A proposed expansion of water runoff rules that the agriculture industry says could cost the Central Coast up to 3,320 jobs and nearly $300 million in lost business is headed back to regulators for revision.

The Central Coast Regional Water Quality Control Board regulates water in a seven-county swath of the coast that includes San Luis Obispo and Santa Barbara counties, as well as coastal areas farther north. It held a public workshop in San Luis Obispo on May 12 that drew hundreds of attendees, many of them from farm groups, water board officials said.

Farm advocates showed up to oppose an expansion of existing rules that could require many Central Coast farmers to clean up or eliminate runoff from their land in as little as two years. Within six years, farmers would need plans for preventing pesticides and fertilizers from reaching groundwater supplies and restoring streamside habitat to buffer out pollutants.

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