Why We Should Care Where Storm Water Goes.

June is usually the beginning of our “dry” season. But with record rainfall and cool temperatures throughout spring and now into June, our gardens are anything but dry. The greater concern now is what happens when all that storm water leaves your property.

Seattle is one of many cities that combines a lot of its storm water with the sanitary sewer system. While this seems like a simple way to carry excess storm water away and prevent the possibility of flooded yards or basements, there is a big problem with this system.

When we have heavy rains, the sewage treatment plants are overwhelmed. To keep wastewater from backing up into people’s homes and businesses, treatment plants release large quantities of raw sewage into Puget Sound to relieve the pressure. This poses a threat to marine life, including salmon and our beloved Orcas.

We also have storm drains that are separate from the sanitary sewer and that dump directly into the nearest body of water. As storm water washes across lawns, gardens, and streets, on its way to storm drains, it picks up pollutants. They include pesticides, motor oil, herbicides, fertilizers, heavy metals, animal feces, and bits of trash. They go directly into the water, poisoning fish and wildlife, and damaging our marine ecosystems. According to the Washington State Department of Ecology, storm water runoff accounts for 30% of the pollutants in our waterways.

In this video,  West Seattle scuba diver, Laura James, shows us what it looks like when a plume of storm water is discharged after a heavy rain. The video also follows researchers studying the difference rain gardens can make to filter out pollutants. They compare the survival rates of fish in filtered storm water and those in a container filled with storm water runoff.  It is dramatic!

The best policy is to keep water from running off or being piped away from your yard in the first place.  King County has more reasons why that is important and recommends 10 things you can do to prevent storm water runoff pollution.

Take this rainy spell to assess the storm water situation on your property. Where do your downspouts go? Is there a way you can retain rainwater in a swale or rain garden? We have the summer months to make changes and prepare for next fall and winter.