CONTENTS 



Page 



CONVERSION FACTORS, U.S. CUSTOMARY TO METRIC (SI) 6 



I INTRODUCTION . 7 



1. Purpose 7 



2 . Background 8 



3. Previous Erosion Reports 10 



II FIELD METHODS 11 



1. Study Area 11 



2. Survey Periods 11 



3. Profile Procedures 14 



III TERMINOLOGY 14 



IV DATA PRESENTATION 16 



1. Shoreline Retreat 16 



2. Recession 20 



3. Encroacliment 24 



V DATA INTERPRETATION 25 



1. Spatial Variation in Retreat Rates 25 



2. Temporal Variations in Average Retreat Rates .... 27 



3. Effects of the Recent Lake Levels on Shore 



Retreat Rates 30 



4. The Timelag Between Lake Level Perturbation and 



the Reestablishment of Profile Equilibrium 33 



5. Comparison of Recent and Historic Changes 35 



6. The Need to Adjust Recession Rates 38 



VI CONCLUSIONS. 39 



LITERATURE CITED 42 



APPENDIX 



A A PROCEDURE FOR ADJUSTING RATES OF SHORE RETREAT TO 



COMPENSATE FOR WATER LEVEL DIFFERENCES 45 



B NEARSHORE PROFILE CHANGES 55 



TABLES 



1 Major increases in annual mean lake level • 8 



2 Survey dates and shoreline positions 15 



3 Comparison of historic with recent recession rates 36 



