Our freshwater streams carry small amounts of pollution from our houses, lawns, gardens, roads, and driveways into the Salish Sea. The San Juan Islands Conservation District has teamed up with SJC Public Works to measure these chemicals in our streams and will report the results this year.


When rain falls on the Islands, it runs off as storm water, carrying chemicals from the land with it into streams and eventually the Salish Sea. Many of these chemicals are healthy and necessary for life, like nutrients and minerals. However, excess amounts of nutrients can be harmful to stream and near shore ecosystems. Spawning salmon are particularly sensitive to excess nutrients, vulnerable in their early stages of life. Less sensitive organisms begin to dominate over the long term, reducing ecosystem biodiversity.


The San Juan Islands Conservation District leads the study related to the detail and levels of nutrients in addition to other chemicals in watersheds on each Island. Previous studies indicated watersheds with excessively high nutrients, especially False Bay and Eastsound watersheds are targeted for extra tests.


There are a few important ways to reduce extra nutrient loss at home, at work, and on the farm.

  • Use organic fertilizer. Or, use inorganic fertilizer with greater care. Both organic and inorganic fertilizer have the same nutrients, and plants cannot tell the difference. However, organic fertilizer is bound up in a strong matrix of organic material, preventing nutrient losses after rainfall. Inorganic fertilizer does not have this protection, but you can still prevent excess runoff by using only as much fertilizer as you need. Gardening soil usually has enough nutrients already!
  • Check the label on your detergents. Make sure your laundry and dishwasher soaps are phosphate free. This is an extremely important source of excess nutrients in many counties around the state, and we are currently looking into it’s importance on our island.
  • Build a raingarden! These are small, specially constructed gardens that capture runoff water from your home or business, filtering it through layers of soil and roots. These gardens are particularly efficient at removing excess nutrients. WSU Extension has a goal to register 12,000 locally-built raingardens by 2016.
  • Use Best Management Practice (BMP) on your farm to keep nutrient waste from horses and livestock from entering the watershed too quickly.
  • Use Low Impact Development (LID) practices during new construction. Soil contains high concentrations of nutrients, which can be carried off with silt from construction sites, and can be avoided with LID techniques.

We can help you with all these storm water management tools. Contact us or come and browse our resource library at the CD office.


© San Juan Islands Conservation District 2016