Marengo Riffles Issue 5 - 2024

Summer has seen a burst of energy in the Lake Superior Basin as our community gets into the water, explores the outdoors, our partners hit their field seasons, and schools get out. The Superior Rivers Watershed Association is pleased to issue our fifth edition of Marengo Riffles. In this issue, we’re exploring the impact of the proposed Line 5 reroute on the Marengo River Watershed. We’re also taking a close look at an important threatened species in the watershed: the Wood Turtle.

The Proposed Line 5 Reroute Project: A Look at Stream Channel Crossings

By Kevin Brewster

We’ve all been hearing about the proposed Enbridge Line 5 reroute for quite a while now. Regardless of anyone’s stance on the project, it is undeniable that it will impact a large number of streams by crossing them. At least 22 stream crossings will be needed in the Marengo watershed alone. For larger streams and rivers, this will require tunneling under the river bed with a process known as horizontal directional drilling (HDD). HDD has been in use for decades to provide passage of pipelines, power and communications lines, and other infrastructure under barriers such as roads, railroads, rivers and other water bodies.  There are a total of 13 HDD crossings planned for the Line 5 project as it crosses eight watersheds. There are several aspects of the process that raise water quality impact concerns.

Drilling Fluid Spillage

HDD uses a fluid called drilling mud to lubricate the drilling tools and carry material out of the drilling cavity. The main constituent of drilling muds is bentonite clay along with a host of unreported proprietary chemicals that act as lubricants, wetting agents, and cavity wall bonding agents. Drilling mud becomes problematic when it escapes the bore cavity and spills into nearby surface water, or contaminates underground aquifers when drilling breaks through natural barriers separating an aquifer from the bore cavity (known as “frac-outs”).  Minnesota DNR monitoring of Enbridge’s Line 3 project in Minnesota reported 28 instances where HDD resulted in frac-outs and water contamination with drilling fluids ( The chemicals used in drilling fluids can severely inhibit plant root growth and generally degrade water quality by increasing turbidity (decrease in light transmission due to suspended particles). Cleanup activities in spill zones result in further damage to wetlands and riparian areas from the use of heavy equipment and high-volume water pumping activities.

Hydrogeological Impacts

Documented HDD streambed and wetland penetration incidents in Canada and Minnesota have resulted in the water bodies being partially or fully drained, destroying fish and other aquatic life ( If a pipeline boring operation pierces an underground aquifer barrier, surface water may be introduced, bringing possible biological or chemical contamination. Likewise, otherwise-separated aquifers may be breached and their waters mixed, changing their chemistry, temperatures, and hydraulic properties. This can be a significant effect, especially if a pressurized (artesian) aquifer is allowed to drain into a stream or into a nearby non-pressurized aquifer. Nearby household drinking water wells may be affected, either by changes in available water volume or by contamination. Any scenario involving comingling of otherwise naturally-separated water sources can lead to impacts on stream water chemistry, flow volume, and temperature. Lasting changes made to any of these water characteristics can lead to multiple, difficult to reverse negative impacts on aquatic ecosystems.

Site Disturbance

A significant amount of vegetation removal and varying degrees of excavation are required for stream and river crossings. Cold water streams, while primarily fed by groundwater sources, are also maintained by shading streamside trees, shrubs, and other vegetation to keep temperatures favorable for brook trout and other cold water species. At sites where crossings will be kept clear of vegetation for maintenance purposes, the loss of shade will be permanent. Soil compaction of the site by heavy machinery and vehicular traffic will alter the drainage dynamics of the site and can obliterate microhabitat for riparian-zone dwelling plants and animals. Of regulatory concern is the wood turtle (see below), WDNR-listed as a threatened species. Wood turtles are found in every township the pipeline corridor project crosses, and multiple wood turtle and other turtle species nesting habitat will potentially be impacted. Juvenile wood turtles rely on shrub thickets near streams for sheltering and feeding habitat during their vulnerable first several years of life. 


Another potential hazard from HDD is creation of surface sinkholes where the bore cavity crosses under previously disturbed or naturally poorly consolidated soils. This can result in damage to existing infrastructure and surface water intrusion into aquifers. 

Line 5 Corridor Water Quality Sampling Locations

We recently received grant funding allowing us to expand our water quality sampling program to include six new locations on the proposed Line 5 reroute corridor. These sites were selected because of their downstream proximity to the planned pipeline, perennial flow, high quality ecological characteristics, and access considerations. Monitoring activities will begin this summer, allowing us to begin collecting pre-construction benchmark water quality and biotic data.

Superior Rivers’ Position Comment Letter to the US-Army Corps of Engineers

To: U.S. Army Corps of Engineers

St. Paul District, Regulatory Branch

180 5th Street E, Suite 700

Saint Paul, MN 55101

June 4, 2024

Re: Enbridge Line 5 – Wisconsin segment relocation (reference: MVP-2020-00260-WMS) 

To the US Army Corps of Engineers: 

The Superior Rivers Watershed Association writes to urge the US Army Corps of Engineers (USACE) to deny Enbridge the requested permit for the proposed Line 5 pipeline relocation and new construction in Ashland County, Wisconsin and Iron County, Wisconsin. 

Superior Rivers Watershed Association (SRWA) is a non-profit organization based in Ashland, Wisconsin whose mission is to promote and protect water resources in Wisconsin’s Lake Superior Basin. We promote healthy connection between the people and natural communities of our watersheds by involving citizens in assessing, maintaining and improving watershed integrity for future generations. We represent seven board members, three staff members, and around 212 volunteer members. Originally formed in 2002 as the Bad River Watershed Association, our organization’s staff and volunteers have collected water quality data across the ten watersheds. This data has been used to give special designations to 180 miles of riverways, inform local decision makers, and help us understand climate change’s effect on waterways around Lake Superior’s South Shore. The proposed Line 5 reroute runs directly through the heart of SRWA’s service area.

We request that US ACE denies Enbridge the requested 404 Clean Water Act permit for the following reasons:

  • The existing Line 5 pipeline and proposed new Line 5 construction threaten the health and integrity of numerous ecologically significant waterways. 
    • The proposed pipeline corridor will be developed within the Mashkiiziibii (Bad River) watershed, which is characterized by numerous high quality water resource streams, wetlands, and the Kakagon Sloughs.
    • The proposed corridor will cross a State of Wisconsin Department of Natural Resources-designated Exceptional or Outstanding Resource Water stream segments nine times.
    • Pipeline construction damages the watershed and increases erosion and sedimentation, which in turn severely impairs many rivers and streams in the sub-watersheds of the Bad River. Parts of the pipeline corridor lie within areas prioritized by regional interagency working groups for reduction of erosion and sedimentation potential. 
    • Creating new, long-term openings in habitat breaks up habitat blocks. Furthermore, heavy equipment is a major vector for invasive plant species that imbalance healthy forest and wetland ecosystems.
    • The proposed route crosses numerous stream system drainages. If directional boring is employed to locate the pipeline beneath these stream beds, this will inevitably result in penetration of aquifers that are presently isolated from surface water. The impact of this redistribution of groundwater has not been adequately studied in terms of thermal and hydraulic volume changes taking place both in the aquifers and in the surface waters that may be artificially commingled. Thermal and hydraulic volume changes may directly impact stream, floodplain, and adjacent wetland ecology.
  • The existing Line 5 pipeline and proposed new Line 5 construction poses a serious risk to the health of native fish and reptile species habitat and spawning grounds.
    • Of concern to the Superior Rivers Watershed Association is that the proposed reroute will increase, not minimize, the potential for water quality degradation by increasing the number of streams and wetlands it will cross. For example, the proposed corridor will cross a US Fish and Wildlife Service-designated critical brook trout fishery stream five times.
    • Additionally, the entire corridor footprint lies in the documented range of the wood turtle, a Wisconsin DNR-listed special concern species. Twenty-one potential nesting habitat sites may experience short term to permanent negative impacts from construction disturbances.
    • Our volunteer-collected, multi-year water temperature data collection at 14 sites in the proposed corridor demonstrate the presence of exceptional cold water resources in the Bad River watershed (see Any removal of shading vegetation cover at pipeline stream crossings has a direct impact on streams where cold water temperatures are at least partially maintained by shading from abundant streamside vegetation.
  • The existing Line 5 pipeline and proposed new Line 5 construction are situated within the treaty-ceded territories of the original peoples of the Great Lakes, the Ojibwe.
    • The Treaty of 1842 between First Nations (the Chippewa Indians of Lake Superior) and the United States recognizes the sovereignty of the Bad River Band of Lake Superior Chippewa and the right to fishing, hunting, and foraging in treaty-ceded territories. The proposed pipeline reroute is set within the boundaries of those ceded territories and any threat or risk to those fishing, hunting, and foraging rights is in direct violation of the Treaty of 1842. 
    • Extensive wetlands critical to the water and cultural resources of the Bad River Band of Lake Superior Chippewa Indians all lie directly downstream of the proposed pipeline reroute, including the Kakagon/Bad River Sloughs ecosystem, which was designated a Wetland of International Importance by the United Nations Ramsar Convention in 2012. This globally unique ecosystem:
      • Supports wild rice;
      • Supports diverse Lake Superior and inland fisheries;
      • Controls flooding; and
      • Filters pollutants from water.
  • We are concerned by both the overall, on-the-ground impacts of new pipeline construction and the risk of pipeline failure, and Enbridge’s poor safety record. 
    • Enbridge pipelines have a history of failure. The ecological and human health risks of yet another pipeline spill threaten the waters Superior Rivers Watershed Association protects and monitors. 
    • Pipeline exposure and destabilization is also a concern. The Bad River watershed is an historically flood-prone region, and has been subjected to three record-breaking flooding events since 2012. These events have resulted in loss of life, property, and infrastructure, twice on a catastrophic scale. Multiple regional climate models forecast increasing frequency of large precipitation events in the future, only exacerbating the risk to any existing or proposed new pipelines. We’ve seen the growing risk of flooding and subsequent erosion on the pipeline at a channel meander site where the Bad River is oxbowing and inching closer to exposing the pipeline.
    • Construction through wetlands and streams results in erosion, gullies, and silt deposits downstream, which both impact aquatic species and exacerbates flooding in the region.
    • In their permit application, Enbridge describes Line 5 as “vital energy infrastructure” (p.1). However, the above-mentioned impacts of climate change in the region make it imperative to shift away from oil and gas energy reserves. It is not in the long-term interest of the communities we serve to support fossil fuel energy infrastructure. 

The Superior Rivers Watershed Association also supports the Bad River Band’s stance that this public input process is premature given that the state has not yet issued a certification under section 401 of the Clean Water Act. This certification is a prerequisite for the Clean Water Act section 404 permit in question and the data and information used in this certification is necessary for adequate analysis for the 404 permit. On top of this, the tribe has not had adequate time to review the Environmental Assessment for this permitting process. With these two crucial steps in the process missing we believe this Environmental Assessment cannot be considered complete.

In summary, the potentially devastating localized effects of pipeline leaks or spills among other impacts of the proposed reroute gravely concerns Superior Rivers Watershed Association. We see the Environmental Assessment as incomplete and inadequate to be used to issue a 404 permit given the lack of state certification and tribal review. Our position is that transportation of hazardous materials, including pipelines carrying oil, gas, and other toxic fluids, should avoid crossing Lake Superior’s watersheds. The past and future impacts that the Enbridge Line 5 pipeline has to wetlands, streams, rivers, the Kakagon Sloughs, the Bad River, Copper Falls State Park, and Lake Superior clearly demonstrate why the USACE should deny the requested permit. We request that the USACE denies Enbridge the requested permit in accordance with Section 404 of the Clean Water Act for discharges of dredged or fill material into waters of the United States.


Superior Rivers Watershed Association Board of Directors

Superior Rivers Watershed Association Staff

The Wood Turtle-A Threatened Natural Treasure of the Marengo Watershed

by Kevin Brewster

Wood turtles can still be found in local abundance near some of the rivers and streams of the Lake Superior basin. However, they are generally in decline over most of their range, which extends from the New England states, Nova Scotia, west to Michigan, northern Indiana, Wisconsin, Minnesota, and south to Virginia. They’re upper shell (carapace) ranges from six to nine inches in length. The carapace has a sculptured appearance, with distinct annular growth rings evident in the shell plates (scutes) of juveniles and younger adults. The carapace colors are tan, grayish brown or brown, with yellow lines radiating from the centers of the scutes. Older turtles exhibit smoother carapaces that tend to be uniform dark gray. The wood turtle’s lower shell (plastron) is yellow in color with irregular black blotches. They can weigh up to just over two pounds. The head is often a dark gray to solid black, while the lower surfaces of the neck, chin, and legs are yellow in our northern populations, and changing to salmon-red in the eastern and southern parts of their range.

Wood turtles inhabit slow-moving streams with sandy bottoms and heavily vegetated banks. The soft bottoms and muddy shores of these streams are used for overwinter hibernation. Nesting areas are typically near streams, requiring open and sandy spaces. This results in them nesting in dangerous locations like road shoulders and embankments, and unstable eroding sandy river banks.

Wood turtles emerge from hibernation in late March or early April. Typically they will take advantage of warm sunny weather to bask in the sun to raise their body temperatures (being reptiles, they are ectothermic-having little or no internal body temperature control). Basking also helps eliminate masses of juvenile leaches often found attached to them in early spring. Breeding occurs in the water in April. Nesting usually begins around mid- to late June, depending on weather. Wood turtles exhibit strong nesting site fidelity, returning to sites for decades. Ideal nesting areas are semi-open to open, allowing abundant sunlight to incubate the eggs. Nesting is an unpredictable process, with females usually digging several “test holes” before settling on a nesting spot. Disturbance by humans or predators will cause a female to abandon a nest excavation and return the next day to complete the process. An average of seven to 11 eggs are deposited several inches underground, carefully covered with sand, and smoothed over by the female dragging her plastron over the filled hole. The nest is then left to be incubated by sunlight and hopefully not be discovered by nest predators like skunks, raccoons, bears, and other scavengers. Hatchlings emerge about 60 days later, and head for the safety of the stream channel and streamside shrub thickets. Once nesting is complete, adult wood turtles disburse into upland semi-open areas including forests, fields, bogswet meadows, and beaver ponds, sometimes over a mile from streams. They spend the summer feeding on various invertebrate prey, plant matter, berries, and fungi.

One of the most significant conservation challenges facing wood turtles is their vulnerability during the nesting and incubation phase of life. Turtles of many species are drawn to nest in dangerous locations like roadside shoulders and embankments because of the presence of dig-able sand or gravel, and available sunlight. They are also attracted to nest on unstable eroding streambanks for the same reasons, with nests often destroyed by bank collapse before they hatch. Human impact on the landscape favors species that tend to prey on turtles nests like rats, raccoons, feral or unsupervised cats and dogs, etc. To reduce the impact of nest predation, the conservation organization Turtles for Tomorrow has established predator-protected fenced nesting plots across Wisconsin. Two of these were built near the Marengo River, which have seen some use by local wood turtles.

In late September to early October wood turtles migrate back to their home streams. In some cases, fall breeding activity may take place, however nesting will not happen until the usual time in the following spring. As colder temperatures take hold, the turtles begin hibernation by burrowing into the edges of stream channels or channel bottoms.

Wood turtles are known for their intelligence. Some behavioral studies involving mazes and other tests suggest they are similar to rats in cognitive abilities. They are also known for a unique feeding behavior known as “worm stomping”, where they deliberately pound their feet or plastrons on the ground to induce earthworms-a favored prey-to come to the surface.

Wood turtles are listed as “threatened” by the WDNR, and have varying degrees of protected status across their range. Besides loss of habitat to development and resource extraction activities, they suffer significant road mortality, particularly during nesting season. The majority of eggs produced seasonally are consumed by nest predators. Hatchlings also face an uphill battle against predation and roadway threats before achieving the somewhat reduced vulnerability of larger size. The illegal trade in freshwater turtles for food, traditional medicine, and pets is a large and lucrative international business. According to International Union for the Conservation of Nature (, freshwater turtle species are among the world’s most illegally trafficked animals. Organized criminal networks sell turtles online and transport them (at staggeringly high mortality loss levels) to illegal markets in the US, Hong Kong and across Asia, and Europe.

What can we do in the Marengo River watershed to help wood turtles and other species continue to play their role in the ecosystem? Some things are simple: If you see a turtle sitting in a road, if possible (i.e. traffic safe), move it across the road in the direction it was heading and set it down off the edge of the shoulder. If it is a snapping turtle-of course famous for its powerful bite-you can still probably help it out. It’s a bit more of a challenge, but you can grasp them at the base of their tails and lift them off the ground to move them. Make sure the turtle is held facing away from your legs! Fortunately, painted turtles and wood turtles are much less aggressive and can be easily moved. Your main risk will be maybe getting urinated on by an alarmed turtle, so hold it accordingly. Raising awareness of the needs of turtles plays an important role. More people are stopping to move turtles out of roads, and “turtle crossing” signs are popping up on roads all over the country. On a larger scale, honest consideration of turtle ecological requirements needs to be consistently included in forestry, development, and infrastructure planning. Habitat assessments and prescribed restorative measures-conducted in good faith by qualified independent consultants-can help reduce negative impacts of development projects on turtles and other wildlife. For now, our region of the Lake Superior basin is blessed with a number of robust (although sometimes isolated) populations of wood turtles. Like so many other aspects of this place’s amazing natural heritage, they are worth working hard to preserve for future generations.

Do you want to contribute to our bi-annual Marengo Riffles Newsletter? Do you have a story, event, or information to share about the Marengo River Watershed? Email us at info @ to submit a piece for our Autumn or Spring edition!

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