OVERFLOW OF RED RIVER OF THE NORTH. 61 



precipitation without overflow. Three conditions make additional 

 surface drainage necessary : (1) Flat or nearly level land surface 

 without natural drainage channels; (2) depressions in which water 

 collects and stands because of lack of outlet; and (3) natural chan- 

 nels too small to serve properly the areas they drain. Heavy soils 

 or other conditions make underdrainage necessary in many localities. 

 The north shore line of Lake Traverse is not well defined (see fig. 3, 

 sheets 2 and 3), and during high stages the lake overflows the land 

 several miles to the north. Much of this land has been or is now 

 cultivated and the remainder is used to some extent as hay land. 



The present channel of the Bois de Sioux is entirely inadequate to 

 carry the water that comes to it from Lake Traverse (see PI. V, fig. 1) . 

 The cross sections (fig. 4) show that near Lake Traverse the stream 

 has practically no channel. As one goes downstream the size of the 

 channel gradually increases until at Breckenridge it is large and well 

 defined. The Mustinka River, which drains 852 square miles, rises in 

 the hills near Fergus Falls and flows south about 25 miles and then 

 west and southwest to Lake Traverse. Practically all of the water- 

 shed of the Mustinka in Traverse County (see fig. 1) has been drained 

 by ditches spaced approximately 1 mile apart. In that county the 

 channel of the Mustinka has been dredged and straightened for a con- 

 siderable portion of its course. The Rabbit River drains approxi- 

 mately 300 square miles lying north and west of the Mustinka. It 

 enters the Bois de Sioux about 10 miles south of Breckenridge (see 

 fig. 3, sheets 3 and 4) . As shown in fig. 1, a considerable portion of its 

 watershed has been drained by open ditches spaced 1 mile apart. 

 From a point about 4 miles south of White Rock, S. Dak., north to 

 Fairmount, N. Dak., there is a strip of land along the Bois de Sioux 

 which is frequently overflowed. From Fairmount north to Brecken- 

 ridge the lands are occasionally overflowed. At times serious damage 

 is caused by water from the Wild Rice River in North Dakota break- 

 ing out of its banks, flowing east, and flooding the land between its 

 channel and the Bois de Sioux. Similar conditions exist on the Rab- 

 bit River and Otter Tail River, which flood land southeast of Breck- 

 enridge. 



As the channel of the Bois de Sioux is too small to remove the 

 water which comes to it when heavy rains occur, much land is flooded 

 and the drainage of the higher-lying lands is obstructed. The flood 

 water drains off slowly through the inadequate watercourse or remains 

 on the land until evaporated. In years when heavy rains occur dur- 

 ing the summer months, the crops are seriously damaged or com- 

 pletely destroyed. This damage becomes more serious if preceded by 

 a wet spring. Floods are frequently caused by the melting of snow 

 in the spring. These spring floods cause some damage by interfering 

 with farming operations and prevent planting at the proper time. 



