Cotati council conditionally directs WAC representative to support Marin–Sonoma water agreement

The Cotati City Council voted to direct its representative on the Sonoma Water Water Advisory Committee (WAC) to conditionally support a restated supplemental water supply agreement between Marin Municipal Water District (Marin Water) and Sonoma Water.

Why it matters: The restated agreement updates a long‑standing supplemental supply arrangement and includes a $12.5 million lump‑sum contribution from Marin Water to Sonoma Water for resiliency projects. The contract keeps total contractual volume unchanged at 14,300 acre‑feet per year and extends terms in line with the restructured contractor agreement timeline.

Background and staff view: City Engineer Craig Scott explained the background: Cotati is a contractor with Sonoma Water under a restructured agreement dating to 2006. Marin Water is not a contractor under that agreement but holds a separate supplemental agreement with Sonoma Water. Staff recommended conditional WAC support because the restated Marin–Sonoma agreement removes language that historically mirrored a clause in the restructured agreement about how a transmission constraint (the Petaluma Aqueduct capacity) could be addressed — a clause that in prior drafts required a funded contribution by parties (for example, Marin) to build parallel transmission capacity to preserve deliveries.

Marin Water presentation: Paul Cellier, Marin Municipal Water District’s Water Resources Director, said the restated agreement clarifies terms and maintains the same total supply volume; he urged council support, noting Marin Water will contribute $12.5 million to Sonoma Water for resiliency and that the restated term aligns with the broader contractor timeline.

Council questions and staff concern: Council members asked for clarity about the clause and its implications. Staff explained that, historically, language anticipated a costly parallel transmission project (the “south transmission system” or parallel pipeline) if flows and capacity compelled it, and that removing mirror language from either side could complicate responsibility if capacity constraints arise before 2040. For that reason staff suggested conditional support until the contractual language and mutual obligations remain clear.

Council action: One councilmember moved that Cotati’s WAC representative conditionally support the restated agreement; the council adopted that motion by roll call vote. The motion’s conditional language asks staff and the representative to ensure that responsibilities for any future transmission expansion remain fully addressed so the city’s interests are protected.

Next steps: The item proceeds to the Water Advisory Committee and the larger contractor process; staff said the restructured Sonoma contractor agreement and related negotiations continue through the end of the year. Council asked staff to continue tracking the matter so Cotati’s representative can negotiate language that preserves clarity about any future transmission expansions and cost responsibilities.