OVERFLOW OF RED RIVER OF THE NORTH. 73 



of 36,000,000,000 cubic feet, which will hold the estimated maximum 

 annual flow of 25,000,000,000 cubic feet with a margin of 44 per cent. 



RED LAKE EIVER. 



The Red Lake River has its source in Red Lake and has a length 

 of 193 miles. It flows in a northwestery direction for 71 miles to 

 Thief River Falls, thence in a southwesterly direction for about 61 

 miles, and thence in a northwesterly direction for about 61 miles to 

 its junction with the Red River of the North at East Grand Forks, 

 Minn. 



For about the first 37 miles at the upper end there is no definite 

 valley, the stream following a tortuous course through the flat, 

 swampy country with its bed about 5 feet below the general land 

 level. Owing to the slight fall the channel has been obstructed and 

 filled in until it is inadequate to carry even the normal high- water 

 discharges without overflowing the. adjacent land. The valley takes 

 form at High Landing; it is about one-eighth mile wide at Thief 

 River Falls and the width increases to three-fourths of a mile at the 

 mouth. Between Thief River Falls and Crookston the river de- 

 scends in a series of short rapids. Below Crookston the fall decreases, 

 giving depth and velocities of flow which permit navigation by small 

 launches between Fisher and East Grand Forks. Below High Land- 

 ing the banks are of sufficient height to prevent overflow under high- 

 water conditions except on the lower portion just below Fisher (fig. 

 3, sheet 13), where at extreme high stages the river breaks over and 

 a part of the flow discharges through the Grand Marais (fig. 3, 

 sheet 14). There are but two tributary streams of importance, the 

 Thief River entering from the north at Thief River Falls, and the 

 Clearwater River entering from the east at Red Lake Falls. 



CONTROL OF RED LAKE. 



The dam proposed for the control of the lake stage is of the ordi- 

 nary type of reservoir dam adopted in that district, and consists of 

 " a reinforced concrete floor resting on pile foundation, which in 

 turn supports alternate piers and stop-log sluices." To prevent the 

 refilling of the excavated outlet by littoral drift, it is proposed to 

 construct jetties of loose bowlders extending about 1,600 feet out into 

 the lake to the end of the excavated channel. The log sluice provided 

 in the dam may be used for the passage of small launches between the 

 river and lake. Tentative location for a regular lock was selected, 

 should navigation ever warrant its construction. 



IMPROVEMENT OF RED LAKE RIVER. 



As the extent of navigation does not warrant the expensive opera- 

 tions necessary to render navigable the stretch of river from Thief 



f 



