A proposed city ordinance would require residential and commercial developments in Los Angeles to capture and reuse runoff generated in rainstorms.
The proposal was originally approved in January by the city’s Department of Public Works. It would require such projects to capture and reuse 100% of runoff generated by a 0.75-in. rainstorm or to pay a stormwater pollution mitigation fee that would help fund off-site, low-impact public developments.
This new approach to managing stormwater and urban runoff is designed to mitigate the negative effects of urbanization by controlling runoff at its source with small, cost-effective, natural systems instead of treatment facilities. Reducing runoff improves water quality and recharges groundwater.
Public Works board members maintain that the new requirements would prevent 104 million gallons of polluted urban runoff from ending up in the Pacific Ocean.
The ordinance would require builders to use stormwater storage tanks, permeable pavements, infiltration swales or curb bumpouts to manage the water where it falls. Builders unable to manage 100% of a project’s runoff on-site would pay a penalty of $13/gallon of runoff not handled there—a requirement the local construction association has been fighting.
A spokesperson for the L.A./Ventura Building Industry Association said that some building projects, such as those in downtown L.A. or areas where the soil has a high clay content, would have difficulty with the 100% retention rule and that the $13-a-gallon mitigation fee is too high. A 1-acre building on ground where runoff could not be managed on-site, could pay a fee of more than $200,000, she said.
At the urging of business groups opposed to an earlier draft, the Board of Public Works has acquiesced on some points.
The board decreased the per-gallon mitigation fee from $20 to $13. The mitigation fees would fund public low-impact developments, including retrofitting with porous pavement, bioretention basins, and other water infiltration strategies designed to capture 2 million gallons of stormwater that would otherwise flow to the ocean.
Board members backing the proposal say they hope the ordinance is approved this year and goes into effect by 2011.