Rain in LA? How green infrastructure can help solve the stormwater problem.
Posted October 30, 2013
For a city which people do not associate with rain, surprisingly stormwater causes a lot of problems in Los Angeles – and I don’t mean a day without sunshine. “Stormwater” is the name for the resulting concoction when rain hits roads, roofs, parking lots, and other paved surfaces of a concrete jungle and picks up gasoline, motor oil, heavy metals, roadside trash, as well as animal waste, bacteria dirt and grime, and pesticides from lawns.
The rain is unable to seep into the ground or be retained by natural vegetation because of the hard surfaces and instead pours down gutters and into storm drains, which in most places, go straight to our rivers and streams, where the stormwater can make waterways unsafe for swimming or fishing. This is the situation in Los Angeles, where we have a municipal separate storm sewer system (“MS4”) which carries untreated stormwater straight to the ocean. However, in over 750 cities around the country, stormwater is carried in the same pipes as sewage from people’s homes and businesses (combined sewer system “CSS”). During dry weather or small storms, light urban runoff is sent to a sewage treatment plant. But when there is too much water for the plant to handle – sometimes as little as 0.2 inches of rain (NRDC, Rooftops to Rivers II, p. 9) - these ancient pipelines are designed to overflow, dumping an untreated mess into our waterways.
(Photo Credit: Los Angeles Waterkeeper)
(Photo Credit: Los Angeles Waterkeeper)
(Photo Credit: Heal the Bay; Santa Monica Beach after the first heavy rainfall of this year.)
Stormwater runoff is a leading cause of urban waterway pollution across the country. It’s not just Styrofoam cups and other large visible trash on the beach – runoff also brings pollutants out into the water (see this Instagram-video of the “first flush”). The pollutants in urban runoff increase bacteria levels in the water, threatening swimmers with illnesses and contributing to beach closings or health advisory days. The significant water pollution from stormwater runoff puts swimmers and local economies at risk. Read my colleague Dylan’s blog on how he risks getting pink eye, gastroenteritis, and bacterial meningitis whenever he goes surfing after a storm. NRDC’s annual Testing the Waters beach water quality report provides data on the water quality and monitoring and notification practices of thousands of the nation's popular beaches.
Green Infrastructure is a Solution!
Luckily, there are solutions out there to stop runoff pollution! The best way to avoid runoff-related pollution and overburdened sewer systems is to reduce the volume of stormwater flowing to the drains in the first place. “Green infrastructure” such as green roofs, street trees, increased green space, rain barrels, rain gardens, and permeable pavement help stop runoff by mimicking or restoring natural conditions. By capturing and retaining rainwater, instead of letting it run straight into the storm drains, we can also store it for use, evaporate it back to the atmosphere, or let it filter into the ground, where it can benefit vegetation and replenish groundwater supplies. Outfitting our paved paradise with green infrastructure also has the added benefits of beautifying neighborhoods, cooling and cleansing the air, reducing asthma and heat-related illnesses, lowering heating and cooling energy costs, boosting economies, and supporting American jobs.
NRDC’s 2011 report Rooftops to Rivers II showcases how fourteen cities use green infrastructure to better manage stormwater and achieve a host of non-water benefits, while reducing capital and maintenance costs. The report identifies key actions that cities should take to maximize green infrastructure investment such as a long-term plan, dedicated funding sources for implementation, and incentives for private-party actions. NRDC’s Water Program just released an update to Rooftops to Rivers II, highlighting the significant progress many of the profiled cities have made in implementing green infrastructure policies and programs.
What You Can Do!
The Environmental Protection Agency (“EPA”) has the opportunity to protect clean water across the country from the Chesapeake Bay to the Puget Sound by updating and modernizing its existing programs to better manage urban runoff. The Agency is considering requiring that a certain amount of rainfall be captured where it falls, before it becomes runoff that pollutes our local waters. The EPA has announced its intention to tackle this issue through new national stormwater regulations but unfortunately, has delayed action.
You can show your support for the EPA’s efforts to strengthen its stormwater programs and better protect our rivers and streams. Take action by tweeting your representatives or send a letter to Administrator Gina McCarthy expressing concern over EPA’s delays and ask them to put pressure on and lead the EPA to move forward on these critical updates to protect clean water and public health.
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