Managing Great Lakes Ice: Preventing Jams and Keeping Water Flowing

By Kevin Bunch, IJC

ice cover st lawrence river
Ice cover was established on the St. Lawrence River by Jan. 10 this year. Credit: International Lake Ontario-St. Lawrence River Board

With winter here, annual efforts to manage ice flows in the St. Marys, Niagara, and St. Lawrence rivers are in full swing. Management efforts in these connecting channels of the Great Lakes aim to prevent ice jams that can cause winter floods and damage to hydroelectric turbines, while contending with difficult or unexpected winter conditions.

In cold seasons, ice typically forms along the Great Lakes and its connecting channels. Unregulated, this ice can take a while to form a solid layer due to currents, leading broken pieces of ice to jam up and cause flooding.

Control structures are in place for shipping and hydropower needs but hydropower dams and ice booms provide a way to influence how ice forms which in turn helps to prevent flooding and protect equipment.

The St. Lawrence River

Prior to dams being built on the St. Lawrence River, ice jams and winter floods were frequent in sections of the river from Ogdensburg, New York, to Montreal, Quebec, said Gail Faveri, co-secretary of the International Lake Ontario-St. Lawrence River Board. Construction of the Moses-Saunders Dam has allowed water managers on both sides of the St. Lawrence a way to control the amount of water flowing out of the river and thus influence how ice forms above and below the dam. By slowing down the velocity, Faveri said, a solid, stable ice cover forms more easily. As ice ages, it smooths out, allowing water flows to increase again without destabilizing the cover.

“When the ice is forming you can lower the flow and slow the velocity, allowing the ice to form (properly),” Faveri said. “Once it gets established, you can go and allow a higher outflow. It functions more like a pipe … and you can drive more water through.”

The gates at the Iroquois Dam at Iroquois, Ontario, also may be used to promote ice formation upstream.

Power companies also install ice booms around Nov. 20 each year between Prescott, Ontario, and Cardinal, New York, to help ice form upstream, Faveri said. Those are handled by Ontario Power Generation and the New York Power Authority, and the IJC is alerted when the booms are installed. Two main booms that stretch across the main channel of the river remain partially open until the Seaway closes to vessel traffic each winter.

Eastern Lake Erie

Now turning upstream, this season’s Lake Erie-Niagara River ice boom was installed on Dec. 16-17 by the New York Power Authority at the outlet of Lake Erie as it has been every ice season since 1964. The IJC issues approvals to the New York Power Authority and Ontario Power Generation to install the boom to accelerate the formation of a naturally occurring ice arch at the outlet of Lake Erie into the Niagara River, said Derrick Beach, secretary to the International Niagara Board of Control. Conditions for the operation of the ice boom are provided in the IJC’s approval to ensure that potential impacts, like flooding to surrounding residents and activities on the lake and river are minimized. The IJC has appointed the International Niagara Board of Control to oversee that the conditions of the ice boom’s approval are met.

“The ice boom reduces the amount of ice that goes down the Niagara River,” Beach said. “The ice naturally (accumulates) in that area on the lake creating an ice arch and the ice boom helps the formation of that natural ice arch that holds the ice back in Lake Erie.”

ice boom New York Power Authority
Lake Erie-Niagara River Ice Boom with ice accumulation from the lake. Each curve along the edge of the ice is where a span of pontoons are anchored to the bottom of Lake Erie. Credit: New York Power Authority

Once the ice arch forms, it naturally reduces the amount of ice entering the Niagara River and the potential of the ice jamming or damaging intakes in hydroelectric power plants along the way. As an added benefit, Beach said the ice boom helps prevent ice from jamming in the Niagara River and causing flooding and shoreline property damage along the river. However, as a floating boom, if high winds or thick ice cause a lot of ice to push against it, the boom will be pushed under water and allow some ice to pass, and then float to the surface again after the ice has passed, allowing some natural transport of ice to continue.

The Lake Erie-Niagara River boom consists of about 1.7 miles (2.7 kilometers) of floating pontoons cabled together, and is maintained by the New York Power Authority on behalf of the hydropower generating facilities on the US and Canadian sides of the Niagara River. Some of these conditions include that the boom cannot be installed each year until the water temperature of Lake Erie drops to 39 degrees Fahrenheit (4 degrees Celsius) or on Dec. 16, whichever comes first. As well, the boom’s approval requires that all floating sections be opened by April 1 unless there is more than 650 square kilometers (250 square miles) of ice remaining in the eastern part of Lake Erie. The latest the boom was taken out was May 3, 1971.

The St. Marys River and uncontrolled channels

Hydropower entities install ice booms in the St. Marys River connecting Lakes Superior and Huron to protect their operations, as does the US Army Corps of Engineers to protect a ferry operator, said John Allis, alternate regulation representative with the International Lake Superior Board of Control and Great Lakes Hydraulics and Hydrology office chief for the US Army Corps of Engineers (USACE) Detroit District. At the start of December, the focus of water managers – much as in the St. Lawrence region – is on reducing water flows using its compensating works flow control structure and hydropower operations so that a solid ice cover can form, allowing a consistent water flow the rest of the winter to reduce the chances of ice jams.

“Even if we could chip ice away from the compensating gates to be able to open them up during the winter, we don’t want to drastically change flows month to month, as you could begin to break up the ice cover and getting that ice flowing, causing ice jams,” Allis said.

ice jam st clair river water levels january usace
An ice jam on the St. Clair River caused water levels downstream to drop the first week of January. Credit: US Army Corps of Engineers

The connecting channel between Lakes Huron and Erie has no control structures, Allis said, but the USACE and Canadian Hydrographic Service (CHS) monitors ice conditions along the St. Clair and Detroit rivers in the winter months in case of ice jams. The US National Oceanic and Atmospheric Administration and the CHS have gauges along the connecting channels, and when a jam is forming water levels can suddenly decline downstream and increase upstream as the water is backed up. When those instances occur, Allis said the Corps notifies the US Coast Guard so it can send an icebreaker to clear the jam before it can cause a flood event along the shoreline.

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

Turning Coastal Infrastructure into Habitat

By Kevin Bunch, IJC

tern decoys
Common tern decoys are used to attract birds to an artificial nesting habitat near Ashtabula, Ohio, on Lake Erie. Credit: US Army Corps of Engineers

The US Army Corps of Engineers (USACE) has counted infrastructure maintenance as one of its duties for decades, and in recent years looked for ways to use maintenance and repair projects to improve habitat for species in the Great Lakes basin. Collaboration with the Canadian government and conservation groups has been a key factor.

The Corps doesn’t build many new structures these days, said Burton Suedel, research biologist with the USACE’s Engineer Research and Development Center-Environmental Laboratory in Vicksburg, Mississippi. In 2010, the Army Corps started looking into ways to better engineer existing structures to improve ecological, social and economic benefits, Suedel said.

“We’re looking at ways we can take advantage of using nature to utilize operational efficiencies, and we’re also trying to identify ways we can get additional benefits with our infrastructure,” Suedel said. The program was dubbed “Engineering With Nature,” as opposed to traditional “engineering against nature” projects, he added. Those older projects might include surveying canals and building up harbors along the shoreline.

Fish Spawning

Most recently, the USACE has replaced manually operated gates with automated ones in the Soo Locks. This gives operators finer control of water flow over the Main Rapids in the St. Marys River. While the gates on the Canadian side will continue to be manually operated, fine-tuning the flow with the automated gates should now be possible. Lake Superior State University has monitored the rapids over time to see which fish are using the rapids and in which ways, which is helpful data to avoid drowning or scouring fish eggs while adjusting the water flow. Suedel said recent workshops with local experts on both sides of the Canada-United States border are helping gate operators figure out the best way to assist with navigation and improving the existing “world class fishery.”

The Detroit ACE district is working alongside Environment and Climate Change Canada (ECCC) to develop a bi-dimensional Integrated Ecosystem Response Model, or IERM2D, for the rapids, said Jean Morin, hydrology and ecohydraulic section chief with ECCC’s National Hydrological Services. Similar models have been developed for other waterways, including the St. Lawrence River and the Rainy-Namakan Lakes system in Ontario and Minnesota.

“The goal is to optimize the gate opening for fish spawning purposes, in order to select the right timing and the right velocities for ensuring an optimal reproduction success,” Morin said.

The Army Corps provided a baseline hydrodynamic model, which ECCC ran with a variety of variables that change based on the amount of water being discharged and to what degree the gates are opened, Morin said; these include water depth, velocity, turbulence, the slope of the river bottom and current directions.

While ECCC didn’t have much biological data on the rapids, they have experience with species that reproduce in swift-moving rapids environments, like lake sturgeon, lake whitefish and walleye, Morin said. His agency was able to use that data to produce the IERM, analyzing a number of gate opening scenarios to see how it could be used and for what purpose. Their final report is expected this fall.

The first Engineering With Nature project in the Great Lakes took place in Cleveland, Ohio, around 2012. The USACE was interested in repairing a rubble mound breakwater in the harbor – a structure designed to protect harbors, beaches and navigation channels from wave action and sedimentation movement – using large concrete blocks around 9-10 tons each to anchor the repair. Additionally, the Corps wanted to create more habitat for benthic macroinvertebrates and algae – species near the base of the food web. This in turn would create more food opportunities for small fish higher up on the web. The USACE added grooves and dimples to the concrete blocks, as their research suggested that would create more diverse habitat for the species they were targeting. The Corps contractor built a mold that would allow them to do this with other projects, he added.

Gulls and Shrimp

Following Cleveland, the Army Corps worked on a similar project in Ashtabula, Ohio, and was able to reuse molds from the Cleveland project. It also contacted local agencies and other stakeholders like The Nature Conservancy to see if there were any other benefits they could add.

“We reached out (to those groups) up front to ask them specific questions about what habitat is lacking in the area, and is there any way we can incorporate that habitat into the redesign of the breakwater?” Suedel said.

Those organizations noted that the common tern had lost nearly all its nesting habitat in that area due development and competition by gulls. While suitable habitat existed kilometers distant east and west along the coastline, Suedel said terns lacked the sandy habitat they preferred on Lake Erie around Ashtabula. Concrete blocks were modified to include suitable habitat in a detached breakwater for the birds. The success of that project is still being monitored, though a 2016 winter storm damaged the site and required repairs during the nesting season.

Also in 2014, the USACE Detroit District’s floating plant crew took up the task of rubble mound repairs in Milwaukee, Wisconsin’s harbor breakwater area. It contacted Wisconsin Department of Natural Resources (DNR) fisheries biologists to find out what that harbor was lacking, and they suggested using smaller stones for the breakwater repairs that fish could spawn on, Suedel said. The Wisconsin DNR helped design the repaired section, which was 500 continuous linear feet along the breakwater, with funding from the US Great Lakes Restoration Initiative.

The University of Wisconsin-Milwaukee has taken on monitoring duties in the harbor.

University of Wisconsin-Milwaukee ecologist James Janssen said they’ve discovered that the Corps has created a rare, cave-like habitat between the large breakwater boulders and the smaller rocks that nonnative bloody red shrimp (Hemimysis) are thriving in.

The shrimp are providing a major local food source for a variety of fish species, including largemouth bass, smelt, rock bass, alewives, and brown trout. Alewives and smelt typically prefer living in the open waters, but Hemimysis are drawing them closer to shore as invasive quagga mussels have reduced the amount of food available in the open lake. Janssen said this should not suggest that Hemimysis be introduced into inland lakes as a food source, however, as conditions vary in harbors.

The spawning side of things is a mixed bag. Janssen said silt coming down the Milwaukee River appears to be drowning eggs in the spring, suggesting that efforts upstream to limit sedimentation might improve spawning grounds. Those that hatch have a ready food source from the Hemimysis, but have to avoid getting eaten by the larger predatory fish in the area.


Janssen said since conditions are different in other harbors throughout the Great Lakes, the work in Milwaukee can’t be used as a guide or an example for other sites. A final report is pending from the USACE. But Janssen said knowing enough about local physical and biological conditions can provide information to predict which species will dominate at a breakwall, and a preliminary study before doing any modifications can help clarify that prediction further.

milwaukee harbor breakwall
The Milwaukee Harbor breakwall modifications under construction in 2014; once completed the water level rose to where the line is drawn and the larger boulders submerged. Credit: John Janssen

“Our key to success is reaching out to stakeholders and identifying which habitat would be most appropriate for us to create,” Suedel added. The USACE didn’t do that in Cleveland since it was focused on the base of the food web, but for other species it has proven successful, he said.

The USACE also is interested in public-private partnerships to help fund restoration projects. While Great Lakes Restoration Initiative funds and money from the Army Corp’s Engineering With Nature initiative have been used for the projects so far, partnerships could help provide outside funds for monitoring and additional construction. He said Milwaukee Harbor is one area that would benefit from funds for additional fishery habitat along other portions of the breakwater.

“It was a relatively modest $20,000 increase over the cost of repair in Milwaukee’s (breakwater) in 2014,” Suedel said. “If we can’t identify that money internally, can one of our stakeholders help fund that additional cost? So that’s that where public-private partnerships could come in handy.”

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

automated gates
The automated gates project in the St. Marys River’s compensating works structure should help fine-tune water flows to the Main Rapids, preventing fish eggs from being scoured or left out to dry. Credit: US Army Corps of Engineers

Return of the Rapids: Restoration Success on the St. Marys River

By Kevin Bunch, IJC

new bridge sugar island under construction
A new bridge to Sugar Island was under construction in 2016 at the St. Marys River. The bridge replaced an aging causeway. Credit: Chippewa County Road Commission 

A portion of the St. Marys River has been restored as fish spawning habitat and recreational space, with a new bridge that provides access to Sugar Island. The work has removed one more obstacle toward delisting the river as an Area of Concern (AOC) by Canada and the United States.

The St. Marys River is a binational waterway that connects Lake Superior to Lake Huron between Michigan and Ontario. Following construction of the Soo Locks in the 1850s to help ships traverse the river, pollution and a variety of changes to the river led to it being designated an AOC by the two nations in 1987. That designation tasked the two nations with restoring the river to a healthy state.

The portion of the river known as the “Little Rapids” was degraded when a mile-long causeway was installed in 1865 with only two 6-foot (2 meter) culverts to allow water to continue flowing. Effectively this turned it into more of an embayment with little water movement, degrading what had been an example of rare rapids habitat, according to a fact sheet from the Great Lakes Commission (GLC).

GLC Program Manager Heather Braun says the new bridge restores the flow through the rapids and should provide greatly improved spawning and foraging habitat for walleye, lake sturgeon, lake whitefish, yellow perch, northern pike, cisco, Pacific and Atlantic salmon, along with forage fish such as suckers and minnows and the invertebrates they feed on.

Swift-water rapids habitat historically could be found throughout the St. Marys River, but is now relatively rare. Upwards of 90 percent of this habitat was lost due to past construction activities such as building the Soo Locks and causeways, dredging and urban development, all of which destroyed three of the four St. Marys River rapids. Restoring the rapids has been a priority of a Binational Public Advisory Council which coordinates activities necessary to delist the AOC. Rapids habitat, characterized by high velocity, shallow depth and a rocky substrate provides optimal spawning conditions for critical populations of fish species in the St. Marys River. According to the GLC, of the four original rapids areas on the river, only a portion of the main rapids has continued to serve as habitat, though gate upgrades by the US Army Corps of Engineers are expected to improve those as well.

Around 20 years ago, members of the Soo Area Sportsmen’s Club started talking about improving the fishing in that part of the river, according to Alicia Krouth, engineer with the Chippewa County Road Commission in Michigan. There had been talk of installing fresh culverts that would have improved water flows at the time, but without funding it went nowhere. Over time, the culverts continued to degrade, making it more vital to either replace the culverts or the causeway. Since the culverts were typically submerged, they also were hazardous to people on the water upstream, Krouth said.

“What we had before were two failing and debris-filled culverts that didn’t allow much for flow,” she said. “It acted more like a weir than a free-flowing culvert.”

Fast forwarding to 2013, the GLC received Great Lakes Restoration Initiative funding through a regional partnership with the US National Oceanic and Atmospheric Administration (NOAA) to support habitat restoration in the St. Marys River, said Braun. Other rapids restoration sites along the St. Marys River had been evaluated, she said, but this one was the only feasible site where rapids habitat could be restored.

“In addition to the historic alteration to the natural flow of the river (in the past), the causeway was beginning to fail and the road commission anticipated some improvements were needed over the next several years,” Braun said.

earthen causeway removed
The earthen causeway was removed in favor of a bridge. In addition, the approach to the bridge was reconstructed to improve the side slopes to improve safety shown here in the construction process. Credit: Great Lakes Commission

Through the bidding process, Krouth said contractors indicated it would be less expensive to build a bridge rather than construct new culverts large enough to achieve the ideal water flow and repair the causeway in the process. The causeway was originally built to direct water toward the shipping channel, but changes to the river since the 1860s rendered it obsolete.

Thanks to funding from the Great Lakes Restoration Initiative and NOAA by way of the GLC, the Chippewa County Road Commission completed the construction of a bridge to replace the causeway in 2016. About $9.4 million was provided through the GLRI. The work was completed almost entirely within the year, with only some additional paving left to do in 2017.

Before and after shots of the Sugar Island crossing and its effect on the water
Before and after shots of the Sugar Island crossing and its effect on the water. Credit: Great Lakes Commission

Lake Superior State University has taken on ecological monitoring duties before, during and after construction and restoration to determine what sort of ecological changes have taken place since the bridge was completed, Braun said. The university is focused on native fish species and invertebrates, the algae didymo (Didymosphenia geminata), which has seen nuisance blooms in the St. Marys River) and invasive species.

Krouth said she’s heard local residents remark on seeing more fish in the water and that fishing has improved this year. More mayflies and other invertebrates integral to the food web have shown up in the Little Rapids area, she added, which also serve as a good indicator of water quality.

Braun said this project was likely the last habitat restoration project needed on the US side of the St. Marys River to remove the “loss of fish and wildlife habitat” beneficial use impairment (BUI) for the river. A draft BUI removal recommendation for the dredging restrictions BUI from Michigan Department of Environmental Quality (DEQ) notes that aside from habitat and dredging, the United States still has to resolve four other BUIs: restrictions in fish and wildlife consumption, fish tumors or other deformities, degradation of benthos, and degradation of fish and wildlife populations.

According to Environment and Climate Change Canada (ECCC), regulatory changes in how industrial wastewater is treated and handled and upgrades at the local municipal wastewater plant have dramatically reduced water quality issues on Canada’s side of the river, along with changes to a local steel mill’s practices. Restoration along the Bar River tributary using trees to reduce sedimentation and improve habitat has been completed, and planning is underway for additional habitat restoration work. ECCC also has been developing a plan alongside Ontario Ministry of the Environment and Climate Change to manage contaminated sediments in the river. ECCC anticipates that all restoration work on the Canadian side of the river should be completed sometime after 2020, said Jon Gee, manager for ECCC’s Great Lakes AOC program.

The latest Michigan DEQ remedial action plan document from 2012 doesn’t estimate how long overall US work will continue. But based on the best information available, the GLC believes the Little Rapids restoration work was the final on-the-ground project required on the US side to delist the St. Marys River Area of Concern.

In a river that has lost upwards of 90 percent of the rapids habitat, Braun said restoring up to 70 acres with the bridge’s completion is a major victory for those rare fish that need it to spawn, and for the river as a whole.

See a presentation below on “Restoring the Little Rapids in the St. Marys River” by Mike Ripley of the Chippewa Ottawa Resource Authority.

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

Major Expansion Coming to Lake Superior State University’s Aquatic Research Lab

By Gregory Zimmerman, Lake Superior State University

Conceptual view of the proposed Center for Freshwater Research and Education outdoor educational park. Credit: LSSU staff

Since 1977, Lake Superior State University’s Aquatic Research Lab in Sault Ste. Marie, Michigan, has been a center for research and outreach around the ecology of the St. Marys River and other aquatic habitats, as well as a focal point for student training in fisheries. The lab is probably best known for its Atlantic salmon hatchery program, in which it raises Atlantics for release into the river and Lake Huron system. Thanks to the lab, the experience of fishing for Atlantics in the St. Marys Rapids is cherished by locals and by visitors from around world.

The hatchery operations are impressive. Lake Superior State University (LSSU) is one of only a few universities that offer students direct work experiences in a hatchery that releases fish into public waters – but the lab does much more. Research projects in the river and Great Lakes, inland lakes, streams and wetlands advance science and provide information for improving the management of our resources.

releases salmon
Richard Barch of Ann Arbor releases a ceremonial portion of the 37,000 Atlantic salmon yearlings that Lake Superior State University stocked into the St. Marys River on June 2-3, while LSSU mascot Seamore the Sea Duck and community members look on. Credit: LSSU staff

Outreach activities inform residents and visitors about the importance of conserving our natural heritage. One example of outreach is the lab’s popular online “fish cam.” The lab is also a model of collaboration between the university, resource management agencies such as the Michigan Department of Natural Resources and Environment Canada, Cloverland Electric and other local organizations. Recent lab activities include a partnership in the Little Rapids Restoration project, the Great Lakes Coastal Wetlands Monitoring Program, sturgeon research, and more.

Now the lab is slated to take a big step in expanding its work. The facility will move from the current, rather cramped, space in the east end of the Cloverland Electric Hydro Plant to much larger space in the former Edison Sault office space on the west side of the plant. The lab will have about three times the space it currently has and be renamed the Center for Freshwater Research and Education (CFRE). The move has been in the works for several years, ever since Edison Sault donated the previous office building to the university. Plans include much-expanded research space for fish culture and fish health, space dedicated to public outreach, a K-12 discovery room, office space for researchers, and an outdoor educational park.

Two major sources of financial backing are moving the plans into reality. Last July, Michigan Gov. Rick Snyder signed an appropriations bill adding CFRE to the state’s capital outlay plan. The state would provide 75 percent of the funding with the university responsible for covering the rest of the costs. Then, this past December, Dick and Theresa Barch donated $500,000 to lead the way in helping the university raise its share of the estimated total of $11.8 million needed to build the Center.

For more information about the lab, visit For information about contributing to CFRE, contact LSSU Foundation Director Tom Coates at (906) 635-6670 or

Gregory Zimmerman is a professor of biology at Lake Superior State University. His research interests include control of invasive plant species in wetlands.

Editor’s Note: You can comment on issues raised in this article as part of the IJC’s public comment period on the Progress Report of the Parties and Triennial Assessment of Progress. Go to

Helping Fish in St. Marys Rapids with the Push of a Button

By Kevin Bunch, IJC

gates st marys river outflow water lake superior huron
Gates at the head of the St. Marys River help control the outflow of water from Lake Superior to Lake Huron. Credit: US Army Corps of Engineers

The flow of water from Lake Superior to Lake Huron has been controlled for almost a century through a series of structures on the St. Marys River, which involves work crews turning manual cranks. But now the US Army Corps of Engineers is moving ahead with a project that will set up some gates to be opened and closed with the push of a button.

Control structures on the St. Marys are under the supervision of the International Lake Superior Board of Control, including a 16-gate structure called the Compensating Works. Opening and closing the gates—eight on each side of the international border—allows the board to help control outflows from Lake Superior for hydropower, navigation, riparian, and environmental interests.

The Army Corps project  will upgrade operations for at least four of the US gates. This will reduce the amount of effort required to work with the gates, and allow the board to be more responsive to water conditions to help provide better habitat for aquatic species in the St. Marys Rapids, said John Allis, the board’s alternate regulation representative and chief of the Great Lakes Hydraulics and Hydrology Office for the Army Corps Detroit District.

When the board is setting the amount of water to release from Lake Superior each month, it needs to allocate enough for municipal and industrial water needs, the Soo Locks used for shipping, and for the rapids’ fish habitat. The remaining water goes to the three hydropower plants on the river. The board has, over the years, gotten a better idea of how best to manage the water to support that fish habitat in the St. Marys Rapids by partially opening more gates by smaller amounts, which in turn has led to more demands on staff to operate the gates with manual cranks.

Since opening and closing gates is currently a labor-intensive process for work crews, it creates practical limits on what kind of gate adjustments are feasible, Allis said.

The automated system will make it easier to open and close gates more quickly, and more slowly—which is important to fish and other wildlife in the rapids. The roughly 80-acre St. Marys Rapids, located just downriver from the gates, is a major spawning and feeding ground for a wide range of fish species, including salmon and trout.

The St. Marys Rapids are a major spawning and feeding location for several species of fish. Credit: US Army Corps of Engineers
The St. Marys Rapids are a major spawning and feeding location for several species of fish. Credit: US Army Corps of Engineers

“Almost every month in the summer through the fall there’s some species that end up using the rapids for spawning,” Allis explained. “It’s one of the most productive areas on the Great Lakes.”

With the current hand-crank system, however, water levels can fluctuate suddenly and cause major problems for the fish. A sudden loss of water can strand fish, while a sudden burst can wash both fish and their eggs out of the rapids. With automated gates, Allis said the board can instead make slower, more gradual changes by opening gates gradually, improving the productivity of the spawning area. While crews can make those slower adjustments with the current crank system, the number and amount of time required of staff makes it unfeasible on the US side.

The US$8 million project to modernize the four gates would get underway in the spring of 2017 and should be complete by December 2018, with funding from the US Environmental Protection Agency’s Great Lakes Restoration Initiative. The remaining manually operated US gates could be automated as part of the project based on additional funding.

The Army Corps operates and maintains the US gates. Brookfield Renewable Energy Group handles the eight Canadian gates on behalf of the Canadian government, none of which are part of the upgrade project. Allis said the board will leverage the automated gates in concert with the manual gates to make sure fish in the rapids have an ideal amount of water and flow while still retaining flow for other needs.

Allis said the project won’t impact water levels of Lake Superior or Lake Huron, since it doesn’t affect the amount of water coming in from Lake Superior each month. This just provides more flexibility for how to release that water throughout the month, adjusting how the flow moves across the rapids and making more gradual changes. A healthier environment for spawning on the rapids could be beneficial to anglers, he said, and would provide some additional habitat for native species.

“Improving spawning conditions (and fish habitat) in the St. Marys Rapids provides a tremendous regional benefit to the Great Lakes ecosystem,” Allis said.

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

The 16 US and Canadian gates help manage outflow. Credit: US Army Corps of Engineers
The 16 US and Canadian gates help manage outflow. Credit: US Army Corps of Engineers

Where are Water Levels Heading on the Great Lakes?

By Kevin Bunch, IJC

lake michigan beach water levels great lakes noaa
A Lake Michigan beach located near Frankfort, Michigan, in September 2015. Credit: NOAA

Forecasting agencies in the United States and Canada expect Great Lakes water levels to remain near or above their long-term average for the next six months.

Water levels are measured on the International Great Lakes Datum, defined as the height above sea level at Rimouski Quebec on the St. Lawrence River estuary. According to the coordinated, binational forecast at the beginning of July, Lake Superior is expected to remain about 6 inches, or 15.4 centimeters, above its long-term average for this time of year through the summer, before falling closer to average levels in the fall. While this forecast is based on normal weather conditions in coming months, lake levels could be higher or lower depending on whether we have a wetter or drier than normal summer and fall. Long-term averages are based on data going back to 1918.

Lake Michigan-Huron, which have a common level due to their connection at the Straits of Mackinac, is expected to be 10-12 inches (30.8 cm) above average in the summer before falling closer to average in the fall. Lake Erie also is expected to be within 1 foot above average in the summer before ending closer to 8 inches, or 20.32 cm, above average in the fall. Lake Ontario’s July level is 1 inch (2.54 cm) below average for this time of year and is expected to remain close to average in the fall.

Jacob Bruxer, Environment and Climate Change Canada senior water resources engineer, said Lake Ontario’s comparatively lower water levels are due to the warm, dry weather conditions around the lake that started around March. Bruxer is also a member of the IJC’s International Lake Superior Board of Control and the Great Lakes-St. Lawrence River Adaptive Management Committee.

“Those conditions would be bad if we started at average levels, but we’re right around average,” Bruxer said. “We’re not seeing any significant concerns to shipping or recreational boaters.”

The higher water levels on Superior, Michigan-Huron and Erie mean some boat launches could be underwater and beaches are smaller than they would be with lower levels. On the flip side, boaters should have plenty of depth to get their boats into their docks, and anglers may find more coastal areas to fish than they would otherwise. Bruxer added that high levels can lead to greater erosion along bluffs and shorelines due to waves and storms.

Drew Gronewold, a hydrologist at the Great Lakes Environmental Research Laboratory in Ann Arbor, Michigan, explained that the Great Lakes typically follow a seasonal cycle where water levels rise in the spring from runoff and peak in early summer. The lakes then fall in the autumn and winter months as evaporation — caused by temperature differences between the warm water and cool air — picks up, reaching their lowest point around January and February.

As of mid-July, Gronewold said there’s no indication that the autumn dip will be stronger than usual in the lakes, or that water levels will increase – something that occurred in the autumn and winters of 2013 and 2014 on Lake Michigan-Huron and Lake Superior. Bruxer said the lakes are expected to remain either near or slightly above seasonal averages for the foreseeable future.

Coordinated six-month forecasts of Great Lakes water levels are published online each month by the US Army Corps of Engineers and Environment and Climate Change Canada (via the Canadian Hydrographic Service). The US National Oceanic and Atmospheric Administration (NOAA) also provides these forecasts on its water level online viewer each month. Forecasted water levels are determined using binational data and several different models that account for possible variations in evaporation, precipitation and runoff on the lakes over the coming months.

While forecasts are typically only for a six-month period, the Army Corps of Engineers has recently developed a 12-month probability outlook.

Lauren Fry, civil engineer with the Corps, said the model provides potential outcomes given climatic scenarios, developed based on current conditions and similar existing historical weather data. For example, with the strong El Niño cycling over the past winter, Fry said the agency used data from  similarly strong 1982 and 1997 El Niño events to determine a range of potential lake level impacts from October 2015 until September 2016. The most recent one-year outlook from April suggests higher-than-average water levels will most likely continue until April 2017.

water levels measured feet meters great lakes michigan huron graph
Water levels are measured in feet or meters above sea level, with data compiled by US and Canadian organizations. The green line represents forecasted water levels, while the red line indicates recorded points for Lakes Michigan and Huron as of June 30. Credit: US Army Corps of Engineers

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.