LAND DBAINAGE BY MEANS OF PUMPS. 9 



for small, isolated tracts of valley land whose reclamation had been 

 deferred because of the heavy expense attached. The future will see 

 the reclamation of both larger and smaller districts. 



LEVEES. 



The protective levee begins at the bluff at one end of the district, 

 follows along the bank of the entering tributary to its junction with 

 the river, thence along the river bank to the other tributary, and up 

 that again to the bluff. Thus, ordinarily, the levee extends con- 

 tinuously around three sides of the district. The correct location of 

 the levee to secure a good foundation and to leave sufficient flood- 

 way for the river, and its proper construction of sufficient strength to 

 resist erosion, undermining, and overtopping, are engineering ques- 

 tions of vital importance to the welfare of the district. It was the 

 unfortunate experience of nearly every one of the early levee dis- 

 tricts on the Illinois River that, as first constructed, the levees were 

 entirely inadequate in size and strength, with the result that they 

 were broken by floods, their interiors were inundated, and years 

 elapsed before the districts recovered from the injury. With the 

 interior of a district in cultivation the damage from one flooding due 

 to a break in the levee might easily exceed the entire cost of building 

 a levee of ample size to protect the district. This has occurred on a 

 number of the levee districts on both the Illinois and the Mississippi 

 Rivers. The levees on the Warsaw-Quincy District were originally 

 built and later repaired and strengthened at a total cost of about 

 8500,000. This district was flooded in four different years, and each 

 time the estimated damage was over $600,000. By spending the 

 proper amount of money originally a saving of at least $1,500,000 

 could have been made. The total cost of the levees, including first 

 cost, repairs, and enlargements on the Sny Island District was 

 about $1,125,000. The estimated damage of five years of flooding 

 between 1876 and 1903 was approximately $2,700,000. Similar 

 damage has resulted in many levee districts. The older a district 

 becomes, the greater the damage which may result from a break in 

 the levee. In the construction of the levees around new districts 

 the need of an ample margin of safety is now generally admitted, 

 and many of the older districts are enlarging levees which have 

 withstood record high-water stages in the adjoining river. Officials 

 and landowners in levee districts should make certain, that the levee 

 i- properly designed, located, constructed, and maintained. 



LOCATION. 



The locution of the levee will influence its design, construction, and 



maintenance. Intelligent location will aid in avoiding poor levee 



material and bad foundation. Every effort should be made to avoid 



locating the levee where it will he. exposed to strong currents or direct 



I Bull. 304 L5 —2 



