Disconnecting downspouts

One of the easiest ways to curb stormwater runoff pollution is to disconnect downspouts from the local sewer system. Chances are most Seattle and King County residents have rain downspouts that run directly into a combined sewer overflow system. (Ecoyards can help you figure out whether you’re one of those.)

Why is this a problem? In most parts of Seattle, Burien, Normandy Park and other cities in King County, stormwater (rain that falls onto roofs and driveways) mixes with wastewater (the stuff that flushes down toilets, sinks, and dishwashers) and is carried into the sewage treatment plant. When we have periods of heavy rain, that combined sewer system overflows — it happens a lot — sending unfiltered pollutants into our waterways. Downspouts that are connected to this combined sewer system can contribute to the problem because it increases the volume of this overflow.

A downspout connected to a combined sewer system.

Disconnecting downspouts from the sewer system can help reduce these overflows and protect our waterways. Homeowners need to do it properly, otherwise you may get other headaches, like wet basements, leaky foundations or flood redirected at your neighbors or down your street.

There are different, safe options for disconnecting downspouts. One option is to run the downspout through underground piping and into a dry well. This works only if your property has well-draining soil and the right topography. You can also run the downspout through underground piping that daylights to a hillside, but again, this requires the right topography. There are a lot of other things to keep in mind, like making sure you’re not disconnecting downspouts too close to steep slopes or redirecting those downspouts to one spot. Ecoyards can help you decide whether it’s appropriate to disconnect your spouts, and where to send that rainwater.

One of the best options in disconnecting downspouts is to redirect that stormwater into a rain garden. We’ve previously written about the benefits of Seattle rain gardens. Very simply, rain gardens are shallow depressions that hold and filter rainwater; they can be designed to fit your needs and can also be attractive additions to your landscapes. The city of Seattle currently provides a generous rebate for qualifying homeowners who install rain gardens on their property. Ecoyards is a licensed contractor with the city’s RainWise program.