SOIL SURVEY OF WRIGHT COUNTY. IOWA. 7 



The county has a simple natural drainage S3'stem, rather poorly 

 developed, since a longer period is needed to develop an elaborate 

 network of streams than has elapsed since the drift was deposited. 

 Two rivers and their few tributaries carry all the drainage water 

 of the county. The tributaries have the form of natural streams 

 only a short distance from their mouths, their upper courses having 

 been straightened and deepened by dredging. Many large open 

 drainage ditches and covered concrete mains empty into them. Some 

 sloughs and depressed areas are still undrained. 



The northern and eastern parts of the county are drained by the 

 Iowa River and its few short tributaries. This river enters the 

 county 4 miles north of Belmond, takes a general southeasterly 

 course, leaves the county 1 mile north of Dows, reenters it about 

 one-half mile south of Dows, skirts the county line for 3 miles, 

 and then turns abruptly eastward into Franklin County. The 

 winding channel of the Iowa River has a somewhat narrow flood 

 plain, ranging from a few hundred feet to three-eighths of a 

 mile in width. The current is rather slow except during high water. 

 A continuous terrace, or second bottom, from one-eighth mile to 2 

 miles in width, extends from the north boundary of the count}^ 

 along the river to within 2^ miles of Belmond. It reappears north 

 of Dows and follows the river throughout the rest of its course in 

 the county. Three and one-half miles south of Dows, where the 

 river leaves the county, the terrace extends back nearly 3 miles 

 along a small creek, which has been dredged to accelerate its slug- 

 gish current. It has an average width of about one-half mile along 

 this creek. 



The West Branch of the Iowa River enters the county 5 miles 

 northwest of Belmond and joins the main stream one-half mile north 

 of Belmond. Its present channel at the county line and northward 

 is a large dredged ditch. 



The Boone River and its tributaries drain the rest of the county 

 west of the morainic hills. This stream flows in a channel ranging 

 from about 10 feet below the level of the upland where it enters the 

 county, to 60 feet below where it crosses the southern boundary. It 

 is sluggish and meanders back and forth across its bottom land, 

 which is from 20 feet to about one-fourth of a mile wide. Occa- 

 sional broken strips of bench-like terraces well above overflow are 

 found in the concave bends of the river. At the lower end of the 

 river these terraces are about 30 to 40 feet above the stream. The 

 valley walls range from short, gentle slopes along the upper course 

 to steep, nearly parallel walls, 50 to 60 feet high, where the river 

 leaves the county. 



