Flood plain information, Ontonagon River, Ontonagon, Michigan and Lake Superior shoreline, Ontonagon County, Michigan

[From the U.S. Government Printing Office, www.gpo.gov]

FLOOD PLAIN INFORMATION

`@.'ObNTONAGON RIVER
ONTONAGON, MICHIGAN
AND

LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY
MICHIGAN

Gift -m

4
------ ------

PREPARED IN COOPERATION
with
WATER RESOURCES COMMISSION
MICHIGAN DEPARTMENT OF NATURAL RESOURCES
THE VILLAGE OF ONTONAGON
and
ONTONAGON COUNTY
by
DEPARTMENT OF THE ARMY
ST. PAUL DISTRICT CORPS OF ENGINEERS
ST. PAUL, MINNESOTA
SEPTEMBER 1970 0

DEPARTMENT OF THE ARMY
ST. PAUL DISTRICT, CORPS OF ENGINEERS

COASTAL ZONE
INFORMATION CENTER

FLOOD
PLAIN
INFORMATION
ON

ONTONAGON RIVER
ONTONAGON, MICHIGAN

AND
LAKE SUPERIOR SHORELINE

ONTONAGON COUNTY, MICHIGAN

US Department of commerce
NOAA Coastal Services Center Library
2234 South Hobson Avenue
Charleston, SC 29705-2413

ST PAUL, MINNESOTA
SEPTEMBER 1970

DEPARTMENT OF THE ARMY
NORTH CENTRAL DIVISION
OF ENENEERIS
211 SOUTH CLARK STREET
CHICAGO ILLINOIS 68605

22 AUGUST 1973
NCDDE

Mr. Robert Knocht
Office of Coastal Zone Management
National Oceanic and Atmospheric Administration
Rockville, Maryland 20850

Dear Bob:

Here is a copy of the U. S. Army Corps of Engineers Flood Plain
Information Report on ONtonagon, Michigan, which I described to
you at the Great Lakes Resin Commission Mesting at St. Clair. I
hope this example will help as you proceed with you important work
of implementing the Coastal Zone Management Act of 1972.

It was a pleasure to meet you. Please call me if the Corps of
Engineers can be of any help with Coastal Zone Management matters
on the Great Lakes.

Sincerely,

1 Incl Ernest Graves
as stated Major General, USA
Division Engineer

August 27, 1973

Major General Ernest Graves
Corps of Engineers
536 South Clark Street
Chicago, Illinois 60605

Dear Ernie:

Thank you very much for sending me the flood plain information
report on Ontonagon, Michigan. Based on a quick perusal, the
report is going to prove very useful as we plan for the
implemenatation of the coastal zone management program in the
Great Lakes area.

Perhaps we can discuss the matter further when we meet at the
next Commission meeting in late November.

With best personal regards,

Robert w Knocht
Director
Office of Coastal Environment

CC:C-1 W/Report

RWKNECHT:bp

CONTENTS

Page

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . I
Summary of Flood Plain and Shore Erosion Situation . . . . . . . 4

Past Floods . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Ontonagon River . . . . . . . . . . . . . . . . . . . . . . 9
Settlement . . . . . . . . . . . . . . . . . . . . . . . 9
Flood Damage Prevention Measures . . . . . . . . . . . . 11
Flood Warning and Forecasting Services . . . . . . . . . 12
The Stream and Its Valley . . . . . . . . . . . . . . . 12
Developments in the Flood Plain . . . . . . . . . . . . 13
Bridges Across the Stream . . . . . . . . . . . . . . . 14
Obstructions to Flood Flow . . . . . . . . . . . . . . . 15

Flood Situation . . . . . . . . . . . . . . . . . . . . . . 18

Flood Records . . . . . . . . . . . . . . . . . . . . . 18

Flood Stages and Discharges . . . . . . . . . . . . . . 18

Flood Occurrences . . . . . . . . . . . . . . . . . . . 21

Duration and Rate of Rise . . . . . . . . . . . . . . . 21

Velocities . . . . . . . . . . . . . . . . . . . . . . . 22

Flooded Areas, Flood Profiles, and Cross Sections . . . 22
Flood Descriptions . . . . . . . . . . . . . . . . . . . . . 23
April 4, 1912 . . . . . . . . . . . . . . . . . . . . . 23
May 1922 . . . . . . . . . . . . . . . . . . . . . . . . 23
April 20, 1923 . . . . . . . . . . . . . . . . . . . . . 23
August 22, 1942 . . . . . . . . . . . . . . . . . . . . 27
April 1, 1963 . . . . . . . . . . . . . . . . . . . . . 30
Future Floods . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Determination of Intermediate Regional Floods . . . . . . . 41
Determination of Standard Project Floods . . . . . . . . . . 42

CONTENTS (Continued)

Page
Frequency . . . . . . . . . . . . . . . . . . . . . . . . 44
Possible Larger Floods . . . . . . . . . . . . . . . . . 44
Hazards of Great Floods . . . . . . . . . . . . . . . . . . . 44
Areas Flooded and Heights of Flooding . . . . . . . . . . 44
Velocities, Rate of Rise, and Duration . . . . . . . . . 45
Past Shore Erosion . . . . . . . . . . . . . . . . . . . . . . . 52
Lake Superior . . . . . . . . . . . . . . . . . . . . . . . . 52
Erosion Damage Prevention Measures . . . . . . . . . . . 52
Erosion Forecasting Services . . . . . . . . . . . . . . 53
The Lake and Its Shoreline . . . . . . . . . . . . . . . 53
Beach Description . . . . . . . . . . . . . . . . . . . . 54
Shoreline Developments . . . . . . . . . . . . . . . . . 78
Mechanisms of Erosion . . . . . . . . . . . . . . . . . . . . 79

Rainfall . . . . . . . . . . . . . . . . . . . . . . . . 79
Wind and Waves . . . . . . . . . . . . . . . . . . . . . 80
Ice . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Lake Levels . . . . . . . . . . . . . . . . . . . . . . . 84
Geology of the Area . . . . . . . . . . . . . . . . . . . 85
Littoral Drift . . . . . . . . . . . . . . . . . . . . . 86
Erosion Situation . . . . . . . . . . . . . . . . . . . . . . 88
Shoreline Changes . . . . . . . . . . . . . . . . . . . . 88
Existing Protective Structures . . . . . . . . . . . . . 89
Storm Descriptions . . . . . . . . . . . . . . . . . . . . . 93
November 1913 . . . . . . . . . . . . . . . . . . . . . . 93
December 1968 . . . . . . . . . . . . . . . . . . . . . . 95
Future Shore Erosion . . . . . . . . . . . . . . . . . . . . . . 101
Design Storm . . . . . . . . . . . . . . . . . . . . . . . . 101
Predicted Shoreline Erosion . . . . . . . . . . . . . . . . . 101

Hazards of Shoreline Erosion . . . . . . . . . . . . . . . . 102

CONTENTS (Continued)

Page
Suggestions and Summary . . . . . . . . . . . . . . . . . . . . lo4
Remedial Measures for Beach Erosion . . . . . . . . . . . . Io4

Guidelines for Use of the Flood Plain and Shoreline . . . . 106

Encroachment Lines . . . . . . . . . . . . . . . . . . 108
Zoning . . . . . . . . . . . . . . . . . . . . . . . . 108
Subdivision Regulations . . . . . . . . . . . . . . . . log
Building Codes . . . . . . . . . . . . . . . . . . . . 110
Regulation of Beach Nourishment . . . . . . . . . . . . III

Pertinent Federal and State Laws . . . . . . . . . . . . . 112

Existing Federal Laws on Beach Erosion Control and
Lake Inundation . . . . . . . . . . . . . . . . . . 112

Federal Role in Beach Erosion Research . . . . . . . . 113
Emergency Flood and Coastal Storm Activities . . . . . 113
State Agencies Concerned with the Beach Erosion
Problem . . . . . . . . . . . . . . . . . . . . . . 114
State Flood Plain Management Program . . . . . . . . . 115
Glossary of Terms . . . . . . . . . . . . . . . . . . . . . . . 117
Authority, Acknowledgments, and Interpretation of Data . . . . 120

Table TABLES Page
1 Relative Flood Heights . . . . . . . . . . . . . . . . . 7
2 Drainage Areas in Watershed of Ontonagon River . . . . . 13
3 Bridges Across Ontonagon River . . . . . . . . . . . . . 15
4 Ontonagon River near Rockland, Michigan--Maximum Annual
Discharges and Stages--1942-1968 . . . . . . . . . . 19
5 Maximum Known Flood Discharges on Streams in the Region
of Ontonagon, Michigan . . . . . . . . . . . . . . . 43
6 Public Owned Lake Superior Shoreline . . . . . . . . . . 54
7 Design Waves . . . . . . . . . . . . . . . . . . . . . . 82

CONTENTS (Continued)

Page
Suggestions and Summary . . . . . . . . . . . . . . . . . . . . 104
Remedial Measures for Beach Erosion . . . . . . . . . . . . 104

Guidelines for Use of the Flood Plain and Shoreline . . . . 106

Encroachment Lines . . . . . . . . . . . . . . . . . . 108
Zoning . . . . . . . . . . . . . . . . . . . . . . . . 108
Subdivision Regulations . . . . . . . . . . . . . . . . 109
Building Codes . . . . . . . . . . . . . . . . . . . . 110
Regulation of Beach Nourishment . . . . . . . . . . . . III

Pertinent Federal and State Laws . . . . . . . . . . . . . 112

Existing Federal Laws on Beach Erosion Control and
Lake Inundation . . . . . . . . . . . . . . . . . . 112

Federal Role in Beach Erosion Research . . . . . . . . 113
Emergency Flood and Coastal Storm Activities . . . . . 113
State Agencies Concerned with the Beach Erosion
Problem . . . . . . . . . . . . . . . . . . . . . . 114
State @Iood P-1-ain Management Program . . . . . . . . . 115
Glossary of Terms . . . . . . . . . . . . . . . . . . . . . . . 117
Authority, Acknowledgments, and Interpretation of Data . . . . 120

Table TABLES Page
I Relative Flood Heights . . . . . . . . . . . . . . . . . 7
2 Drainage Areas in Watershed of Ontonagon River . . . . . 13
3 Bridges Across Ontonagon River . . . . . . . . . . . . . 15
4 Ontonagon River near Rockland, Michigan--Maximum Annual
Discharges and Stages--1942-1968 . . . . . . . . . . 19
5 Maximum Known Flood Discharges on Streams in the Region
of Ontonagon, Michigan . . . . . . . . . . . . . . . 43
6 Public Owned Lake Superior Shoreline . . . . . . . . . . 54
7 Design Waves . . . . . . . . . . . . . . . . . . . . . . 82

PLATES

Plate follows Page
I Watershed Map--Ontonagon River, Ontonagon
Michigan and Lake Superior Shoreline,
Ontonagon County, Michigan . . . . . . . . 4

2 Shoreline Map--Lake Superior Shoreline,
Ontonagon County, Michigan . . . . . . . . 53

3 Lake Superior Stage Hydrograph--Lake Superior
Shoreline, Ontonagon County, Michigan . . 80

4 Wind Rose--Lake Superior Shoreline, Ontonagon
County, Michigan . . . . . . . . . . . . . 81

5 Mean Monthly Lake Levels--Lake Superior
Shoreline, Ontonagon County, Michigan 85

6 Gabion Construction--Lake Superior Shoreline,
Ontonagon County, Michigan . . . . . . . . 105

7 Typical Rock Seawall--Lake Superior Shoreline,
Ontonagon County, Michigan . . . . . . . . 105

8 Index Map - Flooded Area--Ontonagon River,
Ontonagon, Michigan . . . . . . . . . . . 120

9-11 Flooded Area--Ontonagon River, Ontonagon
Michigan . . . . . . . . . . . . . . . . . 120

12 High Water Profiles--Ontonagon River, Ontonagon
Michigan . . . . . . . . . . . . . . . . . 120

13 Cross Sections--Ontonagon River, Ontonagon
Michigan . . . . . . . . . . . . . . . . . 120

14 Index Map - Shoreline Erosion--Lake Superior
Shoreline, Ontonagon County, Michigan . . 120

15-23 Shoreline Erosion--Lake Superior Shoreline,
Ontonagon County, Michigan . . . . . . . . 120

24-26 Beach Cross Sections--Lake Superior Shoreline,
Ontonagon County, Michigan . . . . . . . . 120

F I GURES

-Figure Page

I Relative Datum Planes . . . . . . . . . . . . . . . . 2
2 Ontonagon in about 1865 . . . . . . . . . . . . . . . 10
3 Ontanagon River Bridges . . . . . . . . . . . . . . . 16
4 Flood Scenes in Ontonagon - April 1912 . . . . . . . 24
5 Flood Scenes in Ontonagon - May 1922 . . . . . . . . 25
6 Flood Scene in Ontonagon - April 1923 . . . . . . . . 26
7 Flood Scenes in Ontonagon - August 1942 . . . . . . . 28
8 Flood Scenes in Ontonagon - April 1963 . . . . . . . 31
9 Flood Scenes in Ontonagon - April 1963 . . . . . . . 32
10 Flood Scenes in Ontonagon - April 1963 . . . . . . . 33
11 Flood Scenes in Ontonagon - April 1963 . . . . . . . 34
12 Flood Scenes in Ontonagon - April 1963 . . . . . . . 35
13 Flood Scenes in Ontonagon - April 1963 . . . . . . . 36
14 Flood Scenes in Ontonagon - April 1963 . . . . . . . 37
15 Flood Heights at Hoerner Waldorf Paper Mill . . . . . 46
16 Flood Heights at New Marina . . . ... . . . . . . . . 46
17 Flood Heights along East Side Slough . . . . . . . . 47
18 Flood Heights at Ontonagon County Road
Commission Garage . . . . . . . . . . . . . . . . 47
19 Flood Heights at Citizens State Bank . . . . . . . . 48
20 Flood He ights at IGA Foodliner . . . . . . . . . . . 48
21 Flood Heights at Eagles Club . . . . . . . . . . . . 49
22 Flood Heights at Quality Super Market . . . . . . . . 49
23 Flood Heights at Sears Catalog Sales . . . . . . . . 50
24 Flood Heights at the Fire Hall . . . . . . . . . . . 50
25 Flood He ights at U. S. Post Office . . . . . . . . . 51
26 Flood Heights at Hawley Lumber Yard . . . . . . . . . 51

FIGURES (Continued)
Figure Page
27 Typical Shoreline - Reach No. I . . . . . . . . . . . 55
28 Highway Protection - Reach No. 2 . . . . . . . . . . 56
29 Typical Beach Cross Section - Reach No. 2 . . . . . . 56
30 Typical Shoreline - Reach No. 3 . . . . . . . . . . . 57
31 Property Damage - Reach No. 4 . . . . . . . . . . . . 58
32 Effective Seawall Installation - Reach No. 5 . . . . 59
33 Typical Beach Cross Section - Reach No. 6 . . . . . . 60
34 Typical Shoreline - Reach No. 7. . . . . . . . . . . 61
35 Erosion Resistant Shoreline - Reach No. 9. . . . . . 62
36 Typical Shoreline - Reach No. 10 . . . . . . . . . . 63
37 Typical Beach Cross Section - Reach No. 11 . . . . . 64
38 Marginal Seawall Installation - Reach No. 11 . . . . 65
39 Typical Beach Cross Section - Reach No. 13 - . . . . 66
40 Typical Shoreline - Reach No. 13 . . . . . . . . . . 67
41 Local Shoreline Protection - Reach No. 13 . . . . . . 68
42 Typical Shoreline - Reach.No. 14 . . . . . . . . . . 68
43 Typical Shoreline - Reach No. 15 . .. . . . . . . . . 69
44 Typical Beach Cross Section - Western Reach No. 16 - 71
45 Narrow Shoreline - Eastern Reach No. 16 . . . . . . . 71
46 Local Shoreline Protection Eastern Reach No. 16. 72
47 Typical Beach Cross Section Western Reach No. 18 73
48 Typical Shoreline - Eastern Reach No. 18 . . . . . . 74
49 Typical Shoreline - Reach No. 19 . . . . . . . . . . 74
50 Typical Shoreline - Western Reach No. 20 . . . . . . 75
51 Typical Beach Cross Section - Eastern Reach No. 20 - 76
52 Typical Shoreline - Western Reach No. 21 . . . . . . 77
53 Typical Shoreline - Eastern Reach No. 21 . . . . . . 77
54 Typical Beach Cross Section - Eastern Reach No. 21 - 78
55 Typical Wave Attack - Rocky Shoreline . . . . . . . . 83
56 Typical Wave Attack - Sandy Beach . . . . . . . . . . 83
57 Typical Geological Section - Porcupine Mountains 86

vii

FIGURES (Continued)
Figure Page
58 Concrete and Rock Seawall . . . . . . . . . . . . . . 90
59 Concrete and Timber Seawall . . . . . . . . . . . . . 91
6o Broken Concrete Rubble ''Protection ... . . . . . . . . 91
61 East Ontonagon River Jetty - Shore End . . . . . . . 92
62 East Ontonagon River Jetty - Lakeward End . . . . . . 93
63 Shore Erosion Scenes in Ontonagon County
December 1968 . . . . . . . . . . . . . . . . . . . 96
64 Shore Erosion Scenes in Ontonagon County - I
December 1968 . . . . . . . . . . . . . . . . . . . 97
65 Shore Erosion Scenes in Ontonagon County -
December 1968 . . . . . . . . . . . . . . . . . . . 98
66 Shore Erosion Scenes in Ontonagon County -
December 1968 . . . . . . . . . . . . . . . . . . . 99
67 Shore Erosion Scenes in Ontonagon County -
November 11068 . . . . . . . . . . . . . . . . . . . 100

viii

INTRODUCTION

This report relates to the flood situation along the Ontonagon
River in the vicinity of Ontonagon, Michigan, and beach erosion along
Lake Superior for the Ontonagon County, Michigan, shoreline. Prepared
at the joint request of the Ontonagon Village Council and the Ontonagon
County Board of Supervisors through the Water Resources Commission,
Michigan Department of Natural Resources, this document will aid in the
solution of local flood and shoreline erosion problems and in the best
utilization of the affected land. The report is based upon informa-
tion on rainfall, runoff, historic and current flood heights, and
other technical data bearing upon the occurrence and size of floods
in the Ontonagon area. Lake levels, wave heights, past and present
erosion trends, and other pertinent information are factors used in
determining the rate and extent of shoreline erosion along Ontonagon
County-
Elevations given in this report refer to IGLD (International
Great Lakes Datum 1955) which is mean water level at Father Point,
Quebec. Two other datum planes are in common use for the area.

These are:

Mean Sea Level USGS and USC & GS Datum
Lake Superior Low Water Datum
The latter is used to correlate soundings on U. S. Lake Survey
Charts and for shore structures used for navigational or coast pro-
tection purposes, while the former is the basis of the national
vertical control established by the Coast and Geodetic Survey and
used for U. S. Geological Survey mapping.
The relationship between these three principal datum planes for
Lake Superior is given on Figure 1.

LAKE SUPERIOR LOW WATER DATUM (LWD)

IN TERNATIONAL GREAT LAKES DATUM (IGLD)
MEAN SEA LEVEL LISGS & USC & GS DATUM

Figure 1. -- RELATIVE DATUM PLANES

Two significant phases of the Ontonagon flood problem are covered
in the report. First, records of the largest known floods of the past
on the Ontonagon River are assembled. Secondly, probable future
floods designated as Intermediate Regional Floods and Standard Project
Floods are analyzed. Intermediate Regional Floods have an average
frequency of occurrence on the order of once in 100 years as deter-
mined from an analysis of known floods on the On tonagon River, with
consideration given other streams which have similar physical charac-
teristics and are in the same general geographic region. Standard
Project Floods are of rare occurrence and on most streams are con-
siderably larger than any floods that have occurred in the past.
In problems concerned with the control of developments in the
flood plains of the Ontonagon River, and in reaching decisions on the
size of floods to consider for this purpose, appropriate considera-
tion should be given to the possible future occurrence of floods of
the size of those that have occurred in the past, the Intermediate
Regional Floods, and the Standard Project Floods.
A record of shoreline erosion along Ontonagon County has been
compiled covering the past 110 years. From this information and an

analysis of lake and shoreline characteristics, the extent of future
erosion has been projected for the year 2020. This data will be
useful in the regulation of new developments along the Lake Superior
frontage. Also, the need for protective measures to guard against
future shoreline erosion can be evaluated.
The report contains maps, profiles, and cross sections which
indicate the extent of flooding which has been experienced and which
might occur in the future in the vicinity of Ontonagon. Beach cross
sections and maps showing the outline of the past and projected future
Lake Superior shoreline changes are also included. These plates
should prove helpful in planning the best use of the affected areas.
Floor levels for buildings may be planned high enough to avoid flood
damage, and developments may be located far enough from the lake to
protect against anticipated erosion. Buildings that are located at
lower elevations or closer to the lake will do so with recognition
of the chance and hazards of possible damage.
Plans for the solution of flood and erosion problems are not
included herein. Rather, the report is intended to provide the
basis for further study and planning on the part of Ontonagon County
and the Village of Ontonagon in arriving at solutions to minimize
vulnerability to damages. This might involve local planning pro-
grams for controlling the type of use made of the flood plain and
lake frontage through zoning and subdivision regulations, the con-
struction of flood protection and erosion control works, or a com-
bination of the two approaches.
The St. Paul District of the Corps of Engineers will provide,
upon request, technical assistance to the federal, state, and local
agencies in the interpretation and use of the information contained
herein.

SUMMARY OF FLOOD PLAIN AND SHORE EROSION SITUATION

Ontonagon County is located on the upper penninsula of Michigan
along the south shore of Lake Superior. Lake frontage in this area
is experiencing recreational developments at various locations and
residential, commercial, and industrial growth in and near the Village
of Ontonagon and at other smaller connunities.
The Village of Ontonagon is located on the south shore of Lake
Superior at the mouth of the Ontonagon River. Most of the village is
established along the east side of the Ontonagon River with mainly
industrial development along the west bank. Location of the Ontonagon
River and its drainage basin is shown on Plate 1.
The principal residential development of Ontonagon is located on
high ground east of the Ontonagon River, a substantial distance from
Lake Superior. There are, however, considerable residential and,
particularly, commercial areas which are vulnerable to serious flood-
ing. Portions of this land have been inundated by floods of the past
and a substantially greater area is within reach of the potentially
greater floods of the future. Much of the Ontonagon County shoreline
has been seriously damaged by past erosion, and considerably greater
damage may be expected in the future. The only areas which have been
exempt from extensive erosion have stable rock frontages adjoining
Lake Superior. Some examples include the Porcupine Mountains, Gull
Point, Ten-Mile Point, Fourteen-Mile Point, and Wolf Point.
The U. S. Geological Survey has maintained a stream gaging sta-
tion on the Ontonagon River near Rockland, Michigan, since June 1942.
Records are also available on the tributaries to the Ontonagon River
for a comparable period. No official flow records have been main-
tained on the Ontonagon River at Ontonagon due to poor stage-discharge
relationships caused by lake stage and ice conditions. A staff gage

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DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
0 5 10 15 MILES ST PAUL, MINNESOTA
LEGEND WATERSHED MAP
ONTONAGON RIVER
SHORELINE STUDY REACH ONTONAGON, MICHIGAN
AND
RIVER STUDY REACH LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY, MICHIGAN
SEPTEMBER 1970

PI ATF 1

is located at Ontonagon to give instantaneous readings of Lake
Superior levels. Official Lake Superior levels have been recorded
at Marquette, Michigan, since 18,60.
Residents along the Ontonagon River and Lake Superior have been
interviewed and newspaper files and historical documents searched
for information concerning past floods and erosion history. From
these investigations and from studies of possible future floods on
the Ontonagon River and future shore erosion along Lake Superior,
the local flood and shore erosion situation, both past and future,
has been developed. The following paragraphs summarize the signifi-
cant findings which are discussed in more detail in succeeding sec-
tions of this report.

THE GREATEST FLOOD known on the Ontonagon River occurred in April
1963. The river reached a record flood level which was about two
feet above any previous flood. Ice floes from the river combined
with windrowed lake.ice to form an ice jam at the river mouth. Ice
jams were also experienced at the State Highway 64 and railroad
bridges with resultant flooding in the lower areas of Ontonagon.

THE GREATEST RECORDED DISCHARGE on the Ontonagon River was gaged at
42,000 cubic feet per second (cfs) at the Rockland gage on August
22, 1942. Extensive flooding occurred in the vicinity of Ontonagon

as a result of this summer storm.

OTHER KNOWN FLOODS occurred in 1912, 1922, and 1923, although there
are few details available on these floods relative to stage and dis-
charge.

INTERMEDIATE REGIONAL FLOODS on the Ontonagon River have an average
frequency of occurrence of once in 100 years. In this study, the
Intermediate Regional Flood level was determined from an analysis of
past flood occurrences on the Ontonagon River which were caused by
ice jams, high discharges, or a combination of the two events. The
analysis shows that the Intermediate Regional Flood would be about
0.5 feet higher than the April 1963 flood of record.

STANDARD PROJECT FLOOD determinations are based on a 1.5-foot
increase above the 1963 stage, or about 1.0 foot above the Inter-
mediate Regional Flood stage. A discharge for the Standard Project
Flood was not determined. Due to the significant effects of*ice
jams in the harbor entrance and the lack of data to establish an
accurate open water rating curve, a Standard Project Flood stage,
based on a vertical distance above the Intermediate Regional Flood
stage, appears to be more practicable than attempting to develop a
Standard Project Flood discharge and estimating a stage at Ontonagon
corresponding to that flow.

FLOOD DAMAGES that would result from recurrence of major known
floods would be substantial. Even greater damages would occur dur-
ing an Intermediate Regional Flood or a Standard Project Flood
because of the greater depth and wider extent of flooding. Exten-
sive localized flood damage may result from unpredictable ice jams

or intensive storm runoff for small areas.

MAIN FLOOD SEASON for the Ontonagon River is usually in the spring
of the year when the heavy accumulation of winter snow melts rapidly

during a prolonged period of above freezing temperatures. Rapid
spring runoff following a severe winter tends to break up the river
ice cover and cause ice jams at bridges and at other restrictions
in the channel. One known flood, in August 1942 was caused by
heavy rainfall.

FLOOD DURATIONS depend primarily on the severity of the ice jams in
the harbor entrance and the unpredictable time for release of the
jam. In 1963 the flooding was experienced for about a 24-hour
period before the ice jam suddenly released and stages dropped.

HAZARDOUS CONDITIONS would occur during large floods as a result of
the ice jams, rapidly rising streams, and deep flows.

FUTURE FLOOD HEIGHTS that would be reached if the Intermediate

Regional and Standard Project Floods occurred in the vicinity of
Ontonagon are shown in Table 1. The table gives the comparison of
these flood crests and also shows the comparison with the April
1963 flood of record.

TABLE I

RELATIVE FLOOD HEIGHTS

Estimated Above
River Peak April 1963
Flood Location Miles Discharge Flood
cfs Feet

August 22, 1942 State Hwy. 64 0.66 43,000* Unknown
April 1, 1963 18,200* ---
Intermediate Regional 38,ooo 0.5
Standard Project --- 1.5
*Estimated from stream gaging records on Ontonagon River at
Rockland, Michigan.

A DISASTROUS STORM occurred on Lake Superior in November 1913 which

was described as the most intense on record. Shoreline erosion dam-
age was not believed to be too intense, although many lives were
lost at sea during the storm. The main reason for the minimal ero-
sion was the relatively low lake level maintained at that time.

ANOTHER INTENSE STORM occurred in December 1968 during a period of
high lake levels. Damage from the storm included losses of up to
50 feet of shoreline at some locations'along Ontonagon County.

DAMAGE FROM HIGH LAKE LEVELS occurred in the period from 1950
through 1952. During one 12-month interval erosion caused losses
of up to 50 feet in depth from lots, many of which contained houses
and cabins. About 100 homes and cabins along the Ontonagon County
shoreline were destroyed or had to be moved.

THE EXTENT OF EROSION BY THE YEAR 2020 has been projected for the
Ontonagon County shoreline along Lake Superior. The projected 2020
shoreline outline was determined from an analysis of past erosion
occurrences along Lake Superior which were caused by intense storms,
high lake levels, or a combination of the two events. The analysis
shows that losses due to erosion may be as much as 150 feet of
shoreline within the next 50 years.

SEASONAL VARIATIONS in lake levels occur each year. Normally, the
highest levels are experienced in August or September; however,
localized storms may cause high levels of short duration any time
during the year.

PAST FLOODS

This section of the report is a history of floods on the
Ontonagon River in the vicinity of Ontonagon, Michigan. The Village
of Ontonagon is located in Ontonagon County, along the south shore
of Lake Superior at the mouth of the Ontonagon River. The portion
of the Ontonagon River studied extends from the mouth upstream 3.5
river miles to the S-curve approximately 0.7 miles south of the
Ontonagon Village limits. River mileage is measured from the outer
end of the west pier at the Ontonagon Harbor where the drainage basin
area is 1,390 square miles. There are no tributaries of significance
within the study reach of the Ontonagon River; however, there are
four main branches above Rockland, Michigan.
The U. S. Geological Survey has not maintained flow records at
Ontonagon due to poor stage-discharge relationships caused by lake
stage and ice conditions. A stream gaging station has been in op-
eration on the Ontonagon River at Rockland, Michigan, since June 1942.
Data from Rockland has been reviewed and applied in the absence of

a station at Ontonagon.
Searches of flood history have developed information on the
Ontonagon River and the area in and near the Village of Ontonagon.
The earliest known flood occurred in 1912, although no details are
available relative to stage and discharge. Other floods are dis-
cussed in detail later in this report.

ONTONAGON RIVER

Settlemenl-
The earliest settlers in the Ontonagon area were fur traders.
In the French regime of 1634 to 1759, through the time of British
control from 1759 to 1814, and up to 1840 under American rule, fur

trading was the major factor influencing settling efforts. By 1880,
fur trading had ended and was replaced by copper and silver mining.
Copper mining started in 1845 and experienced a "boom" period
until 1870. Ontonagon County population grew from 380 to 5,400
during this period. A photograph showing the development in Ontonagon
in about 1865 is shown as Figure 2. After the big boom period, cop-
per mining was carried on by individuals and reorganized companies
until 1918 when most of the settlements closed. In 1950 the White
Pine Copper Company began development of a new mine at White Pine.
In 1966 the operations expanded to provide employment for over 1,600
people.

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Figure 2. ONTONAGON IN ABOUT 1865

Silver was mined in the period from 1873 to 1876. Although
silver mining was never profitable, it was a contributing factor
to population growth.

Lumbering played an important part in the economic develop-
ment of the area. From 1880 to 1900, pine was extensively har-
vested. After the pine era, hardwood and hemlock were cut. Some
was sawed into lumber locally but much of it was shipped to other
mills by rail.
When activity in copper mining declined due to price of cop-
per and cost of mining, and when the forests were worked out, farm-
ing became a means of livelihood.
The economy of Ontonagon today is based on tourism, farming,
and industry and supports a village population of 2,360 (1970 POP-
ulation). Ontonagon County reports a total population of 10,335.
'Major industries in the area include manufacture of paperboard and
the mining and refining of copper.

Flood Damage Prevention Measures
In accordance with Section 205 of the 1948 Flood Control Act,
as amended, a reconnaissance investigation was conducted and a brief
report prepared for the Village of Ontonagon in 1963. Two plans of
local protection were studied. Plan I included a levee about 4,000
feet long located on the right bank starting just upstream of the
Chicago, Milwaukee, St. Paul, and Pacific (C.M.St.P.&P.) Railroad
Bridge with the necessary closure structure and interior drainage
facilities. Plan 2 consisted of a continuous levee on the right
bank similar to Plan I and, in addition, would provide a 300-foot
wide diversion channel extending from a point upstream of the
C.M.St.P.&P. Railroad Bridge to Lake Superior, a distance of about
6,000 feet. The diversion channel would provide direct access to
the lake for by-passing excessive flows or to provide relief from
high stages caused by ice jams at bridges or in the harbor entrance.
Both plans were designed to provide protection against the 100-year

flood, but neither plan was economically feasible based on a bene-
fit cost analysis and construction was not recommended.

Flood Warning and Forecastin2 Services
The Ontonagon River basin does not lie within an area served by
Environmental Science Services Administration (ESSA) river forecast
centers and therefore no official river stage predictions are made.
However, as high discharges are experienced at upstream locations
the information is made available to Ontonagon and unofficial pre-
dictions of impending flood stages are made by local village of-

ficials.

The Stream and Its Valley
The Ontonagon River drains 1,390 square miles of a relatively
rough, wooded, and sparsely populated area of northwest Michigan
and northeast Wisconsin. Most of the drainage area consists of
well defined valleys, but near Lake Superior the river meanders
through a broad, gently sloping plain. The upper basin is bowl
shaped with four tributaries: the East Branch,Ontonagon River,
Middle Branch Ontonagon River, South Branch Ontonagon River, and
West Branch Ontonagon River. Plate I shows the watershed and
stream drainage system for the Ontonagon River.
The total fall in the Ontonagon River from its headwaters to
the mouth at Lake Superior is approximately 1,100 feet. The av-
erage gradient is 2.2 feet per mile in the lower reach from Rock-
land to the mouth. In the upper reaches, the tributaries flow
through various lakes but, in general, the gradient is relatively
steep. Lake Gogebic is the largest inland lake in the basin cov-
ering an area of over 20 square miles. The outlet of Lake Gogebic
is the West Branch of the Ontonagon River, which together with the
South Branch flow into the impounded waters of the Vicoria Hydro-
Electric Power Dam operated by the Upper Peninsula Power Company.
Drainage areas in the Ontonagon River basin are shown in Table 2.

TABLE 2

DRAINAGE AREAS IN WATERSHED OF ONTONAGON RIVER

Drainage
Stream Location Area
Sq. Mi.
Ontonagon River Ontonagon 1,390
Ontonagon River Near Rockland 1,340
Ontonagon River, Cisco Lake
Cisco Branch Outlet 51

Ontonagon River,
East Branch Near Mass 272

Ontonagon River,
Middle Branch Near Paulding 190
Ontonagon River,
Middle Branch Near Rockland 671
Ontonagon River, Near Trout
Middle Branch Creek 203

Ontonagon River,
South Branch Near Even 348

Ontonagon River,
West Branch Near Bergland 162

The Ontonagon River passes through the coastal plain in a wide
valley which extends nearly 5 miles inland from the mouth of the
river. Width of the flood plain varies from 1,000 feet near River-
side Cemetery to 6,500 feet at the upper study limits. Areas inun-
dated by a severe flood such as the Standard Project Flood would

extend to substantial distances within the commercial and residen-

tial areas of Ontonagon.

Developments in the Flood Plain
Plate 8 is an index map of the three sheets that show the
flooded areas of the Ontonagon River during the Intermediate Re-
gional and Standard Project Floods. Plates 9 through 11 show the

flood plain of the Ontonagon River for the reach covered by this

report.
Some new commercial areas are being and have been established
within the flood plain in Ontonagon. Some well established resi-
dential, commercial, and industrial areas within the village limits
also fall within the flood plain limits. Upstream from the urban
development of Ontonagon, most of the flood plain is devoted to
forestry or agricultural purposes.
The C.M.St.P.&P. Railroad serves Ontonagon from the southeast.
Portions of the main line and spur tracks within the village limits
are in the flood plain of the Ontonagon River.
U. S. Highway 45, which connects Ontonagon with Rockland to the
southeast, is located out of the flood plain of the Ontonagon River.
Michigan State Highway 64 is the only connection between Ontonagon
and the Lake Superior shoreline to the west. Portions of this route
have been inundated by past floods and would be subject to even
greater flooding during the Intermediate Regional and Standard Proj-
ect Floods.

Several structures in the flood plain of the Ontonagon River
have been damaged by past floods and the potential for furtfler dam-
age is considerably greater. The Standard Project Flood would cause
considerable damage to many additional buildings including resi-
dences, commercial establishments, industrial operations, and bridges.

Bridges Across the Stream
Within the reach covered by this study, there are two bridges
across the Ontonagon River. Table 3 lists pertinent elevations for
the structures and shows their relation to the crest of the flood
of April 1, 1963, and the Intermediate Regional Flood. Figure 3
shows photographs of these bridges.
Michigan State Highway 64 crosses the river at Mile 0.66 with
a 309-foot long bridge. There is a draw span over the main channel

TABLE 3

BRIDGES ACROSS ONTONAGON RIVER

Intermediate April
Regional 1963 Low Ste
Miles Stream Flood Flood Above
Above Bed Floor Crest Crest 1963
Mouth I dent if i cation Elev. Elev. Elev. Elev. Elev. Flood
-Te-et Teet feet feet feet feet

0.66 State Highway 64 579.5 613.1 607.9 606.9 607.9 1.0

1.08 C.M.St.P.&P.RR 583.o 612.0 607.9 606.9 607.2 0.3

NOTE: Flood crests do not include ice cover.

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Figure 3. ONTONAGON RIVER BRIDGES
Upper view is upstream side of State Highway 64 Bridge over the
Ontonagon River at Mile 0.66. Lower view is upstream side of
C.M.St.P.&P. Railroad Bridge over the Ontonagon River at Mile 1.08.

with horizontal clearance of 30.5 feet for the east opening and 31.5
feet for the west opening. The end spans are fixed with a clear
height of 7.8 feet above low water datum. Both approaches to the
bridge are low and would be inundated by the Intermediate Regional
and Standard Project Floods as they were in April 1963.
About 2,200 feet above the highway bridge, a C.M.St.P.&P. Rail-
road Bridge crosses the Ontonagon River. This bridge has two spans
over the main channel which are 108 feet and 100 feet in length with
a 9.4-foot clear height above low water datum. There is no draw
span in this bridge which has a total length of 554 feet. During
the Intermediate Regional and Standard Project Floods water would be
above the low steel of the end spans.

Obstructions to Flood Flow
Obstructions to flood flow are mainly due to the two bridges
discussed previously. During periods of spring snow and ice melt,
ice tends to pile up behind the bridges seriously affecting the dis-
charge capacity of the river. As the ice breaks up in Lake Superior
the problem becomes more intense. "Windrows" of ice, running par-
allel to the shoreline, are formed which choke off the normal re-
lease of river water to the lake. This situation has been charac-
teristic of all of the spring floods on record.

FLOOD SITUATION

Flood Records
No records of river stages are maintained at Ontonagon due to
a poor stage-discharge relationship caused by lake stage and ice
conditions. A stream gaging station upstream from Ontonagon at
Rockland, Michigan, has been in operation since June 1942. Records
from this station have been used in the absence of data at Ontonagon.
To supplement the records obtained at Rockland, local resi-
dents were interviewed for information on dates and heights of past
floods. Newspaper files, historical documents, and records were
searched, and reports of field investigations concerning floods
were reviewed. This information has been used to develop a history
of floods in the Ontonagon area covering the past 60 years.

Flood Stages and Discharges
Table 4 lists the maximum annual discharge and the associated
high water stage for the Ontonagon River at Rockland. Maximum
annual stages caused by ice jams are also reported when they ex-
ceed the stage which occurred during maximum discharge.
The greatest known flood in the Village of Ontonagon occurred
on April 1, 1963. Ice floes from the river combined with windrowed
lake ice to create ice jams at the mouth of the Ontonagon River
and at the State Highway 64 and C.M.St.P.&P. Railroad Bridges.
Elevations of 1963 high water marks in Ontonagon have been deter-
mined and are presented on the profile drawing (Plate 12).

TABLE 4

ONTONAGON RIVER NEAR ROCKLAND, MICHIGAN

MAXIMUM ANNUAL DISCHARGES AND STAGES
1942 - 1967

The table includes maximum annual discharge and stage data for
the Ontonagon River near Rockland, Michigan. Drainage area = 1,340
square miles. Datum of gage = 637.12 feet, IGLD.

Maximum Discharge Maximum Crest
Year During Year Date Stage Elevation
cfs feet feet
1942 42,000 Aug. 22, 1942 28.6o 665-72
1943 12,600 May 6, 1943 15-70 652.82
Max. stage due to ice jam Apr. 2, 1943 20.00 657-12
1944 12,600 Jun. 5, 1944 15.69 652.81
1945 12,800 May 22, 1945 15.80 652.92
Max. stage due to ice jam Mar. 16, 1945 16-30 653.42
1946 17,6oo Jun. 24, 1946 18.48 655.60
1947 No Record Apr. 6, 1947 20.84 657.96
1948 6MO Apr. 11, 1948 11.85 648-97
Max. stage due to ice jam Mar. 26, 1948 13-11 650.23
1949 17,900 Jul. 6, 1949 18-52 655.64
1950 14,700 May 6, 1950 16-73 653.85
Max. stage due to ice jam Apr. 17, 1950 20.11 657.23
1951 16,5oo Jun. 24, 19-531 17-72 654.84
1952 18,4oo Apr. 19, 1952 18-78 655-90
1953 19,500 Aug. 4, 1953 19-38 656-50
1954 16,300 Apr. 26,1954 17.65 654-77
1955 14,300 Sep. 17, 1955 16-50 653.62
Max. stage due to ice jam Apr. 2, 1955 18-05 655-17

TABLE 4 (Continued)

Maximum Discharge Maximum Crest
Year During Year Date Stage Elevation
cfs feet -7e-et
1956 12,000 Apr. 4, 1956 No Record
1957 14,300 Apr. 20, 1957 16.48 653-60
1958 9,46o Apr. 14, 1958 13-56 650.68
1959 8,830 Apr. 8, 1959 13-14 65o.26
1960 22,400 Apr. 24, 1960 20.82 657.94
1961 11,800 Mar. 28, 1961 14.8o 651-92
Max. stage due to ice jam Mar. 27, 1961 19.48 656.60
1962 7,520 May 2, 1962 12.11 649.23
Max. stage due to ice jam Mar. 29, 1962 13.87 650-99
1963 17,700 Apr. 1, 1963 17.49 654.61
Max. stage due to ice jam Mar. 30, 1963 18.81 655-93
1964 18,500 Apr. 13, 1964 17-74 654.86
1965 13,300 May 9, 1965 15-07 652.19
Max. stage due to ice jam Apr. 11, 1965 21.01 658.13
1966 17,800 Mar. 18, 1966 16-97 654.09
Max. stage due to ice jam Mar. 16, 1966 20.68 657.80
1967 17,600 Mar. 31@ 1967 16.90 654.02
Max. stage due to ice jam Mar. 31, 1967 18.66 655-78
1968 15,400 Mar. 19, 1968 15-97 653-09

The largest known discharge on the Ontonagon River at Ontonagon
occurred on August 22, 1942. While flooding was experienced dur-
ing this period of high flow, it was not as severe as the 1963
flood. During the 1942 flood, the discharge at Ontonagon was not
gaged; however, at Rockland the peak flow was 42,000 cfs.

Flood Occurrences
In addition to the previously mentioned floods of 1942 and
1963, other known floods occurred in Ontonagon in 1912, 1922, and
1923. Few details relative to stage and discharge are available
for these high water periods.
Since floods in Ontonagon occur as a result of high river dis-
charges, heavy ice jams, or a combination of the two conditions,
the frequency of flooding is somewhat irregular. Discharges in ex-
cess of the maximum flow of April 1, 1963, have occurred at least
six times during ihe 25 years of record at Rockland. Nevertheless,
none of these periods of high discharge has resulted in a stage as
high as the 1963 Ontonagon flood. This emphasizes the influence
of ice jams on flooding on the Ontonagon River.
As far as river discharges alone are concerned, the potential
for periodic flooding is evident. However, more frequent major
flooding occurs as a result of a combination of only moderately
high discharges and heavy ice jams.

Duration and Rate of Rise
Flood duration in Ontonagon is dependent primarily on the
severity of ice jams near the mouth of the river. There are no
recorded gage heights in Ontonagon from which to measure the rise
and duration of river stages. However, flood descriptions found
in newspaper files have been used to approximate these values for
some of the major floods.
A newspaper account of the April 1963 flood states that in an
18-hour period flood waters rose approximately 5 feet. Flood con-
ditions lasted 24 hours until the ice jam finally broke,,.,-. resulting
in a rapid fall of the water level.
An account of the flood of April 1923 tells that in approxi-
mately 10 hours the river rose from near bankfull to flood the en-
tire lower portion of the village. The newspaper article further

indicates that the flood duration was short. Basically, the flood
was composed of a rapid rise in river stage followed by an extremely
rapid fall when the ice jam broke.

Velocities
During the April 1963 flood, the velocity was quite low as
the flood was caused by large ice jams. In effect, the ice jams
acted as a dam, and the flood waters were relatively quiet except
at the time of release. Floods caused by high river discharge
alone, such as occurred in August 1942, would have been charac-
terized by much higher velocities.

Flooded Areas, Flood Profiles, and Cross Sections
Plates 9 through 11 show the approximate areas along the
Ontonagon River in the vicinity of Ontonagon that would be inun-
dated by the Intermediate Regional and Standard Project Floods.
The actual confines of these overflow areas on the ground may vary
somewhat from those shown on the maps within the limits of the
contour interval and scale of the maps used for presentation.
Some isolated locations shown within the flood outline may actually
be above the flood crest because of elevated foundations and em-

bankments.

Plate 12 shows the high water profile in the vicinity of
Ontonagon for the flood of April 1963. Also shown are the profiles
for the Intermediate Regional Flood and the Standard Project Flood
discussed later in this report.
Plate 13 includes the eight cross sections and two bridge
sketches obtained for the Ontonagon River in the reach studied.
The locations of all sections are shown on Plates 9 through 11. The
elevation and extent of overflow of the Intermediate Regional and
Standard Project Floods are indicated on the sections.

FLOOD DESCRIPTIONS

Following are descriptions of known large floods that have
occurred on the Ontonagon River in the vicinity of the Village of
Ontonagon. These are based on newspaper accounts, historical re-
cords, and field investigations.
April 4, 1912
A serious flood occurred in Ontonagon in April 1912 as a re-
sult of huge ice windrows which formed along the Lake Superior
shoreline. The windrows, which were estimated to be 60 feet high,
sealed off the mouth of the Ontonagon River, causing the flooding.
Few details are available regarding the stage and discharge
during the 1912 flood. Photographs showing the cause and effect of
the flood are presented on Figure 4.
May 1922
Photographs have been obtained which show flood conditions in
Ontonagon in May 1922. No other records pertaining to this flood
have been discovered. Three of the photographs are included as
Figure 5.
A2ril 20, 1923
The flood of April 1923 was caused by spring snow melt and
large ice jams at the mouth of the Ontonagon River. A photograph
of River Street during this flood is shown on Figure 6.

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Figure 4. FLOOD SCENES IN ONTONAGON APRIL 1912
Top view was taken near the mouth of the Ontonagon River where
winds from Lake Superior had caused windrows estimated to be 60
feet in height. The windrows sealed off the mouth of the Ontonagon
River causing the flood of 1912. Lower view is looking along
River Street in Ontonagon during the April 1912 flood.

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Figure 5. FLOOD SCENES IN ONTONAGON MAY 1922
These photographs which were taken in the downtown portion of
Ontonagon show the severity of the May 1922 flood.

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Figure 6. FLOOD SCENE IN ONTONAGON APRIL 1923
This view shows a horse drawn wagon coming down River Street dur-
ing the 1923 flood.

Below is an excerpt from a newspaper account of the 1923 flood.

THE ONTONAGON HERALD
Saturday, Apri 1 28, 1923
LAST FRIDAY'S FLOOD WORST IN MANY YEARS

"The main street from the Board of Trade Cafe to the Citizens
State Bank, as well as several whole blocks, was submerged under
about eithteen inches of water last Friday afternoon (April 20)
when the ice jams at the State bridge and between the piers caused
the water in the Ontonagon River to overflow its banks.
"The melting snow in the woods for miles back caused an un-
usually large amount of water to run to the river, and with the ice
at the mouth of the river, it was impossible for the water to es-
cape, the result being that the lower sections of the town were

flooded.

''The water began to raise very rapidly early in the morning
and by noon it had reached an alarming height. By two o'clock the
lower portions of the town were entirely covered with water. At
three-thirty the water had reached its height, and had also washed
a channel through the ice flows and began to recede. There were at
least ten or eleven village blocks entirely under water. The
majority of the floors of the stores in the blocks between the

Board of Trade Cafe and the Citizens State Bank were flooded to a

depth of from half an inch to seven or eight inches.
''On the opposite or lower side of the street, all basements
were flooded to a depth of nearly two feet."
"There is no possible way of estimating the damage and prop-
erty loss, but it will run into many dollars."

August 22, 1942
The largest recorded flood resulting from rainfall occurred in
August 1942. High water elevations from this flood rank second
only to the April 1963 flood of record. Some photographs taken
during the 1942 flood are included as Figure 7.

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Figure 7. FLOOD SCENES IN ONTONAGON AUGUST 1942
Upper left view shows damaged U. S. Highway 45 1.5 miles north of
Bruce Crossing, Michigan. The stream is the Mile and One-half
Creek, a tributary of the Ontonagon River. Upper right view shows
flood conditions at the Military Bridge (U. S. Highway 45) over
the Ontonagon River two miles south of Rockland, Michigan. Lower
view is looking southwest from Stubb's Museum in Ontonagon.

The following is an excerpt from a newspaper account of the
1942 flood at Ontonagon.

THE ONTONAGON HERALD
Saturday, August 29, 1942
WEEKEND FLOOD DAMAGES BRIDGE AT ONTONAGON; VICTORIA BRIDGE OUT

"Not in the memory of the oldest residents of Ontonagon has
there been such a rain.storm as that which occurred last Friday
evening and Saturday.morning. Stories of the damage having been
done came to note early Saturday morning.
''The driftwood coming down the Ontonagon River piled up
against the abutments at the large cement bridge at the Ontonagon
River in Ontonagon, and before noon the matter became serious. The
logs, trees, and other debris was so thick that two channels were
completely blocked and the tremendous amount of water passing
through the west channel undermined the west pier so that the west
third of the bridge settled gradually until on Sunday it was down
about twenty-four inches.'
"Cars were stopped for a time, for fear that the bridge would
go out, but after a while a few cars were allowed to pass. After
the danger of the bridge drifing,away lessened, an approach was
made from the settled part of the swing part and traffic was again

s ta rted.

THREE MEN DROWNED WHEN HOUSE IS CARRIED AWAY
BY FLOOD WATERS LAST FRIDAY---

''George Dent, age 79 years, Tommy Mason, age 31 and Joseph
Paul Garsanki, age 53, lost their lives in the flood which took
place throughout the north end of Ontonagon County last Friday
night, August 21.

''The flood waters came down the valley (estimated at 10 to 12
feet deep) and swept the house, which was at the side of the creek,
downstream, with all three men asleep. The house, a structure at
least 39 x 36 feet with a lean-to 14 x 18 feet, was carried down-
stream. It struck the Deer Creek Bridge and set the roof of the
building on the bridge and cracked the balance of the house, with
all funiture, to bits. The bodies of the three men were missing
when searching parties went to find them.''

April 1, 1963
The worst flood in Ontonagon history occurred in the spring of
1963. The flood resulted from heavy runoff of melting snow com-
bined with thick ice conditions on Lake Superior. Figures 8
through 14 show the severity of the April 1963 flood of record.
The following excerpts from newspaper accounts indicate the
magnitude of the 1963 flood.

THE DAILY MINING GAZETTE
Houghton, Michigan
Tuesday, April 2, 1963
ONTONAGON SLOWLY APPROACHING NORMAL AS WATERS RECEDE

"The rampaging Ontonagon River was nearly back to its normal
condition during spring thaws this morning as flood waters slipped

back into the river bed after ice blocks had been removed.

"A large crane, the property of the Ontonagon-Huss Paper
Co., had been employed consistently through the day on Monday
removing ice barriers. Along with other volunteer help the water
was finally encouraged to move through ice openings, slowly working
its way to Lake Superior as the ice chunks also plummented for-
ward on their way out."
"The M-64 highway proceeding southerly and westerly from
Ontonagon again was back in use this morning. It was the washed-
out stretch near the Huss mill which caused concern. The highway
bridge's protective piling had been washed into Lake Superior
because of the strong river currents."

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Figure 8. FLOOD SCENES IN ONTONAGON APRIL 1963
Top view is an aerial photograph looking south at the flooded
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Ontonagon River. Note the massive ice jam at State Highway 64
near the center of the photograph. Lower view is looking south-
east along River Street in Ontonagon.

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Figure 9. FLOOD SCENES IN ONTONAGON APRIL 1963
These photographs show the intensity of the ice jam upstream
from State Highway 64 during the April 1963 flood.

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Figure 10. FLOOD SCENES IN ONTONAGON APRIL 1963
These photographs show the extent of the 1963 flood at Riverside
Marine near the east end of the State Highway 64 Bridge.

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Figure 11. FLOOD SCENES IN ONTONAGON APRIL 1963
Upper view shows flood conditions at the residences of Spencer
Ross and Keith Roehm on the "island." Lower view was taken from
State Highway 64 looking toward the Hoerner Waldorf Paper Mill
on the west side of the Ontonagon River.

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Figure 12. FLOOD SCENES IN ONTONAGON APRIL 1963
Upper view shows flooded conditions around the Ontonagon Rail road
Depot. Lower view indicates flooding at a residence in Ontonagon.

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4W
7

..snow

Figure 13. FLOOD SCENES IN ONTONAGON APRIL 1963
These photographs were taken on April 1, 1963, looking northwest
along River Street in Ontonagon.

EAR

Figure 14. FLOOD SCENES IN ONTONAGON APRIL 1963
Top view is looking northwest along the flooded River Street in
Ontonagon. Lower view also shown flooded condition in the com-
mercial area of Ontonagon.
T

THE ONTONAGON HERALD
Thursday, April 4, 1963
ONTONAGON RIVER FLOODS THE ISLAND SUNDAY NIGHT;
CENTER OF TOWN MONDAY

"The Ontonagon River went on a rampage Sunday night and Monday
and caused the worst flood in the village's history. Sunday night
icy waters from the river flowed over the entire Island between the
Ontonagon River and the slough and by Monday noon the center of the
village was completely flooded to a depth of from two to three feet.
"The Village is now attempting to get back to normal after the
water receded early Tuesday morning and found its way out into Lake
Superior despite the two mile ice jam which still held in the lake.
A conservative estimate of the damage has been unofficially placed
at a half million or more.
"Some businesses took the precautions when Sunday's unseasonably
warm temperatures of 72 degrees caused a heavy runoff of melting
snow through the entire area while the thick ice was solid in Lake
Superior."
"Monday morning at 11:30 the first heavy flow of ice came down
the Ontonagon River and jammed heavily at the railroad bridge. The
water then by-passed the bridge on both sides, causing floods in
both the east and west sloughs. Water in the west slough crossed
M-64 just past the highway bridge putting the road under two feet
of water and making a washout four feet wide. This was filled and
the road made passable Tuesday morning after the water receded.
The River Road and 'Cash farm' were also flooded.

"From the east slough the water swiftly rose, crossed the rail-
road tracks and quickly flooded the section from Wagar's Apparel
to the Gamble Store and back past the County Garage, averaging at
least two feet deep. Sunday night and Monday the area of the
Hawley Lumber Yards were also flooded to US-45.

"Hard hit also was the 'Penegor Flats' at the end of Trap
Street. Swirling water in this area dug huge chunks of the lake-
shore bank and endangered the flats from being undermined. These
four families were evacuated. Two cars parked there were up to
the door handles in water and ice.

"The water line under the railroad bridge, serving the west
side of the village was broken during the flood leaving those
residents and the Hoerner Boxes, Inc., without water.
"This was the first flood to strike Ontonagon in 40 years.
The last one was in the spring of 1923 and the old timers say that
although it was a bad one, this one was much worse."

THE ONTONAGON HERALD
Thursday, April 11, 1963
VILLAGE WORKING WAY OUT OF WORST FLOOD

"All floods are caused by obstructions. The water cannot be
carried away by the channel and it overflows its banks causing a

flood as occurred here last week.
"The Ontonagon River has leaped its banks on several occa-
sions, causing property damage along the main street of the village.
All local flooding is the result of ice blocking the river chan-
nel proper or the outlet at the mouth. On one occasion in the past
a huge iceberg was lodged at the mouth of the river as a result of
gale winds forcing the water in big waves that carried the ice-
berg along with it."
"The April 1, 1963, flood was the most destructive up to this
time. There was considerable property damage along the banks of
the river. Boat houses were demolished and the watercraft housed
within them. Small boats were wrecked by the ice and piled high
on adjoining land or washed out into Lake Superior. Nets of com-
mercial fishermen were soaked and caked with mud. They all had

to be rewound on reels.

''The current surge of flooding water was the result of rapidly
melting snow and unusually high March temperatures. The water
damage was very high on the north side of the Ontonagon River where
it went over the island, and where it flooded the buildings on the
south property of River Street . . . . Also greatly damaged was
that area bounded by Copper and Spar Streets going from east to
west and from Brass Street and the C.M.St.P.&P. RR Depot north to
and across Conglomerate Street."
"Water raised fast when it came; there was no time to move

or shift stock in the stores.

"The water varied from three to four feet in depth and soaked
the entire area and mercantile stock in its path. As the flood
waters receded, a thick coat of red silt and in some places oily
substances were deposited over everything the water encompassed.
"Accurate losses may never be determined. One thing is cer-
tain, all property in the submerged area suffered tremendous dam-
age and loss. Business was at a standstill. The cleanup pro-
cesses are slow and are under the direction of the State Pure Food
Inspectors. Truckloads of food and other merchandise have been
taken to the village dump. Precautions were taken to prevent
epidemic of sickness and spread of disease."

FUTURE FLOODS

This section is a discussion of Standard Project Floods,
Intermediate Regional Floods, and some of the hazards involved on
the Ontonagon River in the vicinity of Ontonagon, Michigan. The
Standard Project Flood represents a reasonable upper li,mit of ex-
pected flooding. The Intermediate Regional Flood represents floods
that may reasonably be expected to occur more frequently, on the
average of once every 100 years. Large floods have been ex-
perienced in the past on streams in the general vicinity of
Ontonagon. Heavy storms or spring runoff similar to those causing
floods on other streams in the region could occur over the Ontonagon
River watershed. In this event, floods would result comparable in
size with those experienced on neighboring streams. In addition,
ice jams which frequently occur on the Ontonagon River during spring
runoff could cause even larger floods at Ontonagon. It is, there-
fore, desirable in connection with any determination of future
floods which may occur on the Ontonagon River to consider storms
and floods that have occurred in the region on watersheds with sim-
ilar topography, watershed cover, and physical characteristics.

DETERMINATION OF INTERMEDIATE REGIONAL FLOODS

The Intermediate Regional Flood is defined as having an av-
erage frequency of occurrence in the order of once in 100 years
at a designated location. The flood may occur in any year. Some
probability estimates are based on statistical analyses of stream
flow records for the watershed under study, but limitations in
such records require analyses of rainfall and runoff characteristics
in the "general region" of the area of study. The Intermediate
Regional Flood represents a major flood, although it is much less
severe than the Standard Project Flood.

The Intermediate Regional Flood for the Ontonagon River in the
vicinity of Ontonagon is based on a statistical analysis of the 25
years of records obtained at the U. S. Geological Survey gage near
Rockland, Michigan. Transposition of this data to Ontonagon was
made with consideration of the drainage area difference between
the two locations. Also considered were past flood stages at
Ontonagon and the effect of ice jams and Lake Superior levels.
Table 5 lists the maximum known floods that have occurred on water-
sheds which are comparable with the Ontonagon River, and are within
the same geographical region.
The Intermediate Regional Flood represents a peak discharge of
38,000 cfs on the Ontonagon River at Ontonagon. This flood could
be caused by snowmelt, heavy rains, or a combination of the two.
Intermediate Regional Floods on the Ontonagon River in the reach
investigated would be approximately 0.5 feet higher than the April
1963 flood of record within the village limits of Ontonagon.

DETERMINATION OF STANDARD PROJECT FLOODS

Only in rare instances has a specific stream experienced the
largest flood that is likely to occur. Severe as the maximum known
flood has been on any given stream, it is a commonly accepted fact
that in practically all cases a larger flood can and probably will
occur at some time in the future. A Standard Project Flood for
the Ontonagon River at Ontonagon has been estimated at a level 1.0
feet above the Intermediate Regional Flood crest. This method of
estimating the Standard Project Flood stage appears to be more
practicable than attempting to calculate a flood level from a
theoretical discharge because of ice jams which frequently occur
near the mouth of the Ontonagon River. Also, sufficient data was
not available to establish an open water rating curve at Ontonagon.

TABLE 5

MAXIMUM KNOWN FLOOD DISCHARGES ON
STREAMS IN THE REGION OF ONTONAGON, MICHIGAN

Drainage
Stream Location Area Date
Sq. Mi.

Flambeau River Near Bruce, Wisc. 1,897 May 1, 1954
Menominee River Near Florence, Wisc. 1,78o Apr. 26, 19
Chippewa River Near Bruce, Wisc. 1,630 Sept. 1, 19
Ontonagon River Near Rockland, Mich. 1,340 Aug. 22, 19
Flambeau River At Babbs Island near Winter, Wisc. 1 '000 June 25, 19
Wisconsin River At Rainbow Lake near Tomahawk, Wisc. 750 Sept. 5, 19
Sturgeon River Near Arnheim, Mich. 705 Apr. 20, 19
Bad River Near Odanah, Wisc. 611 Apr. 24, 19
South Branch Ontonagon River At Ewen, Mich. 348 Apr. 24, 19
Sturgeon River Near Alston, Mich. 346 Apr. 24, 19
East Branch Ontonagon River Near Mass, Mich. 272 July 1, 195
White River Near Ashland, Wisc. 269 July 1, 195
Montreal River Near Saxon, Wisc. 262 Apr. 24, 19
Presque Isle River Near Tula, Mich. 261 Apr. 25, 19
Middle Branch Ontonagon River Near Trout Creek, Mich. 203 Nov. 7, 195
Black River Near Bessemer, Mich. 200 Apr. 24, 19
Presque Isle River At Marenisco, Mich. 171 Apr. 25, 19
Sturgeon River Near Sidnaw, Mich. 171 Apr. 24, 19
Middle Branch Ontonagon River Near Paulding, Mich. 164 Apr. 30, 19
West Branch Ontonagon River Near Bergland, Mich. 162 Apr. 26, 19
Otter River Near Elo, Mich. 162 Apr. 19, 19
Iron River At Caspian, Mich. 92.1 July 2, 195
Cisco Branch Ontonagon River At Cisco Lake Outlet, Mich. 50.7 May 1-4, 19

am am WIM a IN Um n a a a a

Frequency
It is not practicable to assign a frequency to the Standard
Project Flood. The occurrence of such a flood would be a rare
event; however, it could occur in any year.

Possible Larger Floods
Floods larger than the Standard Project Flood are possible;
however, the combination of factors that would be necessary to
produce such floods rarely occur. The consideration of floods of
this magnitude is of greater importance in some problems than in
others, but should not be overlooked in the study of any problem.

HAZARDS OF GREAT FLOODS

The amount and extent of damage caused by any flood depends, in
general, upon the extent of area flooded, height of flooding, velocity
of flow, rate of rise, and duration of flooding.

Areas Flooded and Heights of Flooding
The areas along the Ontonagon River flooded by the Standard Proj-
ect Flood and the Intermediate Regional Flood are shown on Plates
9 through 11. An index for these maps is presented on Plate 8.
Depth of flow at a particluar point can be estimated from the crest
profiles which are shown on Plate 12.
The Intermediate Regional Flood profile for the Ontonagon River
was computed using stream characteristics for selected regions as
determined from observed flood profiles, topographic maps, and val-
ley cross sections from a recent survey by the Corps of Engineers.
Clogging of the bridges and harbor by ice jams has also been con-
sidered. Plate 13 presents the eight cross sections and two bridge
sketches used in this study. The Standard Project Flood profile
is estimated to be 1.0 foot higher than the Intermediate Regional
Flood. The elevation of both these floods is shown on the cross

sections of Plate 11. The elevations shown on Plates 12 and 13

and the overflow areas shown on Plates 9 through 11 have been deter-
mined with an accuracy consistent with the purposes of the study
and the accuracy of the basic data.
The Intermediate Regional Flood profile for the Ontonagon
River averages 0.5 feet higher than the April 1963 flood. The
Standard Project Flood would be 1.5 feet higher than the 1963 flood.
Figures 15 through 26 on the following pages show the heights
that would be reached by the Standard Project and Intermediate
Regional Floods on facilities presently existing within the flood
plain in the vicinity of Ontonagon. Elevations of the flood of re-

cord are also shown.

Velocities, Rate of Rise, and Duration
Water velocities during floods caused by high discharge de-
pend largely upon the size and shape of the cross section, the
condition of the stream, and the bed slope, all of which vary on
different streams and at different locations on the same streams.
During floods which result from ice jams the velocity would not be
significant except at the time of release.
Duration and rate of rise are difficult to predict for rivers
subject to ice jams. At Ontonagon, the rate of rise would be rapid
once the river outlet became plugged. The duration of the Inter-
mediate Regional and Standard Project Floods would be dependent on
the severity of the ice jam and the effectiveness of ice clearing
techniques.

ONE- U,
INI '@i IN pN
OEM -
t,311'

:01

ONTONAGON, MICHIGAN

STD PRQJ
1963 FLOOD INT: F 00

Figure 15. -- FLOOD HEIGHTS AT HOERNER WALDORF PAPER MILL
During the April 1963 flood the Hoerner Waldorf Mill was forced to
shut down because of damage caused by flood waters on the Ontonagon
River. Higher levels may be expected during the Standard Project
and Intermediate Regional Floods as shown on the photographs.

--------------- -

STD. PROJ. FLOOD11-
I KV.-R UG .L CD1
1963 FLOOD r - -

Figure 16. FLOOD HEIGHTS AT NEW MARINA
High water levels which may be expected during the Standard Project
and Intermediate Regional Floods at the new marina which is under
construction al ong the west bank of the Ontonagon River are shown
'T

above.

ASTD. PRO.J. FLOOD
INT. REG. FLOW

Figure 17. FLOOD HEIGHTS ALONG EAST SIDE SLOUGH
This residential area located near the east side slough was flooded
to the depth shown on the photograph in April 1963. Future floods
are expected to go even higher as shown by the Standard Project
Flood and Intermediate Regional Flood arrows.

STD. PROJ. FLOOD'
INT. REG. FLO 19 OD

Figure 18. FLOOD HEIGHTS AT ONTONAGON COUNTY ROAD COMMISSION GARAGE
Flood waters covered the,floor of this building located along Trap
Street during the April 1963 flood. Levels which may be expected
during the Intermediate Regional Flood and Standard Project Flood
are shown on the staff gage.

. . .. ......

STD. PROJ. FLOOD
I NT. - R EG-. F -OOD
I
1963 FLOOD

Figure 19. FLOOD HEIGHTS AT CITIZENS STATE BANK
Projected future flood levels and the level experienced during the
1963 flood are shown on this photograph which was taken at the
corner of River and Spar Streets in Ontonagon.

!-3 Jfl-

S JW
-TD., P- FL D
INT. REG. FLOOD

@7,

Figure 20. FLOOD HEIGHTS AT IGA FOODLINER
Merchandise in the store was extensively damaged when flood waters
reached the level shown by the 1963 arrow. Even greater flooding
would occur during an Intermediate Regional or Standard Project
Flood.

Sol

T-1

@QSTD, PROJ, ELOOD, NT. REG. FLOOD
1963 FLOOD

Figure 21. FLOOD HEIGHTS AT EAGLES CLUB
Past and projected future flood heights are shown at this location
near the intersection of Quartz and Michigan Streets in Ontonagon.

SUPER

MARKET

STD. PROJ. FLOON
INT. REG. 1963 FLOOD

Figure 22. FLOOD HEIGHTS AT QUALITY SUPER MARKET
In April 1963 food stock within this store was damaged extensively.
The level reached by the 1963 flood and levels which may be ex-
pected during an Intermediate Regional Flood and a Standard Project
Flood are shown on the staff gage photograph.

PrIP11"

. .. .......
370. PROJ. FLOOD
MT. REG. FLOOD
1" 4963 FLOOD

Figure 23. FLOOD HEIGHTS AT SEARS CATALOG SALES
This store located at the corner of Copper and Michigan Streets
in Ontonagon may expect flood waters to be 1.8 feet and 2.8 feet
deep during the Intermediate Regional and Standard Project Floods.
The crest of the 1963 flood was slightly over I foot deep at this
location.

STD. P
. . .. .... 19 FLOOD INT. REG.

Figure 24. FLOOD HEIGHTS AT THE FIRE HALL
Flooding which extended for several blocks on River Street in 1963
was also evident at this location at the Ontonagon Village Fire
Hall. Even greater depths, 2.0 feet for the Intermediate Regional
Flood and 3.0 feet for the Standard Project Flood, may be antici-
pated.

PROJ. FLOOD _4
963 FLOO-D imp

Figure 25. -- FLOOD HEIGHTS AT U. S. POST OFFICE
Although this building was not damaged by the 1963 foood it is
vulnerable to the design floods of the future as shown on this
photograph.

o",

STD. PROA,
1963 FLOOD
G. F OQD,

7,7

Figure 26. FLOOD HEIGHTS AT HAWLEY LUMBER YARD
This building located on iron Street in Ontonagon was subject to
the 1963 flood and may expect even higher levels during the Inter-
mediate Regional and Standard Project Floods. The projected flood
crests are shown above.

PAST SHORE EROSION

LAKE SUPE RIOR

Erosion Damage Prevention Measures
In response to a resolution of the Committee on Public Works
of the House of Representatives dated March 26, 1952, a preliminary
examination report was made, which, among other things, determined
the extent of shore property damages from the high water levels on
the Great Lakes during the one year period from May 1951 through
April 1952. The report stated that from 15 miles west to about 5
miles east of Ontonagon, erosion caused losses of up to 50 feet in
depth from lake front lots. In addition, many of the nearly 100
homes and cabins in this reach of shoreline were destroyed or had
to be moved. The report further stated that cribbing and riprap
that had been used to protect a few of the improved properties were
too light in construction to be effective. To this date, essentially
all erosion prevention measures have been small scale efforts by
individual property owners.
The role of the Federal Government in erosion damage prevention
is one of making studies of the problem areas and then participating
in the cost of approved erosion prevention measures. A complete
description of the applicable Federal Government programs is pre-
sented subsequently in this report.
Several local property owners along the Lake Superior shore-
line in Ontonagon County have banned together to form the "Ontonagon
County Lake Shore Erosion Association." This group has been active
in seeking more rigid control of lake levels as a means of reducing
erosion damage.

Erosion Forecasting Services
There is no official erosion forecasting service for the area.

The Lake and Its Shoreline

Lake Superior, the largest of the.Great Lakes,.has a water sur-
face area of 31,700 square mile's and a drainage a -rea of 8o,loo
square miles. The United States portion of Lake Superior con5ists
of 20,600 square miles of water surface and 37,500 square miles of
drainage area. Of the 1,622 miles of shoreline in the United States,
there are 1,041 miles in Michigan, 367 miles in Wisconsin.- a nd 214

miles in Minnesota.

The shoreline studied in this report comprises two sections of
the Ontonagon County, Michigan, lake frontage which have been sub-
ject to shoreline erosion. The "West Coast" study area, as shown
on Plate 2, extends from the most northerly point of the P orcupine
Mountains (about 1.5 miles west of Union Bay) easterly nearly 25
miles to a point 3,000 feet northeast of the mouth of the Firesteel
River. Also shown on Plate 2 is the "East Coast" study area which
covers about three miles of beach northeasterly from the Misery River
to the Houghton County line. Other sections of beach in Ontonagon County
outside the two study reaches have not been subject to significant erosion.
Numerous streams enter Lake Superior from Ontonagon County,
providing this portion of the lake with a large sediment inflow.

The locations of the streams are shown on Plate 2.

The only major village in the coastal area is Ontonagon, having
a populati on of about 2,500. Smaller communities include Silver
City and Green, 13 miles and 6.5 miles west of Ontonagon, respec-
tively. As shown in Table 6, approximately 41,600 linear feet
(7.8 miles) of the 28-mile study area is in public ownership.
Therefore, approximately 72 percent of the shoreline is privately

owned.

DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
ST PAUL, MINNESOTA

SHORELINE MAP
LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY, MICHIGAN
SEPTEMBER 1970

0 5 10 15 20 THOUSAND FEET

PLATE 2

TABLE 6

PUBLIC OWNED LAKE SUPERIOR SHORELINE

Approximate
Ownership Location Frontage
]in. ft.

State of Michigan Porcupine Mountains State Park 30,000
State Highway Dept. Union Bay 7,6oo
Silver City Community Park 300
Ontonagon Township Park i,6oo
On tonagon County Park at Firesteel River 2,100
Total within study reach 41,6oo

The resistance of the coast materials to all forms of erosive
action varies from stable at rock outcrops to vulnerable at clay
cliffs. The general plan of the coastline shows a pattern of rocky
headlands and receding beaches. Occasionally, sufficient beach
material is transported and deposited in front of the receding
areas to form an effective barrier against further erosion. The
effectiveness of the beach becomes greatly reduced however, when

lake levels rise.

Beach Description
For convenience of identification, the two coastal strips
comprising the west and east coast study areas have been sub-
divided into reaches as shown on Plate 2. These may be described

as follows:
Reach No. 1. This reach begins at the westerly end of the
study area and comprises the first 11,000 feet of shoreline.
Along this reach, the shoreline follows a wave cut cliff in erosion
resistant red sandstone with no sand beach. A typical view of
Reach No. I is shown on Figure 27.

S-WAI M I Ex
U-j;

Figure 27. TYPICAL SHORELINE REACH NO. I

Reach No. 2. State Highway 107 parallels the shoreline in
the vicinity of Union Bay and is threatened by erosion. At one
section in the middle of this reach, the recession of 1968 neces-
sitated placement of about 1,000 feet of random stone seawall pro-
tection as shown on Figure 28. Similar protection has been re-
quired at several locations east of the Union River.
Along Reach No. 2, the beach width ranges from 15 to 50
feet. The wave cut scarp for the first 3,000 feet of Union Bay
is comprised of a red clay that is very hard when dry, but plastic
when wet. A typical cross section of this reach is presented on
Figure 29.

East of Union River the bank has cut back to within 10 feet

of the highway at several locations and stone fill has been placed

at several locations.

Figure 28. HIGHWAY PROTECTION REACH NO. 2

-j BANK OF PLASTIC
-j
-.620 RED CLAY 620 CD

SLUMPED
LU -
Uj CLAY
U- MATERIAL--\ Uj
610 610 U-
LAKE SAND WITH FINE 200,
SURFACE TO COARSE GRAVEL
Co ;7
C>
151
L 600 600
LU
-j 15' LU
Uj -i
Uj

Figure 29. TYPICAL BEACH CROSS SECTION REACH NO. 2
@N CD WIT H FI
0ARSE GR

Reach No. 3. East of Union Bay State Highway 107 leaves the
shoreline and the sandy beach ends. Figure 30 shows the heavy cobble-
stone beach which is typical of Reach No. 3. Rocky outcrops have
prevented recession for this 3,000-foot reach except for two small
embayments.

'Al

Figure 30. TYPICAL SHORELINE REACH NO-_3

Reach No. 4. This reach extends from the rocky point on the
east bank of the Little Iron River to another rocky point 1,800

feet east. Shoreline recession is active here. Several houses are
threatened; at least two may be destroyed in the near future. The
extent of erosion is depicted by the accompanying photograph (Figure
31) which was taken along Reach No. 4.

F
@@ @10

@Jl J),

7-Ui 54-
77 7 7

Figure 31. PROPERTY DAMAGE REACH NO. 4

Reach No. 5. The distance between the end of Reach No. 4 and

Silver City at the mouth of the Big Iron River is about 3,000 feet.
Big Iron River discharges into the lake between two rocky points
that act as natural jetties, but which fail to impound littoral
material. All along Reach No. 5, the upland is of low relief,
being only about five feet above lake level. One house, located
about 500 feet to the west of the Big Iron River, has been pro-
tected by a timber mat and concrete seawall located only 12 feet
lakeward of the house (see Figure 32). The top of the concrete is
about 4.5 feet above the present lake level which allows waves
and spray to overtop it during storms. West of this protection
the shore has receded to the back of the house.
ww
@' IT

Figure 32. -- EFFECTIVE SEAWALL INSTALLATION REACH NO. 5

Reach -No-.- 6. Gull Point, which lies 5,200 feet east of the
Big Iron River, represents the east end of Reach No. 6. The west-
erly half of this reach has a narrow, steep beach terminating on
the east with a slight erosion resistant point. This portion of
the shoreline is straight and subject to only limited recession
because of th e heavy red sandstone shingle and gravel beach. A
typical section is shown below as Figure 33.
Active erosion is evident in the westerly half of the reach
to Gull Point with not more than 10 feet of steep beach between
the lake and the tree line. Gull Point is rocky with a lake-
ward extension in the form of a sm.all rocky island. It is gen-
erally non-erodible and fixes the shoreline at this position.

620 620
_j
CM _j

Uj F-
LU LU
U_ LU
10, 12' 100 U_
610 610

F_ STATE
LAKE iEAVY SANDSTONE HIGHWAY 64
Uj LEV SHINGLE
_j Uj
Uj SAND ON _j
L_ 600 SH I NGLE 600
--GRAVEL

Figure 33. -- TYPICAL BEACH CROSS SECTION - REACH NO. 6

Reach No. 7. This reach extends from Gull Point to a sharp
rocky sandstone point about 3,000 feet east. Between these stable
points the embayment has reached a depth of 600 to 700 feet. The
beach, which is fed by sand size materials deposited by Mineral
River, has a substantial width of 75 feet or more, but the up-
land is of low relief as shown in the following photograph (Figure
34). The beach berm has been overtopped during storms and sand
has occasionally washed back as far as State Highway 64.

U.- "@i"

Figure 34. TYPICAL SHORELINE REACH NO. 7

Reach No. 8. To the east a second embayment extends another
2,000 feet and terminates in a broad headland of non-erodible ma-
terial (see Figure 35). Erosion and shore recession is active be-
tween these points leaving only a narrow, steep beach between the
lake and the tr ee line. This embayment is about 600 feet deep
from a line drawn between the adjacent headlands.
Reach No. 9. The next 10,000 feet extending almost to the
mouth of Stony Creek is armored with a heavy red sandstone
shingle which provides a resistant shoreline. A small embayment
in the middle of this reach is completely armored. Here the beach
is steep and narrow but is all of heavy sandstone shingle. The
red sandstone along Reach No. 9 is stratified, fractured, semi-
blocky, and dipping lakeward. It appears that these sandstone
formations break down into heavy shingle by freezing and thawing
activity.

@,A

qW,

Figure 35. -- EROSION RESISTANT SHORELINE REACH NO. 9

Reach No. 10. The next 2,600 feet of beach centering on Pine
Creek is steep and sandy-with only about 15 feet wide between the
lake and the tree line. Figure 36 is a photograph of a typical
portion of Reach No. 10. Pine Creek appears to be a heavy con-
tributor of sand and a delta 100 feet wide has formed at its
mouth. Houses at the east end of this embayment are generally
located a sufficient distance from the eroding beach and only one
appears to be in danger. The beach cross section is similar to
that of Reach No. 6 as shown on Figure 33. The eastern 1,000 feet
of Reach No. 10 consists of a rocky headland and erosion resistant
rocky beach. This is the last such headland for a considerable
distance along the coast.

Figure 36. TYPICAL SHORELINE REACH NO. 10

Reach No. 11. Reach No. 11 consists of 11,000 feet of shore-
line terminating on the east at Green. The beach is fairly uniform
with shore material which is readily erodible. Midway of Reach No.
11, sandstone appears at the surface near the waters edge. This
sandstone may assist in preventing recession during periods of low
lake levels but would be insufficient to be effective during high
lake levels. A beach section typical of this area is shown on
Figure 37.
In 1935, a 250-foot length of vertical concrete seawall was
constructed about 2,000 feet west of Green. The 10-foot beach
originally in front of this seawall was lost, allowing undermining
of the structure which collapsed. Recession has now reached 50
feet shoreward of its remains. The unprotected flanks have eroded
more intensely and the shoreline has recessed an additional 40

feet to the east.

610 401 1 610
Uj
Ui
Ui
U_ Uj
M U_
LAKE SAND
LEVEL I TO 2 FOOT SCARP
AT TREE LINE
600 600
F-

Figure 37. TYPICAL BEACH CROSS SECTION - REACH NO. 11

Further to the west, other localized efforts have been made to
prevent building losses and shoreline recession.by various types of
short seawalls ranging from 100 to 150 feet in length. One typical
installation is shown on Figure 38. The seawalls are of various de-
signs including stone filled timber cribs fronted by short groins,
stone filled timber cribs with concrete caps, and triangular con-
crete blocks laid end to end. Substantial maintenance is required
as the walls are often overtopped by storm waves. The protection
provided by the seawalls is marginal as the shoreline continues to
recede on each side of the structures. Additional extensions shore-

ward at the ends of these walls will become necessary as erosion

continues.
_@S A N @D
I To 2 FOOT SCARP
LI
@ATTRi`ENE@@
6C

Figure 38. MARGINAL SEAWALL INSTALLATION REACH No. 11

A muni.cipal park in the community of Green has a good beach
with a general appearance of stability, although eroding areas have
developed at both ends. Stability appears to be reinforced by ma-
terial brought to the beach by rivers on each side, the park being
possibly at a nodal point. Little evidence of serious erosion
exists for a distance of 1,000 feet centering on the park. Gravel
was noted along the plunge point zone.
Reach No. 12. For the 4,000-foot reach eastward from Green
to the mouth of the Cranberry River, the beach is fairly wide except
for the last 600 feet where it narrows down and several buildings
are threatened. Recession was particularly active here during the
1968 period of high lake levels.

The Cranberry River is a sediment contributor and a west-
ward trailing spit has developed at its mouth. This spit indicates
that' at this particular location the net littoral transport is from
east to west nourishing Reach No. 12.
Reach No. 13. From the Cranberry River eastward to the Potato
River, a distance of about 9,000 feet, the beach ranges from 80
feet in width immediately east of the Cranberry River to 30 feet in
width at the Floodwood River. Basically, the beach steepens as it

becomes narrower. A new house was noted under construction near the

Floodwood River. This building is located about 30 feet from the
top of the beach berm. A typical cross section of this reach of
beach is given below on Figure 39. The general appearance of this
area is shown in the photograph on the following page (Figure 40).

_j
10, 30' TO 80'
610 610
F-
Uj
Uj LU
U_ 41 SCARP U_
LAKE ERODiBLE MATERIAL
SURFACE

CD
F- 600 SANDY BEACH 600

_j
LU LU

Figure 39. TYPICAL BEACH CROSS SECTION REACH NO. 13
TER I AL

Figure 40. TYPICAL SHORELINE REACH NO. 13

On the west bank of the Potato River a house constructed on

the edge of the scarp is protected by rock filled timber crib and
old truck tires filled to break up wave action. A photograph of
these efforts is included as Figure 41. Similar to the Cranberry
River, the Potato River trails to the west denoting a localized
long-term net westerly littoral transport.
Reach No. 14. From the Potato River to Dreiss Creek, a dis-
tance of 5,200 feet, the beach forms a series of shallow scallops
having lakeward points consisting of deposits of 3- to 4-inch cob-
bles (see Figure 42). Otherwise, the beach is uniform, 40 to 45
feet wide, ending in a 2- to 4-foot scarp in friable materials

with active recession of the shoreline. Dreiss Creek does not

appear to carry much sediment.

him

Figure 41. TYPICAL SHORELINE PROTECTION REACH NO. 13

Figure 42. TYPICAL SHORELINE REACH NO. 14

Reach No. 15. This reach includes the 12,000 feet of shore-
line from Dreiss Creek to the west jetty at Ontop'agon Harbor. For
the west half of Reach No. 15, the beach is appr6xi'mately 70 feet
wide as shown on Figure 43 below. Ground elevat'lop is about 8 feet
above lake level. At about the midpoint of Reach No. '.15, a drag-
line is used to move sand and gravel from the beach to a stockpile
for construction use. A slight scallop is apparent at this point.
East of the dragline the beach widens to about 90 feet for the first
3,000 feet and then narrows to not more than 40 feet for the re-
maining distance to the accretion fillet caused by the west jetty.
At locations where the beach is narrow, about 100 feet of dune sand
and dune grass lie between the top of the beach berm and the tree

line. It is believed that this is the remains of an old relic dune

presently being eroded.

Figure 43. TYPICAL SHORELINE- REACH Nb. 15

The fillet on the west side on the Ontonagon River mouth starts
to widen about 2,000 feet west of the harbor and is 300 feet wide at
the west jetty. On the east jetty, the sand fillet does not extend
as far lakeward; a difference of 400 feet exists between the west

and east sides of the harbor. Stabilization of the shoreline in

this position appears to be due to the angle the jetties make with
the shore combined with the direction of wave approach which creates
a greater sheltered area on the west side. Also, land fill has been
placed near the west jetty by the adjacent paper mill. During peri-
ods of easterly drift, sand builds up against the west jetty and
becomes trapped there during periods of westerly drift. The reverse

is true on the east side of the harbor.
Within the study area more sediment-carrying streams enter the

lake to the west of the harbor than to the east. This is another
reason for the greater extent of the west fillet.
Reach No. 16. This reach includes the shoreline from the

Ontonagon River to the west end of Township Park, a distance of
about 6,000 feet. The beach fillet and wide beach extend eastward
for about 2,000 feet from the Ontonagon Harbor. Figure 44 shows
a cross'section representative of this area. Further east the
beach is typified by a narrow, steep section only 20 feet wide
fronting a 2-foot scarp, as shown on Figure 45. The shore is about
6 feet- above lake level and is of erodible material. Lake Shore
Road lies 120 feet back from the top of the scarp but erosion is
active. This condition continues for about 4,000 feet to Town-
ship Park.

620 620-

VARIES 201 - 2251 -j
151 Ole 33:@

Ui
LL- 610 U-
610 = I

WATER
L
EVEL

U.j SANDY BEACH Ui
-i
Ui -600 6010 -J "J

Figure 44. TYPICAL BEACH CROSS SECTION

WESTERN REACH NO. 16

to,
11,5SM

Figure 45. NARROW SHORELINE,- EASTERN REACH NO. 16
F

The remains of an old pier lie 1,000 feet west of Township
Park. Between this pier and the park, a house has been protected
by a short seawall constructed of broken concrete, brick, stone,
and concrete filled tires with two short 10-foot groins constructed
of old tires and piles (see Figure 46). The shoreline has receded
15 feet on the west side and 20 feet on the east side of the sea-
wall. While the seawall is holding fairly well, extensions will be
required along the sides in addition to periodic maintenance.

Ati

AA,

Figure 46. LOCAL SHORELINE PROTECTION EASTERN REACH NO. 16

Reach No. 17. Reach No. 17 extends from the west end of Town-
ship Park to Paddys Creek, a distance of 4,500 feet. Recession
of at least 50 feet at the park buildings is indicated by the re-
mains of an old concrete structure. This section of the coast is
comprised of a highly erodible material. Near the east end of the
park, the erodible material changes to a more erosion resistant,
highly-laminated shale which continues for 600 feet. Between this
shale area and Paddys Creek the material is erodible and recession
has been active even though the banks are higher.

Reach No. 18. The reach between Paddys Creek and Bear Creek
is about 12,000 feet. Shale is exposed to the east of Paddys Creek
and has caused a point to form about 300 feet from the creek. A
50-foot wide beach with scattered boulders is continuous from the
end of the shale for the next 5,000 feet to the east. A typical
profile is shown on Figure 47.

CD 501 CD1
- 74@ ---------
-610 610

Uj
LU W
U_ SAND BEACH -2 TO 4 U_
LAKE FOOT
LEVEL SCARP
ERODIffLE
C)
600 MATERIAL
LAM[NA'
TED SHALE 600
OUTCROP
Uj Uj

Uj Uj

Figure 47. TYPICAL BEACH CROSS SECTION WESTERN REACHNO. 18

The last 7,000 feet easterly to Bear Creek has steep, nar-
row beaches showing active shoreline recession and outcropping of
non-resistant laminated.:shale formations (see Figure 48). In
some of the shale areas, recession is essentially dormant.
Reach No. 19. The 13,000-foot shoreline from Bear Creek to
the Flintsteel River is designated as Reach No. 19. The beach
here is uniformly wide as shown-on Figure 49 and offers no erosion
problem during present lower lake levels. Net littoral movement
in this area is from west to east as evidenced by Bear Creek

which trails to the east.

Figure 48. TYPICAL SHORELINE EASTERN REACH NO. 18

vw 11;-

Figure 49. TYPICAL SHORELINE REACH NO. 19

Reach No. 20. From the Flintsteel River to the east end of the

''West Coast" study area is about 7,000 feet. The beach through the
west part of this reach averages about 50 feet in width fronting a
4- to 5-foot scarp of easily erodible material (see Figure 50).
Farther east the beach narrows and steepens to a width of about 35
feet with a I- to 2-foot scarp. A typi..cal section in, this reach is
sketched as Figure 51.
The Firesteel River enters Lake Superior ahout 4,@20Q feet east
of the Flintsteel River. Both rivers appear to be substantial sedi-
iment contributors. A delta has formed at the mouth of the Flint-
steel River with a slight trend to the west; however, no specific
direction of littoral drift predominates.

Figure 50. TYPICAL5HORELINE:- WESTERN REACH NO. 20

35'
J

610 610

W
W W
W
LL_
TO S! C A `RP
MATERIAL
=LL EROD I BIE
LAKE
SUR E 'SAND BEACH

600 600

LU
_J _J
LU UJ

Figure 51. TYPICAL BEACH CROSS SECTION EASTERN REACH NO. 20

Reach No. 21. The last reach of shoreline included in this
study is that extending easterly from the mouth of Misery River for
a distance of about 18,000 feet to the Houghton County line. Besides
Misery River, several small creeks and the Little Elm River enter
the lake in this reach. Only Misery River appears to be a sub-

stantial source of littoral material.

For the firs t 2,000.feet east of Misery River the beaches are
up to 125 feet wide fronting a low water berm and a 2-foot scarp.
The elevation of the coast is 10 to 12 feet above lake level.
Evidence of sand dune formation is apparent. Figure 52 is a
photograph of this area.
Beyond the first 2,000-foot section of Reach No. 21, the
beach narrows to widths ranging from 30 to 50 feet. The adjacent
bluffs range from 5 to 35 feet in height with the greatest height
at the eastern end of the study area. The upland is comprised of
relic sand bars that are easily eroded. A typical portion of this
beach is shown on Figure 53.

x
4'i

Figure 52. TYPICAL SHORELINE WESTERN REACH NO. 21

F,igure 53. TYPICAL SHORELINE EASTERN REACH NO. 21

The small streams tributary to the Lake Superior in Reach No.
21 all trend to the east. However, the appearance of the sand spits
lakeward of the streams would indicate this to be a temporary con-
dition rather than a long-range trend. A typical section through
this area is included as Figure 54.

EL. 101 TO 351
620 620-
_J _J
RELIC
SAND BARS

U_ U_
610 610 -

TALUS SLOPE
C) SCARP
I.-- LOW WATER BERM

UJ UJ
_J _J
uJ L-- 600 101 10, VARIE!J 600

Figure 54. TYPICAL BEACH CROSS SECTION - EASTERN REACH NO. 21

Shoreline Developments
A recent questionnaire, completed by owners of property adja-
cent to the Lake Superior shoreline, shows a variety of building
Values ranging from cabins at $500 to homes valued at $20,000 and
above. The average value of bui-ldings within the study area is
approximately $18,000. Shoreline development is expected to be-
come more intense in the future, especially near Ontonagon as the
demand increases for more recreational and building sites.
The greatest concentration of present development is in Reach
Nos. 4 through 7 and 11 through 17. Also, Reach No. 2 has been

moderately developed in the vicinity of the state park at the west
end of Union Bay. Elsewhere, the study area is sparsely settled.
Existing buildings are, for the most part, summer homes along
the beach and permanent residences concentrated near Silver City,
Green, and Ontonagon. A few commercial structures such as motels
are located in areas which will become endangered by erosion in the

future.

Some highway construction close to the lake is also threatened
by erosion. The most critical section is along State Highway 107
immediately east of Union Bay. Other affected locations have been
described in the previous section of this report.

MECHANISMS OF EROSION

Rainfall

Rainfall contributes to shoreline erosion or accretion in sev-
eral ways. The impact of falling raindrops on steeply sloped cliffs
frequently erodes soft materials near the waters edge at a rate
comparable to the more obvious effects of wave attack. Rainwater
percolating through the ground adjacent to the lake front often
initiates slides. Shorelines periodically become more susceptible
to erosion due to the destructive forces of ice formation in rock
crevices and between soil particles.
By far the most destructive influence of rainfall on shoreline
erosion is a rise in lake levels caused by excessive precipitation.
During a period of high lake levels, beaches, which normally pro-
tect the shoreline by causing waves to break at a distance, become
inundated enabling waves to attack formerly protected areas.

The influence of rainfall upon lake levels is demonstrated by
a review of a recent period of high levels centered upon the year
1968. The average annual rainfall over the Lake Superior Basin for
the period from 1900 through 1967 was 21.9 inches. Du ;r'ing the ten-
year period ending in 1967-this long term average was exceeded by
about three percent. In the,,yea r 1568 recorded rainfall was 29.7
inches or about 36 percent higher than the long term average.
Plate 3, which is extracted from the'"Hydrograph of Monthly Mean
Levels of the Great Lakes" produced by the U. S. Lake Survey, shows
Lake Superior levels for the years 1965 through 1969. The lake
level response to the high rainfall of the year 1968 is typical.
Damages to the shoreline which occurred in 1968 are discussed sub-
seque ntly in this report.
Experience of the response of the lake to precipitation and
runoff has enabled the Lake Survey District, Corps of Engineers to
predict levels for a few months in advance. These forecasts pro-:
vide advance warning of exceptionally high levels which should be
heeded by those with property subject to damage by severe erosion.
Longer term forecasts, except for a general pattern, are not possible
based upon present inability to predict meteorlogical events. As a
basis for p lann.ing, it should be.as.sumed that lake levels in the
future may reach or:exceed past.record levels.
In an indirect way, rainfall can assist in shoreline acc retion.
Following a period of heavy rainfall, streams normally carry a heavy
sediment load consisting of sand and,gravel. This material is de-
posited along the coast near the mouth of the streams and serves to
"nourish" the beaches forming erosion protection for the shoreline.

Wind and Waves

While wind alone contributes little to shoreline erosion, its
action in forming.waves constitutes the major factor,in 'coastero-,
sion. A secondary effect of wind influencing lake current s is o f
far less importance.

602.0 . ..... .... 602.0
. . .. . ... ....-

. ........ .... F
F 11

@.1 . .. ....
--4
T
.... ..... .-
J.:
41: 4, . . .... .
.. . .... . . . ....L
601 0
601 .0

600.0 44 600.0

.. ..... ...

... .. . . .. .. . ....

77- . . .....

A-@
r CD
599.0 599.0
1950 1951 1952 1953 1954 1955 1956 1957 1958 1959
LLJ Lu
LLJ Lu
LL YEAR u-

602.0 602.0
.. . . .. ......
4

..... . . ....
Lu
. .. .. ..... .
t F
LLJ
Lu
.. ... . . .....
. . .... ..I lt
f
:T
601.Q 601.0
J� j-

t A-
600.0 600.0
4 VVIA-v-

. .... .. ..... ....

. . ... .... .
L
599.0 599.0
1960 1961 1962 1963 1964 1965 1966 '1967 1968 1969
YEAR.
DEPARTMENT OF THE ARMY
NOTE: STAGES REPRESENT ST PAUL DISTRICT, CORPS OF ENGINEERS
MONTHLY MEAN LAKE ST. PAU L, MINNESOTA
LEVELS
LAKE SUPERIOR
STAGE HYDROGRAPH
LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY, MICHIGAN
SEPTEMBER 1970

PLATE 3

The closest wind recording station to the study area is at
Keweenaw Waterway about 50 miles to th e east. Results obtained at
this location are considered representative of the study area.
Plate 4 shows the wind rose based on the period 1911 to 1930. It
is apparent that winds from every..quadrant are represented. Winds
blow from the west 32.5 percent of the time, from the north 24.4
percent of the time, from the east 14.6 percent of the time, and
from the south 28.5 percent of the time. Maximum daily winds range
between 10-and 20 miles per hour (mph) for about 50 percent of the
time and exceed 20 mph for 26 percent of the time.
Wind generated waves travel in approximately the same direction
as the wind. As the waves approach the shore they break and run up
the beach carrying abrasive sand and gravel particles which grind
away at any cohesive material with which they come in contact. This
results in erosion near the water line. Sometimes, erosion of this
type proceeds sufficiently fast to undermine an overlying cliff caus-
ing its collapse. Waves approaching at an angle to the coastline
wash abraded particles in a zigzag pattern along the beach giving
rise to the net transport of material know as "littoral drift."
The coastline of Lake Superior in the study area is oriented
in a general west-southwest to east-northeast direction. Only winds
coming from a direction north of this alignment are effective in
generating waves which contribute to shore erosion in the area.
The resultant effective energy of the contributing winds is from a
direction approximately north 32 degrees west or slightly to the
east of a line drawn normal to the general orientation of the coast.
A slight general tendancy for littoral drift from the west to east
is therefore to be expected with local reversal where the coast
runs in a more southwesterly to northeasterly direction. Temporary
reversal of the littoral drift may also occur during individual
storms from the north and northeast.

VELOCITY
M I LES PER HOUR

3 TO 10
10 TO 20
- 20 TO 30
w E -30 TO 40,
-40 TO 50

.DAILY MAXIMUM WIND DATA FROM KEWEENAW WATERWAY
LENGTHS OF RADIATING LINES INDICATE AVERAGE DURATION
IN DAYS PER YEAR THUS-

0 10 20 30 DAYS

PERIOD 1911 TO 1930 INCL.

NO WIND DATA AVAILABLE AT ONTONAGON HARBOR

DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
ST PAUL, MINNESOTA

WIND ROSE
LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY, MICHIGAN

SEPTEMBER 1970

PLATE 4

No records of accurate wave height measurements have been found
for Lake Superior along Ontonagon County, however, historical descrip-
tions of past storms report waves as high as an estimated 35 feet.
Theoretical deep water wave heights have been calculated from consid-
eration of wind velocity, duration, and length of fetch (open water)
over which wind may act. The resultant data, as presented in Table
7, indicate a design deep water wave of 20 feet for the study area.
As is apparent@_f_rom -his-to,ric records, waves of greater magnitude
may occur, however, their occurrence would be very infrequent.

TABLE 7

DESIGN WAVES

Wind Comeuted Deep Water Wave
-Pirection Fetch Velocity Duration Height Length Period
miles mph hours feet feet seconds
N 80' W 112 65 4.4 20.0 522 10.1

NW 73 67 4.6 20.0 522 10.1

North 59 56 6.6 16.3 .443 9.3
N 15 0 E 50 45 12.0 11.5 320 7.9
N 26' E 50 45 12.0 11.5 320 7.9

Source: "Review Survey, Lake Superior, Misery River, Michigan, Small
Boat Harbor" by the Corps of Engineers dated April 6, 1970.
Deep water waves usually break well before they reach the shore.
Smaller waves which continue to the shoreline are responsible for
erosion damage. The height of the shallow water waves is dependent
upon the type of shoreline as well as the magnitude of deep water
wave. Assuming a stillwater lake level of Elevation 604.0 (maxi-
mum water elevation of the past plus two feet allowance for seiche)
and a typical rocky shore profile as shown on Figure 55, the maxi-
mum waves to reach the shore will be about 3.4 feet high acting

against the rocky cliff with a run-up to Elevation 606.3. Under
similar conditions, but against a typical sandy beach (see Figure
56), maximum breaking waves to reach the shore will be about 3.3
feet high running up the sloping face of the beach to Elevation
607.3.

_j
_j
-610 LOCUS OF WAVE CREST 610

- EL. 606.3
LU
LU

U_
U_
2C hc= 2.3' hb 73741

SWL EL. 604

d 4.31
F- B
.< EL. 600
L600 600
U.j 33
_j Uj
LU _j
ROCK LU

Figure 55. TYPICAL WAVE ATTACK ROCKY SHORELINE

610 610
LU EL. 60 APPROX LU
W _- I'S OF WAVE CREST h
U_ [email protected] U_
10
2.31
SWL EL. 604
C) =L. 600 _12-31, 600
L 600 F-

Uj _j
_j U.J
LU

Figure 56. TYPICAL WAVE ATTACK SANDY BEACH

Preliminary design of erosion protection facilities along the
Ontonagon County coast may be estimated from the two cases described
above. Protective works should generally be effective to about Ele-
vation 607.0 with a more precise determination depending upon the
actual profile of the coast line at the specific location.

Ice
The period of ice formation on Lake Superior differs each year
depending on climatic conditions, however, it may be expected be-
tween early November and the middle of March.
Ice formation may periodically cause considerable damage to
shorelines or shoreline structures in local areas, but the net ef-
fect of ice is generally beneficial. Wave formation is suppressed
by an ice cover on the lake itself and protective ice ususally forms
on the bank and adjacent structures. Ice piled on shore by wind
and wave action does not, in general, cause serious damage to the

shoreline.

Freezing and thawing tend to break up the laminated red sand-
stone formations along several reaches of shoreline within the study
area. The result is the formation of a heavy shingle that protects
the adjacent shore from erosion. In other reaches, freezing causes
erodible banks to become more stable during winter months, however,
the net effect of freezing and thawing is a degradation of the shore-
line stability.

Lake Levels
The water surface elevation of Lake Superior is influenced by
direct rainfall and runoff from tributary streams, discharge through
St. Marys River, and evaporation losses. Since runoff and evapora-
tion vary on a daily and annual basis, a pattern of irregular long
term lake level fluctuations exists. U sually, however, low lake
levels occur in the early spring with peaks following in July or

August. As discussed previously, the level is responsive to suc-
cessions of wet or dry years. Plate 5, extracted from the "Monthly
Bulletin of Lake Levels" published by the Lake Survey District of
the Corps of Engineers, shows average and extreme levels of Lake
Superior since 1860.
In 1921, improvements were made at the outlet from Lake Superior
to control lake levels and increase discharge capacity. This con-
sisted of a gated outlet control structure at Sault Ste. Marie and
channel improvement in the St. Marys River. The question of level
control of the Great Lakes is becoming more important as the effect
of high lake levels upon erosion becomes more widely appreciated.
It is apparent that the lakes cannot be considered individually,
but must be regarded as a system. Increasing releases at a time of
high water in Lake Superior may cause an increased problem down-
stream. Studies showing the economic effect of high levels in all
the lakes will be of assistance in formulating plans for best use of
the regulating capability of the Lake Superior outlet.
Local lake level variations often occur as the result of wind
and sometimes barometric pressure differences.. These uncontrollable
elements have the effect of producing short period seiches in the
lake resulting in level fluctuations from a few inches to two or
three feet. Design for erosion protection should provide for recur-
rence of high average water levels of the past with an additional
allowance of two or three feet to allow for these short period
seiches. Seawalls and similar protective measures should extend
to sufficient elevation to protect against likely wave action coin-
cided with these high lake levels.

Geology_of the Area
Bedrock consists of northward-dipping red, Lake Superior sand-
stone and highly laminated shale. To the west of Union Bay, these
rise to form the front station of the Porcupine Mountains. Beneath

LEGEND
AVERAGE LEVELS (1860 - 1969)
AVERAGE LEVELS (1960 - 1969)
1951 EXTREME HIGH & LOW LEVE@S & YEAR
OF OCCURANCE (1860

1926
604 F=
604

.. . . . .... . . ....
F@-
J.-

603;'
603

7-
i 4
76'
18
-87
---'1951
602
77717-
Lu
8 602
Lu
u-
O@5
LL'
LLI
u-

. .. .... .... . .
91-2
F9
601
6 01 CD
S
A -<

LLI
Lu
uj
-'600
LLI
600
-7-

-1 25

-2.6 - - ----- @599
599
-92,5-
6-- [:9!6
iL
1- -1 C26
'A".9 -6.:, f-l-
598
@'598
JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEP. OCT. NOV. DEC.

1969

DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
ST PAUL, MINNESOTA

MEAN MONTHLY LAKE LEVELS
7j@
[L@Lj

92
t

LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY, MICHIGAN
SEPTEMBER 1970

D1 ArC C

the sandstone and shale, the formation consists of conglomerate,
lava flow, and felsite as shown on Figure 57.

EL. 1300, LAKE OF THE CLOUDS

LWD 6001

LAKE
SUPERIOR -4

<Q
41

<
'P

Figure 57. TYPICAL GEOLOGICAL SECTION PORCUPINE MOUNTAINS

Throughout the study area these rocks form erosion resistant
headlands. Between headlands, depressions in the sandstone, now
filled with erodible relic dune material, have led to the formula-
tion of shallow embankments. Also present are alluvial sands and
red lacustrine clays.

Littoral Drift

Littoral drift, the mechanism by which beaches are eroded or
built up is not only a result of erosion, but also a factor which
influences erosion of an area. In the previous discussion of wind

and waves, the presence of a weak overall tendency of littoral drift
from west to east was predicted from an analysis of wind records.
No determinations of net littoral transport rates have been
made. It should be noted that wind data indicate that the strongest
movement of beach material will be offshore during periods of strong
wave action followed by a return of material to the beach during
periods of low wave activity.

One total barrier to littoral drift exists at the harbor at
Ontonagon.. Here, two parallel jetties have been constructed to
help maintain a navigable river entrance. Interception of littoral
drift from west to east has resulted in the building of an exten-

sive beach to the west. A lesser beach is to be seen to the east

of the jetties. This is formed during easterly gales, but is shield-
ed from re-erosion by the jetties. The alignment of the beach de-
posited at the western jetty runs approximately N 400 E. This natur-
al equilibrium angle is indicative of the angle at which beaches
might form behind protective groins constructed in the area.
Beaches, such as those adjoining the Ontonagon Harbor, can only
form when supplied with material from an updri ft direction. Princi-
pal sources are rivers or rapidly eroding beach areas. Conversely,
beaches may suffer by being starved of such materials. When this
occurs the natural forces producing drift remove existing beaches
without replenishing them. The net effect is erosion. No serious
erosion is apparent for some distance downdrift (east) of the mouth
of the Ontonagon River, possibly because the river itself constitutes
a source of replenishment of materials intercepted by the jetties.
At some locations along the study area, deposits of sand and
gravel on the beach are being mined as a source of construction
materials. Each cubic yard of material so removed must be compen-
sated for by erosion downdrift. These mining operations should be
carefully regulated as their influence is frequently felt a consid-

erable distance from the area of removal.

In many areas, erosion protection accompanied by enhanced at-
tractiveness for recreational purposes is most economically accom-
plished by construction of groins to trap littoral drift. Beach
building materials are not plentiful in the area and their transport
rates are relatively slow. The possibility of groins ''robbing" some
downdrift use of littoral material should therefore be considered in
all cases. Construction of groins should be regulated by a respon-
sible authority who will carefully examine this aspect before a per-

mit for construction is issued.

EROSION SITUATION

Shore] ine Changes
The earliest maps which accurately depict the shoreline of Lake
Superior in the study area were prepared from an 1855-65 "Survey of
the N. & N.W. Lakes" by the Corps of Engineers. These maps have
been used in conjunction with a 1950-56 series of U. S. Geological
Survey 15-minute quadrangle maps and 1943, 1964, and 1970 aerial
photographs to establish a history of shoreline erosion for Ontona-
gon County. The 1943 aerial photographs do not cover the entire
study area and are, therefore, supplemented by 1964 photographs in
the eastern portion.
Plates 15 through 23 show a 110-year history of shoreline
changes plotted on reproductions of 1970 aerial photographs. An in-
dex of these aerial photographs is presented as Plate 14. The shore
outlines, which indicate the waters edge, have been developed by
comparative means using the available maps and aerial photographs
discussed above. The accuracy of the 1860 outline is dependent upon
the early maps which do not allow detailed reproduction of the shore-
line. Later shore outlines are presented with more detailed accura-
cy. I n add i t i on to the past shore out 1 i ne, P I ates 15 th rough 23 i n-
clude a projection of the probable shoreline in the year 2020.

Surveyed beach cross sections, typical of the various reaches of
shoreline studied, are included in Plates 24 through 26. These cross
sections provide an indication of the status of erosion or deposition
of the present time. Location of each cross section is shown on the
aerial photographs (Plates 15 through 23).
Erosion rates have been calculated from a comparative analysis
of shoreline changes along the study area of Lake Superior. Losses
of 50 to 100 feet of shoreline width since 1943 are not uncommon.
In the last 27 years, extreme rates of erosion have amounted to an
average of 4.0 feet per year at the embankment near the mouth of
Pine Creek and 3.0 feet per year immediately east of Green. Erosion
rates are often accelerated beyond these average values during in-
dividual years or especially during storm periods.
The maximum rate of accretion occurred adjacent to the Ontonagon
Harbor entrance at an average of 8.0 feet per year. Since 1860, some
accretion has occurred at Union Bay but this reach is currently ex-
periencing erosion. Elsewhere along the coast, accretion is non-
existant except for localized temporary "build ups" occurring at
river mouths. Rocky headlands have remained essentially unchanged
during the past 110 years.

Existing Protective Structures
Approximately 1,000 feet of random stone seawall was constructed
following the 1968 period of high lake level damage to protect State
Highway 107 adjacent to Union Bay. A photograph of a section of this
seawall was presented previously in this report as Figure 28. From
examination of the form of construction used, it is anticipated that
frequent damage of the seawall may occur when lake levels are high.

A number of private structures has been constructed particularly
in the vicinity of Green and to a lesser extent near Ontonagon. Sea-
walls ranging in length from 100 to 250 feet have been constructed to
a great variety of designs including concrete wall, precast concrete
shapes, rock-filled timber crib, composite crib and concrete construc-
tion, concrete blocks, and miscellaneous mixtures of random stone,
broken concrete, bricks, and old tires filled with concrete. Photo-
graphs of typical privately constructed seawalls are included on
Figures 58 through 60.
Groins also have been attempted with almost invariable lack of
success. Short groins, 10 to 15 feet in length, are common and these
have been ineffective in trapping and maintaining beaches. They
commonly suffer from lack of toe protection against scour which has
led to their settlement and subsequent failure. Also, inadequate
strength to withstand storm waves, inadequate height to prevent over-
topping by storm waves, and lack of maintenance characterize the short
groins.

Figure 58. CONCRETE AND ROCK SEAWALL

Figure 59. CONCRETE AND TIMBER SEAWALL

F.igure 60. BROKEN CONCRETE RUBBLE "PROTECTION"

Generally, the privately constructed coast protection works are
poorly designed and constructed and do not enhance the appearance of
the area. Lacking support of similar construction on adjoining prop-
erty they soon become isolated headlands vulnerable to destruction
f rom the f I anks.

The jetties at the mouth of the Ontonagon River are adequately
designed with heavy corner stone to withstand wave action and with
sufficiently high and massive shore ends to resist outflanking. The
following photographs of this structure illustrate the type of con-
struction necessary to be durable for this purpose. The heaviness
of construction is in contrast to many privately constructed works
in the area and the general appearance is far more satisfactory..

Figure 61. EAST ONTONAGON RIVER JETTY SHORE END

Figure 62. EAST ONTONAGON RIVER JETTY LAKEVIARD END

STORM DESCRIPTIONS

Following are descriptions of known severe storms that have
occurred on Lake Superior in the vicinity of Ontonagon County.
These are based on field investigations, newspaper accounts, his-
torical records, and other publications.

November 1913
Little information is available relating to the 1913 storm
except for the following account from the book "Lore of the Lakes"
by Dana Thomas Bowen:
. . . Thus it was on that Saturday, November 8th, of that
year, as lake shipping battled what started to be just another early
winter blow. Captains then had no way of knowing that this blow
was going to be worse than any other that they had ever encountered.

'No lake master can recall in all his experience,' reported
the Lake Carriers Association afterwards, 'a storm of such unprece-
dented violence with such rapid changes in the direction of the wind
and its gusts of such fearful speed. Storms ordinarily of that
velocity do not last over four or five hours, but this storm raged
for sixteen hours continuously at an average velocity of sixty miles
per hour, with frequent spurts of seventy and over.
" 'Obviously with a wind of such long duration, the seas that
were made were such that the lakes are not ordinarily'familiar with.
The testimony of masters is that the waves were at least thirty-five
feet high and followed each other in. quick succession, three waves
ordinarily coming one right after the other.
H 'They were considerably shorter than the waves that are
formed by the ordinary gale. Being of such height and hurled with
such force and such rapid succession, the ships must have been sub-
jected to incredible punishment.
" 'Masters also relate that the winds and sea were frequently
in conflict, the wind blowing one way and the sea running in the
opposite direction. This would indicate a storm of cyclonic
character. It was unusual and unprecendented and it may be centuries
before such a combination of forces may be experienced again.'
"in the big cities that border the lakes, and throughout the
surrounding country, land traffic was paralyzed. Communication
and power lines were wrecked. Street and interurban car s were left
stranded in the streets, stalled by the snow and the ice that formed
on the wires and rails. Thousands of persons were marooned in what-
ever shelter they could find while the storm raged. Railroads aban-
doned trying to operate their trains. But to the men aboard ships
on the lakes it was stark tragedy."

December 1968
A recent storm struck Lake Superior in December of 1968. The
unusually high lake levels which existed during 1968 were a factor
contributing to the intense shore]!-ne erosion damage caused by this
storm. Figures 63 through 67 include photographs showing some of
the damage caused by the December 1968 storm.
The following are excerpts from a newspaper account which indi-
cate the severity of the December 1968 storm.
THE ONTONAGON HERALD
Thursday, December 19, 1968
STORM SENDS LAKE ON RAMPAGE

"The severe storm which struck the Upper Peninsula last week
caused the closing of all schools in Ontonagon County Friday morn-
ing, cancelled numerous meetings and basketball games, kept the
County Road Commission on a round-the-clock schedule and sent Lake
Superior on another rampage.
"A heavy downpour of rain Thursday turned into snow early
Friday morning and,continued well into Saturday. W inds with gusts
of morethan 50.miles per hour caused blizzard.conditions and haz-
ardo us driving as there was a sheet of pure ice under the snow
"Rampaging Lake Superior eroded more beach over a wide area,
gouged-deeply into Lakeshore property and felled numerous trees as
the high wat@ers washed them out by the roots."
V
.. ater rose about 2.5 feet at Lakeshore Cabins, swept a canoe
which was leaning against a cabin and floated it amid ice and other
flotsam over 300 feet toward M-107 and left it resting about 50
feet from the highway.
"A truck driver who went over Highway M-107 Friday morning
reported that waves from the lakes were coming over the highway
near Union Bay, but the County Road said the highway is in no danger
and two-lane traffic is being maintained. About a month ago the
Michigan State Highway Department placed signs in this area warning
drivers to proceed with caution."

_i4

W41

-7,

ALM,
7@

WON

44@

Figure 63. SHORE EROSION SCENES IN ONTONAGON COUNTY - DECEMBER 1968
Top view is looking west toward the Porcupine Mountains from the
Union River adjacent to Union Bay. The State Highway 107 sign gave
way to Lake Superior shortly after this photograph was taken. Lower
view shows the result of damages along this same section of high-
way.

Figure 64. SHORE EROSION SCENES IN ONTONAGON COUNTY DECEMBER 1968
The man in the upper photograph is standing on State Highway 107
adjacent to Union Bay. Lower view shows erosion damage and debris.
washed ashore at a cottage near Green, Michigan.
Vill

k7k

Figure 65. SHORE EROSION SCENES IN ONTONAGON COUNTY DECEMBER 1968
Top view shows failure of locally attempted shore protection measures
at a property west of Ontonagon. Bottom photograph was taken along
the beach near the mouth of the Big Cranberry River. The large birch
trees, which were uprooted by Lake Superior erosion, were located on
the Wallace Jarvi property.

7f
W @. WA

VIM*

Figure 66. SHORE EROSION SCENES IN ONTONAGON COUNTY DECEMBER 1968
Top photograph was taken at the Kirouac property at Green. Lake
Superior has gouged deeply into this property and has undermined
several cottages as well as destroyed trees. Lower view shows
Lake Superior shoreline threatening a building approximately four
miles west of Ontonagon. 99

-'j

vo,", ON PAW!
*A
mv
*r
Op
i,9

Figure 67. SHORE EROSION SCENES IN ONTONAGON COUNTY NOVEMBER 1968
This photograph was, taken November 7, 1968, prior to the severe
storm which occurred later that year. Damages shown at Township
Park include uprooted trees as well as a swiftly diminishing beach
caused by the high lake levels alone.

100

FUTURE SHORE EROSION

DESIGN STORM

The design storm for the Ontonagon County shoreline along
Lake Superior is based on wave studies of the Misery Bay area com-
pleted by the Corps of Engineers in April 1970. Consideration
for the design storm includes direction, velocity, and duration of
winds to give maximum heights of deep water waves. Results of
these studies, which were presented previously in Table 7, show
a design deep water wave height of 20 feet which would occur with
wind directions oriented from the northwest quadrant between
N 45@@ W and N 800 W. The design wind velocity would be 65 to 67
miles per hour for a duration of.4.4 to 4.6 hours.
As the deep.water waves approach the shore, they break and
form smaller waves. The maximum height of shallow water waves
which would be expected to reach the shore is 3.3 to 3.4 feet
depending on the type of coast line. Figures 55 and 56 show
sketches of typical waves which would confront rocky shorelines
and sand beaches during the design storm.

PREDICTED SHORELINE EROSION

Experience has demonstrated that the beach zone along Lake
Superior is constantly in a state of adjustment due to the effect
of lake levels, storm waves, and shore, currents. With changes in
the action of these agents seasonally and during storms, the
shoreline changes its location, sometimes eroding or receding
landward and at other times accreting or advancing lakeward.
Like the flood plain which is a normal part of the river during
flood periods, a part of the low areas along a shoreline are
really a part of the lake during high stages.

101.

Future shoreline changes have been predicted for the study
area in Ontonagon County. In general, these forecasts assume
erosion and accretion rates to continue in the future as they
have in the recent past. This is considered to be a valid
approach assuming no major changes are introduced to disturb the

current trend.

Plates 15 through 23 show the projected shoreline for the
year 2020., Plate 14 is an index map of the individual shoreline
erosion maps. Local variation from the predicted shoreline may
occur because of individual efforts toward shoreline protection
or unknown geological formations. More extensive changes from
the present trend may be caused by uncontrolled mining of beach
materials, alterations within the drainage basin which will
affect the sediment load of streams emptying into the lake, and
construction of major erosion control facilities. Past records
show that erosion is far more prevalent than accretion and there-
fore, the predicted shoreline for 2020 is, in most-cases, farther
inland than the present shoreline.

HAZARDS OF SHORELINE EROSION

Shoreline erosion has the potential of creating serious
disasters. Loss of life and personal property and destruction
of buildings, roads, and trees may be attributable to shoreline
erosion. Land which is eroded by the lake represents a con-
siderable loss not only to the property owner but also as reduced
tax revenue for governing agencies.
Along the Lake Superior shoreline of Ontonagon County,
severe damage has resulted from past erosion and considerably
greater potential damage may occur in the future. Although
there are no large population centers located in the study area,

102

many of the homes, resort developments, roads, and other facili-
ties which are located near the shoreline are subject to being
destroyed or damaged by shoreline erosion.

103

SUGGESTIONS AND SUMMARY

REMEDIAL MEASURES FOR BEACH EROSION

Two possible approaches are available for coping with ero-
sion problems in Ontonagon County. One would be to limit erosion
losses by controlling developments near the shoreline. This is
discussed subsequently in the "Guidelines for Use of the Flood
Plain and Shoreline" section of this report. The seco-nd approach
involves erosion control. Several alternative means for arresting
the current erosion problem are discussed below.
One method which is often applicable for sparsely settled
areas involves protecting only those sections of beach which
have been developed or are otherwise considered relatively valu-
able. In the undeveloped reaches, erosion is allowed to continue
unchecked. This method may have application in the portions of
Ontonagon County which are relatively undeveloped. In conjunc-
tion with such an approach, restrictions should be instituted to
control development in the unprotected areas.
The three most economical plans for preventing shoreline
erosion in Ontonagon County include lake level regulation, pro-
hibiting mining of beach materials, and controlling developments
on the beach. Of,,the three, lake level control would be the
most influential in reducing shoreline erosion, particularly on

a short-term basis.
Protective measures are also available to help stabilize the
shoreline. Groins may be applicable at some locations but, be-
cause of the shortage of littoral material in the area, they
generally should not be employed. For approved uses, groins
should be of sufficient length to retain the derived beach which
will form at a pre-determined angle to the present shoreline.

104

Groins should be of adequate height at the shore end to confine a
beach of sufficient width to absorb wave run-up and be of adequate
design to withstand toe erosion and wave forces. The method of
original filling of groin systems with beach material must be con-
sidered as well as possible effects of robbing downdrift beaches
of their natural replenishment.
Beach formation by the supply of additional materials arti-
ficially is feasible in some areas. Beaches downdrift from points
where the material is introduced become enlarged as the supply
of material exceeds the natural transport rate. Thus, wider pro-
tective beaches may be constructed without resorting to groins.
Provision for the continuation of supplying beach nourishment
materials is a necessary part of such a plan. Indications are
that suitable beach building materials are not readily available
in the area and the necessity of transporting them a considerable

distance would not be feasible.
Seawalls appear to be the best suited method of coast pro-
tection for the area. For seawalls to be effective, they must
be continuous over long reaches of coast line. In addition, they
must be sufficiently high to prevent serious erosion by wave
overtopping and heavy enough to withstand wave action and soil
pressures. A filter should be provided to prevent leaching of
soil through the wall. Toe protection is essential to prevent
failure by undermining. Typical designs which might be used suc-
cessfully in the area are shown on Plates 6 and 7.
The costs of the two types of seawall illustrated on Plates 6
and 7 are about equal. Gabion construction has become recognized
as a method well adapted for construction by individual home
owners but should be integrated with protective measures employed
by neighboring property owners. The polyvinyl chloride (PVC) wire

105

15 15

BACKFILL

F-
uj NYLON FILTER CLOTH
10 10
3c r
8.67 JOB GABION 13'-I"X3'-3"X3T-3"
rll-@-PVC COATED GABION 13 '-1 "X3'-3"XI 1-8"
5.42 PVC COATED GABION MATTRESS 6'-6"X[2'X9"
5 - uj 5
i OnO
TYPICAL ROCK OR
3.00 CONCRETE PIECES

0 LOW WATER DATUM 0

TYP I CAL

GAB ION BASKET

DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
ST PAUL, MINNESOTA
8-67 GABION CONSTRUCTION
LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY, MICHIGAN
SEPTEMBER 1970

Pt ATF R

NOTE: GRADED STONE 430 LBS. TO 3.5 TONS
FILTER STONE 10 MM TO 25 LBS.
(QUARRY WASTE - SHOVEL RUN)

SCALE: I"= 51

TOP OF SCARP

EL. EL. 608
VARIES SLOPE I ON 1 1/2
L 61
GRADE D STONE EL. 604

NATURAL
GROUND LINE
VARIES FILTER BLANKET LAKE LEVEL
EL. 600

LINE OF POSSIBLE EROSION

DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
ST PAUL, MINNESOTA

TYPICAL ROCK SEAWALL
LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY, MICHIGAN
SEPTEMBER 1970

mesh basket which forms the gabion is filled with stone of suffi-
cient size to be retained by the mesh. The completed gabion is
then sufficiently massive to resist wave action but retains flex
ibility so that it is not easily destroyed.
Occasionally, offshore breakwaters are constructed in deep
water to prevent waves from attacking the shoreline. These must
be of very massive construction to withstand the larger waves to
be encountered in the deeper water. Use of offshore breakwaters
is seldom economically justified; they do not appear to have appli-
cation in this area.
tt may be concluded that successful administration of the
coast cannot be left to private initiative. Co-ordination plans
must involve long reaches of coast line. The optimum approach
would also include regulated develo pment on the adjacent lake
frontage as discussed subsequently.

GUIDELINES FOR USE OF THE FLOOD PLA IN AND SHORELINE

Man has been building on and occupying the flood plains of
rivers and streams since the coming of the pioneer settlers. The
steams first provided transportation and water supply. Later,
mill dams were built and early highways and railroads were con-
structed along the gentle valley grades. Today, the continuing
growth of cities results in ever increasing encroachment on the
flood plains.
The increase in flood hazards and flood damages, despite the
expenditure of billions of dollars of tax funds for the construc-
tion of flood control works, has led to a new approach to the
reduction of these hazards and damages. This involves exercise of
control over the land lying adjacent to the stream through the
planned management and development of flood hazard areas. The
flood plain management program can prevent the creation of new

lo6

flood hazard areas if fully integrated into the comprehens ive
land use and development plan of an area and enforced by means of
appropriate zoning, subdivision, and building regulations. While
flood plain areas probably never can be considered flood free,
planning will allow selection of the type of development which is
consistent with the flood risk. Also, it will allow a reasonable
level of protection to be built into a project during initial con-
struction.

Regulation of the flood plain can be carried out by a variety
of means--encroachment lines, zoning ordinances, subdivision
regulations, and modifications or additions to building codes.
These methods will be described subsequently in some detail. How-
ever, it is not within the purpose of this report to recommend the
specific technique to be used. flood plain regulations are the
responsibility of State and local governments, and these report
data are provided to furnish a basis for appropriate regulatory
action. The basic data in this report can be used in conjunction
with comprehensive plans to develop a reasonable and desirable
plan for use of flood plain land along the Ontonagon River and
the Lake Superior shoreline in Ontonagon County.
Fortunately, the need for flood plain planning has been recog-
nized by local interests. This means that future damages in the
study area can be reduced at little or no cost to the taxpayer by
the enactment and enforcement of flood plain regulations. The
flood data in this report, together with the planning program for
future land use, will enable State and local interests to minimize
flood damage risks.
Flood plain management may also include other methods which
are helpful, particularly in special localized areas. These in-
clude park and open space developments, evacuation, urban rede-
velopment, flood proofing, tax reductions, and warning signs.

107

Several approaches are also available for regulation of
developments along shorelines subject to erosion damage. Primarily,
zoning ordinances and regulation of beach nourishment are con-
sidered applicable for this study area.

Encroachment Lines
A designated floodway is the area of channel and those por-
tions of the flood plains adjoining the channel which are reason-
ably required to carry and discharge the flood flow of a specific
flood without unduly raising upstream water surface elevations.
Encroachment lines or limits are the lateral boundaries of this
floodway. They are two definitely established lines, one on
each side of the river. Between the encroachment lines no con-
struction or filling should be permitted which w*ill cause an
impedance to flow.
If possible, encroachment limits should be established be-
fore extensive development has taken place in order that costly
clearance of existing structures may be avoided. Final choice of
the magnitude of the flood, which will determine the size of the
floodway, is a matter for state and local decision.

Zoning
Zoning is a legal tool used by cities, villages, and counties
to control and direct the use and development of land and property
within their jurisdiction. Division of a municipality or county
into various zones should be the result of a comprehensive plan-
ning program for the entire area, with the purpose of guiding its
growth. The planning program, as such, has no legal status.
Zoning is a legal tool that is used to implement and.enforce the
details of the planning program. Its objectives are the conser-
vation of property value and the achievement of the most appro-
priate and beneficial use of available land.

108

Flood plain zoning is not a special type of ordinance, but
merely another set of provisions which can be incorporated into
a comprehensive zoning ordinance so that flood damage can be
minimized. Zoning regulations may be used in lieu of encroach-
ment laws as well as a supplement to them. Designated floodways
may be zoned for the purpose of passing flood waters and for other
limited uses that do not conflict with that primary purpose. The

ordinance may also establish regulations for the flood plain
areas outside the floodway, such as designating elevations above
which certain types of development must be constructed.
Zoning for shoreline erosion control involves a planning
program for minimizing property damage along Lake Superior. A
11set back" zone established along the lake front would define the
area subject to erosion damage within a specified number of years.
Development within the zone would be restricted to low value
investments with the developer fully aware of the potential damage.
The use of portable facilities in the potential erosion zone may
also be considered. Buildings, roads, or other permanent facil-
ities should not be constructed within a specified safety distance
from the projected shoreline.
The required technical data for institution of shoreline
zoning are included in this report in the form of a projected shore
outline for the year 2020. Projections further into the future
will be required periodically to keep the zoning ordinances cur-

rent.

,Subdivision Regulations
Subdivision regulations are used by local governments to
specify the manner in which land may be subdivided within the
entire area under their jurisdiction. Regulations may state the
required width of streets, requirements for curbs and gutters, size

109

of lots, elevation of land, freedom from flooding, size of flood-
ways, and other points pertinent to the welfare of the community.
It has been found that responsible subdividers favor such regula-
tions because they discourage land speculation and prevent unscru-
pulous competition from other subdividers who might develop flood
hazard land with less than minimum desirable standards. Experience
has also shown that various municipal costs are reduced during
flood periods and that the annual-maintenance required for streets
and utilit ies is minimized. Subdivision regulations provide an
efficient means of controlling development in areas which are
presently undeveloped. By introducing such regulations eariy in
these areas, planned flood plain development can take place with-
out being hampered by nonconforming uses.

Building Codes
The primary purpose of building codes is to set up minimum
standards for controlling the design, construction, and quality
of materials used in buildin gs and structures within a given area,
so that life., health, property, and public welfare are safeguarded.
Since it may not be practicable to prevent the location of any
building in all areas subject to flooding, building codes can be
used to minimize structural and consequential damages resulting
from flood velocities and inundation. Some of the methods adapt-
able to building codes are:
(1) Prevent flotation of buildings from their foundations
by specifying anchorage.
(2) Establish basement elevations and minimum first floor
elevations consistent with potential flood occurrences.
(3) Prohibit basements in those areas subject to shallow,
infrequent flooding.

110

(4) Require reinforcement to withstand water pressure or
high velocity flow and restrict the use of materials which deteri-
orate rapidly in the presence of water.
(5) Prohibit equipment that might be hazardous to life when
submerged. This includes chemical storage, boilers, and electri-
cal equipment.
Regulation of Beach Nourishment
Beach nourishment is provided for by an inflow of sediment
to the shoreline and subsequent transport along the shoreline. As
discussed below, any alteration of either the supply of sediment
or its transport may affect shoreline erosion. Regulation of such
changes is essential to insure the most economical use of the
shoreline.
Sediment inflow to the shoreline along Ontonagon County is
primarily provided by streams emptying into Lake Superior. Any
alteration of the sediment transport by the stream, such as reser-
voir construction, may seriously reduce the sediment supply to the
beach. The economic aspects of additional erosion losses should
be considered in evaluating the economical ju stification for all
stream improvements proposals.
The construction of groins, while improving a limited shore-
line reach, may increase erosion in adjacent, downdrift areas by
decreasing the natural inflow of littoral drift. In the evalua-
tion of groins, or any project which acts as a littoral. drift
barrier, consideration must be given to the effect of this de-
crease of littoral material in the downdrift area.

Currently, beach materials are being mined from the Ontonagon
County shoreline for construction use. Regulations are needed to
restrict this practice because of the potential erosion which may
occur downdrift of the mining area.

PERTINENT FEDERAL AND STATE LAWS

Existing Federal Laws on Beach Erosion Control and Lake Inundation
The Federal Government's role in shore erosion control is
defined in the provisions of Public Law 826, 84th Congress, approved
July 28, 1956, as amended by the River and Harbor Act of 1962
(PL 87-874), approved October 23, 1962, and as further amended by the
River and Harbor Act of 1965 (PL 89-298), approved October 27, 1965.
Under this statute the Corps of Engineers participates in the solu-
tion of shore erosion problems by making studies of eligible shore-
lines entirely at Federal expense. The present policy for Federal
participation in the cost of works for shore protection applies,
generally, to publicly owned shores. Privately owned shores may be
eligible for Federal assistance only if there are significant public
benefits arising from public use or from p-rotection of nearby public
property, provided that the protective works are economically justi-

fied.
The Corps of Engineers also conducts beach erosion control sur-
veys or reviews and updates previous reports on the basis of indi-
vidual directives from the U. S. Congress. The directives are in the
form of either a resolution of the Pub) ic Works Committee of the
Senate or the House or a separate item in a public works authoriza-
tion bill. The Soil Conservation Service, Department of Agriculture
has broad authority to undertake studies for upland watershed pro-
tection. These stu dies deal primarily with means of reducing flood

flows into the Great Lakes.

The provisions of Section 111 of the River and Harbor Act of
1968 authorizes the Corps of Engineers to investigate, study, and
construct projects for the prevention or mitigation of shore damages
attributable to Federal navigation works. Investigation of the

112

feasibility or desirability of work under this authority must be
formally requested by a state, county, or other properly constituted
local authority.
Federal Role in Beach Erosion Research
Public Law 166, 79th Congress, authorizes the Chief of Engineers
through the Coastal Engineering Research Center to make general in-
vestigations with a view to preventing erosion of the shores of the
United States by waves and currents and determining the most suitable
methods for protection, restoration, and development of beaches.
These general studies are for the purpose of developing or determining
physical phenomena, techniques, principles, and procedures related to
the protection, restoration, and'development of beaches and shores.
They provide the technical "know-how" to assist in arriving at sound,
economical solutions to shore erosion problems generally. They do
not result in the formulation of specific plans of protection or re-
media] works for a particular locality, since a separate study is
required to develop such plans for each locality. General investiga-
tions are Federally financed and are initiated by the Chief of Engi-
neers through the Coastal Engineering Research Center.

EmergencyFlood and Coastal Storm Activities
The authority for Federal assistance in emergency flood and
coastal storm activities is set forth in Public Law 99-84 (33 United
States Code 701n) as amended by Section 206 of the Flood Control Act
approved October 23, 1962; and in Section 9 of the Flood Control Act
approved June 15, 1936 (33 U.S.C. 702 9-1). Preceding and during
flood and coastal emergencies, the primary missions of the Corps of
Engineers are authorized as follows:
(1) Preserve Federally owned and maintained flood control works
and other facilities operated by the Corps of Engineers.

113

(2) Furnish appropriate technical assistance to state and local
authorities upon request, advising them in their efforts to maintain
the integrity of flood control works and Federally authorized shore
and hurricane protection projects under their jurisdiction.
(3) If responsible state or local authorities are unable to
cope with the flood or coastal storms situation, direct Federal assis-
tance may be provided either by supply of needed materials or equip-
ment or by undertaking Federal flood fighting or emergency protection.
The Federal Disaster Act of 1950 (Public Law 875-81) authorizes
Federal assistance to state and local governments in a major disaster.
A major disaster is defined as any "flood, drought, fire, hurricane,
earthquake, storm, or other catastrophe which, in the determination of
the President, is or threatens to be of sufficient severity and magni-
tude to warrant disaster assistance by the Federal Government to supple-
ment the efforts and available resources of state and local governments
in alleviating the damage, hardship, or suffering caused thereby.

State Agencies Concerned with the Beach Erosion Problem
Several state agencies have been given certain responsibilities
related to beach erosion problems. Although none of these agencies is
authorized to provide financial help to property owners, they are able
to supply information and advice on matters pertaining to this prob-

lem.
In Michigan, the 1949 Legislature conferred certain limited
powers and duties with respect to this problem upon the Water Re-
sources Commission. A section of this act designates the Commission
as the state agency to cooperate and negotiate with other governments,
governmental units, and agencies thereof in matters concerning the
water resources of the state, including, but not limited to, flood con-
trol and beach erosion control.

114

During 1952, the Michigan Legislature passed three acts with
permit some participation of counties and townships in beach erosion
problems. These are described in the following paragraphs.
Public Act No 42, P.A. of 1952, is an amendment to Section I of
the county rural zoning enabling act, making it possible for county
boards of supervisors of those counties fronting on the Great Lakes
to establish appropriate set-back or building lines in areas outside
of incorporated villages and cities. This is for the purpose of pro-
tecting individuals or groups from building in locations that are
subject to inundation or erosion.
Public Act No. 43, P.A. of 1952, is an amendment to the special
improvements act for townships and villages, Act 116, P.A. of 1923.
This amendment permits the construction of beach and soil erosion
control projects by such agencies on a special assessment basis.
Public Act No. 44, P.A. of 1952, is an act which gives all
political subdivisions authority to make beach erosion studies either
independently or in cooperation with other political subdivisions or
any agency of the Federal Government. This bill also opens the way
for Michigan political subdivisions to qualify for Federal assistance,
should they care to seek it in connection with the investigating-and
planning of works for beach protection.

State Flood Plain Management Program '
in recognition of the many problems associated with flood plain
development, the State of Michigan has enacted the following two laws
since January 1, 1968, which regulate such development:
Act 288, (Plat Act), Public Acts of 1967, which establishes
minimum standards for subdividing land and for new development
for residential purposes within flood plain areas. This act

115

requires that preliminary plats be submitted to the Water

Resources Commission for review and determination of flood

plain limits. Upon completion of review and establishment of
flood plain limits, the preliminary plat may be approved and
minimum building requirements specified.

Act 167, (Flood Plain Control Act), Public Acts of 1968, which
requires that a permit be obtained from the Water Resources
Commission before filling or otherwise occupying the flood plain
or altering the channel of any watercourse in the state. The
purpose of this control is to assure that the channels and the
portion of the flood plains that are the floodways are not
inhabited and are kept free and clear of interference or
obstruction which will cause undue restriction of flood carrying
capacities.
It is important to note that these laws are intended to be minimum
requirements only. Although the power to zone, which carries with it
police powers for enforcement of zoning provisions, rests initially with
the State, Michigan has delegated this authority to the smallest govern-
mental entity. Michigan strongly encourages local governmental units to
adopt reasonable regulations, which equal or exceed State minimum require-
ments, to guide and control development in flood hazard areas. It is
believed that such joint State-local regulations will provide the most
effective and satisfactory means of regulating flood hazard areas.

116

GLOSSARY OF TERMS

Beach Erosion. The carrying away of beach materials by wave
action, littoral currents, or wind.
Beach Width. The horizontal dimension of the beach as measured

normal to the shoreline.
Cross Section of Beach. The intersection of the ground surface
in the beach zone with a vertical plane.
Discha rge. The quantity of flow in a stream at any given time,
usually measured in cubic feet per second (cfs).
Fetch. The continuous area of water over which the wind blows
in essentially a constant direction.
Flood. An overflow of lands not normally covered by water, that
is used or usable by man. Floods have two essential characteristics:
the inundation of land is temporary; and the land is adjacent to and
inundated by overflow from a river, stream, ocean, lake, or other body
of standing water.
Normally a "flood" is considered as any temporary rise in stream
flow or stage, but not the ponding of surface water, that results in
significant adverse effects in the vicinity. Adverse effects may in-
clude damages from overflow of land areas, temporary backwater effects
in sewers and local drainage channels, creation of unsanitary conditions,
or other unfavorable situations by deposition of materials in stream
channels during flood recessions, rise of ground water coincident with
increased stream flow, and other problems.
Flood Crest. The maximum stage or elevation reached by the
waters of a flood at a given location.
Flood Peak. The maximum instantaneous discharge of a flood at
a given location. It usually occurs at or near the time of the flood

crest.

117

Flood Plain. The relatively flat area or lowlands adjoining
the channel of a river, stream, or watercourse; or ocean, lake, or
other body of standing water, which has been or may be ocvered by

floodwater.
Flood Profile. A graph showing the relationship of water sur-
face elevation to location, the latter generally expressed as dis-
tance above the mouth of a stream of water flowing in an open channel.
it is generally drawn to show surface elevation for the crest of a
specific flood but may be prepared for conditions at a given time or
stage Flood Stage. The stage or elevation at which overflow of the
natural banks of a stream or body of water begins in the reach or area
in which the elevation is measured.
Head Loss. The effect of obstructions, such as narrow bridge
openings or buildings, that limit the area through which water must
flow, raising the surface of the water upstream from the obstruction.
Height of Wave. The vertical distance between a crest of a
wave and the preceding trough.
Hydrograph. A curve denoting the discharge or stage of flow
over a period of time.
IntermediateRegional Flood. A flood having an average fre-
quency of occurrence in the order of once in 100 years, at a designated
location, although the flood may occur in any year. It is based on
statistical analyses.of stream flow records available for the water-

shed.
Left Bank. The bank on the left side of a river, stream, or
watercourse, looking downstream.
Littoral Drift. The material moved in the shore zone under the

influence of waves and currents.

118

Low Steel.. The lowest point of a bridge or other structure over
or across a river, stream, or watercourse that limits the opening
th rough wh i ch wate r f I ows .
Right Bank. The bank on the right side of a river, stream., or
watercourse, looking downstream.
Run-up The vertical height above still water level that the
rush of water reaches following the breaking of a wave.
Seiche.. A periodic oscillation of a body of water thought to
be initiated chiefly by local variations in atmospheric pressure
aided in some instances by winds and tidal currents.
Standard Project Flood. The flood that may be expected from the
most severe combination of meteorological and hydrological conditions
that are considered reasonably characteristic of the geographical area
in which the drainage basin is located, excluding extremely rare com-
binations. Peak discharges for these floods are generally about 40 to
60 percent of the Probable Maximum Floods for the same basins. Such
floods, as used by the Corps of Engineers, are intended as practicable
expressions of the degree of protection that should be sought in the
design of flood control works, the failure of which might be disastrous.
Still Water Level. The elevation of the water surface if all

wave action were to cease.

119

AUTHORITY, ACKNOWLEDGMENTS, AND

INTERPRETATION OF DATA

This report has been prepared in accordance with the authority
granted by Public Law 86-645 (Flood Control Act of 1960).

Assistance and cooperation of the U. S. Weather Bureau, U. S.
Geological Survey, Michigan State Highway Department, Ontonagon
County, Village of Ontonagon, and private citizens in supplying use-
ful information are appreciated.

This report presents the local flood and shore erosion situation
for the Village of Ontonagon, Michigan, and Ontonagon County, Michigan.
The St. Paul District of the Corps of Engineers will provide, upon
request, interpretation and limited technical assistance in applica-
tion of data presented herein.

This report was prepared by Stanley Consultants, Inc., Muscatine,
Iowa, International Consultants in Engineering, Architecture, Planning
and Management, for the St. Paul District, Corps of Engineers.

120

2000 4000 FEET

4@ TV - -

x
%
A,

CIO'

LEGEND DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
INDEX NUMBER OF ST. PAUL, MINNESOTA
DETAIL SHEETS
STANDARD PROJECT FLOOD INDEX MAP -FLOODED AREA
CROSS SECTION ONTONAGON RIVER
ONTONAGON, MICHIGAN
RIVER MILES SEPTEMBER 1970

0 500 1000 FEET

LEGEND OVEI ZFLOW LIMITS

TANDARD
INTERMEDIATE PROJECT
-L[REGIONA LFLOO FLOOD

MI LES ABOVE MOUTH

CROSS SECTION

DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
ST PAUL, MINNESOTA

FLOODED AREA
ONTONAGON RIVER
ONTONAGON, MICHIGAN
SEPTEMBER 1970 SHEET I OF 3

PLATE 9

0 500 1000 FEET

LEGEND
OVERFLOW LIMITS

TERMEDIATE STANDARD
PROJECT
REGIONAL FLOOD
FLOOD

MILES ABOVE mOUTH

CROSS SECTION

DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
ST. PAUL, MINNESOTA

FLOODED AREA
ONTONAGON RIVER
ONTONAGON, MICHIGAN
SEPTEMBER 1970

SHEET 2 OF 3

PLATE 10

DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
ST PAUL, MINNESOTA

HIGH WATER PROFILES
ONTONAGON RIVER
ONTONAGON, MICHIGAN
SEPTEMBER 1970

PLATE 12

LEGEND:

STANDARD PROJECT FLOOD

INTERMEDIATE REGIONAL FLOOD

DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
ST PAUL, MINNESOTA

CROSS SECTIONS
ONTONAGON RIVER
ONTONAGON, MICHIGAN

SEPTEMBER 1970

PLATE 13

LEGEND

6 INDEX NUMBER OF AERIAL PHOTOGRAPHS

DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
ST PAUL, MINNESOTA

INDEX MAP -SHORELINE EROSION
LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY, MICHIGAN
SEPTEMBER 1970

PLATE 14

DEPARTMENT OF THE ARMY
LEGEND ST PAUL DISTRICT, CORPS OF ENGINEERS
SHORELINE IN 1860 ST PAUL, MINNESOTA
SHORELINE IN 1964 0 500 1000 1500 FEET SHORELINE EROSION
SHORELINE IN 1970 - LAKE SUPERIOR SHORELINE
PROJECTED SHORELINE IN 2020 ONTONAGON COUNTY, MICHIGAN
SEPTEMBER 1970
BEACH CROSS SECTIONS

a
PLATE 15

.LEGEND DEPARTMENT OF THE ARMY
SHORELINE IN 1860 ST PAUL-DISTRICT, CORPS OF ENGINEERS
ST PAUL, MINNESOTA
SHORELINE IN 1964 0 500 1000 1500 FEET
SHORELINE IN 1970 SHORELINE EROSION
PROJECTED SHORELINE IN 2020 LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY, MICHIGAN
7 t A BEACH CROSS SECTIONS SEPTEMBER 1970

PLATE 16

LEGEND DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
SHORELINE IN 1860 ST PAUL, MINNESOTA
SHORELINE IN 1964 0 500 1000 1500 FEET SHORELINE EROSION
SHORELINE IN 1943

LAKE SUPERIOR SHORELINE
SHORELIN`E IN 1970 ONTONAGON COUNTY, MICHIGAN
PROJECTED SHORELINE IN 2020 SEPTEMBER 1970
7t BEACH CROSS SECTIONS

PLATE 17

DEPARTMENT OF THE ARMY
LEGEND ST PAUL DISTRICT, CORPS OF ENGINEERS
SHORELINE IN 1860 ST PAUL, MINNESOTA
SHORELINE IN 1943 0 500 1000 1500 FEET SHORELINE EROSION
SHORELINE IN 1970
PROJECTED SHORELINE IN 2020 LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY, MICHIGAN
7f BEACH CROSS SECTIONS SEPTEMBER 1970

PLATE 18

LEGEND DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
SHORELINE IN 1860 ST PAUL, MINNESOTA
SHORELINE IN 1943 0 500 1000 1500 FEET
SHORELINE IN 1970 SHORELINE EROSION
PROJECTED SHORELINE IN 2020 LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY, MICHIGAN
BEACH CROSS.SECTIONS SEPTEMBER 1970

PLATE 19

LEGEND DEPARTMENT -OF THE ARMY
SHORELINE IN 1860 ST PAUL DISTRICT, @CORPS OF ENGINEERS
ST PAUL, MINNESOTA
SHORELINE IN 1943 0 500 1000 150O.FEET
SHORELINE IN 1970 SHORELINE EROSION
PROJECTED SHORELINE IN 2020 LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY, MICHIGAN
7t BEACH CROSS SECTIONS SEPTEMBER 1970

PLATE 20

LEGEND DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
SHORELINE IN.1860 ST PAUL, MINNESOTA
SHORELINE IN 1943 0 500 1000 1500 FEET
SHORELINE IN 1970 SHORELINE EROSION
PROJECTED SHORELINE IN 2020 LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY, MICHIGAN
7t BEACH CROSS SECTIONS SEPTEMBER 1970

PLATE 21

DEPARTMENT OF THE ARMY
LEGEND ST PAUL DISTRICT, CORPS OF ENGINEERS
SHORELINE IN 1860 ST PAUL, MINNESOTA
SHORELINE IN 1943 0 500 1000 1500 FEET
SHORELINE EROSION
SHORELINE IN 1970 LAKE SUPERIOR SHORELINE
PROJECTED SHORELINE IN 2020 ONTONAGON COUNTY, MICHIGAN
7t t BEACH CROSS SECTIONS SEPTEMBER 1970

PLATE 22

LEGEND

SHORELINE IN 1970
7 BEACH CROSS SECTIONS

0 500 1000 1500 FEET
NOTE: THROUGHOUT THIS REACH NO
EROSION HAS OCURRED FROM DEPARTMENT OF THE ARMY
1860 TO THE PRESENT AND
NONE IS PROJECTED UP TO ST PAUL DISTRICT, CORPS OF ENGINEERS
THE YEAR 2020. ST PAUL, MINNESOTA

SHORELINE EROSION
LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY, MICHIGAN
SEPTEMBER 1970

PLATE 23

DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
ST PAUL, MINNESOTA
BEACH CROSS SECTIONS I
LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY, MICHIGAN
SEPTEMBER 1970

PLATE 24

NOTE:

ALL BEACH CROSS SECTIONS TERMINATE
AT LAKE SUPERIOR SHORELINE (OCTOBER 1969).

DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
ST PAUL, MINNESOTA

BEACH CROSS SECTIONS
LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY, MICHIGAN

SEPTEMBER 1970

PLATE 25

NOTE:

ALL BEACH CROSS SECTIONS TERMINATE
AT LAKE SUPERIOR SHORELINE ( OCTOBER 1969).
DEPARTMENT OF THE ARMY
ST PAUL DISTRICT, CORPS OF ENGINEERS
ST. PAUL, MINNESOTA

BEACH CROSS SECTIONS
LAKE SUPERIOR SHORELINE
ONTONAGON COUNTY, MICHIGAN

SEPTEMBER 1970

PLATE 26

3 6668 14101 7451