SAN FRANCISCO (AP) — A wealthy Silicon Valley-backed campaign to build a green city for up to 400,000 people in the San Francisco Bay Area has submitted what it says are enough signatures to qualify the initiative for the November election.

The campaign submitted more than 20,000 signatures but would need only about 13,000 valid ones to qualify for the ballot. If verified by Solano County’s elections office, voters will decide in the fall whether to allow urban development on land currently zoned for agriculture. The land-use change would be necessary for the development to be built.

Jan Sramek, a former Goldman Sachs trader who heads the company behind the campaign, California Forever, said at a news conference Tuesday that he heard from thousands of people who want careers and homes in the county where they grew up but can no longer afford to live there because of high housing costs and a lack of nearby work.