PART I. MISSISSIPPI FLOOD CONTROL BASIS FACTORS IN FLOOD FREQUENCY IN THE LOWER MISSISSIPPI RIVER.. Lewis F. Thomas, Associate Professor of Geography, Washington University, St. Louis THE GEOGRAPHY OF THE MISSISSIPPI VALLEY. Frank E. Williams, University of Pennsylvania THE IMPROVEMENT OF OUR MID-WEST WATERWAYS.. Herbert Hoover, Secretary of Commerce THE REPORT OF THE COMMITTEE ON MISSISSIPPI FLOOD CONTROL APPOINTED BY THE UNITED STATES CHAMBER OF COMMERCE..... Frederic A. Delano, Chairman of the Committee Major General Edgar Jadwin, Chief of Engineers WHAT FORESTS CAN DO FOR THE MISSISSIPPI RIVER. E. A. Sherman, Associate Forester, United States Forest Service A POLICY FOR THE MISSISSIPPI... Arthur E. Morgan, President, Dayton Morgan Engineering Company, Vice President, SOME ESSENTIAL PRINCIPLES OF CONSERVATION AS APPLIED TO MISSIS- PART II. THE ST. LAWRENCE WATERWAYS FROM THE LAKES TO THE SEA Fayette S. Warner, University of Pennsylvania A SYNOPSIS OF THE HOOVER REPORT ON THE ST. LAWRENCE SHIPWAY.. G. B. Pillsbury, Lieut. Colonel, Corps of Engineers, United States Army WHAT THE ST. LAWRENCE WATERWAY MEANS TO THE UNITED STATES.. W. L. Harding, President, Great Lakes-St. Lawrence Tidewater Association THE ECONOMIC AND NATIONAL SIGNIFICANCE OF CONNECTING THE PART III. BOULDER DAM PROBLEMS OF THE COLORADO RIVER.. 123 Arthur P. Davis, Chief Engineer and General Manager, East Bay Municipality District, WHAT THE BOULDER DAM PROJECT MEANS TO CALIFORNIA AND THE 127 Clyde L. Seavey, Member of the California State Railroad Commission 133 THE COMPANY POINT OF VIEW REGARDING BOULDER DAM.. 141 143 R. O. E. Davis, Fertilizer and Fixed Nitrogen Investigations, Bureau of Chemistry and Soils, United States Department of Agriculture NITROGEN AT MUSCLE SHOALS. 166 Chester H. Gray, American Farm Bureau Federation, Washington, D. C. THE PUBLIC SERVICE OF MUSCLE SHOALS... 172 Mrs. Harris T. Baldwin, Living Costs Committee, National League of Women Voters BOOK DEPARTMENT.... 177 INDEX.. 185 SUPPLEMENT GREAT BRITAIN'S RECENT TREND TOWARD PROTECTION.. 189 ARE Mississippi River By LEWIS F. THOMAS, PH.D. Associate Professor of Geography, Washington University, St. Louis, Missouri 172,000 or 14 per cent, Missouri River 528,850 or 42 per cent, Ohio River 203,900 or 16 per cent, Arkansas River 186,000 or 15 per cent, Red River 90,000 or 7 per cent, and Lower Mississippi River 70,150 or 6 per cent. RE great floods becoming more as follows: Upper Mississippi River frequent in the Lower Mississippi River? In terms of volumes of water involved, the answer is no, since the fundamental physical causes of these floods are substantially unchanging. In terms of dollars in losses, the answer is yes, since the economic development of the areas affected is progressively becoming more valuable. The greatness of a flood may be expressed in various ways, (1) by the size of the areas inundated, (2) by the value of the economic losses sustained, (3) by the height of the gage readings, and (4) by the volume of the waters discharged. The records of the United States bureaus show that there have been notable floods in the years, 1815, 1828, 1844, 1849, 1850, 1851, 1858, 1859, 1862, 1865, 1867, 1874, 1882, 1884, 1890, 1893, 1897, 1903, 1912, 1913, 1916, 1922 and 1927. Since 1871 careful and detailed flood records have been kept at all strategic flood points in the Mississippi Basin. Because of the data available, the floods subsequent to 1871 have been studied individually and collectively. The floods prior to 1871 are known only in a general way through the compilation of data from numerous and miscellaneous sources. A resume of the general conditions which exist in the Mississippi Basin gives the setting of flood causation. THE MISSISSIPPI RIVER BASIN The Mississippi Basin comprises some 1,250,900 square miles which are apportioned among its major divisions The Upper Mississippi River is about 1200 miles in length. It has as its important tributaries the Leach Lake, Crow Wing, Minnesota, St. Croix, Chippewa, Wisconsin, Rock, Illinois, Iowa, and Des Moines rivers. The headwaters of the rivers which rise in northern Wisconsin, upper Michigan, and northern Minnesota wind in circuitous courses through lakes, swamps, and bogs in the timbered morainic hills of sand and gravel. These features tend to check rapid run-off and as a consequence few floods arise from this region. The prairie portions of the Upper Mississippi Basin are in southern Wisconsin, southern Minnesota, eastern Iowa, and northern Illinois. The once vast tree dotted grasslands are now productive with abundant farm crops, and numerous livestock. The Missouri River, which is formed by the confluence of the Jefferson, Madison, and Gallatin rivers, in the southwestern part of Montana, flows 2824 miles in a southeasterly direction to join the Mississippi River a few miles above St. Louis, Missouri. Its principal tributaries are the Milk, Marias, Sun, Yellowstone, Grand (South Dakota), Cheyenne, White, Niobrara, Platte, Kansas, Osage, Grand (Missouri), and Gasconade rivers. The few of the rivers which rise on the eastern slopes of the Rocky Mountains are fed from springs, lakes, and snow fields of that region. The major portion of the Missouri Basin lies in the semi-arid Great Plains. Here the streams are sluggish, turbid, full of shoals and islands, and bordered by easily eroded banks of sand and clay. On the flood plains fields of irrigated crops have replaced the sickly fringe of cottonwoods and willows which once lined the water courses. On the wide gently undulating interstream areas ranching prevails with some dry farming. The tributaries of the lower Missouri Basin drain the western portion of the Corn Belt, or the northern slopes of the Ozarks. The rivers of the Corn Belt section in eastern Nebraska, eastern Kansas, western Iowa, and northern Missouri have numerous tributaries which have carved the uplands into belts of gently rolling hills or flat-topped ridges. The northern slopes of the Ozarks are maturely dissected hills whose steep rocky sides favor swift streams, rapid run-off and sudden floods. The basin of the Gasconade River is typical. The length of the Ohio River from Pittsburg, Pennsylvania, to Cairo, Illinois, is 965 miles. The headwaters, the Allegheny and Monongahela rivers, together with the tributaries Licking, Muskingum, Little Kanawha, Great Kanawha, Big Sandy, Kentucky, Cumberland, and Tennessee rivers drain the wooded rugged, rocky hills of the Appalachian Plateaus. The clearing of some of the forests together with the steepness and completeness of surface drainage provide conditions favorable for sudden rises in these rivers in periods of heavy rains. Other important tributaries to the Ohio River are the Scioto, Miami, and Wabash rivers. These rivers in western Ohio, Indiana, and eastern Illinois (the eastern Corn Belt) are similar to those in the western Corn Belt. The Arkansas River rises in central Colorado, in the Rocky Mountains. After passing through the Royal Gorge, it emerges on the Great Plains; crosses eastern Colorado, southern Kansas, northeastern Oklahoma, and central Arkansas; and empties into the Mississippi River in southeastern Arkansas. In its 1610 miles, it resembles the Missouri River features. Its headwaters are clear on a bed of pebbles and rock. In the Great Plains section, the Cimarron and Canadian tributaries add their contribution of mud and quick sand to that of the Arkansas. The lower Arkansas flows through a region rich in agriculture of the plantation type where cotton and rice predominate. The most volume is added by the White River which rises in the rugged hills of the Ozarks and Boston Mountains. The Red River is about 800 miles in length from its sources in west Texas to the Lower Mississippi in Louisiana. Its flow through much of its course is scanty and precarious, since it is dependent solely upon immediate run off from rains. In its lower course it fares better in a region of more abundant and regular rainfall. The Lower Mississippi River extends from the mouth of the Missouri River to the passes at the Gulf of Mexico. About half of the basin is alluvial floodplain type comprising some 30,000 square miles. These plains are about 600 miles in length, but the river meanders through a course exceeding 1100 miles. The surface has a very low gradient which combined with the oxbow lakes, sloughs, and bayous, and with the timbered sections favors very slow run-off of precipitation. Prior to the building of levees and the organization of drainage districts much of the basin was subject to inundations and as a consequence lay idle. Since these projects have been completed large sections are cultivated and devoted to cotton growing. It is this basin that suffers most from floods in the Mississippi River system. OCCURRENCE OF SEVERE FLOODS The comparative severity of floods is usually determined by levels reached by the various floods on the same gage. By way of illustration, the gage at the mouth of White River, Arkansas, may be selected as typical of readings along the Lower Mississippi River. The gage is located 391.7 miles below Cairo, Illinois, and has its zero at 108.86 feet above mean Gulf level. The highest annual minimum is 14.20 feet, while the majority of such readings are below 7.00 feet. The flood stage at this station is 48.00 feet. The years when floods attained or exceeded this mark are: 1862, 48.20; 1882, 48.40; 1883, 48.00; 1886, 48.20; 1890, 50.40; 1892, 49.27; 1893, 49.48; 1897, 52.42; 1898, 51.05; 1899, 48.49; 1903, 53.70; 1904, 49.50; 1906, 49.80; 1907, 51.90; 1908, 49.50; 1909, 49.95; 1911, 48.33; 1912, 56.35; 1913, 55.35; 1916, 56.50; 1917, 51.57; 1919, 49.38; 1920, 53.10; 1922, 56.85; and 1927, 60.25. It is quite apparent that there is a tendency toward higher and higher readings culminating in the record breaking flood of 1927. An examination of other Lower Mississippi River stations reveals similar trends. Further survey of the flood data shows that stations on the major tributaries have their record maximum in different years, and that even on the same tributary stations may have had the records set in different years. On the Upper Mississippi River, these gages recorded their maximum as indicated; St. Paul, Minnesota, 1881; Winona, Minnesota, 1880; Rock Island, Illinois, 1892; Burlington, Iowa, 1851; Nashville, Iowa, 1888; Hannibal, Missouri, 1903; St. Louis, Missouri, 1844. On the Missouri River, the record maximum was made at Kansas City, Missouri, in 1844, and at St. Charles, Missouri, in the same year. On the Ohio River, the records were broken at Pittsburg, Pennsylvania, 1907; at Cincinnati, Ohio, 1884; at Louisville, Kentucky, 1884; at Evansville, Indiana, 1844; at Paducah, Kentucky, 1913; and at Cairo, Illinois, 1927. On the Red River at Shreveport, Louisiana, and on the Arkansas River at Little Rock records were set in 1927. The area of the overflowed land has varied during the various great floods due to the holding, extension or breaking of the levees. Before 1880 the Lower Mississippi River had practically free, open, and unrestricted channel conditions, so that the areas flooded by severe floods were about the same each time: 29,790 square miles. Beginning in 1880, there has been progressive extension, raising, and strengthening of levees. By 1916 the river was practically canalized from Cairo to the Gulf. The effects of this levee building have been more pronounced than the figures indicate, because the flood marks at stations below Cairo, Illinois, have been changed to meet the new conditions several times since 1896. Contemporaneous with the building of levees has occurred a general shrinkage in the area flooded as is indicated: 1897, 13,580; 1903, 6,820; 1912, 17,605; 1922, 13,200; and in 1927 when the levee system collapsed, estimated 15,000 to 18,000 square miles. The losses may be classified as, (1) property losses exclusive of crops, (2) crop loss and damage, (3) damage to farm lands, and (4) losses occasioned through enforced suspension of business. The estimated losses for 1897 were $15,000,000 for agricultural damage. In |