The agency that delivers drinking water to Mill Valley, Corte Madera, Larkspur and Tiburon has a new leader. The Marin Municipal Water District board voted Tuesday, Aug. 18, to appoint Shaun Horne as general manager.

He starts Oct. 1.

Horne has spent seven years at Marin Water as director of watershed resources, overseeing the district's 22,000-plus acres of Mount Tamalpais watershed land. He led the ongoing update to the Mt. Tam Watershed Roads and Trails Plan, helped advance the Lagunitas Creek Restoration Project and directed implementation of the Biodiversity, Fire, and Fuels Integrated Plan.

He replaces Ben Horenstein, who announced plans to retire after nearly eight years running the district. Horenstein will shift to an advisory role through the end of his contract to support the transition.

Board President Jed Smith said Horne stood out during a nationwide search for his collaborative leadership and record of navigating complex initiatives across the district's operations, according to the district's announcement. Smith said the board is confident Horne "has the experience and perspective needed to guide Marin Water into its next chapter."

Horne takes over a roughly $188 million budget, more than 250 full-time-equivalent staff and a service area covering about 147 square miles and 191,000 residents, according to a July district budget review reported by the Marin IJ. The district is also in the final year of a four-year rate hike and launching a rate study expected to recommend new rates for 2027 and beyond by December.

Before Marin Water, Horne spent seven years at the Napa County Flood Control and Water Conservation District, where he directed the Napa River Restoration Project. He also worked at Sonoma Water coordinating flood control and ecological restoration. He holds a master's degree in international water resource management and was selected as a Water Education Foundation Water Leader in 2013.

Outside the district, Horne serves on the boards of Fire Safe Marin and Together Bay Area and sits on the One Tam Lands Stewardship Steering and Executive Committees.

The next regular Marin Water board meeting is scheduled for Tuesday, Sept. 1. Residents can find agendas and public comment instructions at marinwater.org.