SAN FRANCISCO (Legal Newsline)- A special fee on some Silicon Valley homeowners to pay for open space acquisition was struck down Monday by the California Supreme Court.

Over the past seven years, the county of Santa Clara has collected more than $50 million in fees to bankroll green space acquisition and pay for parks and trails.

But the state's highest court found that the 2001 special assessment by the county's Open Space Authority violated a 12-year-old voter-approved law known as the "Right to Vote on Taxes Act."

Outlined in Proposition 218, the law limited local governments' ability to raise taxes without voter approval.

The San Jose-based Silicon Valley Taxpayers Association challenged the countywide levy, arguing that it should have been put to city voters before it was enacted in 2001.

Officials had said they would likely refund the money to homeowners if they lost the case in the state Supreme Court.

"An assessment calculation that works backward by starting with an amount taxpayers are likely to pay, and then determines an annual spending budget based thereon, does not comply with the law governing assessments, either before or after Proposition 218," Associate Justice Ming Chin wrote for the court.

From Legal Newsline: Reach reporter Chris Rizo at chrisrizo@legalnewsline.com.