32 



Development of the Vegetation Inside the Levee Following the 

 High Water of 1927 



By Clair A. Brown 



In July 1926 a new levee was constructed about three miles 

 south of Baton Rouge, La., and opposite the site of the new 

 campus of Louisiana State University. This section of the 

 levee runs approximately north and south and the river side 

 or the "inside" of the levee slopes to the west. In the con- 

 struction of the levee a depression was excavated many feet 

 from the river bank (section A to B Fig. 2). The earth removed 

 was used to build up the levee. The strip of land parallel to 

 the levee is surrounded by water when the river reaches a 

 height of twenty-five feet on the guage, stage known as "bank 

 full." This strip for convenience has been termed the "Island" 

 and corresponds to section "C" of the profile in figure 2. 



In October 1926 the writer visited this place for the first 

 time and found a large, relatively bare mound of earth with 

 many little gullies cut in the levee by the rains. At this time 

 there were six species of plants found growing on the river 

 side of the levee, none very abundant, but conspicuous on the 

 bare earth. 



Senecio lohatus Pers Medicago lupulina L. 



Sonchus asper (L). All. Capriola Dactylon (L). Kuntze 



Erigeron philadelphicus L. Ru'mex sp. basal rosettes. 



Since it was impossible to reach the "island" without a 

 boat, a complete list of the plants on the island is lacking, but 

 it was covered with vegetation. The most conspicuous forms 

 v/ere Salix, Populus, Platanus and Adelia. 



At this time the river was running at "bank full" and in 

 the latter part of December rose to the "flood stage" of thirty- 

 five feet. The water stayed at the flood stage until April 1927, 

 when a rapid rise started, which culminated in one of the worst 

 floods ever experienced in the lower Mississippi valley. The 

 water reached the high peak of 47.9 feet May 15, 1927, and it 

 is believed that it would have gone higher if breaks had not 

 occurred. The elevation of the levee at the point of the writers 

 observations was 49 feet. The accompanying graph shows the 



