Water and wells in SLO County: what buyers should check, town by town

Cambria is the strictest water regime in the county. The Cambria Community Services District declared a Water Code Section 350 water-shortage emergency in November 2001, and it has never been lifted: the district is issuing no new residential or commercial water or wastewater connections, and no new Intent-to-Serve letters have gone out since 2001.

The wait list is not a queue that moves. It closed to new applications on December 31, 1990, more than 600 parcels sit on it (the district’s draft 2025 Urban Water Management Plan counts 665 single-family positions), and there has been no movement since the moratorium began. Positions are transferable to eligible parcels and carry a small annual administration fee, but holding one is not a water connection. The county’s adopted growth rate for Cambria is zero.

The practical consequence: a vacant Cambria lot without a water position is effectively unbuildable until the moratorium changes, however attractive the price. Parcels with existing service are a different conversation entirely, which is why the same street can hold a functioning home and a lot that has waited three decades.

The long-term supply question runs through the district’s Water Reclamation Facility, which would make the 2014 emergency supply system permanent. That project cleared the county in 2026: the Planning Commission approved its Coastal Development Permit unanimously on February 26, and the Board of Supervisors denied all six appeals on June 16. The district publicly anticipated a further appeal to the California Coastal Commission; as of our July 16, 2026 review, no filing had been publicly confirmed, and we re-check this quarterly.

Los Osos spent roughly 35 years under a building restriction that ended when the Coastal Commission certified the Los Osos Community Plan in December 2024. What replaced it is real but narrow: on December 16, 2025 the county Board of Supervisors set the 2026 residential allocation at 25 new dwelling units, a 0.4 percent growth rate, with 75 percent of those units reserved for parcels inside the sewer service area.

A new home also needs habitat-mitigation credits under the Los Osos Habitat Conservation Plan. The first credit pool became available May 1, 2026 and is limited; the county processes Development Request Forms received on or after that date, and a successful applicant must file construction permit applications within 45 days to keep the reserved credits.

The groundwater basin underneath is adjudicated, managed by three purveyors and the county under a 2015 stipulated judgment, and carries a state critical-overdraft designation. The county and Coastal Commission staff cited current science in early 2026 saying the basin is no longer in overdraft and can support the planned growth; some local groups still contest that. Both positions are part of the record a buyer should know.

One more Los Osos-specific check: the community sewer was completed in the mid-2010s, and some parcels still carry assessment balances. Ask for the parcel’s water and sewer assessment history in escrow.

Templeton Community Services District rations new water connections under a policy requiring at least a 20 percent supply buffer. New "water units" are released only when the annual buffer-model review shows surplus supply, and releases have been minimal in recent years; a single unit was released after the February 18, 2025 review.

If your plan involves a new build, a second unit, or any intensification of use on a TCSD parcel, confirm water-unit availability with the district first. It is the gating item, and it is not a formality.

The Paso Robles groundwater subbasin is state-designated critically overdrafted. Its Groundwater Sustainability Plan was approved by the Department of Water Resources, the five-year evaluation was submitted in January 2025, and in August 2025 landowners rejected a proposed Paso Robles Area Groundwater Authority funding fee, leaving long-term management funding unresolved.

City of Paso Robles customers are largely insulated: the city runs a multi-source portfolio of Salinas River underflow, Nacimiento Lake water, basin wells, and recycled water. The diligence load lands on rural and acreage parcels served by private wells over the subbasin, where the well itself is part of what you are buying.