The month of March brings both change and hope. Trumpeter
swans have returned to our waters and bird enthusiasts are watching the migratory
“radar” for the ebb and flow of migrations heading for parts north. All seems
to be going according to plan with rivers opening up flowing ice-free as they
head north to Lake Superior. Historically, spring runoff has been a time when
rivers are most actively evolving. Major runoff events and peak flows change
the course of waterways over time in natural processes where erosion and
sedimentation balance each other out in a healthy watershed.
Unstable banks like this one at Copper Falls State Park
are found along many area streams.
Photo by Diane Daulton
|
Land use changes since pre-settlement times in the Lake
Superior basin have greatly influenced our geologically young landscape,
especially in recent years with significant rainfall events and subsequent
flooding. Why, one might wonder? Back in the 1950’s after a series of large
floods and washouts, the Red-Clay Interagency Committee was tasked with
studying and demonstrating techniques for reducing upland and roadside erosion
and stabilizing river bluffs and streambanks. Most people don’t realize that
deforestation, subsequent farming, and channelization from road building and
culverts forever changed the landscape resulting in a significant nonpoint
source pollution problem that we still face today.
In the upper reaches of Lake Superior’s watershed, red clay
soils and sands resulting from past glacial Lake Duluth shorelines converge in
a steep transition zone of ravines and valleys making for a “perfect storm”.
The increased volume and power of runoff results in an imbalance that fuels
gullying, disconnects headwaters’ wetlands, degrades streambanks…scouring out channels
and perching floodplains, while vast amounts of sand and sediment are
transported downstream. Research Hydrologist, Faith Fitzpatrick, with the U.S.
Geological Survey (USGS) cautioned that small land use changes can matter. She
explains, “Because of the steepness and clay soils (that promote runoff), a
small change in the amount of runoff, from changing the vegetation type,
decreasing roughness of the land surface, or altering drainage pathways may
easily destabilize a ravine and cause gullying and groundwater sapping.” Although
recent years’ extreme rain events have exacerbated this problem, it is not new,
just evolving…as are efforts to study and better understand the watershed as a recovering
fluid system.
Fitzpatrick has been studying fluvial geomorphology in
our watershed since the 1990’s, looking at historic erosion and deposition, studying
the function of our streams and their interaction with the landscape around
them. One has only to paddle the White or Bad Rivers to see >100-foot tall
slumping banks along bends in the river where mass bank erosion is obvious. Fitzpatrick
noted, “The extreme floods in 2016 and 2018 that hit northern Wisconsin will
likely leave a sedimentary signal that will live on in the geologic record. The
floods caused major geomorphic change over a period of hours. New valleys were
formed and, in some places, more sediment was deposited on floodplains than
that which accumulated over the last 150 years since land clearing and
Euro-American settlement.
Flood events exacerbate unstable hydrologic conditions causing damage. |
Deep sand deposits are clearly visible on N. Fish Creek
downstream of US Hwy 2.
Photos by F.Fitzpatrick, U.S. Geological Survey
|
Mary Jo Gingras, Ashland County Land Conservationist
explains, “The FEMA grant will help inform efforts to repair hydrologic
conditions by analyzing fluvial erosion hazard features, specifically where
flood storage areas have been reduced, or lost, in the upper watershed due to
degraded wetlands or compromised floodplains. In the 2016 and 2018 floods, the
Marengo River watershed experienced substantial flooding; resource managers
have made connections between flood damage to roads, culverts, and bridges and
degraded natural conditions that could have helped mitigate storm damage.” Wisconsin
Wetlands Association Specialist Kyle Magyera warned that flood resiliency in
our area will not take place overnight. He noted, “We will have to let rivers
move and repair themselves naturally, but we can help kick-start the process by
repairing hydrology and reconnecting streams, floodplains, and wetlands to
better control water movement.”
Small changes in land use can destabilize a ravine causing gullying and groundwater sapping. Photos by Kyle Magyera, Wisconsin Wetlands Association |
Recent history has taught us that nature is not always in concert with the latest engineering standards and that, over the years, humans have made costly mistakes either from lack of insight or differing value systems. In the last decade, the Northland has faced threats to water quality posed by increased rainfall events, such as massive culvert failures and washed out roads, but also potential impacts from large-scale agricultural expansions, and long-term implications of iron mining in the Penokees.
Source: www.enbridge.com |
While these issues are dormant for the moment, the effort
to re-route Enbridge’s Line 5 pipeline is bringing back the age-old dichotomy
of clean environment versus the economy. Opinions are sharply divided amongst
people living in the watershed and many landowners have already signed
agreements with Enbridge to lease their land in perpetuity or to sell outright.
According to Enbridge Energy, a multinational Canadian company, “Line 5 is a
vital link to propane and other energy supplies for the upper Midwest. Every
day, this 645-mile-long, 30-inch diameter pipeline plays a critical role
transporting 540,000 barrels of light crude oil, light synthetic crude oil, and
natural gas liquids to a regional network for this area.” Since the Bad River tribe
has requested removal of the existing pipeline on the reservation, the
company’s plan “B” is to skirt around that approximately 12-mile section by
moving further upstream in the watershed. Common sense suggests that this
alternative neither benefits the Bad River Tribe or Ashland County, as it enlarges
the watershed that would be at risk. Further, the project could put groundwater
aquifers at risk, as little is known about the exact path of local groundwater,
except that it provides drinking water for many rural residents.
Aerial imagery shows historic movement of Bad River channels and resulting oxbow lakes where the river intersects with existing pipeline corridors. Google Photo courtesy of Joe Bates |
According to Enbridge’s Public Service Commission of
Wisconsin Public Interest Determination
Application (Feb 2020), the proposed 41 mile-long re-route for the pipeline encompasses 182 new river crossings, along with 86.6 acres of wetland impacts, all of which are still located within the Bad River (Lake Superior) watershed. Under stable conditions rivers naturally change course over history cutting themselves off, forming oxbow lakes, and evolving in ways we may not anticipate, so why would we take chances under less than stable watershed conditions? It seems self-evident that we owe it to future generations to carefully consider the risks and economics of any endeavor that requires a commitment in perpetuity.
Application (Feb 2020), the proposed 41 mile-long re-route for the pipeline encompasses 182 new river crossings, along with 86.6 acres of wetland impacts, all of which are still located within the Bad River (Lake Superior) watershed. Under stable conditions rivers naturally change course over history cutting themselves off, forming oxbow lakes, and evolving in ways we may not anticipate, so why would we take chances under less than stable watershed conditions? It seems self-evident that we owe it to future generations to carefully consider the risks and economics of any endeavor that requires a commitment in perpetuity.
For landowners interested in learning more about Line 5, facts
and disclosures regarding easements, and how to make informed decisions for
their property
and the watershed. Midwest Environmental Advocates has partnered with Wisconsin's Green Fire (a nonpartisan group dedicated to management of natural resources) to produce a series of guides that educate the public on the various regulatory processes involved with the proposed reroute of Enbridge's Line 5. Links can be found at www.wigreenfire.org or www.midwestadvocates.org under the "issues and actions" tab.
Lake Superior is a freshwater inland sea worth protecting. Photo by NOAA |
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