Spring Rain: Keeping it Clean for our Salmon

April showers might bring May flowers, but they can also carry lots of pollution in rainwater runoff, which can harm local salmon. We’re thankful for rainy weather because it nourishes plant life and provides us with water to store for the drier summer months. However, with a deluge of raindrops, stormwater runoff often causes pollutants such as car oil, fertilizer, and soap to flow into our local waterways. Luckily, we can take action to keep our water clean and our fish healthy.

Our vehicles are a source of several common stormwater pollutants. Car oil leaks are easily carried by runoff to storm drains, ending up in local rivers, lakes, and Puget Sound. It’s especially important to maintain your car during rainy periods to prevent any fluid leaks that could become a water contaminant. 

Another common pollutant associated with cars is soap. When you wash your car in a driveway or on the street, the soap freely runs into storm drains. This is a problem because soap damages the gills and protective mucus coating on salmon and other fish, making them more susceptible to bacteria. Soap can also create a lethal environment for aquatic macroinvertebrates–also known as water bugs–which are an important food source for salmon and other fish. You can help prevent these undesirable effects by washing your car at a car wash or on your lawn. Both of these solutions can keep harmful detergents out of runoff and out of our waters.

Reducing the use of fertilizers and instead using natural lawn care can also go a long way towards protecting water quality. Fertilizers on your landscape can wash into nearby waterways, increasing nutrients such as nitrogen and phosphorus and promoting quick algae growth. Gradually, the algae will start to decay, using up oxygen in the water. When this happens on a large scale, lakes and rivers can get so low on dissolved oxygen that it leads to the death of fish and other organisms. To help prevent these kinds of events, check out our Natural Yard Care page to get ideas for alternatives to synthetic fertilizer.

Actions you can take:

- Regularly check your car for oil leaks

- Bring your car to the car wash or wash it on your lawn

- Practice natural yard care methods

- Install a rain garden on your property

- Plant a riparian buffer

If you’re interested in getting more involved with protecting your local watershed, you may consider installing a rain garden in your yard or planting a native plant buffer along waterways on your property.

Rain gardens are specifically designed to filter pollutants, reduce flooding, and recharge groundwater. The base of the rain garden is a depression in the ground that is filled with a special blend of highly absorbent soil and mulch. This provides a rich environment for planting native vegetation that is low-maintenance and can thrive in wet conditions. This combination of soil and plants increases the amount of water that gets absorbed into the ground, and traps pollution to prevent it from entering storm drains and local bodies of water. 

Rain gardens have more benefits than just cleaning up stormwater. They’re also a very attractive, low-maintenance option for your yard. Additionally, the native plants used in a rain garden provide habitat for pollinators and other wildlife. Learn more about the benefits of rain gardens on our website.

Similar to rain gardens, planting native vegetation filters pollutants from surface water before it reaches rivers, streams, lakes, and wetlands. Areas planted with native vegetation near streams or wetlands are called riparian buffers. Check out our website for information about installing a riparian buffer. Snohomish Conservation District also provides free technical assistance to landowners and we can give recommendations and help you get started!

There are many ways to fight watershed pollution, whether you opt to bring your car to the car wash or consider a bigger project like building a rain garden or riparian buffer. When we all make changes, water quality improves, allowing our local salmon to reap the benefits.

This project has been funded wholly or in part by the United States Environmental Protection Agency under an assistance agreement with the Washington State Department of Ecology through their Water Quality grant program. The contents of this document do not necessarily reflect the views and policies of the Environmental Protection Agency or the Department of Ecology, nor does the mention of trade names or commercial products constitute endorsement or recommendation for use.