OVERFLOW OF RED RIVER OF THE NORTH. 17 



were tabulated or plotted as curves showing various relations. Run- 

 off records were studied and the problem of the relation between pre- 

 cipitation and run-off was approached from various angles in an 

 effort to reach reliable conclusions as to maximum rates of flow 

 which may occur in the different parts of the Red River, the coinci- 

 dence of heavy flow in the various tributaries, and the probable time 

 intervals between damaging flood stages. 



DRAINAGE. 



The drainage situation over the watershed was studied in consid- 

 erable detail. The flat land along both sides of the main watercourse 

 was considered separately from the higher, baddy ing areas, as its 

 drainage is more intimately related to the conditions of flow in the 

 main channel. Areas affected by present drainage of these flats were 

 determined and estimates made as to probable future drainage and 

 its effects. 



Considerable areas of land along the Bois de Sioux River lie only 

 slightly higher than the normal water surface in that stream. Under 

 high- water conditions these lands are submerged and form a part of 

 the bed of Lake Traverse. At all times these areas are marshy and 

 unfit for agricultural purposes. Estimates were made as to the 

 amount of such land reclaimable and the extent of improvement pos- 

 sible. Details for the complete drainage of the areas were not worked 

 out, but plans for the main channel improvement of the Bois de 

 Sioux include the layout of main outlet ditches necessary for the 

 disposal of overflow water and of the flow from future local drains. 



The general conditions of drainage systems in all parts of the 

 watershed were investigated. The question of tile drainage, its prob- 

 able development and general effect on the outlet channels, was also 

 considered. 



FLOODS. 



In studying the flood situation the main object was to determine as 

 accurately as possible the extent of damaging flow with correspond- 

 ing river stages, the probable frequency and magnitude of future 

 floods, and the maximum flow that may be expected. The studies of 

 precipitation, run-off, and effects of drainage were made mainly for 

 this purpose. Information concerning floods from whatever source 

 was considered and given such weight as its importance and relia- 

 bility seemed to warrant. 



MEASURES FOR RELIEF. 



Relief measures were considered under two heads, drainage and 

 flood relief. The question of draining the wet lands along the Bois 

 de Sioux River was taken up along with that of the detention reser- 

 70352°— 22 2 



