152 
IOWA ACADEMY OP SCIENCE 
The magnitude of some of these undertakings may h^ve been over- 
looked by some members of the academy. Kossuth County has one 
drainage ditch costing in the neighborhood of $483,000 for the mains 
alone. The laterals which the land owners will lay will amount to fully 
four times the cost of the original ditch, making a total expenditure of 
approximately $2,500,000. This project is. a logical extension of the 
East Branch of the Des Moines River and brings easily and quickly 
within the water-shed this acreage which formerly has had no outlet, 
except such outlet as was gained by overflow from the depressions, when 
rainfall became excessive, and the other outlet is straight up, by evapo- 
ration, which is, of course, too slow an outlet to render the land of agri- 
cultural value. 
A second type of river improvement found necessary for the reclama- 
tion of lands, can be, ^studied in the Harrison-Monona Ditch, which dif- 
fers so widely from the one, just mentioned that it might well become 
the subject of an entirely independent study, were it not for the fact 
that the problems involved are so intimately related to the problems and 
the work of the first type of reclamation that it is deemed permissable 
and wise to discuss it in relation to the former. In this second case of 
the improvement of the Little Sioux Riyer in Harrison and Monona 
Counties, the project costs nearly the same, one-half million of dollars. 
It is there planned to straighten the native channel of the river, until 
three times the original carrying capacity is secured. Parallel to this 
new river channel an immense ditch is being dug that, in places, is 
eighteen feet deep, 90 feet from berm to berm on top and 30 feet across 
the bottom. The capacity of this dug ditch is estimated at four times 
the original carrying capacity of the native river channel, making an 
increased power of run-off fully seven times that of the native stream. 
The object sought in this case is to provide free run-off for the waters, 
which formerly have flooded the low flats of the river valley. Those of 
you who have examined the flood plains of the tributaries running into 
the Missouri River form Western Iowa, have discovered that, in many 
cases, if possibly not in all, the river has built levees for itself until it 
meanders through alluvial soil of its own deposit at a level considerably 
higher, sometimes as much as four or five feet, than the level at the foot 
of the blufls some miles away. 
A third feature sought for in the drainage of these Iowa lands is the 
reclamation of swamp, bog and shallow lake. .These are, again, a sepa- 
rate problem in drainage engineering and are frequently so treated; 
Yet, to the hydrographer, whom we, unfortunately, have not had on our 
drainage work, these lakes and bogs at once appeal as being intimately 
