Three public agencies will meet tonight to discuss a revised conceptual plan for Rancho Potrero open space in Newbury Park.

The Thousand Oaks City Council, Conejo Recreation and Park District and Conejo Open Space Conservation Agency will be asked by the city staff to endorse the plan for the 326 acres as recommended by an intergovernmental committee.

After listening to the concerns of a focus group, the intergovernmental committee agreed to revise an earlier plan. The revision would allow an area next to the city's Circle K equestrian center to be used as trailhead access, and the building of a shade structure for up to 60 people near the entrance to Rancho Sierra Vista/Satwiwa.

The committee had met in December and agreed to drop plans for a proposed shaded picnic area for up to 200 people, dubbed by opponents as a "party pavilion."

The City Council also could adopt a resolution tonight initiating the pre-zoning of 306 acres of Rancho Potrero as open space and a 20-acre equestrian center site as public land.

Park District Manager Jim Friedl said he doesn't anticipate problems in getting the approval of all three bodies for the revised plan.

"I feel really great about the process," he said. "We asked folks what they thought, and we listened."

City Councilwoman Claudia Bill-de la Peña — who, along with Mayor Jacqui Irwin, was a member of the intergovernmental committee — voted for the revised plan with the understanding that she will never support the introduction of electrical lines and sewage lines on the property.

"I feel very strongly that the area must be protected and free of disturbance," she said.

Irwin also has said utilities won't be allowed in the wilderness area.

If the City Council, Park District and Conservation Agency formally agree to the revised conceptual plan, city staff will begin the process of drawing up a more detailed plan for the future use and management of Rancho Potrero.

The proposal will be submitted to Ventura County's Local Agency Formation Commission for approval. The agency oversees annexations and other boundary changes of government entities.

The meeting is at 6 p.m. in the council chambers at the Civic Arts Plaza, 2100 Thousand Oaks Blvd., Thousand Oaks.