Des Plaines River Watershed Workgroup
The Des Plaines River Watershed Workgroup, DRWW, formed in 2015 with a primary goal of improving water quality in the Des Plaines River basin in Lake County through a collaborative, locally led process. Membership in the group consists of 40 municipal and county government agencies, publicly owned treatment works, POTWs, park districts, consulting firms, and environmental not-for-profits.
Nutrient Assessment Reduction Plan
The DRWW continued its work with Geosyntec to develop a Nutrient Assessment Reduction Plan, NARP. The NARP, required by special condition in the National Pollutant Discharge Elimination
System, NPDES, permits of multiple DRWW members, aims to address phosphorus-related impairments in waters receiving discharge from POTWs. In 2023, Geosyntec used the watershed models to analyze several management scenarios to evaluate the effectiveness of watershed-based strategies in improving water quality. These scenarios were compared with the baseline scenario which represents the existing conditions in the watershed. The management scenarios included load reductions from POTWs, upstream sources and nonpoint sources as well as combined scenarios. There were five key findings from the analysis:
- POTW total phosphorus reductions beyond 0.5 mg/L have minimal impact on water quality.
- Upstream total phosphorus reduction reduces sestonic chlorophyll a and improves dissolved oxygen during high flows.
- Tributary total phosphorus reductions reduce sestonic chlorophyll a but have minimal impact on dissolved oxygen.
- A combined reduction in the load from POTWs, nonpoint sources, and upstream improves the water quality in the Des Plaines River.
- Improving upstream dissolved oxygen addresses the impairment in upper reaches of the Des Plaines River.
The NARP report also presented recommended actions for addressing phosphorous related impairments along with an implementation plan and schedule. The report was submitted to Illinois EPA on Dec. 29, 2023.
As of spring 2025, the DRWW has yet to receive feedback or approval of its NARP from the Illinois EPA. In 2024, the DRWW reviewed its NARP implementation plan with membership and began moving forward cautiously as the group awaits feedback. In 2024, the DRWW engaged with the Wisconsin Department of Natural Resources on its ongoing Total Maximum Daily Load, TMDL, study within the Wisconsin portion of the Des Plaines River watershed. The DRWW also met with the U.S. Geological Survey, USGS, about adding one of its super gages near the state line to gather real-time monitoring of nutrients and other parameters as Wisconsin progresses through its TMDL implementation in the watershed.
Monitoring Program
The DRWW continues to conduct water quality and bioassessment monitoring. Data from this monitoring is the foundation of the Integrated Prioritization System, IPS, and NARP models that will be
used by individual members to prioritize and implement water quality improvement projects. The Monitoring Committee meets frequently with stakeholders to update and adapt the monitoring plan as needed. The committee reviewed and approved the DRWW 2022-23 Water Quality Monitoring Report, completed by Macroinvertebrate Biotic Index, MBI. Similar to previous years' reports, the results suggest that quality of aquatic life in the Des Plaines River mainstream improves downstream through the workgroup area.
Lakes Committee
The DRWW Lakes Committee continued to monitor the lakes within the watershed and coordinated outreach and education opportunities targeting topics including lake management plans, invasive species, routine monitoring of lake and stormwater inlets, nutrient reduction, and project implementation. The DRWW continued to monitor the water quality of project lakes and carp removal efforts.
The DRWW Lakes Committee has also been reviewing the NARP Implementation Plan. The Committee reviewed actions that provide benefits to the watershed and is working to review practices such as street sweeping and leaf litter pickup. The committee is designing a survey to distribute to the DRWW membership to assess those practices. The leaf collection survey will be distributed at the February 2025 annual meeting.
Deicing Workshops
The DRWW continues to sponsor and support the Northeastern Illinois Regional Deicing Workshop. The deicing workshops focus training efforts on ways to keep public and private sector professionals up to date on best management practices for winter maintenance that safely reduces road salt use. The 2023 virtual workshops trained over 1,000 individuals in winter best management practices for both public roads, parking lots, and sidewalks.
On Sept. 20, 2023, the DRWW also supported a Deicing Calibration Day, which was the collaborative effort of several Lake County departments: Stormwater Management Commission, Health Department and Community Health Center, and Division of Transportation, LCDOT. This event focused on sharing hands-on experience to calibrate winter maintenance vehicles before winter in Illinois. LCDOT staff demonstrated calibrating a vehicle for 21 participants, who can now practice responsible road salt use for their own vehicles. The participants also toured LCDOT’s in-house liquid blending systems and operations to view the salt brine and beet juice winter maintenance alternatives.
The DRWW’s website is drww.org.
