404 A NATIONAL PLAN FOR AMERICAN FORESTRY 



ARKANSAS AND RED RIVER DRAINAGES 



The Arkansas River heads in the Rocky Mountains of southern 

 Colorado and northern New Mexico, and after flowing tlirough the 

 plains passes through the mountains in Arkansas to reach the Missis- 

 sippi. The Red River rises in the foothills of the Rockies in west 

 Texas, flows through the Red Plains, skirts the southern edge of the 

 mountains in Arkansas, and empties into the Mississippi River in 

 central Louisiana. The region drained by these rivers is shown in 

 figure 6, which indicates also the location of the forests in these drain- 

 ages and their relative influence upon watershed conditions. Of the 

 total forest area of 52,220,000 acres 34,560,000 acres, or 66 percent, is 

 classed as having a major influence upon watershed conditions, 

 15,525,000 acres, or 30 percent, as having a moderate influence, and 

 only 2,135,000 acres, or 4 percent, as having little or no influence. 



FLOODS AND EROSION 



The Arkansas and Red River drainages contribute proportionally 

 more to the floods of the Mississippi River than any other section of 

 the great Mississippi Basin. The greater part of this contribution 

 has its source in the Ouachita-Ozark Mountain area of southern Mis- 

 souri, Arkansas, and eastern Oklahoma; records of the Mississippi 

 River Commission show that at the times of the great flood disasters 

 of 1915, 1922, and 1927, and at other times, this mountain area, 

 although constituting only about 5 percent of the total area of this 

 Mississippi River Basin, has contributed as much as 40 percent of the 

 flood waters in the delta region of the Mississippi. The records show 

 also that the Ouachita-Ozark section contributed more than 50 per 

 cent of the peak flow on May 1, 1927, and nearly 25 percent of the 

 peak on May 7, 1927. 



The White River, a tributary of the Arkansas River that drains 

 northern Arkansas, contributes heavily to these flows. W. W. Ashe, 

 using data of the Chief of Engineers, United States Army, has shown 

 that the drainage of the White River, although it contains only 2 per- 

 cent of the total Mississippi Basin, contributed 7.3 percent of the 

 flood waters of the lower Mississippi in the period 1911-27, inclusive. 

 He pointed out that the western portion of the Arkansas River drain- 

 age, although a much larger area, contributed less than 2 percent of 

 the same flood waters. The White River, as its name implies, origi- 

 nally ran clear. For the year 1927 its silt burden was estimated by 

 Ashe at nearly 3 million tons, or 105 tons per square mile of drainage 

 area, or 11 percent of the total silt load of the Arkansas. 



Ashe estimated the total annual silt load carried by the Arkansas 

 at some 26 million tons. Of this, he estimated only 5 million tons 

 came from the Ouachita Province. A large part of this silt load 

 reaches ^the Gulf; the heavier and coarser material, however, is de- 

 posited in slack water at or near the mouth of the Arkansas and is the 

 chief cause of shifts of the stream banks and of the channel at that 

 point which sometimes have serious consequences in time of flood. 



The western part of the Arkansas and Red River drainages is 

 characterized by different stream-flow conditions. Floods are much 

 more rare, and where the Arkansas passes out of the Rockies it usually 

 runs clear. The water problem is one of getting sufficient supplies 

 for irrigation ; in a considerable portion of southeastern Colorado and 



