In a move that reinforced the reason for its initial creation, the Midpeninsula Regional Open Space District's board of directors voted unanimously on Wednesday night to support a proposal limiting development in Stanford University's foothills for 99 years, unless the development is approved by four of five members of the Santa Clara County Board of Supervisors.

The decision supports a recommendation by the county Planning Commission and staff to amend key documents governing development on Stanford property. The foothills and other campus greenspaces comprise about half of the university's 4,000 acres. Currently, growth in the greenspace areas is limited under a regulation that expires in 2025.

Board member Yoriko Kishimoto said there was strong support for the district's recommendation to the county.

"We're a regional board, and this (measure) goes back to the original intent of the district to protect open space in perpetuity" or for as long as possible, she said.

Protecting the Stanford foothills has special significance to the district. Saving Coyote Hill, which is part of the open space at the southwest corner of Page Mill Road and Foothill Expressway, was the first battle fought by local residents who later formed the district.

The protracted battle with Stanford took place in the mid-1960s, when the university planned to build an animal research laboratory on the site.

"To have the room to breathe was the initial call to action," Kishimoto said about the district's formation and its continued mandate.

Stanford has no specific plans to develop Coyote Hill or the other foothills. The university's currently seeking the county’s approval of a new general use permit allowing construction of more than 3.5 million square feet within its "academic growth boundary." The boundary includes the core campus and most areas east of Junipero Serra Boulevard. The proposed permit would expire in 2035.

A related county document, the Stanford University Community Plan, established the academic-growth boundary in 2000. The boundary is to remain in place until 2025, and under the current permit, any proposal to build outside of the boundary requires approval by four out of five supervisors.

As part of reviewing the general-use permit application, the supervisors are considering amending the Community Plan to maintain the academic-growth boundary for 99 years, and requiring the four-fifths vote for any development proposals outside the boundary.

As amended, the Community Plan would no longer characterize the boundary as a temporary measure that should only remain in place "until a defined level of development intensity has been achieved on lands within the growth boundary." Instead, the academic growth area would be in place "on a long-term basis if planned development can be accommodated within its boundaries."

A separate 2018 document the county created, the Stanford University Sustainable Development Study Supplement, developed three theoretical scenarios to estimate the university's development potential. It found that in the next 100 years, the university could triple its size and still keep development within the academic boundary by using smart-growth strategies. The university would still be at a comparable density to other major universities within the academic boundary footprint.

The evaluation led the county to consider the 99-year protections for the foothills, Supervisor Joe Simitian told the Weekly in an interview on "Behind the Headlines" last May.