LOUISIANA. 



503 



nearly complete, except at the sea ends, where 

 the least depth of channel (23J feet) exists. 



These improvements in their incomplete 

 state have aroused an unusual interest in the 

 States bordering on the Mississippi River. The 

 demand now is for the improvement of the 

 river itself, so that it shall become the outlet for 

 the immense crops on its banks and those of 

 its tributaries. The nature of these improve- 

 ments consists in constructing and maintaining 

 embankments or levees along the river and its 

 tributaries, wherever the same may be needed 

 to prevent crevasses and the inundation of the 

 people whose houses and fields are endangered ; 

 and to deepen the channels of the tributaries 

 so as to afford easy and uninterrupted transpor- 

 tation at low water. In the basin called the 

 Valley of the Mississippi, the waters which fall 

 upon an area of more than a million square 

 miles descend from the Alleghany Range on 

 the east and the immense barrier of the Rocky 

 Mountains on the west, and are gathered into 

 a single channel which drains this wide-extend- 

 ed tract, and conducts its surplus waters to the 

 sea at a point more than four thousand miles 

 distant, by the course of the streams, from the 

 sources of the Missouri. The area of the coun- 

 try drained by this magnificent river system is 

 more than equal to all of Europe, exclusive of 

 Russia and Scandinavia. Its extent is more 

 than sixteen times that of France, and more 

 than eleven times that of the British Islands; 

 and more than two thirds of it is capable of 

 supporting a population as dense as that which 

 is embraced within the limits of the most pop- 

 ulous commonwealths of Europe. In exact 

 figures, the drainage area of the Mississippi is 

 1,244,000 square miles ; the mean annual down- 

 fall of rain is 30*4 inches ; the annual discharge 

 is 21,300,000,000 cubic feet, and the mean dis- 

 charge per second is 675,000 cubic feet. From 

 the mouth of the Missouri to the Gulf there is 

 a fall at high water of 416 feet. The average 

 width of the river between its banks from 

 Cairo to Memphis is 4,470 feet; from Gaines's 

 Landing to Red River Landing, 4,080 feet ; 

 from Baton Rouge to Donaldson vi lie, 3,000 

 feet ; from Oarrollton to the head of the pass- 

 es, 2,470. The depth at high water, taking the 

 flood of 1858 as a standard, is 96 feet at Colum- 

 bus, 119 feet near Randolph, 83 feet at Mem- 

 phis, 88 feet below the mouth of the Arkansas, 

 87 feet at Lake Providence, 120 feet seven 

 miles above Vicksburg, 111 feet at New Car- 

 thage, 118 feet at Natchez, 126 feet at Red Riv- 

 er Landing, 103 feet at Baton Rouge, 128 feet 

 just below Plaquemine, 180 feet below Bonnet 

 Carre Church, 82 feet below the Bonnet Carre 

 crevasse, 138 feet seventeen miles above New 

 Orleans, 137 feet at Carrollton, and 151 feet at 

 Fort St. Philip. The range between high and 

 low water is: at Cairo, 51 feet; at Memphis, 

 40 feet; at Natchez, 51 feet; at Red River 

 Landing, 44'3 feet ; at Baton Rouge, 31 'I feet ; 

 at Donaldsonville, 24'3 feet; at Carrollton, 

 14-4 feet; at Fort St. Philip, 4'5 feet; at the 



head of the passes, 2-3 feet ; and at the Gulf, 

 zero. The highest point of the water above 

 the mouth of the Arkansas, in the spring, is 

 usually attained in the month of March. The 

 river then subsides until the arrival in June of 

 the Rocky Mountain rise, swelled by the early 

 summer rains of the lower Missouri and the 

 eastern Mississippi basin. It then falls till Oc- 

 tober, when the lowest point is reached. Soon 

 it again rises more rapidly than at any time un- 

 til checked by the freezing and diminution of 

 rain in the upper rivers. 



In the year 1874 there were thirty crevasses 

 or breaks in the Louisiana levees alone, and 

 these occurred at intervals along the whole dis- 

 tance from the Arkansas line to Point-a-la- 

 Hache, about fifty miles below New Orleans. 

 The number, in fact, was much greater, be- 

 cause in some cases two or four, and in one 

 case as many as eleven, breaks occurred at sep- 

 arate but neighboring points, and afterward 

 combined into one. A crevasse in the levees 

 of this river may be at first a slender thread of 

 water percolating through a crawfish-hole, or 

 a slight abrasion in the upper surface caused 

 by the waves set in motion by a passing steamer 

 or by a sudden storm ; but in a few hours the 

 seemingly innocent rill is swollen to a resistless 

 torrent, the great wall of earth has given way 

 before the tremendous pressure of the mighty 

 river, and the waters rush through the open- 

 ing with a force which soon excavates it to a 

 depth of thirty or forty feet, with a great roar 

 and a velocity sufficient to draw an incautious 

 steamer into the boiling vortex. The effect is 

 not simply that of an overflow, which may sub- 

 side in a day or two. The level of the river 

 at its flood is above that of the surrounding 

 country ; and consequently, when the embank- 

 ments break, it is as if an ocean were turned 

 upon the land. In a short time the neighbor- 

 ing country is converted into a sea. Cattle and 

 horses are swept away and drowned, or forced 

 to seek refuge on the few dry spots which re- 

 main among the seething waters ; the crops are 

 destroyed, and the people are in many cases 

 forced to abandon their homes. Sometimes, 

 indeed, the land itself is greatly injured by 

 these inundations ; for, while the floods which 

 come from the Red River, or the Ohio, or even 

 the Arkansas, bring some compensation in the 

 fertilizing character of the deposits which 

 they leave behind, those of the Missouri, being 

 charged with sand and alkaline earths swept 

 down from the great deserts of the West, have 

 a pernicious and sometimes even a ruinous 

 effect on the lands which they invade. The 

 overflow of 1874 inundated in Arkansas the 

 counties of Chicot and Desha; in Mississippi, 

 the counties of Tunica, Coahorna, Bolivar, Sun- 

 flower, Washington. Issaquena, and Warren ; 

 and in Louisiana, the parishes of East Car- 

 roll, West Carroll, Madison, Tensas, Concordia, 

 Morehouse, Richland, Ouachita, Franklin, Cald- 

 well, Catahoula, Avoyelles, Pointe Coupee, St. 

 Landry (in part), East Baton Rouge (in part), 



