The Los Angeles County Board of Supervisors on July 17 voted to place a parcel tax on the November ballot to raise a projected $300 million a year to reduce runoff of polluted stormwater.

The 4-1 vote puts on the ballot the Safe Clean Water Program, which imposes a 2.5-cent tax on each square foot of “impermeable land” that runoff cannot percolate through, such as concrete sidewalks and patios and asphalt roofs. The tax would apply to almost all of Los Angeles County, except portions of the Antelope Valley and Catalina Island.

On a typical 2,000-square-foot single family home on a 700-square-foot lot, the tax would amount to roughly $80, according to the Los Angeles County Department of Public Works.

The tax is projected to raise $300 million a year to fund a wide array of projects designed to keep stormwater runoff from reaching the ocean, including replacing concrete and asphalt surfaces with “permeable materials” such as grass or soil.

“The Safe Clean Water program not only dramatically increases the amount of stormwater we capture, it will provide health benefits to residents by reducing trash and toxins and increasing green space throughout the county,” Los Angeles County Supervisor Hilda Solis said in a statement. “Clean water is not only an issue for coastal communities: what ends up in the ground and in our water affects us all. Everyone will benefit from improved water quality and enhanced water conservation efforts, including underserved communities with unique water needs.”

Some business groups oppose the parcel tax, saying it would increase the cost of housing and drive up rents for small business owners.

In testimony before the board, Peter Herzog, assistant director of legislative affairs for the Los Angeles chapter of the National Association of Industrial Office Properties, said the measure represents a new permanent parcel tax. “This will tremendously increase the cost on small business owners, the ones with small margins that can least afford this,” he said.

Economy, education, energy and transportation reporter Howard Fine can be reached at hfine@labusinessjournal.com. Follow him on Twitter @howardafine.