65 



« 



5, 1878, February 17, 1883, and March 15, 1907. The flood of 1913 reached 

 a mark 22 inches higher than the record of 1883 at Lafayette, Ind., and ex- 

 ceeded all records at Peru and Logansport by as high as 8 feet. The flood of 

 1883 was produced at Lafayette by an ice jam which formed about a mile 

 below the city. The damage done was due to slack water, while the present 

 flood caused the partial destruction of three large steel bridges bj' extra- 

 ordinary erosion of the river bottom in the restricted sections. 



One student lost his life in an attempt to rescue men marooned on the 

 Brown-street levee, when the latter washed out on the west of them and the 

 bridge fell on the east of them. High water closed the gas works, the two 

 water-works pumping stations, the city heating and lighting plant and many 

 ind.ustries; one light and power plant continued in operation although its 

 condensers and pumps were under 7 feet of water. 



The drainage area with its tributaries above Lafayette, as shown in Fig. 

 1, includes an area of about 7,300 square miles, of which 400 are in Ohio. The 

 whole of this area is in a glaciated area, the depth gradually decreasing east 

 of this point until near Logansport, Ind., the bed of the river is in rock. East 

 of that point the deposit varies in thickness. 



The drainage area is practically clear of forests and under cultivation. 

 The average fall of the river is about 18 inches per mile here and increases 

 in the upper portions. There are numerous islands and sand bars which form 

 and are swept away in periods of high water. The soil wash is high and the 

 loss therefrom is a matter of great moment. The high turbidity is, of course, 

 a factor in the erosive action which is so characteristic of the rivers of the 

 Mississippi Valley. 



The elevation of the head waters above M. H. T., New York harbor, is 

 about 1,000 feet; at Huntington, 699 feet; at Logansport, 583 and at Lafayette, 

 500 for low water. 



Rainfall data preliminary to the hydrograph, Fig. 3, are given in Table L 



TABLE I. RAINFALL DATA OVER WABASH RIVER DRAINAGE AREA. 



(Measured by Experiment Station at Purdue I'niversity.) 

 Date Inches. 



Average annual precipitation 50 



Greatest annual precipitation, 1909 55 



Greatest monthly precipitation June, 1902 11.37 



Greatest precipitation in twenty-four hours, August 12, 1912 4 . 30 



Rainfall for March, 1913 7.05 



The hydrograph shows a remarkable relationship between rainfall and 

 runoff for a watershed of this area — 7,300 square miles. From March 1 to 

 5—1010 



