What is Stormwater?

Stormwater is water runoff from rainfall or snowmelt that flows at the ground’s surface. Stormwater is created when water flows on impermeable surfaces such as rooftops, gutters, parking lots, driveways, roads, yards and other hard surfaces that do not allow water to infiltrate or seep into the earth.  The continuous expansion of city and urban boundaries has replaced the natural landscape with impermeable surfaces. Stormwater runoff is a leading source of pollutants to our rivers, streams, lakes and coastal waters by carrying trash, biohazard waste, chemicals, oils, dirt, metals, and sediment.  Stormwater is typically not directed to wastewater treatment plants but rather directly to the nearest body of water or undeveloped land.

In order to protect our environment, we must be responsible and proactive with managing stormwater runoff through BMP’s (Best Management Practices).

Why Did i receive a letter of non compliance?

Compliance letters are the government's way of notifying you that there is a problem with a privately owned stormwater system.  Each agency manages compliance differently, but generally there is a grace period of 30 days in which you will need to provide the issuing agency a plan to remediate the issue(s).  If you don’t, fines may soon follow and may be expensive—up to $300 per day. If your privately owned stormwater system has multiple homeowners, each homeowner may be fined the full amount on a daily basis until the problem is fixed; this can get expensive quickly so give us a call. See how we guarantee to keep you in compliance.

I Thought this was managed by others. why me?

The short answer is: private stormwater systems affect others and the environment.  Many cities and counties are part of the NPDES stormwater permitting program. This program is intended to protect the nation’s waterways by regulating pollution.  Since stormwater runoff is a leading source of pollution, these government agencies are responsible to monitor the stormwater in their jurisdiction. Private stormwater systems typically release treated and untreated stormwater runoff into City and County conveyance lines that ultimately end up in our lakes, streams, and rivers.  Compliance inspections are performed by these government agencies as part of their NPDES MS4 Stormwater permit. These agencies maintain publicly owned property, but not private property so compliance letters are the government’s way of notifying you that there is a problem with a privately owned stormwater system. We can help you get your stormwater system back into compliance.

Why Maintain your Stormwater system?


Government agencies are responsible for protecting the State’s land and waterways from stormwater runoff pollution, but most will not maintain privately a owned stormwater system. Privately owned stormwater systems are designed to either treat stormwater run off, infiltrate into the earth or drain directly into a government owned stormwater system. This means a privately owned stormwater system may allow runoff carrying pollutants to discharge directly to a local waterway or seep into the ground and migrate to neighboring properties.  To stay in compliance with the city or county, privately owned stormwater systems must be maintained.

City of Vancouver Stormwater, Surface Water & Groundwater

Clark County Stormwater Management Regulations

Maintenance should follow the manufacturer’s specification for the structure(s) installed and/or per the local requirement.  A typical requirement is to have your stormwater system inspected annually and maintained as needed by a certified maintenance provider.  Some stormwater structures require inspection and maintenance more often than others. Not everyone has a Stormwater Maintenance Plan (SWMP) but they should to ensure your system is inspected and maintained on schedule.


Engineers are responsible for designing stormwater systems according to local building codes.  City and County Engineers review the submitted stormwater plans to ensure they meet the current standards.   Each stormwater system was designed for a purpose and is specific to the property(s) it serves. Since stormwater is a leading cause of pollution to waterways, it is taken seriously by the agency reviewing and approving construction plans.


Need help maintaining and managing your storm system? See our process.


Types of Facilities


Media Filters

There are many different types of filtered stormwater structures made by multiple manufacturers.  Filtered structures may include: catch basins, manholes, filterra, jellyfish, linear, peak diversion, and vaults.  These structures are typically cast in concrete and contain built-in plumbing to take treated water from the filters to a downstream outflow or infiltration chamber.  The size of the structure and number of filters are determined through an Engineer’s review of the site. Filtered structures typically require an annual inspection and an inspection after a major rain event to ensure they are working properly.  Manufacturers of these products have strict guidelines establishing when maintenance is required. Generally speaking, maintenance should be performed if there is more than 4” of sediment build up in the bottom of the structure; there is approximately ¼” of sediment build up on top of the filters, or there is a pronounced scum line on the inside wall of the structure.  Any of these conditions inform the inspector that the filters have done their job of trapping sediment and no longer work effectively.


Storm Drains, Catch Basins, and Street Drains

Catch basins, storm drains, or street drains are chambers or sumps designed to capture and convey stormwater runoff. They are usually built at the curb line or in parking lot valleys. Inspection and maintenance is the first line of defense when it comes to ensuring your stormwater system work properly.  Sediment, trash, and debris can build up, fill the underground pipes, and create a blockage that floods the immediate area. Damaged structures will not work properly and allow migrating soils to enter the system, clog the drainage pipe, and create subsidence or sinkholes in the surrounding area.



Drywells capture stormwater runoff from upstream structures like catch basins or street drains.  Drywells are typically 6’-12’ deep but some are much deeper. They are made of concrete with holes in the side and surrounded by drain rock with a few feet of drain rock in the bottom.  The holes in the drywell allow water to slowly infiltrate through the rock and into the ground while the suspended sediment and debris settle to the bottom. Eventually, drywells need to be cleaned and, depending on their age and condition may need to be repaired or replaced.


Underground stormwater detention systems

Underground stormwater detention systems are plastic or concrete chambers built to capture stormwater from upstream stormwater structures like catch basins or filtered structures.  Your structure may have a permeable fabric and gravel base allowing infiltration into the ground or a poured concrete floor designed to capture and retain stormwater with a metered release to a city or county stormwater system.  In some cases the underground structure will have the first chamber designed to capture trash and debris before releasing water to other chambers. Underground tanks have also been used to capture stormwater. Most stormwater detention systems have an emergency outflow pipe to release excess stormwater during a major rain event.


Swales, Detention Ponds & Rain Gardens

Swales, detention ponds, and rain gardens are methods of capturing and treating stormwater.  Swales and detention ponds collect runoff for infiltration into the ground. They may contain plants, shrubs, and grasses to help filter and absorb stormwater.  Each system also has an emergency outflow pipe to handle excessive flow during a major rain event. Rain gardens are similar to swales but contain a perforated storm pipe buried within drain rock wrapped in fabric with plants, and engineered soils.  Rain gardens typically release treated stormwater to a city or county stormwater system. Maintenance for rain gardens usually consists of replacing the special soils and plants every few years. Maintenance of swales and detention ponds usually consists of routine landscape maintenance.  Over time sediment will build up reducing the system’s ability to infiltrate the stormwater. The built-up sediment will need to be excavated and the grass and plants replanted in order to continue working properly.

why clean creek?

Clean Creek is a certified maintenance provider of Contech (Stormfilter), Oldcastle (Perkfilter) and Baysaver (Bayfilter) stormwater products.  We are recognized in the community as a local leader in stormwater maintenance services. Clean Creek can create a customized stormwater management plan (SWMP) for your property. With a maintenance agreement specific to your property, we will guarantee your compliance with local government agencies. Visit our company page to learn more about us.

stormwater history

Maintaining your stormwater system hasn’t always been a requirement. The earliest federal action toward protecting our nation’s water was the Refuse Act in 1899.  This act outlawed the dumping of refuse that would obstruct the navigable waters with certain cases allowed with a federal permit). In 1948, the Water Pollution Control Act was passed and was considered the first major U.S. law to address the nation’s water pollution.  In 1972 the Clean Water Act was created as an amendment to the Water Pollution Control Act of 1948 due to the growing public awareness and concern for controlling water pollution. In 1972 the NPDES (National Pollutant Discharge Elimination System) was created in Section 402 of the Clean Water Act which prohibits the discharge of pollutants from any point source into the nation's waters except as allowed under an NPDES permit.  The NPDES gave the EPA authority to regulate discharges into the nation’s waters by setting limits on the effluent that can be introduced into a body of water. In 1977 Congress amended the Clean Water Act to enhance the NPDES program, shifting the focus from controlling conventional pollutants to controlling toxic discharges. In 1987 Congress passed the Water Quality Act which called for increased monitoring and assessing of water bodies to ensure that water quality standards were met—not just on paper. 

Most states are now authorized to implement the stormwater NPDES permitting program.  The EPA still remains the permitting authority in a few states, territories, and in most Indian country.  In Washington State the Department of Ecology administers the NPDES municipal stormwater permits known as MS4 permits.  The permits require local governments to manage and control polluted stormwater runoff so it does not pollute downstream waters.  These permits are broken into Phase I and Phase II city and counties, based on population.

Environmental Protection Agency

Washington Department of Ecology