Weather conditions bringing worse floods to Whatcom will prompt ‘painful’ conversations
On Monday morning, braced against the gusts of the storm pounding Whatcom County, Chris Elder stood at the edge of the Nooksack River’s South Fork.
Elder works for Whatcom County and is the primary county employee managing climate change action. His view from the river bank was of a heavily flooded agricultural field, which he said was mostly pastureland for a herd of bison.
It was nothing like he had ever seen, after living on his current property for eight years.
“It’s wild, it’s the highest I’ve ever seen it,” he said on the phone as he looked out over the field Nov. 15.
The total scope of the flooding won’t be understood until the quiet that follows, he said, but local officials are already comparing it to 1990 flooding along the Nooksack River that caused $21 million in damage.
Climate change will increase the frequency and severity of floods in the region, scientists say, and Whatcom County and its cities have their work cut out for them if they’re going to protect the public from the worst impacts, Elder said.
“We’ve come to recognize more so that we have a lot of development in areas that are extremely vulnerable with these types of floods,” he said, pointing to towns like Sumas and Everson. Coastal communities are also at higher risk.
How can the warming of the planet’s temperature by a matter of degrees cause worse floods? As fossil fuels continue to burn worldwide and climate change intensifies, rain falls where snow once would have under colder conditions, said Robert Mitchell, a professor at Western Washington University who studies hydrogeology and watershed hydrology.
All that rain gets to Whatcom’s streams much quicker, leading to an increase in fall and winter flows.
At the same time, the pressure systems that move across the Pacific Ocean and bring winter rainstorms to Whatcom are able to hold more moisture when global temperatures are higher, Mitchell said.
Mitchell is currently chipping away at research intended to determine how much climate change will increase the severity of flooding in the Nooksack River, but he expects findings to parallel those from his previous work in the Stillaguamish River. That research shows that there will be on average a 25% increase in peak flows in the fall and winter months.
As Monday’s storm illustrates, flooding takes a significant toll on infrastructure, property and public safety. Flooding can damage roads and bridges, ruin building foundations and cut off travel pathways into entire cities. That’s what happened to Sumas, Everson, Deming and Maple Falls, which are all isolated due to flooded roads, according to Whatcom County Public Works on Monday morning.
Extreme precipitation can also trigger landslides, multiple of which were already been detected across the county on Monday morning, Elder said. Washington is one of the most landslide-prone states in the U.S., according to the Washington Department of Natural Resources.
Increased flooding can even take a toll on salmon habitat restoration work, Mitchell said. Warmer waters can kill spawning salmon, and one of the primary strategies to increase the amount of cool water pools along the Nooksack River is engineered log jams, which can be damaged in big floods. Floods also deliver sediment to streams, which can negatively impact wildlife, including salmon.
The county has made progress incorporating climate change into its planning, last week passing a Climate Action Plan. But Monday’s flooding reinforces how important it is for local jurisdictions to reconsider how and where they allow development in the floodplain, Elder said.
Much of the land in the Nooksack River floodplain is agricultural. That can be positive, Elder said, since pasture land on dairy farms can actually recover from big floods relatively quickly. Berry farmers are not so lucky — their crops and infrastructure are more easily devastated by flooding, Elder explained.
However, “the county isn’t in the business of prioritizing which types of agriculture reside somewhere,” Elder said.
That raises another crucial but controversial question: If the county and other local jurisdictions know that flooding is expected to worsen, what is their role in controlling further development in vulnerable areas? It’s a “painful conversation,” Elder said, and the county doesn’t have a dedicated fund to buy out property owners in vulnerable areas.
It’s especially difficult to have these conversations when some cities are opposed to framing flood response as a climate issue, Elder said. Sumas, for example, chose not to participate in county efforts to incorporate climate change resilience into local comprehensive plans.
Elder wonders if framing the issue as disaster preparedness would help hesitant jurisdictions overcome their opposition.
“The reality is the impacts are happening,” Elder said. “How do we come together as a community to be more resilient? We are sometimes getting hung up on this climate change word, and it stops us from being able to address it.”
This story was originally published November 15, 2021 at 12:37 PM.
