SOME GEOLOGICAL ASPECTS OF ARTIFICIAL DRAINAGE IN 
IOWA. 
BY G. G. WHEAT. 
Nature's unfinished work in the Wisconsin drift areas of Iowa has 
left the lands peculiarly subject to submergence in times of heavy pre- 
cipitation. The magnitude of the drainage projects which would be 
required to carry out the incomplete work of Nature’s young river sys- 
tems, for a long time held back the development of drainage. Recent 
legislation, making possible the creation of drainage districts upon the 
petition of a reasonable number of land holders interested, has led to a 
most rapid growth in farm land drainage. Those who are familiar with 
the topography of the Wisconsin Drift area, in the counties of Cerro Gor- 
do, Hancock, Palo Alto , Eastern Clay, Humboldt, Pocahontas, Eastern 
Buena Vista, Calhoun, Webster, Hamilton, Worth, Winnebago, Kossuth, 
Emmet and Dickinson, are aware that the Des Moines, Iowa and Cedar 
rivers have developed very few tributaries; that these are not deeply 
eroded and that the headwaters of these branches frequently rise in a 
marsh. The second typical feature of this region is the saucer-like basins 
or upland ponds, which usually have no outlet, except that one side may 
be a little lower than the other by a few inches. Drainage districts in this 
area almost always show chains of these ponds, united by extremely 
shallow depressions, unworthy of* the name of ravine, coulee, or even 
swale. Depressions so slight as to be invisible to any but the practiced 
eye, when the fields are uniform in color in winter. 
The methods used at present in drainage, are those which first sug- 
gested themselves to the mind of man who has no other desire than to 
get rid of the water. Beginning at some point where an outlet can be 
secured, at the lower end of the drainage system, open ditches are con- 
structed, leading toward the upper limits of the water-shed. Frequently 
other open ditches are branched from this in dendritic system, although 
sometimes a drainage plat makes me want to use another term and say, 
the branches are in hieroglyphic fashion. When the open ditch has been 
carried far enough so that a 30-inch diameter tile is sufficient to take 
care of waters from the remaining water-shed above, tile are then laid, 
the extreme limits of the drainage system being the last small branches 
laid by individual farmers, draining their acres. 
