The Des Plaines River Watershed Workgroup, DRWW, was 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 41 Municipal and County government agencies, Publicly Owned Treatment Works, POTWs, Park Districts, Consulting Firms, and Environmental not-for-profits. For more information, see drww.org.
Nutrient Assessment Reduction Plan
In 2021, the DRWW contracted with Geosyntec to develop a Nutrient Assessment Reduction Plan. 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 publicly owned treatment works. The objectives of this plan include establishing water quality targets, identifying measures to eliminate the phosphorus-related impairments, and determining mechanisms to facilitate cost-effective implementation of the NARP.
In 2021, Geosyntec completed an extensive review of the water quality data collected by the DRWW and began developing a watershed model that will be used to estimate phosphorus loading to the mainstem Des Plaines River from its tributaries. The initial review indicated the phosphorus impairments in the Des Plaines River may be strongly influenced by upstream loading from Wisconsin. Preliminary findings also indicated that point source pollution in the watershed had decreased from 2013 to 2018.
In 2022, the major efforts in Phase 2 included the development of modeling tools to identify relationships between phosphorus inputs and identified instream impairments. To estimate discharge rates and pollutant loads from the land surface and tributaries, a Soil and Water Assessment Tool, SWAT, watershed model was developed by project partner Kieser & Associates. The SWAT watershed model estimates non-point source nutrient loads to the mainstem Des Plaines River. The results of the SWAT model output were then input into a QUAL2kw instream model developed by Geosyntec Consultants. The QUAL2kw model estimates hydrodynamics and water quality according to the governing physical and biological processes for the 2020 growing season (May – October). The instream model was calibrated with historical water quality data from 35 miles of the mainstem Des Plaines River, 7 miles on Hasting’s Creek, and 4 miles on Mill Creek. The modeling tools developed in 2022 will be used in Phase 3 to assess watershed management strategies for the best ways to address phosphorus-related impairments within the watershed.
Monitoring Program
The DRWW continues to conduct water quality and bioassessment monitoring. Data from this program provides the foundation of the Integrated Prioritization System, IPS, and NARP models that will be used to prioritize and implement water quality improvement projects. The Monitoring Committee meets frequently with Geosyntec Consultants for updates and decisions on next steps for completion of the 2023 DRWW NARP. The Committee reviewed and approved the DRWW 2020 Water Quality Monitoring Report, completed by MBI. Similar to previous years' reports, the 2020 report suggests that the quality of aquatic life in the Des Plaines River mainstream improves downstream through the workgroup area.
Illinois EPA Section 319 Grant Projects
In 2018, the DRWW began partnering on three 319 grant applications in the watershed. All three 319 grant applications received funding and have now been completed.
- The DRWW partnered with Lake County Health Department, Lake County Forest Preserve District, and Lake County Stormwater Management Commission and completed the Removal of Carp to Reduce Nutrient Enrichment Project in October of 2022. Eight lakes within the Des Plaines River Watershed were selected: Crooked, Hastings, McDonald 2, Slough, Des Plaines, St. Mary’s, Big Bear, and Little Bear Lakes. Carp removal was identified as a high-priority action at all project locations within the Des Plaines River Watershed-Based Plan.
In total, 11,721 carp, equaling 57,433 lbs, were removed from the lakes throughout this project. The amount of phosphorus removed from each lake system ranges from an average of 161–351 lbs/year. This project reduced a source of phosphorus for internal loading in the lake, removed phosphorus contained in the flesh of the carp, allowed the re-emergence of aquatic plants to grow, and increased water clarity. The Lake County Health Department plans to continue to monitor the water quality of the project lakes and carp removal efforts.
- The DRWW partnered with Lake County Forest Preserve District on the Van Patten Woods Hydrologic Restoration and Enhancement Project. In Spring 2021, LCFPD completed their 96-acre retirement of row crop farm field into native plant restoration at the Van Patten Woods Forest Preserve. This project included 20 acres of wetland creation and enhancement, 716 native tree and shrub plantings (36 acres), 11,150 feet of drain tile disabled, one trail berm to restore natural flow path and wetland hydrology and 13 rock check dams.
Deicing Workshops
The Des Plaines River Watershed Workgroup continues to sponsor and support the Northeastern Illinois Regional Deicing Workshop. The deicing workshop focuses training efforts to keep public and private sector professionals up-to-date on best management practices for winter maintenance that safely reduce road salt use. The 2022 workshops trained over 900 individuals in winter best management practices for public roads, parking lots, and sidewalks. The DRWW encourages members to look for ways to reduce road salt use while ensuring safe travel on transportation surfaces.
