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Project Overview

Region 1 Planning Council has received Section 319 Grant funding from the Illinois Environmental Protection Agency (IEPA) to conduct outreach and activities to educate and encourage local watershed stakeholders to adopt nonpoint source (NPS) pollution control best management practices (BMPs). The project includes the construction of two demonstration BMP projects: a bioretention basin in the Spring Creek-Rock Creek Watershed, and a bioswale in the Kent Creek Watershed. These BMPs will help protect water quality in the South Fork Kent Creek, Levings Park Lagoon, Buckbee Creek, and the Rock River.

This project is being conducted in partnership with Illinois Environmental Protection Agency, Winnebago County, City of Rockford, Winnebago County Soil and Water Conservation District, Rockford Township, Rockford Park District, and Olson Ecological Solutions.

NPS Pollution

Nonpoint Source (NPS) Pollution

Nonpoint source (NPS) pollution is the United States’ main contributor to water quality concerns. The Illinois EPA identifies NPS pollution as the “primary factor limiting waters in Illinois from attaining their designated uses.” [i] NPS pollution is caused by water flowing over or through the ground, picking up pollutants, and depositing the pollutants into nearby waterways and groundwater. Common sources of NPS pollution include urban and construction site runoff, agricultural runoff, and resource extraction.

In Winnebago County, both Buckbee Creek Watershed and South Kent Fork Kent Creek Watershed face stormwater runoff and nonpoint source (NPS) pollution concerns. Water sampling conducted in the region indicates a presence of NPS pollutants in both watersheds, including total suspended solids, total nitrogen, and total phosphorus.

NPS Infographics

Click through the documents below to learn more about the various types of nonpoint source pollution, including definitions, problems, and solutions.

Best Management Practices

Best Management Practices (BMPs)

Best management practices (BMPs) are methods of managing stormwater runoff and mitigating pollution entering waterways by controling peak stormwater runoff rate, improving water quality, and managing runoff volume. [i] BMPs do this by capturing, storing, and filtering stormwater runoff. Common BMPs include bioretention basins, bioswales, constructed wetlands, green roofs, porous pavement, retention ponds, and urban tree canopies. This project focuses on the implementation of a bioretention basin and a bioswale.

Green Infrastructure BMPs. Listed from left to right: bioretention basin, bioswale, urban tree canopy, green roof, permeable pavement, constructed wetland,. Source: U.S. EPA.

Bioretention Basin

A Bioretention basin is a shallow, vegetated basin that hosts a variety of plants and typically includes an underdrain, which is a drainage feature installed underground. Also referred to as rain gardens, bioretention basins improve water quality and filter stormwater runoff through the use of engineered soil that removes solids, metals, and organic chemicals from stormwater runoff.

On average, bioretention basins filter out 77% of wastewater total suspended solids concentrations, 50% of total nitrogen, and 50% of total phosphorus. [i] They also remove nearly 100% of heavy metals found in stormwater runoff. [ii] [iii]

Bioretention basins have a simple design compared to other BMPs, making them easy to implement and incorporate into a wide variety of landscaped areas, such as landscaping islands, cul-de-sacs, parking lot margins, commercial setbacks, open space, rooftop drainage, and streetscapes. [iv]

For more information on bioretention areas and rain gardens click here.


A bioswale is a stormwater control measure that uses bioretention to promote infiltration and filtration of stormwater runoff as it moves downstream. Bioswale design measures typically include engineered soil and an underdrain. They maximize the time water is stored to allow for the capture and breakdown of pollutants.

Bioswales demonstrate a high storm runoff storage capacity by removing up to 99% of surface and stormwater runoff. [v] Depending on the intensity of stormwater flow and vegetation conditions, bioswales can reduce pollutants (TN and TP) carried in surface runoff by up to 99% [vi] and can remove anywhere from 47 to 86% of TSS. [vii]

Bioswales have flexible siting requirements, allowing installment within many sites, such as medians, cul-de-sacs, bulb-outs, and other public spaces or traffic calming strategies. [vii]

For more information about bioswales click here.

Left: Bioretention Basin. Source: NJ Developers Green Infrastructure Guide. Right: Bioswale. Source: Lower DuPage Watershed Coalition.

BMP Resources

Click through the documents below to learn more about stormwater best management practices for agricultural, residential, and commercial land.

Key Terms

Best management practices (BMPs) – the primary method to manage stormwater runoff and mitigate pollution entering waterways. BMPs are tools, practices, and methods of stormwater management that control peak stormwater runoff rate, improve water quality, and manage runoff volume. [i]

Bioretention – the process of reducing pollutants in water by storing water in addition to other biological processes, such as infiltration. [ii]

Bioretention basin – a shallow, vegetated basin that hosts a variety of plants and typically includes an underdrain, which is a drainage feature installed underground. [iii] Also referred to as rain gardens or biofiltration cells.

Bioswale – a stormwater control measure that uses bioretention to promote infiltration and filtration of stormwater runoff as it moves downstream. [iv]

Heavy metals – an ill-defined group of inorganic chemical hazards that may leach into soil and water from industrial sites, mines or landfills and can cause numerous health issues. [v] Heavy metals include lead, chromium, arsenic, cadmium, and mercury.

Illinois Environmental Protection Agency (IEPA) – state agency established in 1970 to safeguard environmental quality, consistent with the social and economic needs of the State of Illinois, to protect health, welfare, property, and the quality of life. [vi] The IEPA administers Section 319 funds on behalf of the US EPA.

Nonpoint Source (NPS) Pollution – occurs when runoff from rain and snowmelt carries pollutants into waterways, derived from the concept that there is no single point from which the pollution occurs. [vii]

Section 319 – Federal program under the 1987 Clean Water Act to address the need for greater federal leadership to help focus state and local nonpoint source efforts. [viii]

Total nitrogen – the total amount of nitrogen, including organic nitrogen, nitrate, nitrite, and ammonia. [ix]

Total phosphorus – the total amount of phosphorus, including organic and inorganic particulate and dissolved phosphorus. [x]

Total Suspended Solids (TSS) – suspended organic and inorganic materials. Sources of TSS include pavement, vehicle exhaust emissions, vehicle parts, building and construction material, road salt, road paint, pedestrian debris, soil material, plant and leaf litter, and atmospheric deposition of particles containing toxic substances and metals. [xi]

Vegetated Swale – shallow, open channels densely populated with vegetation, typically in the form of turf grass. [xii] Also referred to as grass swales.


Technical Assistance

Property owners who require additional help with evaluating potential BMP improvements to their specific location can request technical assistance with staff from Olson Ecological Solutions. For more information, or to schedule a consultation, please contact Olson Ecological Solutions, Alden O’Connor, via email at

Project Partners

This webpage was prepared using United States Environmental Protection Agency funds under Section 319 of the Clean Water Act distributed through the Illinois Environmental Protection Agency. The findings and recommendations contained herein are not necessarily those of the funding agencies.

Contact Us

Have questions or want to learn more about a project, contact us below:

Phone 815-319-4180