46 FIELD OPERATIONS OF THE BUREAU OF SOILS, 1918. 



DRAINAGE. 



The principal drainage problem of Louisa County lies in protecting 

 the river bottoms from overflow and at the same time taking care of 

 the drainage from the uplands as well as the heaviest precipitation 

 on the bottom lands. 



The first bottom along Cedar River is narrow and of comparatively 

 little importance. No attempt has been made either in this county 

 or, as far as known, in the one to the north to construct levees along 

 this stream. 



The first bottom of the Mississippi River is protected from over- 

 flow by a levee under Government control, which roughly parallels, 

 at a short distance, the bank of the river. This levee occurs in this 

 county in two parts. The northern one comes into the county from 

 the north within a hundred yards of the river bank and, except in a 

 few high places where a levee is unnecessary, continues in a general 

 southerly direction, tying into the upland bluff just north of Tooles- 

 boro. The southern part of the levee is an extension of the one along 

 the south side of the Iowa River and roughly follows the bank of the 

 Mississippi River, continuing on into the county south. 



The drainage of the bottom inclosed by the northern part of the 

 levee is accomplished by canalizing what was formerly Muscatine 

 vSlough and other former ponds, sloughs, and lakes, and by connect- 

 ing these and other artificial drainage ditches, conducting the water 

 to the pumping station just north of Port Louisa, and there raising 

 it over the levee and into the river. The drainage of the land south 

 of the pumping station is less satisfactor\^ than that of the land to the 

 north, owing to the fact that the natural fall of the land is in the op- 

 posite direction from that in which the water must drain to the pump- 

 ing station. At the point where the levee blocks the Muscatine Slough 

 from flowing into the river, pipes have been constructed which allow 

 water to flow from the slough to the river when the water is lower in 

 the latter and prevent any flow from the river to the slough when 

 conditions are reversed. The construction of a second pumping 

 station in the south end of this district is now under consideration. 



Drainage of the land inclosed by the southern part of the levee is 

 accomplished in a similar manner. Iowa Slough is the main drain- 

 ageway. A pumping station located on the levee 1 mile south of the 

 south county boundary handles the water from this area. 



The drainage of the Iowa River bottoms is for the most part in 

 charge of the county board of supervisors. It is organized by dis- 

 tricts, each comprising a separate area protected by a levee. The 

 methods of drainage are tlie same as those used in the Mississippi 

 River bottoms, except that the drainage channels are much smaUer 

 and that in some districts, instead of pumping stations, ''pipes" 



