Vegetation and Lake Level Correlations at Catahoula Lake, Louisiana

Abstract

C ATAHOULA LAKE has an extreme variation of water level of more than 40 feet and a normal seasonal variation of more than 25 feet. The local inhabitants have a unique characterization of the lake: a place to hunt ducks in winter, to fish in spring, and to graze cattle in summer. The variation in the water level of Catahoula has been known for a long time. In I804 Dunbar' recorded that in the dry season, from July to November, the bed of the lake was dry except for the meandering channel of the Little River. He noted that the exposed bottom became clothed in the most luxuriant herbage: the bed of the Lake then becomes the residence of immense herds of Deer, of Turkeys, Geese, Ducks, Cranes && feeding upon the grass and grain. The leasing of the lake bottom for exploration for oil has necessitated the delimitation of the various stages of water level. Early measurements, made at a time when the cost of the survey was more than the value of the land, are of little value. Legal decisions in the past have set mean high-water level as the legal boundary for lakes and streams. Catahoula Lake is in the southeastern part of La Salle Parish, La. (Fig. i). It is a rim-swamp lake occupying a depression between bluffs on the northwest and flanking levees elsewhere. At high water it is about I2 miles long by 3 to 4 miles wide and has an area of slightly more than 40 square miles. The larger streams, such as the Little River, the French Fork of the Little River, and Big Saline Bayou, either drain or fill the lake according to the height of the water in their drainage systems.2 Thus if the water level of the Red, Black, Tensas, and Mississippi Rivers is low, the Little River is the principal outlet for Catahoula Lake; if it is high, the backwater pressure causes the Little River to reverse its direction of flow and thereby fills the lake. Thus the water-level variation of Catahoula Lake is governed chiefly by changes in the water level of the adjoining drainage systems.