THE EFFECT OF STRUCTURES AND LAKE LEVEL ON BLUFF AND 

 SHORE EROSION IN BERRIEN COUNTY, MICHIGAN, 1970-74 



by 

 William A. Birkemeier 



I. INTRODUCTION 



The staggering loss of public and private property along the Great Lakes 

 during the period of high lake levels, which peaked in 1973 and 1974, focused 

 renewed interest on understanding the lakeshore erosion problem and on develop- 

 ing methods to minimize it. 



This study examines, by use of aerial photos and other available data, the 

 shoreline and bluff-line erosion which occurred along Berrien County, Michigan, 

 between November 1970 and November 1974, a period of rising lake levels. A 

 major enphasis of the study is the investigation of the spatial and temporal 

 variation in bluff recession along both protected and unprotected shorelines. 

 The effect of lake level is also discussed but the period covered by the data 

 set is too short to adequately cover this phenomena. 



1. Study Area . 



The study area is located in the southeastern section of Lake Michigan 

 near Stevensville, Michigan (Fig. 1). Shoreline use includes summer and 

 permanent residences, undeveloped parkland, and the Donald C. Cook Nuclear 

 Plant which was under construction during the study period. Five 1.6- 

 kilometer reaches of shoreline were selected for study; three of the reaches 

 (A, B, and C) are north and two (D and E) are south of the nuclear plant (see 

 Fig. 1 for locations of each reach) . Selection was based on bluff type, 

 height, and local structures. The reaches were selected away from the power- 

 plant to minimize the influence of the construction of a temporary harbor and 

 an associated sand-bypassing project at the plant. The temporary harbor and 

 its effect are discussed in Johnson and Hiipakka (1976). General character- 

 istics of the study reaches are given in Table 1. 



Reaches A and B form a continuous 3.3-kilometer stretch of shoreline com- 

 posed of predominantly sand bluffs ranging from 3 to 15 meters in height. The 







Table 1 



General characteristics of 



Study re 



aches . 





Reach 



Ori 



entation 



LeiiEth 



Beach 



width 



Bluff 

 height 



Bluff 



tyi'c 



Offshore 

 slope' 



Shore 

 protection 

 structures 



Residences 



Distance 

 from nuclear 

 powerplanl 









(t-m) 



Cm) 



Cm) 









CNo.) 



CknO 



A 



N. 



27° K. 



1.71 



'1 to 8 



10 to 15 



Sand-till 

 bluff 



0.0073 



Minor 



11 



7.7 N. 



B 



N. 



26° E. 



1.62 



6 to 11 



3 to 14 



Sand-till 

 bluff 



0.0072 



Major 



28 



6.0 N. 



C 



N. 



26° E. 



1.52 



5 to 13 



3 to 7 



Sand 

 foredune 



0.0081 



None 







3.0 N. 



D 



N. 



19° 0. 



1.62 



2 to 9 



3 to 7 



Sand 

 foredijpe 



0.0095 



Minor 



33 



3.0 S. 



E 



N. 



30° E. 



1.62 



6 to 17 



3 to 7 



Sand 

 foredune 



0.0089 



None 







7.0 S. 



