Residents in Santa Clara County could face fines of up to $500 — and in extreme cases, $10,000 — for wasting water, under new drought rules approved Tuesday afternoon that are among the toughest of any urban area in California.

Citing the worsening drought, dwindling local water supplies and residents’ failure to hit conservation targets, the board of the Santa Clara Valley Water District, a government agency based in San Jose that serves as the wholesale water provider to 2 million residents, voted unanimously to set up an enforcement program to warn, and then fine, property owners who are violating outdoor watering rules.