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The watershed in your backyard

Updated: Nov 19, 2021

Skagit County watershed map

You may have notice that the sky has been shedding quite a bit of water recently, cleaning the land after a long dusty summer. Washing all the dirt and debris away.

In natural areas this is a healthy process, but where urbanization has increased, so has the variety and amount of pollutants carried into our waters.

  • Sediment

  • Oil, grease and chemicals from motor vehicles

  • Pesticides and nutrients from lawns and gardens

  • Viruses, bacteria and nutrients from pet waste and failing septic systems

  • Road salts

  • Heavy metals from roof shingles, motor vehicles and other sources

  • Thermal pollution from impervious surfaces such as streets and rooftops

  • Etc...

2 Men in wading boots, standing in the stream outflow of a huge culvert.

These pollutants can harm fish and wildlife populations, kill native vegetation, foul drinking water, and make recreational areas unsafe and unpleasant.

What makes things worse is that in urban and suburban areas, much of the area is covered by impenetrable surfaces, such as buildings, pavement and compacted landscapes. These surfaces do not allow for infiltration, so more water runs over the surface of the land.

Surface runoff is the primary mechanism for transporting nonpoint source pollutants from land to our waters. Climate, geology, topography, soil characteristics, and amount of vegetative cover all affect how quickly and how much runoff becomes streamflow. The speed and depth of the runoff affects the amount of pollutants transported. Water is a mover... And the water runoff is carrying pollution to our rivers, lakes, and oceans.

Pollution is a problem.

Let's pause for a minute and talk about the difference between "Point source" pollution and "Nonpoint source" pollution.

According to Section 502(14) of the Clean Water Act, "Point source" pollution is "pollution coming from any discernible, confined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged. This term does not include agricultural storm water discharges and return flows from irrigated agriculture."

Also in section 502(14) of the Clean Water Act, "Nonpoint source" pollution is defined to mean any source of water pollution that does not meet the legal definition of "point source".

In case that wasn't clear, I made a diagram...

Non-point vs. Point source pollution diagram

The news is full of talk about Big manufacturers causing pollution and contaminating water (Point Source Pollution), but did you know that Non-Point Source Pollution is just as big of a problem? Maybe even bigger, because it's in ALL of our back yards and that really adds up!

Fortunately, if we all do our share, we can clean up or eliminate a lot, maybe even most of our pollution. As the old saying goes, "Many hands make light work"

Here's our Clean Water "To do" list:

•Keep pet wastes, litter, leaves, and debris out of street gutters and storm drains--these outlets drain directly to lake, streams, rivers and wetlands.

• Apply lawn and garden chemicals sparingly and according to directions.

• Dispose of used oil, antifreeze, paints, and other household chemicals properly--never in storm sewers or drains.

• Clean up spilled brake fluid, oil, grease and antifreeze. Don't let them get into the street where they can eventually reach local streams and lakes.

• Control soil erosion on your property by planting ground cover and stabilizing erosion-prone areas.

• Have your septic system inspected and pumped, at a minimum every three to five years, so that it operates properly.

• Purchase household detergents and cleaners that are low in phosphorous to reduce the amount of nutrients discharged into our lakes, streams and coastal waters.

And Remember, "Only Rain down the Drain!

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