Tumwater urban forester provides update on city's tree canopy situation as some areas in city are getting hotter than others

Certain areas of Tumwater are heating up more than others, and that is due to the lack of a good tree canopy, according to Tumwater Urban Forester Brian Caughlan.

Caughlan heads up the city's Canopy Equity Program, which city staff just launched after receiving funding from a U.S. Forest Service grant the city was awarded in 2024. Along with providing money for Caughlan's own position, the grant also stipulated the city must start a Canopy Equity Program to comply with federal requirements.

A tree canopy assessment was done in the Thurston County city of around 28,000 residents in 2025, revealing the city had lost 11% of the existing tree canopy area documented in a 2019 assessment, dropping from 49% to 38%.

"We've annexed quite a bit of UGA (urban growth area). We've had a lot of development, and we've planted a lot of trees," Caughlan said. "That number is probably going to continue to go down before it goes back up."

While the city is still above its minimum sustained tree canopy area threshold of 30%, some areas in Tumwater are still getting much hotter than others.

On the hottest day of the year in 2025 on Aug. 12, there was an 18-degree temperature difference between the hottest and coldest parts of the city. The hottest area was around George Bush Middle School at 110° F.

"Bush Middle School is consistently the hottest place we have. There's not a whole lot of trees there. It's near I-5," Caughlan added. "... These are startling numbers, and one of the differences in these communities is trees versus no trees."

That's where the Canopy Equity Program comes in, and Caughlan and his staff will begin by first going to residents in neighborhoods with severe heat to educate them about the benefits of tree canopy, and provide them with four possible species to plant in the area. Those species are blue spruce, Alaskan cedar, London plane and Ginko trees.

"We want to encourage them to plant one in their front yard and back yard, in a place that's going to give them the greatest benefits. There is a little science that goes into it, so hopefully we can encourage them to take us up on our offer," Caughlan said.

They plan on hosting educational workshops for both residents and renters too, along with coordinating tree pickup and delivery. They will also assist Tumwater residents with ordering mulch, mycorrhizae and water bags.

Using data from the Trust for Public Land ParkServe data, city staff have even identified specific parts of certain neighborhoods hotter than others, and will be focusing Canopy Equity Program outreach to residents in these hotspots.

Additionally, city staff have already been planting trees on public property, with 480 seedlings planted at Tumwater Hill Park, Deschutes Valley Park and other city properties over the past year, Caughlan added.

Caughlan has also been combatting tree canopy loss in Tumwater by simply talking to residents who submit tree removal permit applications at the city. Once he sees an application, he reaches out to the applicant to see if they can find some other solution to their problem, rather than cutting down the tree.

City staff have also been walking Tumwater's streets lately, as they are working on creating an inventory of every tree in the city. A sidewalk repair with tree retention program has also been created.

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