The City of Bonney Lake maintains 61 Stormwater Ponds, 80 Dry Wells, 41 miles of Stormwater Pipe, 384 Manholes and 2,089 Catch Basins and Inlets.

Stormwater is rain and snow melt that runs off surfaces such as rooftops, paved streets, highways, and parking lots. As water runs off these surfaces, it can pick up pollution such as oil, fertilizers, pesticides, soil, trash, and animal waste. From there, the water might flow directly into a local stream, lake, or it may go into a storm drain and continue through the stormwater collection system until it is released untreated into a local waterway.

In addition, the large impervious surfaces in urban areas increase the quantity of peak flows of runoff, which in turn cause hydrologic impacts such as scoured streambed channels, instream sedimentation and loss of wildlife habitat.


Stormwater Ponds

Stormwater Ponds are manmade features generally located near your neighborhood or business. They are designed to mimic the ecological function of naturally occurring ponds and wetlands. Water from these ponds drains to a lake, river, stream, wetland, or may infiltrate into the ground.

Depending on the age of the pond, it may serve one or two stormwater management functions. Older ponds were designed to slow the flow of stormwater and discharge it at a rate to minimize downstream flooding. Newer ponds are designed to manage water volume as well, but also provide a water quality benefit. A properly designed stormwater pond will remove a substantial amount of sediment and other pollutants from stormwater before releasing this water downstream. Some ponds are planted with wetland plants and are known as stormwater treatment wetlands.

What should a pond look like?

Next to being properly designed to store and convey stormwater, landscaping is the most critical component in the proper functioning of the stormwater pond. Historically, many ponds were designed to have mowed grass edges as a form of "sales appeal" for the developer, rather than being landscaped for the long term benefit of the pond. Mowed grass to the water's edge on all shorelines means the pond is not providing its full ecological value. Un-mowed vegetative buffers are essential to long term health of ponds and waterways.

Buffers should also extend into the pond where possible using emergent wetland plants. The most important factor when designing a buffer is to choose the proper vegetation for the slope and soils. The buffer should include a diverse plant community that provides both habitat and aesthetic appeal. The proper buffer will provide both a water quality and wildlife component:

  • Water Quality: The proper plant community will prevent shoreline soil erosion (bank slumping) around the pond. It will also prevent herbicides and pesticides from going directly into the pond. Eliminating the need for fertilizers and frequent mowing will reduce the potential for algae blooms.
  • Wildlife: A diverse plant community will provide habitat for a variety of wildlife, including predatory insects, amphibians and birds which keep mosquito populations in check. Tall native grasses will also discourage Canadian Geese from taking over the pond and adjacent lawns.
  • Fences: Ponds are generally designed with gentle slopes so if someone falls into the pond, they are able to climb out. In locations where walls or steeper slopes are incorporated into the pond, a safety fence may be added. Many ponds have fences installed to help identify the presence of the facility and indicate in a passive way that they are not swimming or play areas. However, since ponds are intended to be natural areas, like streams or natural ponds, the City avoids use of fences where possible.

How are ponds maintained?

Much pond maintenance, such as sediment and aquatic plant removal requires the equipment and expertise of a professional. Some work, like weed control or planting of approved plants can be performed by volunteers. Native plant buffers around the pond and its discharge waterway require maintenance to prevent non-native invasive species from taking over. This is critical because the native plants often require more time to become well established than the weedy species. Debris removal and weeding will be required as small plants develop. Plant identification is very important for this operation since it is difficult in the beginning to distinguish between the non-native and native plants. Invasive plant removal will be an annual task but will diminish as the native plants fill in.

Who maintains Bonney Lake's ponds?

Public stormwater ponds are maintained by City crews. The Stormwater Division has two full-time employees responsible for maintaining nearly 120 acres of stormwater ponds. During the summer months, 6 to 7 temporary employees are hired by the City to assist the full-time Stormwater Division employees.

Regulatory required maintenance is focused primarily on water quality benefits and ensuring that ponds have adequate sediment storage and inlets and outlets are not blocked by plants or debris. At times, these maintenance activities may detract from pond aesthetics, but efforts are made to reduce any such negative impact. Private ponds are maintained by private landowners and inspected by City staff.

Stormwater crews are limited by budget constraints, so resources are focused primarily on functional pond attributes like storage, access, and water quality, and less on pond aesthetics. Also, before regular spring/summer pond maintenance begins, the right of way and common areas throughout the City are maintained. Once that is complete, then pond maintenance can begin in earnest. Depending on the effort required with the right of way maintenance, pond maintenance may be delayed.

How can I help?

The biggest impact homeowners and businesses can have is to prevent pollutants from entering these ponds. Ponds are designed to remove pollutants, but they are not able to remove all pollutants.

In particular, soaps used to wash cars cannot be removed by ponds and actually suspend other pollutants to reduce the effectiveness of ponds. Don't wash your car in a place that drains into a pond. Using natural yard care practices and limiting the use of chemicals around the home are good measures everyone can take to reduce the source of pollutants, rather than relying on imperfect pond facilities to remove those pollutants.

Street Sweeping

The street sweeping program is funded under the stormwater division of the Public Works Department. The program is necessary to comply with National Pollution Discharge Elimination System, Phase II (NPDES II) stormwater regulations. The program also projects a good image of the City of Bonney Lake as the streets are clean, safe and aesthetically pleasing to residents and visitors.

Stormwater runoff from streets with curb and gutter in newer developments are normally channeled to a stormwater pond whereas older streets without curb and gutter are channeled through a vegetated swale that filters the runoff before it reaches its destination. The goal of the program is to pick-up debris on the surface of the street before it can enter the system, thus, reducing the need for costly removal of sediment within the system. The streets without curb and gutter benefit from the program in that less debris accumulates on the shoulder of the street, reducing disruption of the runoff from the street to the swale. The Street Sweeping Schedule is a general guideline for when the streets and gutters are swept. Following a weather event, some of the streets without curb and gutter may be swept using the city's side cast sweeper. This will enable the city crew to expedite sweeping during cleanup operations.

The street sweeping waste is dumped at the Cuty decant site where the water is separated from the waste. When the debris reaches a certain amount, the waste is then tested and hauled to a Department of Health authorized site.

The fall/winter leaf season produces the largest amount of waste due to falling leaves. The sweepings are dumped at the decant site where the water is again separated from the vegetation. This vegetation is then loaded into a dumpster, the dumpster is then picked up and delivered to a transfer station for compost.

The homeowner is responsible for the proper disposal of yard waste generated on their property. A blue receptacle is available from the solid waste service provider to collect yard waste specifically. We ask that all of our citizens please take advantage of this service so that we can focus our efforts on collecting the other natural and unnatural litter that accumulates within the City-owned right of way. Unfortunately, we just do not have the staff or equipment to collect everyone's yard waste. Please refer to the Bonney Lake Municipal Code Chapter 8 regarding litter in the right-of-way for more information.

NPDES Stormwater Permit
The National Pollutant Discharge Elimination System (NPDES) permit program is a requirement of the Federal Clean Water Act, which is intended to protect and restore waters for "fishable and swimmable" uses.  The Federal Environmental Protection Agency has delegated permit authority to state environmental agencies.  In Washington, the NPDES-delegated permit authority is the Washington State Department of Ecology.  Since Bonney Lake operates a small municipal storm sewer system that serves less that 100,000 people, it is designated as a Phase II community and must comply with Ecology's Western Washington Phase II NPDES Municipal Stormwater Permit.

The Permit allows municipalities to discharge stormwater runoff from municipal drainage systems into the State's water bodies (i.e., streams, rivers, lakes, wetlands, etc.) as long as municipalities implement programs to protect water quality to the "maximum extent practicable" through application of Best Management Practices.  These required practices, specified in the Permit, are collectively referred to as the Stormwater Management Program (SWMP).

The Permit requires the City to report annually by March 31st of each year on program implementation for the prior year and requires municipalities to update the SWMP to describe the actions planned to achieve and maintain permit compliance in the upcoming year.

Stormwater Management Program:

2024 Stormwater Management Program

We want your feedback regarding the development, implementation, and update of the Stormwater Management Program.  Please send comments to the Assistant City Engineer.

NPDES Phase II Annual Report:

2023 Annual Report

Stormwater Education Resources:

Used Oil Recycling Flyer
Rain Garden Installation Handbook
Natural Yard Care Flyer
Curb Marker Program Flyer
Spill Response Information Flyer
Household Stormwater Pollution Prevention Flyer
"Just Doo It" Pet Waste Flyer
Mobile Business Flyer
"Don't Feed Ducks" Flyer
Good Cleaning Practices - Residences
Good Cleaning Practices - Auto Industry
Good Cleaning Practices - Restaurants
Report Water Pollution Flyer

Stormwater Management Action Plan:

Public Involvement

The City of Bonney Lake values the comments and feedback of our community. The public comment period is now closed. The City of Bonney Lake is reviewing the comments received from the public in considering future stormwater management actions. Thank you for your participation!


Story Map


You are invited to learn more about the Stormwater Management Program Planning process on the interactive Story Map.



Source Control Program

Did you receive a welcome letter in the mail to introduce the new Business Source Control Inspections or the Dumpster Lid Program?


Story Map

You are invited to learn more about these new programs and find links to helpful resources on the program Story Map.

Other Stormwater Resources:

Illicit Discharge Detection & Elimination Program
WA State Department of Ecology Stormwater Program
Pierce County Stormwater & Site Development Manual

Stormwater Pollution Prevention & Water Conservation Calendar

Each year the City of Bonney Lake develops a calendar to promote pollution prevention and water conservation practices. To help convey this message, the City holds an art contest open to students in grades K-12 attending qualifying schools or home schooled in Bonney Lake! Each month in the calendar displays artwork from area students related to water conservation, recycling, and stormwater pollution prevention.

A limited number of calendars are printed each year and available for free at City offices. Call 253-862-8602 to see if calendars are still available.

2023 Calendar Artwork

Office Hours:
Monday - Thursday
9:00 - 4:00
By Appointment Only

Stormwater Department

Public Services Center
21719 96th ST E
Buckley, WA 98321

City of Bonney Lake
Attn: Public Works
21719 96th ST E
Buckley, WA 98321


After Hours Emergency Phone: 253-287-4455