 
  • Warmer air drives more evaporation (from land) and transpiration (from plants). 
  • Atmospheric and oceanic circulation patterns are largely driven by differences in temperature, so as temperatures change, these circulation patters—which drive precipitation—can change. 

“As the climate changes, these principles can lead to an overall drying effect (or wetting in some areas), more variable swings in precipitation, and more extreme storms.” Winchell said. “We need to be thinking about how these changes impact our systems and working on adapting to a range of possible future scenarios.” 

Climate adaptation strategies

Construction siteIn addition to water supply, climate change impacts all organizational functions of a water utility, Winchell said. This could mean impacts to water quality, outdoor workers, supply chains, bond ratings, insurance packages, infrastructure materials and design, watershed health, and others. 

To understand and manage these challenges, all business functions within a water utility will need to adapt, Winchell said. He shared Leading Practices on Climate Adaptation from the Water Utility Climate Alliance (WUCA), of which Denver Water is a member. WUCA also offers climate adaptation case studies about heat impacts and engineering.

“To make the business case for climate adaptation takes time and resources, but importantly, it can also save time and resources,” he said. 

Finally, Winchell made the case for water sector greenhouse mitigation. “The more that we’re able to mitigate greenhouse gases as a global community, the less the impacts of climate change will be and the less we’ll have to adapt,” he said. “The water sector is a trusted leader, and our mitigation efforts will ripple out to the broader community.”