The town faces major challenges, namely the continued efforts to harden homes to protect them against wildfires. The town is also working through the process of getting approval of its controversial state-mandated housing element.
Derwin joined the council in 2005, while Richards was elected four years later, in 2009.
Mayor Craig Hughes has pulled candidate papers to run for reelection and four others have expressed interest in running. They are Mary Hufty, Dale Pfau and Planning Commissioners Judith Hasko and Craig Taylor.
Derwin, a resident of Portola Valley since the early '90s, thanked the community in a July 19 letter for having faith in her leadership even when her stands were controversial.
"As a seasoned elected official once told me, 'If you aren't making people unhappy, you aren't doing your job, and ... sometimes you must lead people where they don't want to go,'" she said. "Ever aware of the bigger picture and the greater good, I tried to live by these words, wrenching at times as it could be."
During her tenure on the council, Portola Valley completed the Town Center, created the Spring Down vernal pond and convened the town's Race & Equity Committee. She also oversaw the creation of an inclusive community process for the 2023-31 housing element and the passage of the strictest home hardening ordinance in San Mateo County.
As a member of San Mateo County boards and committees, she helped create the first-ever water agency in San Mateo County, One Shoreline, and the first Highway 101 Express Lanes project. On the San Mateo Library Joint Powers Authority (JPA), she worked to restructure the distribution of funding to make it more equitable, and approved funds for new libraries in Half Moon Bay, Brisbane and Atherton.
She also served on the San Mateo City/County Association of Governments, where she worked on efforts like expanding bike/pedestrian access, green infrastructure, climate action and housing.
Former Councilwoman Ann Wengert said Derwin represents the best in town government. Wengert described Derwin as "eloquent, fiery and impassioned."
"Part cheerleader and part pusher, Maryann doggedly encouraged us, her colleagues, to get involved with our county and regional counterparts by participating on committees and in regional events," Wengert said in a statement. "Maryann truly deserves credit for Portola Valley's emergence from its past isolation."
Derwin said she plans to endorse Hughes for reelection.
Richards, a retired architect, said it was simply time for him to move on.
"I mostly decided 13 years is long enough on the council," he said. "I will miss the companionship of the other people on the council and having people in the community reach out with questions and comments."
Richards moved to Portola Valley when he was 4 years old and attended elementary school in the Old Schoolhouse before graduating from Woodside High School.
"Hopefully we can actually bring some of the lower-income parts of society back into the community; a broader mix than today," he said of efforts to create more housing in town. "When my folks moved here it was the cheapest place around to live back in the '50s. It's a healthier community to have that kind of mix."
As mayor, Richards spearheaded a gas-powered leaf blower ban, "which seems to have made a difference," he said.
About a decade ago, he helped start the Town Center farmers market.
Before joining the council, Richards served on the Portola Valley Planning Commission in the 1990s.
Richards said plans to endorse Hughes, along with Planning Commissioners Taylor and Hasko for the council this fall. He said the council's greatest challenges will remain fire safety and housing.