Complying with a federal law Scott Lewis mentioned in his recent post — a law designed to protect public health and water resources — shouldn’t be rocket science.
Stormwater pollution sickens thousands of San Diegans and visitors to the region every year when they go to the beach or are exposed to untreated runoff. Common sense solutions exist today that can dramatically reduce the potential for people to come into contact with polluted waters, and can provide multiple benefits to the community.
Building green infrastructure —water quality management techniques like green roofs, tree plantings, rain gardens and permeable pavement that mimic a site’s natural hydrology — into our urban areas is a cost-effective way to capture rainwater on-site (and to add a needed, sustainable local supply of water during periods of drought), instead of allowing it to funnel pollution to creeks and rivers or the ocean.
Not only does building with green infrastructure often cost less than using traditional systems of gutters, drains, and pipes to manage stormwater runoff, but there is ample evidence that private developments with well-designed green infrastructure can see substantial economic gains — higher property values, increased retail sales, energy and water savings, reduced infrastructure costs, and even increased mental health and worker productivity for office workers.
But the city’s questionable cost estimates largely ignore opportunities to engage commercial and other properties that green infrastructure practices would benefit. Instead, the estimates focus heavily, if not exclusively, on making use of public lands to install stormwater controls.
For example, to clean up Chollas Creek, rather than encouraging or assisting private developments to invest in green infrastructure, which could help beautify surrounding communities and stimulate economic revitalization, the city’s estimate relies on spending upwards of $900 million to buy private land for stormwater projects. The city fails to point out that a potential alternative scheme, which would use green streets to improve water quality instead of private land acquisition, could save it more than $880 million.
The city needs to look to ways of promoting green infrastructure in the community that would benefit the region’s economy. A recent report by the Natural Resources Defense Council points out that well-designed landscaping for office buildings boosts average rental rates by 7 percent, and that retail customers are willing to pay 8-12 percent more for products in shopping centers that have a mature tree canopy overhead.
An even midsize retail shopping center could see as much as $24 million in economic benefits over a 40-year period as a result of green infrastructure improvements, while helping reduce runoff and pollution to San Diego’s waters.
A green roof with as little as three to four inches of soil can generally absorb between one-half to one inch of rain from a given storm, greatly reducing surface runoff. At the same time, green roofs provide shade and cooling that can reduce the energy needed for building cooling on the floor below the roof by upwards of 50 percent — the Target Center Arena’s green roof in Minneapolis (which captures nearly 1 million gallons of stormwater annually) lowered energy costs for the building by $300,000 per year. Even better, green roofs have been shown to increase the lifespan of a building’s roof, delaying and reducing replacement costs.
These types of pollution controls should be championed by San Diego. Now is a time when we need for cities to lead our efforts to clean up our waters and revitalize our communities, not to make excuses and shrink from the challenge.
Noah Garrison is a water attorney with the Natural Resources Defense Council in Santa Monica. Garrison’s note has been lightly edited for style and clarity. See anything in there we should fact check? Tell us what to check out here.