Don’t put people and property at risk

At the other extreme, atmospheric rivers and torrential rains falling on geologically unstable slopes will trigger more landslides which could threaten homes, roads and utilities.

We need to do everything possible to avoid placing more people and property at risk from these multiple hazards.

On Tuesday, July 12, the San Mateo County Board of Supervisors has an opportunity to do just that when they consider an appeal of the Planning Commission’s unanimous (5-0) denial of a risky subdivision on Open Space-Resource Management zoned land in the San Mateo Highlands-Baywood Park Area.

The “Zmay” subdivision would create three new parcels with home sites on extremely steep, landslide-prone slopes at the top of the 60-acre property along Parrott Drive. The proposed home sites are within a Cal Fire designated Very High Fire Severity Zone — the state’s highest category of risk. As noted by the Santa Barbara County Fire Department: “Fire burns 10-16 times faster up-hill due to pre-heating and radiant heat.”

The site’s extremely steep slopes have the same geology (Franciscan Melange) as the nearby Polhemus Road landslide, where retaining structures similar to what’s proposed for the “Zmay” property failed in the 1997-98 winter storms. To make matters worse, the 3,000-foot-long sewer transmission line on “Billy Goat Hill” that would serve the three proposed parcels is failing, due to repeated earth movement/landslides. The project proposes fixing only a 200-foot-long stretch, leaving the most deteriorated part unaddressed.

The Resource Management Zoning for this property prohibits development in areas deemed “unsuitable for reason of exposure to fire, susceptibility to landslides, or other features harmful to … health, safety and welfare.”

The planning commissioners determined that the proposed location of the three new home sites atop extremely steep slopes at greatest vulnerability to wildfire and landslide hazards is inconsistent with the Resource Management Zoning and County Subdivision regulations. The Planning Commission’s well-considered denial was appealed by the project owners/applicants to the Board of Supervisors.

Fortunately, there are less hazardous areas at the bottom of the property along Crystal Springs Road, where the owners/applicants have already built one home. Nine gently sloping acres in this area are designated “to remain buildable” on their proposed Subdivision Map. The three new parcels could be located within these 9 acres; there may be other suitable safer sites as well.

The Board of Supervisors has taken the lead to address increased risks from climate change. The supervisors now have a golden opportunity to apply their “climate ready strategies” to this real life, consequential land use decision.

As Planning Commissioner Hansson eloquently noted: “We are looking at a piece of land that for a lot of reasons hasn’t been developed … wetlands in the area, water underground, failing sewer system, steepness, landslides, old fill and fire hazard … a concoction of everything you have thrown at it except for nuclear waste sitting here.”

We urge the supervisors to uphold the Planning Commission’s decision. We can’t — and shouldn’t — go back to business as usual when it comes to safety of people and homes under “California’s New Normal.”

Lennie Roberts is the legislative advocate for Green Foothills.