BANK EROSION CONTROL WITH VEGETATION 

 SAN FRANCISCO BAY, CALIFORNIA 



by 



Curtis L, Neuaombej James H. Morris, 



Paul L. Knutsorij and Carol S. Gorbics 



I . INTRODUCTION 



The San Francisco Bay system is comprised of four large bays inter- 

 connected by constricted straits (Fig. I). Prior to 1850 the bay system 

 consisted of approximately 2,038 square kilometers of open water, tidal 

 flats, and intertidal marshlands. A total of 810 square kilometers of 

 marsh formed the Suisun, San Pablo, Central, and South San Francisco 

 Bays. Since the mid-19th century, approximately 30 percent of the bay 

 system has been either filled or diked-off and drained in land reclama- 

 tion activities (U.S. Army Engineer District, San Francisco, 1977). 



Intertidal marshes have been the primary target of these reclamation 

 projects. Seventy-five percent of the San Pablo Bay marshes and 85 per- 

 cent of South San Francisco Bay marshes have been appropriated for urban, 

 commercial, industrial, and agricultural uses. The marshy fringe which 

 once protected the shore from erosion has been greatly reduced or elim- 

 inated. Today, much of the shoreline is characterized by near-vertical 

 eroding banks, a small band of intertidal marsh, and a nearly continuous 

 system of levees and landfills. 



Considering the historical distribution of marsh vegetation on the 

 margins of the bay, planting intertidal plants may be an effective ero- 

 sion control measure in San Francisco Bay and other bays and estuaries 

 on the Pacific coast. 



II. OBJECTIVE 



The objective of this study was to determine the feasibility of 

 using intertidal salt marsh vegetation to control erosion on the open 

 shores of the San Francisco Bay system. Specific objectives were: 



(a) The development of techniques for propagation, trans- 

 plantation, and maintenance of plants for shoreline erosion 

 abatement ; and 



(b) the field testing of plants and planting techniques 

 for shoreline erosion abatement. 



III. PREVIOUS WORK 



In 1946, a property owner of the Rappahannock River in Virginia 

 graded an eroding bank and planted several varieties of salt-tolerant 

 grasses. This work represents one of the earliest known attempts to 



