Runoff Quality in Mountlake Terrace

Rain falls on our roofs and streets and flows into storm drains. Whatever goes down the drains flows to our creeks and lakes. Rain water picks up what it touches, like oil from the road, yard chemicals and pet waste. This polluted water then runs off into our creeks and lakes and Puget Sound.  There is no filter or treatment to clean the water. This polluted water can be highly toxic to our fish and wildlife.  When houses, streets, shopping centers, and businesses are built, natural soil and plants are replaced by hard surfaces, such as roofs and pavement. When rain falls on these hard surfaces, it cannot soak into the ground, so it quickly becomes runoff that can cause flooding.

The Hall Creek - Lake Ballinger drainage basin collects stormwater runoff from Mountlake Terrace as well as the cities of Lynnwood, Edmonds and Shoreline.

All these areas have experienced expansion of impervious areas with increased development. More impervious areas such as streets, parking lots, and building roofs increase runoff to surface streams and lakes. This runoff also carries with it pollutants picked up from streets, lawns, construction sites and commercial properties. Common water quality problems from polluted runoff include depleted dissolved oxygen levels, increased water temperature, excess nutrients, hydrocarbons, heavy metals and pesticides.

For this reason, all new development and redevelopment projects must meet state water quality standards for stormwater runoff during and after the construction portion of the project.

Unpaved surfaces absorb rain

Sponge up rainwater around your home

New: Mobile Cleaning Best Management Practices

Mobile Cleaning Businesses - Best Management Practices (PDF)


What You Can Do

While these practices can help keep surface water clean there are some simple things you can do to help ensure that our streams remain healthy such as:

  •  Clean up after your pet by using a pet waste disposal station or garbage can.
  •  Choose natural methods of pest control and if pesticides must be used, use them sparingly.
  •  Maintain stream buffers by protecting shrubs, vines and other plants along streams.
  •  Use fertilizers sparingly on lawns and gardens, and use natural organic fertilizers. Consider using natural and organic methods of lawn care.
  • Keep toxins out of stormwater drains (including engine oils, paint, paint thinners, and pesticides.) Dispose of them safely at a household hazardous waste collection site.