The Fox River Study Group (FRSG) is a diverse coalition of stakeholders who have been working together since 2001 to preserve and enhance water quality in the Fox River watershed. In 2015, FRSG completed the Fox River Implementation Plan (FRIP), which is the community’s road map to eliminate water quality impairments due to low dissolved oxygen (DO) levels, high total phosphorus levels, and nuisance algae in the Fox River from the Stratton Dam in McHenry County to the mouth of the river in LaSalle County. The group’s study area encompasses 1,405 square miles of the Fox River watershed.
Major wastewater treatment plants that discharge to the Fox River are completing upgrades at their facilities so that total phosphorus discharges will meet an annual average limit of 1 mg/L. This will result in approximately a 75 percent reduction in total phosphorus loading to the river during summer months as compared to the 2010–13 load. These improvements will be adopted through 2022. The Fox River watershed dischargers have also committed in their NPDES permits to meet a total phosphorus limit of 0.5 mg/L annual geometric mean by 2030 unless FRSG determines that a greater phosphorus reduction is necessary and achievable before then.
The Fox River Study Group is now in its 17th year of water quality data collection in the watershed. On a monthly basis, an all-volunteer and in-kind effort by FRSG member groups collects and analyzes samples from seven main stem locations and seven tributary locations along an 80-mile stretch of the Fox River from McHenry to Yorkville. To fill data gaps, FRSG is also funding the United States Geological Survey (USGS) to collect more continuous water quality data on the Fox River during the growing season. During water years 2016–18, USGS collected data near Algonquin (USGS Station #05550001) and is collecting seasonal data during water years 2018–21 at the Stratton Dam (USGS Station #05549501).
The Illinois State Water Survey (ISWS) maintains the FoxDB environmental database, where all available data for the Fox River watershed is compiled and publicly available (ilrdss.sws.uiuc.edu/fox/). The water survey released a report commissioned by FRSG—Water Quality Trend Analysis for the Fox River Water-shed: Stratton Dam to the Illinois River— that presents trend analysis for nutrient-related water quality parameters (www.ideals.illinois.edu/handle/2142/103009). Sufficient data were available to report on trends in water quality at eight sites along the Fox River and seven tributary streams. Over the last decade (2006–16), ISWS analysis found that most nutrient-related pollutants levels are declining or show no trend in the Fox River between the Stratton Dam in McHenry County and Yorkville in Kendall County. Loading levels of most water quality parameters decreased across all seasons in the Fox River at Montgomery, which is the only station on the main stem with the required concentration and flow data to calculate loads. On an annual basis, flow-normalized loads decreased for all parameters, by 11% for organic nitrogen, 14% for ammonia, 16% for nitrate, 7.8% for total Kjeldahl nitrogen (TKN), 21% for total phosphorus, 25% for dissolved phosphorus, and 6.3% for suspended solids. Loads of chlorophyll a, a measure of the amount of algae in the water column, dropped by 8.8%.
The story for tributary streams is different. For the two tributaries with available flow data, Blackberry Creek and Poplar Creek, annual loads of total phosphorus and ammonia increased in both streams. Annual loads of TKN increased in Poplar Creek by 42%, but decreased by 19% in Blackberry Creek.
To make informed decisions about how best to maintain and improve the quality of the Fox River in this urbanizing watershed, FRSG has developed two computer models—watershed loading (HSPF) and instream (QUAL2K). Geosyntec Consultants is currently updating these models for FRSG. In 2018, Sierra Club volunteers greatly assisted this work by formatting data for input into the HSPF model. The instream model has been updated to QUAL2kw, a dynamic version, and is being recalibrated with data collected since the 2015 FRIP was completed. The models will be used to assess different management scenarios to address low DO and nuisance algae problems in the Fox River, and to update the FRIP for submittal to Illinois EPA by 2022.
The Fox River Study Group and the Chicago Metropolitan Agency for Planning are also updating and recalibrating the HSPF model for the Mill Creek subwatershed, which will be used in the development of a watershed-based plan for that Fox River tributary.
The study group continues to work with the U.S. Army Corps of Engineers and the Illinois DNR to complete the Fox River Habitat & Connectivity Study. This study, which is half-completed, will evaluate the efficacy and cost effectiveness of fish passage and riverine function restoration methods at 10 low head, run-of-the-river dams on the Fox River. The group has offered to cover the local cost-share contribution of the study for the Illinois Department of Natural Resources. BlueStem Communications also worked with FRSG to conduct three focus groups in 2018 to understand public thoughts and feelings about the Fox River and its dams.
In 2017 and 2018, FRSG conducted 23 outreach activities, mostly presentations that informed the public about Illinois NLRS, the adverse impacts of high algae levels on drinking water from the Fox River (which provides for over 300,000 watershed residents), and the efforts the watershed community is undertaking to reduce phosphorus levels and nuisance algae blooms in the river.
