- Clear out sediment traps and curb openings.
- Look for standing water or bare spots that may show a channel problem.
- Mow and manage weeds.
- Remove trash and debris on a routine basis, especially during wet seasons.
Stormwater Management
Public Works | Natural Resources Division
What Is Stormwater?
Stormwater is rain runoff from roads, roofs, parking lots, and other developed surfaces. As the water flows, it can pick up pollution like chemicals, oils, and dog poop. The stormwater then carries these things into waterways, polluting streams, rivers, lakes, and the Puget Sound.
About Our Program
The County stormwater system is made up of storm drains, pipes, ditches, culverts, and ponds that all need to function properly to keep water off of streets and out of parking lots. These facilities all flow to streams, rivers, lakes and bays. Usually, stormwater doesn't get filtered, cleaned, or treated before going into natural waterways.
Our stormwater program makes sure that stormwater flows to our natural waterways without polluting them. We monitor an maintain stormwater facilities and work with the public to keep pollutants like chemicals, car oils, fertilizer, and human and animal waste out of the water.
Our program covers a specific area of Skagit County that we have a permit from the Washington State Department of Ecology for. This area is called the National Pollutant Discharge Elimination System (NPDES) permit area.
Because pollution in runoff comes from many different sources, we have to use many different methods to keep it out of our water. Our main methods are:
- Educating the public about sources of pollution that they can control.
- Educating our own employees to ensure that county facilities do not contribute to pollution.
- Hosting a spill response hotline and participating in spill cleanup as needed.
- Monitoring stormwater management facilities to ensure they function properly.
- Monitoring stormwater outfalls and receiving waterways for pollution.
- Investigating and eliminating sources of pollution when they are found.
- Controlling runoff from new development, redevelopment, and construction sites.
2026 Stormwater Management Program (SWMP) Plan
Skagit County has developed a comprehensive Storm Water Management Program (SWMP) to meet Permit requirements and reduce the amounts of pollutants transported into our natural water resources by runoff.
The 2026 Stormwater Management Program (SWMP) Plan outlines actions the County has proposed to comply with the Western Washington Phase II Municipal Stormwater Permit issued to Skagit County by the Washington State Department of Ecology. The version of the 2026 SWMP Plan posted here is the final plan. The public comment period for the draft 2026 SWMP Plan has ended, but we always accept and appreciate feedback from the public. Please direct comments on the Plan, as well as any stormwater-related comments or questions, to Jason Quigley, Stormwater Permit Program Coordinator.
Stormwater Facilities
This section covers surface facilities, underground facilities, and commercial facilities. It also covers facility maintenance.
Stormwater facilities collect stormwater to slow it down and allow it to drop out pollutants before it mixes with other natural waters like ground water, streams, lakes, and bays.
These facilities are the only treatment rainwater gets before it enters other waterways, unlike sewer and drinking water systems.
Stormwater facilities come in many forms throughout urban areas. Homeowners associations (HOA) or private landowners often own and maintain them, but public agencies can own them as well.
Reach out to your HOA, look in your property deed, or contact a local agency to learn more about facilities in your neighborhood.
For more detail, review the Stormwater Management Manual for Western Washington.
Surface Facilities
Surface facilities can look like open spaces or ponds, but they are actually working landscapes. For safety reasons, some have fencing, but some are not that obvious.
When you recognize that an open space is a stormwater facility and not a dog park or playground, you help keep the system working as designed.
These facilities can include:
Swales
- Biofiltration swale
- Bioretention cells
- Vegetated filter strips
Ponds
- Detention or dry pond
- Infiltration basin
- Retention or wet pond
- Treatment wetland
Other surface facilities
- Permeable pavers and pavement
Underground Facilities
Underground facilities operate below the surface. They hold water to prevent overwhelming flows, catch sediment, and remove pollutants.
These facilities act as a junction for polluted runoff before it flows through pipes to natural waterways. They often appear as manhole covers and curb drains, but they can also sit below permeable cement in places like parking lots.
Because these facilities are confined spaces, it is highly recommended that you hire a contractor for maintenance. See our contractor list (pdf) for potential options.
Underground facilities can include:
- Catch basin inlet or manhole
- Drywell
- Vaults
Maintenance
Routine maintenance is important to keep your facility working and to avoid expensive repairs. Private property owners are responsible for maintaining their stormwater facilities.
Every facility should have a maintenance plan, someone in charge of managing that plan, and a record of all maintenance completed. Contact your local agency for regular inspections.
Inspection and maintenance needs vary for different types of facilities. Maintenance plans should be based on all of the built features listed in the engineering plans.
Most system maintenance focuses on soil and sediments, weed control, and trash that clogs systems. It is important to watch for these issues in your system to ensure it works properly.
- Clear outlets and spillways of blockages and check for leaks.
- Mow, manage weeds, and remove trees as needed.
- Remove sediments as needed.
- Remove trash and debris on a routine basis, especially during wet seasons.
Permeable Pavement Maintenance
- Look for standing water.
- Refill aggregate between pavers as needed.
- Replace broken sections.
- Sweep and remove moss with a dry broom on a routine basis.
Underground Facility Maintenance
Contractor maintenance is recommended due to confined spaces and safety hazards. See our contractor list (pdf) for potential options.
Facilities may require specific contractors due to name-brand systems and parts.
- Clear trash from inlets and outlets.
- Perform filter maintenance and replacement.
- Use vacuum and jetting with proper disposal of material.
