In winter 2018, the last thing we needed to worry about was stormwater pollution. We only got 3.77 inches of rain in the official 2017-2018 water year in San Diego.
Now here we are in 2019, and our first blog post of the year is about the pollution effects of all the rain we’ve been getting.
It’s great news in Sana Diego to get some drought relief, watching our reservoirs fill back up and enjoying snow in the mountains. But now we need to be concerned about managing the negative effects of all this water, such as stormwater pollution.
Stormwater runoff is the single biggest contributor to poor water quality in San Diego. If you notice, after it rains the news is full of warnings about staying out of the surf due to elevated pollution. Like this one.
Ever wondered why? Hard surfaces in our urban environments have replaced our natural watersheds full of trees and plants, allowing precipitation access to the ground, which can absorb rainwater. Now the rain hits roofs, parking lots, roads, sidewalks and buildings. It doesn’t get absorbed. Instead, the water flows over these surfaces and eventually runs into our storm drains down to the oceans.
Stormwater washes off all the pollutants that have built up on these surfaces during our long dry spell. Think about all that stuff being flushed off those surfaces rushing down to the Pacific Ocean via our storm drain system.
According to the San Diego County Department of Environmental Health, our ocean and bay waters are unsafe for human contact 72 hours after every rainstorm. Urban runoff pollution eventually builds up in fish tissue, which isn’t good for the health of anyone eating these fish. We lose money from tourism when people can’t enjoy our beaches.
San Diego’s storm drain system is actually the single biggest infrastructure system in the city. It covers more miles underground than our streets, our drinking water pipes, even our sewer pipes. The City reported in 2018 it is struggling to keep up with repairs.
Storm drains don’t connect to our wastewater (that’s sewage) treatment system. When it goes in those drains like the ones in front of your house on the streets, everything eventually ends up in the ocean with no processing.
Business parking lots and roads are covered with chemicals, cleaners and spills from vehicles, dirt, trash, and cigarette butts. Our residential areas contribute too. The fertilizers and pesticides we use on our yards, any chemicals or paints not properly stored, and even the dog poop we forgot to pick up is multiplied by three million residents. It really adds up.
With more hard surfaces and less natural watershed, we suffer from problems with pollution, faster water flow and increased erosion, keeping the negative cycle going. Our human activity has disrupted the natural sponge effect of the watershed. It only takes the loss of 10 percent of our watershed to affect water quality.
There are a few steps we can all take to prevent stormwater runoff’s worst effects. San Diego Coastkeeper has an excellent list of ten tips to get you started, and you should follow these all year long when we eventually dry out.
How about Tip #11 from Good Earth Plant Company? Replace some of your hard surface areas with plants. Consider installing a living wall or even a green roof. While a green roof is admittedly a major project, a green roof can hold 60 to 80 percent of a rain event; water released is slowed, delayed and filtered of particulate matter so it doesn’t get dumped into our storm drains.
A living wall is not as complex or expensive a project, and living walls also help process stormwater in a similar way to a green roof. The wall slows down the water flow. It absorbs plenty, and whatever is left travels onto the hard surfaces more slowly. It won’t wash as much of the pollutants off.
Picture the difference between having the water strike the surface hard like a strong spray from a hose, versus a gentle soaker that doesn’t disturb anything on the surface. It’s similar to the difference between a rainstorm running off a hard roof and walls versus the gentle filtering from a green roof or living wall.
There is no more beautiful way to address stormwater pollution, but this is just the beginning of the many benefits of a green roof or a living wall. You can learn more about these on our website. Our Good Earth Plant Company professionals are available to answer your questions and discuss your project ideas anytime – rain or shine!