Fox River Connectivity & Habitat Study, IL

Chicago District
Published Jan. 9, 2024

Additional details can be found at

Additional details can be found at

   Project Description and Background

  • The Fox River Connectivity and Habitat Study Area includes a reach of 10 dams from Algonquin in McHenry County to the Montgomery Dam in Kane County.
  • The results of this study can lead to a project that would result in habitat restoration, fish and mussel recolonization, water quality improvement and enhance human safety.

    Current Status

  • Team has completed the Draft Fox River Connectivity & Habitat Study and has tentatively selected full removal as the preferred alternative and is conducting public meetings to gather local input.
  • Proposed activities for FY24 include execution of the Project Partnership Agreement (PPA) and the initiation of design.

    Project Authorization

Section 519, Water Resources Development Act 2000

   Section 519 Fox River Connectivity and Habitat Study FAQ - February 2024


A final decision has not been made. The Tentatively Selected Plan (TSP) described in the draft Project Implementation Report and Integrated Environmental Assessment dated September 2023 is the removal of all existing dams alternative. A final Recommended Plan will be presented in the final version of the report, which will include revisions and updates based on feedback received during public and agency review, as appropriate. With the support of induvial dam owners as the non-federal sponsor, USACE is expected to make a final decision whether to proceed with the next phase of the project in early 2025. Upon approval of the report, USACE will seek federal funding to proceed to the design phase of the project. If federal funding is received, USACE would proceed with executing project partnership agreements with the owners of each dam prior to initiating design and construction. USACE cannot move forward without committed non-federal sponsors willing to provide the necessary real estate and cost sharing requirements to implement the project.

USACE is not planning additional public meetings for the Fox River Connectivity and Habitat Study at this time, but individual local governments may be hosting additional meetings.

It is anticipated the earliest the design phase could be initiated is 2025. Construction contract award is tentatively planned for summer 2027 subject to appropriations and non-federal sponsorship.

Riparian property ownership on navigable rivers in Illinois extends to the thread (center) of rivers and streams unless currently restricted by deed, with the public holding an inalienable easement to navigation over the water’s surface. The public's easement would be removed from lands which are no longer submerged, allowing the existing owners to utilize them as they would the rest of their parcels while still allowing the public to navigate on the water’s surface at its new elevation.

Dam removal is not expected to significantly affect the values of riverfront properties along the Fox River. In order to investigate this further, property sales data obtained from the Kane County GIS-Technologies Department was used to perform a regression analysis of 15,322 residential property sales that took place in Kane County between January 1, 2020 and December 31, 2022. This analysis found that location relative to the river (riverfront vs. non-riverfront, as well as distance from river) could not be used to reliably explain the variation in property sale prices (overall or per square foot) in any municipality or township within the project area. In addition, comparative sales analysis of a random selection of riverfront and non-riverfront properties found that homes in any given neighborhood of similar age, size, and condition sold for similar prices regardless of whether or not they had river frontage.

Finally, USACE realty specialists consulted with certified real estate appraisers and the township assessors within the project area for their opinions on potential impacts to property values. The consensus was that there is expected to be little to no impact on property sale prices or assessed values if dams are removed, as the river itself has little effect on property values in its current state. Factors such as home age, size, and condition, school quality, and the overall real estate market play the largest role in home value.

Different alternatives were evaluated during the plan formulation process to maximize ecosystem benefits and meet study objectives. Measures including fish ladders and rock ramps were screened from further consideration because they failed to meet one or more of the screening criteria. Full dam removal was selected as the Tentatively Selected Plan because it supports all USACE’s planning criteria and ecosystem restoration objectives, and it provides the greatest ecological output for the least cost. USACE has not identified another viable plan that would justify federal funding under this study authority.

No. Implementation of the proposed project would have negligible impacts on the flow regime of the Fox River because the existing dams are run-of-the-river type dams and do not provide any appreciable flood storage. There would be no noticeable impacts to flowrate during the full range conditions from low base flows to flood conditions because of dam removal.

Dam removal would result in a decrease in water levels in areas that are currently impounded upstream of the existing dams. Water level reductions would be greatest immediately upstream of where the dam was previously located and would diminish with distance upstream of the former dam location. Generally, due to the relatively low height of the existing dams and spacing between dams along the Fox River, most of the impounded effects of a given dam fade before the next upstream dam. Therefore, upstream areas of each reach between dams would not experience a change in water depth as a result of dam removal.

The Fox River is currently listed as an impaired waterway by the state of Illinois. Under the No Action Plan, the Fox River water quality would continue to be impaired, partially as a result of the existing dams. Increased water temperatures, lower dissolved oxygen levels, and increased algal biomass production in the impounded area would likely continue to occur. Implementation of the Tentatively Selected Plan includes reestablishing natural riverine hydraulics within the currently impounded segments of the river, allowing water to flow over substrates and other riverine materials (trees, aquatic vegetation) and pass through turbulent riffle zones. The result would be improved water quality in the study area.

Dam removals have positive effects on the environment and are viewed as an aquatic ecosystem restoration opportunity to improve water quality and both the amount and diversity of habitat for native riverine fish, mussels, and macroinvertebrates. Benefits to aquatic life can also provide improved foraging opportunities for birds and other predators that rely on aquatic life as a food source.

Dam removal is not expected to have an adverse impact on bald eagles. The Tentatively Selected Plan is compliant with the Bald and Golden Eagle Protection Act, and USACE is coordinating with the U.S. Fish and Wildlife Service to ensure compliance with this and other acts, including the Endangered Species Act and the Fish and Wildlife Coordination Act. Dam removal would restore the riffles, pools, and runs that are present in unaltered riverine systems, improving habitat for riverine fish, which are a major food source for bald eagles. The shallower river would be swifter and would freeze less often than the impoundments, so fishing opportunities for bald eagles would be more evenly distributed rather than being confined to the free flowing stretches of the river immediately downstream from the dams.

Yes. Several data sources will be updated in the final report to include the most recently available data collected for water quality as well as fish, mussels, and macroinvertebrate species found in the Fox River.

If you need reports for this project not listed on this page, please contact the Public Affairs Office at and let us know what report you are looking for.