Chapter 1 - The Les Cheneaux Watershed

 

 

Natural Features

 

The Les Cheneaux Watershed is considered a sub watershed of the Pine-Carp Watershed located in Michigan’s Eastern Upper Peninsula.  Specifically, the Les Cheneaux Watershed is located in eastern Mackinac County with one subwatershed located in south-central Chippewa County.  Natural features define the Les Cheneaux Watershed.  The area boasts 200 miles of Lake Huron coastline, which includes a 36–island archipelago known as the Les Cheneaux Islands.  

 

 

The islands area is strewn with bays, coastal marshes, dune and swale communities, rock and sand beaches, fens, swamps, peat bogs, and relatively undamaged northern forests.  In fact, natural features inventories indicate that some of the best examples of Great Lakes coastal marsh, interdunal wetlands, and northern fen remain intact in the watershed.

 

These habitats support numerous rare species, including bald eagles, ospreys, wolves, colonial nesting birds, caspian and black terns, threatened fish species, and moose. The coastline supports such threatened flora including dwarf-lake iris, Houghton’s goldenrod, Pitcher’s thistle, Hart’s tongue fern and the Lake Huron tansy (TNC).  The state of Michigan also recognizes several areas within the watershed as Environmental Areas (Artizone), including parts of St. Martin Bay, Mismer Bay, Mackinac Bay, Goose Island, Voights Bay, Duck Bay, Sheppard Bay, Scottys Bay, Crow Island, and Prentiss Bay (MDNR). 

 

 

 

Geographic Scope

 

The Les Cheneaux Watershed drains approximately 115 square miles within the Carp-Pine Watershed. The watershed covers all of Mackinac County’s Clark Township (80 square miles) and approximately 35 square miles in both Marquette (Mackinac) and Raber (Chippewa) Townships.  The project area is bordered on the west by the Nunn’s Creek watershed, to the east by several lake drainages including Trout and Albany Creeks, and to the north by the Munuscong watershed, which drains into the St. Mary’s River. The most concentrated developments within the watershed are located at the villages of Cedarville and Hessel.

 

 

 

 

Hydrology

 

The watershed can be broken up into distinct subwatersheds which are each drained by their own respective low gradient creek. These creeks include Steeles Creek, Law Creek, Mackinac Creek, Pollock Creek, Pearson Creek, Cedarville Creek[1], Flowers Creek, McKay Creek, Prentiss Creek, and Beavertail Creek as well as several shoreline drainage regions.  Chemical and biological surveys completed by project volunteers, Les Cheneaux Community Schools, and MDEQ personnel indicated that these surface waters and their aquatic wildlife are relatively healthy and enjoy a relatively good diversity of macro-invertebrates (MDEQ, LCCS).

 

The principle water source for these creeks is groundwater, so flows are relatively stable, year around. That groundwater occurs in several aquifer layers below the ground’s surface. A shallow unconfined aquifer underlies the ground surface in areas of glacial drift, including the higher elevated areas at the north end of the watershed. Where this shallow aquifer intersects the surface in topographical depressions or valley bottoms between ridges, the resulting water materializes as creek or contributing spring. Groundwater is of special concern in the watershed due to past on-site well bacterial contamination, the prevalence of older on-site septic systems, and the limitations of the geographic area to sustain residential development and accompanying infrastructure. As a result, the watershed community adheres to a moratorium on drilling wells less than 100 feet and special well casing protective measures (LMAS).

 

Inland lakes throughout the watershed include Bay City Lake, Mud Lake, Bass Cove Lake, Leach Lake, Loon Lake, and a few small, unnamed lakes.

Land Use

 

Much of the watershed is covered with second growth timber (71%), primarily upland conifer, cedar, aspen, and maple. Over 16% is classified as some form of wetland, the majority of which dominated by lowland conifers. Agriculture is scarce, accounting for only about 1% of the total land area. The urban landscape makes up about 8% of the total acreage in the landscape. The remaining watershed consists of open and barren lands (CTPC, EUPRPDC)

 

 

The urban landscape includes the two small villages, Cedarville and Hessel, that are joined by M-134, a state trunkline that intersects the entire watershed from west to east.  The other major road is M-129, which runs directly north and south through Cedarville.  Cedarville is located at the approximate center of the watershed and enjoys the most activity of the population centers, including Les Cheneaux Community Schools.  The majority of development and growth is occurring along both highways as well as to the north on Three Mile Road, which runs directly north of Hessel.  According to EUP Regional Planning and Development Commissions Comparison Analysis of Land Use in Clark Township, residential areas are also expanding along West St. Ignace Road, West Chard Road, Swede Road, and Nordquist Road.[2] Additional growth is occurring along the shoreline and expanding more to the Les Cheneaux Islands. The growth patterns determined through this study suggest a need for zoning revisions along the lakeshore in Clark Township. Suggestions include a waterfront or shoreline district should be added to existing districts, and developed in a manner that provides the township with as much control as is legally acceptable over future development along the Great Lakes Shoreline.  (EUPRPDC).

 

 

Physiography

 

Walk through the Les Cheneaux Watershed and you’ll notice characteristics of the Niagaran Escarpment within which the watershed is located.  The Niagara Escarpment is a complex landform consisting of sedimentary bedrock of marine (salt water) origin overlain by glacial deposits.  More specifically, the geology of the watershed consists of a thin mantle of lucustrine clays and sands underlain by Paleozoic sedimentary limestones, dolomites, shales, and sandstones. Limestone and dolomite of the Middle Niagara Series forms the bedrock surface of the watershed, covering cherty dolomite of the Manistique and Burnt Bluff Groups.  The limestones, dolostones, shales and sandstones of the Niagara Escarpment bedrock date from the Ordovician and Silurian Periods. They were formed between 425 and 450 million years ago when the area was inundated by a tropical salt water sea.  However, the watershed we can see today was formed as a result of erosion that occurred over the last 250 million years.  Softer shales have eroded away, leaving the more resistant limestone, which can be viewed at or near the ground surface throughout the watershed.  In fact, more than half of the Les Cheneaux watershed area has bedrock within ten feet of the ground surface (St. Antoine).

 

At the onset of the ice age, about two million years ago, the Niagara Escarpment lay buried from time to time under several hundred yards of ice. However, the oldest Ice Age (glacial) deposits associated with the Escarpment today are less than 25,000 years old. The glaciers also left trademarks such as the polished, scratched and cracked bedrock surfaces.  Boulders of granites (called erratics), were brought by the glaciers from Canada and lie haphazardly in forests and fields, may be seen many areas in the watershed (St. Antoine and CTPC 1994).

Glaciers also influenced the level to gently rolling topography of the Les Cheneaux watershed.  The hills and ridges, including the islands which rise out of Lake Huron (called drumlins) all are generally angled in a southeasterly direction and were formed by the underlying sediments being streamlined in the direction of the glacial movement by the advancing glacier.  Retreating glaciers left behind deposits of lake plain sand, gravel and clay (till) in the form of various topographic features – or moraines - that cover the Les Cheneaux Watershed bedrock.  These moraines of the Les Cheneaux Watershed lack the steep inclines which can contribute to erosive conditions.  Gently rolling plateaus with slopes of less than 10% dominate the landscape.  The elevation of the region ranges from 580 feet above sea level to approximately 1000 feet in the northwest half of the watershed near the Rockview Ridge area.  The islands, with their elaborate system of cobble beaches and exposed bedrock, consist of elevations around 50 to 60 feet above lake level  (St. Antoine and CTPC 1994).

 

 

Topography

 

What we gain from the glaciers in the aesthetics of our landforms, we lose in potential for effective use of these landforms in terms of development.  The lack of soil cover allows water to seep into cracks in the carbonate bedrock (i.e. limestone or dolomite).  Over thousands of years, rain falling through the atmosphere, picks up carbon dioxide (CO₂), which dissolves in the droplets. Once the rain hits the ground, it percolates through the soil and picks up more CO₂ to form a weak solution of carbonic acid: H₂O+CO₂=H₂CO₃.  The infiltrating water naturally exploits any cracks or crevices in the rock.  Over long periods, with a continuous supply of carbon dioxide enriched water, carbonate bedrock begins to dissolve.  Openings in the bedrock increase in size and an underground drainage system begins to develop, allowing more water to pass, further accelerating the formation of karst.  Eventually this underground water moving by laminar flow within narrow fissures leads to the development of subsurface caves (PICD).  This geological process, which has occurred over many thousands of years, has resulted in unusual surface and subsurface features ranging from sinkholes (Swede Road), vertical shafts, disappearing streams (Flower’s Creek), and springs, to complex underground drainage systems and caves.  Add to this the fact that much of our watershed contains very little glacial till, which leaves too little filtering soil for ridding surface waters of contaminants before entering the groundwater through the cracks of the limestone.  The thin, excessively permeable soil cover that occurs in the area includes stony (calcareous) soils throughout, as well as sandy soils to the north of the watershed consistent with the Carbondale-Shelter-Alpena Association indicated by the Mackinac County Soil Survey (NRCS).

 

 

Climate

 

The Les Cheneaux watershed being directly adjacent to northern Lake Huron, enjoys a relatively milder climate than its upland regions.  The area enjoys cooler springs with later leaf-flush and less chance of frost.  The autumn warm season tends to be longer as is the growing season (period in which the average temperature each day exceeds a base temperature (50 degrees F)) (USDA 1993) In winter, snowfall is lower compared to upland areas as little as 10 miles north.  In fact the watershed realizes an average snowfall of 70 inches per year compared to over 180 inches for neighbors to the north (Lake Superior watershed).  The average rainfall per year is approximately 26.9 inches, with the majority of that falling between April and September.  Average temperature is 41 degrees F with the winter average being a cool 19.5 degrees and the summer average being 63 degrees F (USDA 1993).

 

Socio-Economical Character

 

According to the U.S Census Bureau (2000), EUPRPDC, the Clark Township Master Plan, and CFED, the Les Cheneaux watershed’s economic prosperity is directly linked to the beauty, abundance, and health of the area’s natural resources.  Over 60% of the communities’ employment centers around resource utilization and recreation.  Traditional economic factors in the watershed include Michigan Limestone Operations’ limestone extraction operations, lumbering and other wood-related operations, as well as recreation and resort-oriented economic activities (CFED 1998/CTPC 1994).  In the past, a thriving perch fishery drew fishermen and helped sustain the economy.  However, in the 1980’s the bottom dropped out of the fishery, ultimately changing economic resources.  The change spurred community leaders into planning for sustainable growth with the desire to protect natural resources.  This sustainable development planning revealed the dependency of the local economy on the areas’ natural resources (CFED).

 

Despite the change in the local economy, the resident population has changed little over the past few decades.  The full-time resident population of the Les Cheneaux Watershed is approximately 2,200 people, with approximately equal numbers male and females, with a median age of 44.6 years.  Over 88% of the residents have at least a high school diploma with almost 20% attaining a bachelor’s degree or higher (Census Bureau).  According to EUPRPDC, there are 739 seasonal dwellings in the watershed, with an approximated 3.2 visitors per dwelling, or 2,364 tourist visitors.  On a beautiful summer day, the 259 resorts, motels and campgrounds, consisting of 1,295 rental units could bring that total up by 2,000 people (EUPRPDC-Clark Plan updates).