Baraga County: Lake Superior shoreline erosion study - Summary and Maps
The DEQ Water Resources Division (WRD) conducted an update of its shoreline recession rate study of the Lake Superior shoreline in Baraga County. The original shoreline recession rate study was conducted in 1983. Changes in the high-risk erosion area (HREA) boundaries and projected shoreline recession distances are proposed. Letters explaining the proposed changes and information regarding the opportunities for input have been sent to property owners, local officials and legislators. A webinar and a local public meeting are planned for August 1 and August 8, 2017, respectively. The webinar will be held at 1:00 p.m. EDT, August 1, 2017. Registration is required online at www.mi.gov/shorelands, select “Baraga County: A webinar to discuss the latest Lake Superior shoreline erosion study.” or put the following link into your internet browser https://attendee.gotowebinar.com/register/3010147660827463683. The public meeting will be held in the District Courtroom at the County Courthouse, 16 N. 3rd Street in L’Anse at 6:30 p.m. Property owners have until September 8, 2017 to provide comments before the final HREA designations will be established by certified mailings to the affected property owners. The affected property owners have sixty days from the receipt of their designation letter to appeal the designation.
The HREA program identifies rapidly eroding coastal reaches and establishes setback requirements for construction in these hazard areas to prevent property loss. The proposed changes in the HREAs are the result of a recession rate study conducted on January 23, 2017 to identify changes in the long-term rate of erosion occurring along the Great Lakes shoreline pursuant to R 281.22 (22) of the Great Lakes Shorelands Administrative Rules promulgated pursuant to Part 323, Shorelands Protection and Management, of the Natural Resources and Environmental Protection Act, 1994 PA 451, as amended (Part 323). The study identified shorelines where recession is occurring at an average rate of at least one foot per year over a minimum of 15 years. A longer study time period was used when technically possible to span a wider range of water levels and shoreline fluctuations.
The Update Study
The erosion hazard line (EHL) as defined in R 281.21 (1) (c) means the line along the shoreland that is the landward edge of the zone of active erosion or the line where the 604.4 feet, 1985 International Great Lakes Datum, contour on Lake Superior meets the shoreland, whichever is furthest landward. The zone of active erosion means the area of the shoreland where the disturbance or loss of soil and substrate has occurred with sufficient frequency to cause unstable slopes or prevent vegetation of the area [R 281.21 (1) (r)]. The recession rate study compared the EHL on historical aerial photographs to the EHL on modern aerial photographs. Historic aerial imagery from 1980 was used for the shoreline in Baraga Township; 1979 imagery was used in L’Anse Township; and 1977 imagery was used in Arvon Township. The modern imagery was from 2015. The study spanned periods of 35, 36 and 38 years, respectively.
The historic EHL was determined by viewing the vegetation lines along the shoreline on the aerial photograph. The modern EHL was determined using the same method with the added information provided by low-level oblique aerial photographs, 2012 USACE Great Lakes Oblique Imagery, which shows detailed views of the shoreline from an offshore vantage point. An additional resource was the Great Lakes Shoreline Geodatabase, which gives the approximate location of areas of various bluff heights among other attributes. Cross-referencing these resources with the modern imagery was helpful in determining the modern EHL. The shoreline was reviewed and the EHL was determined for all previously designated HREAs and areas of apparent erosion.
Transects were drawn perpendicular to the shoreline at 150 foot intervals along the shoreline and recession rates calculated along the transect lines. Similar rates were grouped into high risk erosion areas (Area). Average recession rates were calculated within each Area. Projected recession distances were determined for each Area. Parcel boundaries and owner data was received from the Baraga County Equalization Department. The current Area and parcel data were compared to the 1983 data to determine designation changes.
Within these hazard areas, placement of new construction requires a permit and must meet setback distances based on projected recession distances when combined with the type of construction and other site specific conditions. The projected recession distance is the calculated rate of recession for the area over a 30 year [for readily moveable structures, as defined in R 281.21 (1) (k)] or 60 year [for permanent structures, as defined in R 281.21 (1) (i)] period as determined by R 281.22 (2). The required setback distance is based on this rate but may be greater in areas of bluffs over 25 feet in height.
Affected parcels were classified under one of the following four categories:
De-designation: These are parcels where the average rate of recession was documented to be one foot per year or greater during the previous study; however, the current study found the long-term rate of recession has fallen below the one‑foot‑per‑year threshold required for HREA designation. The HREA designation is therefore removed, also eliminating the permit requirements under Part 323.
New: These parcels were not designated during the previous study as being in an area of high risk erosion; however, the current study found the long-term rate of recession has increased to, or is above, the one-foot-per-year threshold required for HREA designation. The properties are designated and subject to the regulations and permit requirements under Part 323 and the promulgated rules for high risk erosion areas.
Lower: These are parcels where the average rate of recession was documented to be greater than one foot per year during the previous study and are currently designated as being in an HREA. The current study documented a decrease in the long-term recession rate, but the erosion rate is still at or above one foot per year resulting in a decrease in the projected recession distances.
Increasing: These are parcels where the average rate of recession was documented to be greater than one foot per year during the previous study and are currently designated as being in an HREA. The shorelines of these parcels continue to erode at a rate greater than the previous study.
There are approximately 70 miles of Lake Superior shoreline in Baraga County among the villages of Baraga and L’Anse and three townships: Baraga, L’Anse and Arvon. The entire shoreline was viewed using the USACE 2012 oblique imagery to determine study sites. Field work included measuring points along Second Sand Beach at the public access site. During the current study 53% (37 miles) of the shoreline was identified as needing study because it was either previously designated or showed signs of erosion. Of the shoreline studied 10% (3.7 miles) was determined to be in an area of high risk for erosion. Of the currently identified areas of high risk erosion 70% (2.6 miles) will be designated for the first time. In 1983, approximately 5 miles of Baraga County shoreline was designated as being at high risk for erosion. Of the originally designated shoreline 22% (1.1 miles) remain designated. Nearly four miles of shoreline will be de-designated.
The study will affect a total of 64 parcels. Twenty-four parcels will be newly designated, one parcel in Lightfoot Bay and five parcels near Pequaming will have lower projected recession distances. A total of 32 parcels will be de-designated and will no longer require new structures, or their additions, to be set back a specific distance from the erosion hazard line per Part 323. Preliminary High Risk Erosion Area Update maps are available below for review.
Baraga Township and Village of Baraga – A new HREA (Area) was noted south of the Houghton County line, eroding at a rate of 1.3 feet per year over approximately 300 feet of shoreline. The existing Area south of Beartown Road continues to recede and has the highest rate of shoreline recession in the county. The 1983 recession rate of 1.8 feet per year has increased to 2.4 feet per year in the north end of the area and decreased from 1.3 feet per year to less than 1 foot per year in the south end of the 1983 designated area. The projected 30-year recession distance increased from 70 feet to 85 feet and 60-year recession distance increased from 125 feet to 160 feet. A new Area south of Little Carp Creek is eroding at a rate of 1.7 feet per year over approximately 140 feet of shoreline. The existing Area in the Village of Baraga was determined to be eroding at a rate of 1.5 feet per year in 1983. The current study determined the area is no longer eroding at this rate and shoreline change is less than an annual average of 1 foot per year over the study period of 35 years.
Village of L’Anse and L’Anse Township - The existing Areas designated in 1983 in L’Anse and west of L’Anse had calculated average annual recession rates of 1.8 and 1.2 feet per year, respectively. Recession is these Areas was measured to be less than an average annual rate of 1 foot per year. A new Area is proposed to be designated north of Pequaming on the tombolo. The Area is receding at a rate of 1.3 feet per year. The proposed 30-year projected recession distance and the 60-year projected recession distance is 55 feet and 95 feet, respectively. At Rock Beach Point the Area is receding at an average annual rate of 1.4 feet per year. The proposed 30-year projected recession distance is 55 feet and 60-year projected recession distance is 100 feet. The existing Area at Sand Beach was measured in 1983 to be eroding at a rate of 1.1 feet per year. Current measurements determined the rate to be less than 1 foot per year. Previously designated areas not found to be eroding at an average rate of one foot or greater over the study period of 36 years will be de-designated.
Arvon Township – The existing Area at Lightfoot Bay continues to recede although the rate has decreased considerably. In 1983 the Area was receding at rates of 4.1 and 2.6 feet per year, respectively. The current study identified rates of 1.6 feet per year and 1.1 feet per year.
Traveling east around the point to the Area Lightfoot Bay 2 the recession rate has decreased to 1.2 feet per year from 5.0 feet per year in 1983. There is some shoreline between these two areas which was measured to be receding at a rate of 2.6 feet per year in 1983 but the rate has now fallen to less than 1 foot per year. Shoreline east of Lightfoot Bay 2 that was designated in 1983 as receding at rates of 5.0 and 1.5 feet per year are now showing rates less than 1 foot per year. The existing Area, Huron Bay, continues to erode albeit at a slightly lesser rate. In 1983 the rate was 1.5 feet per year, currently the rate is 1.4 feet per year. This Area now extends further east than it did in 1983. The proposed 30-year and 60-year projected recession distances are 55 feet and 100 feet, respectively. The existing Area on the Marquette county line measured as receding at a rate of 1.5 feet per year in 1983 is now receding at a rate of less than 1 foot per year over the study period of 38 years.
Public Meetings and Notification
A public webinar will be conducted from Lansing and a public meeting and a meeting with local officials will be held in L’Anse to explain the high risk erosion program and the current recession study to local officials and property owners. Prior to these meetings legislators will be sent written notification of the WRD’s proposed action. The meeting with local officials will include building code and zoning officials, sanitarians, and other affected local governmental agencies. These meetings provide WRD staff an opportunity to explain the pending regulatory changes by presenting information and maps showing the current HREA boundaries, recession distances, and proposed changes. Through these meetings, local officials and property owners have an opportunity to discuss concerns, provide additional information and ask questions.
The information gathered at these meetings will be incorporated into the final recession rate studies and projected recession distances. WRD staff will address all comments and concerns prior to implementing the proposed HREA designations.
The final phase consists of certified mailings, R 281.22 (3), sent to the owners of affected properties. These letters establish the designations proposed in the first mailing and discussed with property owners and local officials. Property owners have up to sixty days from their receipt of the certified mailing to submit appeals of the WRD’s actions. WRD staff will review the property owner’s concerns, make adjustments if appropriate, or proceed with an administrative contested case hearing.