Renton Stormwater Management Action Planning (SMAP)

Johns Creek basin was chosen as the priority catchment for the City of Renton's Stormwater Management Action Plan (SMAP). Your input was important to the success of Renton’s SMAP. The period for public comment is closed and the City has reviewed the community's feedback and produced the SMAP.

Rainwater runoff from urban areas – also known as stormwater – is a leading pollution threat to natural waters like lakes, rivers, streams and marine water bodies in Washington State. Pollution in natural waters is harmful to fish and animals, people who swim and play near the water, and the economy of industries that rely on clean water bodies.

Runoff contamination comes from common land uses like vehicular traffic areas, landscaping with fertilizer and pesticides, building materials, spills from activities conducted outdoors, and illicit wastewater connections to the drainage system. Polluted runoff can carry metals, nutrients, pesticides, and harmful organic compounds to natural waters if left untreated.

As part of the Clean Water Act National Pollutant Discharge Elimination System (NPDES), the Washington State Department of Ecology required the City to implement the SMAP process as outlined in the Western Washington Phase II Municipal Stormwater Permit. More information on the Stormwater Permit can be found at  this link to Ecology’s website . The goal of the SMAP process is to achieve water quantity and quality improvements in a specific water body by prioritizing actions on the land that drains to it.

• Improve water quality in water bodies
• Help reduce flood risk
• Protect aquatic habitat and environmental resources
• Create potential opportunities for new open spaces, parks, and trees
• Reflect the community’s values on water quality and inform how and where future actions are implemented

The SMAP was developed by your stormwater management team at the City using the process shown in the following infographic.

Scroll through the series of maps below to learn about what spatial data is used in the SMAP process to prioritize Johns Creek basin.

Environmental and socioeconomic stressors, which can contribute to ongoing health inequalities, were considered in the SMAP process. U.S. Census, U.S. Environmental Protection Agency (EPA), and City data were used to create an equity screening tool that includes a Demographic Index, an Environmental Hazards Index, and an Environmental Opportunity Index. The Combined Equity Index, intended to serve as a general check for extreme scenarios or other patterns, is an average of the other three. The Combined Equity Index was reviewed along with the other three, not in their place. As part of the SMAP prioritization process, the analysis was refined to show specific results for geographic areas across the City (based on US census data). Each of the demographic and environmental hazard indicators were reviewed as part of the ranking and screening process in order to select a priority basin. These indicators identify areas with populations that are potentially susceptible or vulnerable to environmental pollution, and identify areas with the greatest amounts of compounding exposure to environmental pollutants by evaluating their proximity to known sources.

The City included several outreach events and opportunities for public comment during the SMAP process. These are some examples:

• This web-based Story Map was shared with the community early in the SMAP process to provide information and collect feedback with a survey, input map, and comment box.

• SMAP team members attended in-person events like the City Farmer's Market in June 2022 to provide information, answer questions, and solicit responses to the SMAP survey

• SMAP team members attended the City Council Utility Committee Meeting on February 6, 2023, to inform council members on the progress of the SMAP

• SMAP outreach and involvement opportunities were advertised through the City’s social media accounts, emails to community organizations, and with utility bill mailings.

Public comments and feedback received included the following topics:

• Concerns over new development and land use changes

• Support to increase stormwater-related maintenance

• Support to address pollutant sources, like vehicles

• Concerns over runoff pollution into streams and river

• Desire for more wetland and native growth area protection

• Desire for protection and maintenance of tree canopy

• Desire for more public education

• Concerns over utility rate increases

• Support for equitable dispersion of projects

The City included public feedback during two major steps in the SMAP process:

• Selecting the Priority Catchment: As part of selecting a priority catchment, the City reviewed the public responses to the SMAP survey for perspective on what types of issues common to each catchment were the most important to the public. The City also evaluated existing and forecasted water quality and flow impacts to the receiving waters, and improvement project opportunities in each catchment.
• Deciding on Stormwater Management Actions: The second round of public comments were considered during the final selection process for potential stormwater management actions. The comments received were considered by the SMAP interdepartmental planning group as the actions were developed and refined.

The City of Renton values and appreciates all of the comments and feedback received from the community during the SMAP Process. The survey and public comment forms are now closed, but the comments that were received from the public will continue to be considered when selecting and prioritizing future stormwater management actions. Thank you for your participation!

Through the basin prioritization process described above, the review of public comments, and additional evaluation by the City, Johns Creek Basin was selected as the SMAP priority catchment. The Stormwater Management Action Plan for Johns Creek Basin was required to include at least one planned action from each of the following categories:

Scroll to learn about each of these stormwater management actions (SMAs) categories.

Retrofits are projects that add new stormwater management (pollutant-removal and/or control of runoff volume) in areas that were developed long ago without any stormwater facilities or with facilities that have since become out-of-date. These retrofits can range from an underground concrete treatment vault to a rain garden on the surface with plantings that help filter and infiltrate water into the ground. Below are a few examples of the kinds of retrofits the City of Renton considered.

The map below of Johns Creek Basin shows the locations which were considered for stormwater retrofits. All candidate retrofit locations were first identified based on historically developed areas without modern stormwater management. In addition, these locations on the map are well-suited for retrofits because they represent existing facilities that need upgrades or areas within the city's property or right-of-way where new facilities would fit.

Map Notes: A, B, C... Each potential project location on the map has randomly been assigned a letter label for identification. 1. These potential project locations were identified as part of the current SMAP process to address runoff that would not be addressed by other plans. 2. The City completed a Stormwater Facility Retrofit Study in February 2021. These potential water quality project locations reflect those that were identified with high priority in the Johns Creek Basin. 3. The City completed the Sunset Area Surface Water Master Plan in April 2011. These road retrofit projects reflect those that were identified with some of the highest priority within the Johns Creek Basin.

Land management actions are designed to improve or protect streams and other natural waters by addressing the way the City regulates new development and management of already built-out areas.

Examples of land management actions are:

1. Growth management: Coordinating with other City departments to update comprehensive plans across the City in ways that include long-range stormwater management and pollution-reducing strategies.
2. Developer incentives: Instituting incentives for developers to encourage designs that minimize impacts to natural waters.
3. Codes: Reviewing the existing City ordinances and codes for potential updates to development requirements or fee collections that help prevent pollution-generation and help fund the cleanup of historically untreated areas.
4. City policies: Update city policies, for example, the way the City tracks and credits tree planting, especially considering the types and height of the trees and how many are planted in groups.
5. City programs: Create new programs, such as one to review and track lands within the city that might need additional protection or could be candidates for restoration grants.

The City already has a program for managing stormwater that includes specific elements required by the State Stormwater Permit. The SMAP process involved enhancing one or more parts of the City’s existing program. This meant targeting, prioritizing, customizing, or increasing the frequency of one or more of the following:

1. Source Control inspections at institutional, commercial and industrial sites (source control involves inspections to identify pollutant sources and provide education, technical assistance, and enforcement to prevent pollution from these sites)
2. City Stormwater Facility Inspections
3. City Stormwater System Maintenance
4. Public Education and Outreach
5. Illicit Discharge Detection and Elimination (IDDE) Field Screening (identifying non-stormwater sources that might be discharging to the storm drain system either accidentally or illegally)

All photos, unless otherwise noted, are property of the City of Renton.