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Safety At Dams

Governor Pat Quinn, then Lieutenant Governor of the State of Illinois, launched the Illinois Dam Safety Initiative in June 2006 to educate the public about dam safety, and propose much needed changes to make our waterways safer.

Since then, progress has been made on safety measures, including the passage of legislation calling for standards of signs, buoys and other ways to communicate risks to the public about the dams on public waterways.

October 2012, Governor Quinn announced the removal or modification of 16 low-head dams throughout the State over the next few years.

Cook County: Armitage Avenue Dam, Chick Evans Golf Course Dam, Fairbanks Road Dam, Hofmann Dam, River Park Dam, Tam O'Shanter Dam, Winnetka Road Dam and Dam 1, 2 and 4.
Kendall County: Blackberry Creek Dam
LaSalle County: Buzzi-Unicem Dam
Vermilion County: Danville Dam, Ellsworth Dam

Of these, Fairbanks Road Dam, Hofmann Dam and Armitage Dam were removed in 2012 by the U.S. Army Corps of Engineers with IDNR/OWR acting as the local sponsor.

Seven dams owned by the Forest Preserve District of Cook County (Dam 4, Touhy Ave, Dempster Street, Dam 2, Dam 1, Winnetka Road and Chick Evans Gold Course) will be removed/modified through a cooperative endeavor between FPDCC, The Corps and IDNR/OWR. The FPDCC is providing land rights and funding to the Corps of Engineers for planning level and pre-design activities through the Corps’ Planning Assistance to States Authority. IDNR/OWR will be providing the hydraulic analysis, final design analysis, contract advertizing and letting, construction supervision and project funding.

The Office of Water Resources and Forest Preserve District of Cook County removed Dam #1 and Dam #2 on the Des Plaines River in 2014 and reconnected nine miles of river for fish and recreational users. These roughly five-foot tall dams were owned by FPCC and removed as part of a broader restoration effort that will eventually involve removal of five additional dams between Wisconsin and Joliet, Illinois. Restoration of the Des Plaines River began in 2010 with the removal of the Ryerson Woods Dam. Since then, a total of six dams have been removed.

The modification of the North Branch Chicago River Dam at River Park is a joint endeavor between the Metropolitan Water Reclamation District of Greater Chicago (MWRD) and IDNR/OWR which will result in preliminary designs for the dam modification.

Tam O’Shanter Dam is owned by the Niles Park District. The removal/modification of this dam will be the responsibility of IDNR/OWR. The analysis of this dam removal/modification is in the very initial phase.

Public Act 095-0020 mandates improved safety at run-of-river dams on public waters when those dams are not subject to federal regulations for safety. Development of administrative rules for Public Act 095-0020 and the development of signage, buoy and exclusion zone plans for each of the dams covered by the public act are components of this work. Structural modifications to dams are being considered to lessen the dangers passed by the low head dams.

Personal safety at Illinois run-of-river dams has been managed through signage and river markings upstream and downstream of dams. Many run-of-river dams present hazards to the public which they may not be clearly aware of. These hazards include dangerous flow conditions below the spillway, scour holes in the river below the dam, vertical abutments, swift water in the pool, limited canoe and kayak portages, and other hazards.

CTE completed a Safety at Dams Study in July 2007.

Abutment signs have been installed at state owned dams.

Additional signs have been offered to other dam owners.

Hofmann Dam, Riverside, IL

The first dam at the Hofmann site was built in 1827 upon a natural waterfall formed by a limestone shelf, also known as the Riverside Ford. The dam powered the first sawmill of Northeastern Illinois but made of simple timber construction, was short lived.

In 1866, the Fox Brothers purchased the site and established a grist-mill with a stone and timber dam in the shape of a horseshoe that lasted 31 years.

In 1907, the dam and surrounding properties were purchased by George W. Hofmann Jr. in order to create Niagara Park along the banks beside the dam.

In 1908, an improved horseshoe dam with a concrete base and wooden struts atop matching the height of the Fox Dam was built, comprised of a section of a larger superstructure connecting it with the Hofmann Tower and platforms on either side of the Des Plaines.

The pool behind the dam which had been used for recreational purposes began to be used as a sewage outlet for the city leading to the Sanitary District of Chicago building a by-pass at the Hofmann dam in 1928 along the north bank of the river in order to divert the trapped sludge and sewage when the unhappy owner refused to open the dam flood gates.

Between 1930 and 1933 additional improvements implemented above the Hofmann dam resulted in dispersal of approximately 4 feet of sludge from behind the dam. In 1936 the Works Progress Administration (WPA) removed the failed wooden crest atop the concrete dam which effectively lowered the dam’s crest and headwaters. The WPA also constructed a retaining wall on the riverbank of Swan Pond at this time.

The current dam was constructed by the State of Illinois in 1950 following much public concern over the crest level. Eventually, a concrete dam was erected in a straight line spanning the entire width of the Des Plaines with a crest level at 25.56’ equal to the heights of the prior dams of wood or partial wood construction.

Certain concrete walls lining the river, original to Hofmann’s design, were removed or reconstructed in 1950. Additional aspects of Hofmann’s design including the retaining walls east of the Tower on the south bank were removed in 1984. The only original elements of Hofmann’s design remaining today are the wall and boat docks on the south bank of the river west of Hofmann Tower and the Tower itself.

Construction is scheduled for completion at Hofmann Dam at Riverside, IL at the end of October 2012. A drainage culvert is to be installed in Swan Pond with a culvert 3 or 4 feet tall and 10 to 15 feet wide and an asphalt walking path. 32 new trees will be planted in the park. The channel is now 5-6 feet deep in the narrowest part with a chokepoint of 15-20 feet wide.

Hofmann Dam was notched to permit greater fish passage and safer recreation opportunities. Two older dams behind Hofmann Dam were discovered and removed, one remaining from 1908 and one rock crib style dam from before that time.

Fish testing by the IDNR Division of Fisheries shows that there are now 20 species of fish living above the now-notched dam, and in far greater numbers.


Vermilion River Near Oglesby, IL.

The Vermilion River in LaSalle County, Illinois runs through property owned by Lone Star Industries, Inc., doing business as Buzzi Unicem USA ("LSI"). Limestone is quarried for use as a raw material in the production of cement on site. Water is used in this process and a low head dam (Cement Plant Dam) at river mile 4.75, in the river at their facility, is used to ensure low flow water supply volume in the river.

The river from mile 2.7 to 10.5 is frequently used by boaters because of the unique whitewater nature of the river. The dam at LSI has a notch in the right 20 feet that allows for boat passage over the top of the dam without encountering the reverse currents at the base of the dam. This notch also allows the unrestricted movement of fish in the river.

In June 2009 a drowning occurred at the dam after a boater was thrown out of their raft. Shortly thereafter, LSI closed the river along their property to the public from river mile 4.0 to 6.7. This action effectively closed the river from mile 2.7 to 10.5 because there are no other accessible locations to put in or take out boats along this stretch of river. To restore public access to this section of the Vermilion River, LSI leased their portion of the river to the State in return for the completion of public safety upgrades to the dam and liability assumption and in order to provide recreational opportunities for boaters and rafters.

The Buzzi-Unicem Dam is a privately owned dam on a privately owned reach of the Vermilion River near Oglesby, Illinois. Phase 1 and 2 of the dam removal/modification involved installing enhanced warning signs to inform boaters of the presence of the dam and the placement of large concrete blocks in the scour hole below the dam to decrease the strength of the submerged hydraulic jump. The design of Phase 3 is in progress and will depend on the future water needs of the owners of the dam.

Public safety improvements at the dam are divided into three phases. Phase 1 installed signage and hanging buoys around the dam to better warn river users of the presence of the dam. The hanging buoys also delineate a restricted area designation that was put into the State of Illinois boating code both upstream and downstream of the left side of the dam. Phase 2 filled the river bottom scour hole below the dam with precast concrete blocks and cut exposed rebar flush with the dam to increase safety. Phase 3 is intended to provide long term safety modifications at the dam site to allow for safer boat passage and is currently being investigated.

March 31, 2012 The Vermilion River near Oglesby was declared open for rafting after two years of closure following safety modifications to the low head dam there. Phase 1 and Phase 2 are both complete.


Glen D. Palmer (Yorkville) Dam and Marge Kline Whitewater Bypass Channel at Yorkville, IL

The Yorkville Dam has completed stepped spillway modifications and The new Marge Cline Whitewater Course at Yorkville is now open to the public free of charge. A Phase 3 pedestrian bridge will begin construction across the whitewater course later this year.

Renovation of the Glen D. Palmer (Yorkville) Dam was implemented to reduce public safety hazards at the dam, provide the opportunity for fish passage, and provide safe canoe and kayak boat passage through the dam with opportunities for white water boating recreation.

Initial attempts to reduce the dangerous scour roller effect that had developed at the dam were attempted in the 1970's with some success. Further attempts and studies resulted in the modification of the Dam in 2011.

To improve the ecological integrity of the dam site and fishing on the Fox River, the Yorkville Dam modification bypass is intended to encourage migration of local fish species by providing fish passage near both abutments of the dam via a Denil fish ladder and the bypass channel. This Denil is the first of its kind in the mid-west.

Large boulders and planted riprap along the perimeter of chutes and pools were included in the bypass design along with space between pool bottom boulders to replicate a natural channel and provide cover and protection to juvenile fish during higher flow conditions.

The bypass channel includes two whitewater challenge routes adjacent to the principal boat passage route with 7 chute or riffle sections and 7 pools and a continuous paved portage trail designed for experienced and novice paddle boaters. The channel's standing waves, drop and eddy channel features are characteristic of a Class 3 whitewater channel, with a safe slope for novice paddle boaters.

Members of the Illinois Paddling Council (IPC) and the Chicago Whitewater Association assisted the Department during construction and testing to share observations, and to identify potential whitewater boating hazards and concerns.

IDNR and the United City of Yorkville are continuing to work with the USGS to install a permanent USGS gage at the site to monitor river stages above and below the dam, and in the bypass channel.

The DNR Office of Water Resources and Teng & Associates (now ESP, Inc.) received the Illinois ACEC Illinois Engineering Excellence Honor Award and the prestigious Grand Award in the American Council of Engineering Companies (ACEC) 2012 Engineering Excellence Awards (EEA) for the project "Yorkville Dam Safety Improvements & Bypass Channel". Teng & Associates was IDNR's principal consulting design engineer for the project.


Armitage and Fairbanks Dams

The low head Armitage and Fairbanks Dams on the Des Plaines River have been removed for ecosystem improvements and safety considerations.

The Armitage Dam spillway was 110 feet long, constructed of reinforced concrete, with an adjacent 5.5 foot wide boat portage at the west abutment. The dam crest was approximately five feet above the dam apron. The dam apron and supporting abutments remain in place. Armitage Dam was located in the Cook County Forest Preserve within River Grove, IL.

A solicitation for bids was posed in September 2010 by the U.S. Army Corps of Engineers. Removal was delayed over sediment that was found to need to be removed and then by higher than expected water levels. Armitage Dam was removed in late 2011 and early 2012.

Small dam on Des Plaines River north of River Forest will be history by mid-October -

Fairbanks Dam is assumed to be constructed of reinforced concrete. Cross sectional dimensions are approximately two feet by two feet and the dam is158 feet long. The Fairbanks Dam crest is shaped like a peaked roof. There exists a partial breach at the south bank. At the north bank, the dam is joined to the bank by a stepped concrete wall with three of the five steps of this stepped wall being removed as shown in the drawings. Fairbanks Dam is located between the Village of Riverside, Illinois and the Town of Lyons, Illinois in Cook County.

Demolition began on January 31st, 2012 and ended a week later.

Riverside bids adieu to Fairbank Dam - Riverside - Brookfield Landmark

Danville & Ellsworth Park Dam Modification Projects, Danville, IL.

Due to the hydraulic conditions of the Danville and Ellsworth Park Dams and that no riverbed protection was placed below the dam upon construction, a submerged hydraulic roller occurs. Over time the turbulent forces generated by a hydraulic roller, have eroded a scour hole in the original bed material at the base of the dam. The tailwater submerges the hydraulic jump creating the submerged hydraulic roller. These rollers typically pull in and hold objects, including people which often leads to emergency rescues or drownings. There have been 4 reported losses of lives at the dams since 1995.

Sediment Sampling is complete at Danville Dam and analysis under way, preliminary to river and stream bank stabilization components of the plan. While the nearby Ellsworth Dam is expected to be only partially removed, the Danville dam on the Vermilion River will be as it is structurally unsound. Ellsworth Dam is to be lowered one foot and a 150-foot long rock ramp put in place downstream making a less abrupt drop off for boaters.

Cost of dam removal has not yet been estimated but alternatives, pre-construction monitoring, testing and sediment transport modelling by the USGS are complete. Final design and land rights acquisition are expected to be completed in late 2013 with construction start at the end of the year if City Council and local fishing groups agree. The Strategic Planning Study for the Dams is undergoing internal review, and includes full removal, partial removal, stepped spillway and rock ramp alternatives.

Both the Danville Dam and the Ellsworth Park Dam are owned by the City of Danville. IDNR/OWR is finalizing a strategic planning study of the options for removal/modification of these two dams. IDNR/OWR will review the results of this study with the City of Danville to determine with which option to proceed.

Blackberry Dam Modification Project, Yorkville, IL.

The Blackberry Creek dam (owned by the Yorkville-Bristol Sanitary District) currently fragments Blackberry Creek and the Fox River by creating a barrier that denies fish and other aquatic organisms, including threatened species, access to quality habitat upstream of the dam. The dam currently blocks Fox River fish and microinvertebrates access to 32 miles of spawning and rearing habitat in Blackberry Creek that would provide increased fitness, distribution, and diversity of fish and microinvertebrates in Blackberry Creek and the Fox River.

The west abutment of the dam has developed a large diagonal crack that has allowed movement of this abutment such that failure of the dam abutment is imminent potentially resulting in a massive headcutting and uncontrolled release of large quantities of sediment into Blackberry Creek and the Fox River, and the potential loss of a public bridge immediately downstream of the dam.

The timeframe for the removal of this dam has been accelerated due to the rapid deterioration of an abutment that the dam shares with a county road. Phase 1 of the removal project, notching the dam by two feet to lower upstream pool stages, wetland mitigation and construction access roads has been completed and Phase 2, involving complete removal of the dam and upstream channel restoration, main channel sediment excavation, and stabilization is under contract and expected to be complete soon in early Spring 2013.


Kankakee River Wilmington Dam

The Wilmington Dam project originally involved a dam breach condition at the Mill Race (East Channel) occurring in 1990 that was temporarily closed with concrete blocks. An old rock filled crib dam structure in the East channel breached as a 30 foot section crumbled, causing all flow of water to divert around Wilmington Dam through the East Channel. There is potential flooding of Wilmington Island due to a shortened weir length of the temporary dam.

Investigation continued to develop a plan to eliminate the existing public safety hazard and restore fish and canoe passage through the dam modification or removal.

Modelling was completed in 1996 and land rights acquisition begun. The Kankakee River Dam Transfer Act was approved in 1992 by the state legislature but the City of Wilmington does not own the entirety of the structure. Once transferred, the State can begin modifications.

Frazile ice formation in this reach of the Kankakee River was included in a U.S. Army Corps of Engineers study at OWR request.

Three further deaths occurred at Wilmington main stem dam in 2006.

Batavia Dam at Batavia, IL

The Batavia Dam is a low overflow structure with a modified 0gee spillway. The Batavia Dam partially failed in 1978, causing an eroding 15' breach in the 300' long dam at the left abutment. Repairs completed in 1975 are no longer holding and the removal of the dam is recommended.

Preliminary design for the dam removal and river restoration was completed in 2005 including improved infrastructure with fish and canoe passage. The restoration of Depot Pond and Causeway Island are included along with a major sediment management component.

Creation of islands and a vegetated overbank will narrow the river to a natural width. The project is on hold pending funding, land rights, permits and local approval.

Spillway Optimization at Batavia Dam

Belvidere Dam, Kishwaukee River

Modifications or removal of the Belvidere Dam are being considered to address ecosystem concerns, especially fish passage and easier canoe passage.

Using a C-2000 grant, the Belvidere Park District has completed an analysis of three options for increasing the quantity of fish that pass upstream of the dam which is owned by the State of Illinois. The Office of Water Resources provided survey data to the USGS used to create a hydraulic model of the river in the dam's vicinity and a sediment transport model.


Geneva Dam, Fox River

IDNR funded a consultant report entitled "A Run-of-River Dam analysis for Geneva Dam" dated September 2008, that evaluated and recommended models of design velocities of a potential rock ramp spillway, hydraulic characteristics and riprap selection methods to design a spillway rock ramp to eliminate or minimize a hydraulic roller effect at Geneva Dam.

Future work includes conceptual plans for a partial dam removal option and a full dam removal option before public review and comment can begin.



The brochure can be acquired on our online publications site (on the right-side column, the link that reads "new" click on that and it will take you to all our publications). Do a search of "Dam Safety" - this is a free brochure