456 A NATIONAL PLAN FOR AMERICAN FORESTRY 



Another reason for preventing silting of the Columbia River is the 

 use of the river for navigation. The value of shipping and of rafts 

 of logs and piling moved on the Columbia River annually from 1926 

 to 1930 amounted to about $383,000,000. 



PRESENT WATERSHED CONDITIONS ON FEDERAL AND OTHER 



LANDS 



In the Columbia River Basin fire is by far the most damaging influ- 

 ence on the watershed-protection values of the forest. Summers are 

 normally rainless, and with relative humidities often below 10 percent. 

 Under such conditions the heavy accumulation of litter, the drying 

 of herbaceous vegetation, and the density of the timber growth com- 

 bine to make a serious fire hazard. Insect killing of such species as 

 lodgepole pine over extensive areas has added to the depth of the 

 litter and to the difficulty of controlling fires once they are well started. 



Fires burn hundreds of thousands of acres in the Columbia River 

 Basin nearly every year. In dry years the fire situation becomes 

 almost catastrophic. Very drastic and energetic measures have been 

 taken by the Forest Service to overcome the extreme natural fire 

 hazard and reduce the national-forest area burned yearly to a point 

 at which, serious impairment of timber growth or watershed values 

 will not be involved. In northern Idaho, for example, for watershed 

 areas where the watershed-protection values of the forest are classed 

 as moderate the best information available places the permissible 

 burn at about 0.7 percent per year, or 7 percent in 10 years. Where 

 the watershed-protection values of the forest are rated as high, the 

 limit of annual burn should not be greater than one half of 1 percent. 

 Even on national-forest lands, unfortunately, the average area burned 

 during the 10-year period 1921-30 exceeded the allowable percentage, 

 particularly in the valuable commercial timber types such as the 

 larch-fir, western white pine, and cedar-hemlock. On the Clark Fork 

 River drainage 24 percent of the western white pine area was burned 

 over. If such losses continue, profitable timber growing in these 

 valuable types will become impossible. For timber production, 

 allowable burns in these types would normally be less than those 

 indicated above for watershed protection. Accordingly if fires can 

 be so far controlled as to permit profitable timber production, it is 

 reasonable to assume, watershed-protection requirements will be met. 



On private lands outside the national forests fire protection is even 

 less satisfactory. It is probable that few private owners will attempt 

 to carry their cut-over land until it is ready for another cut, for much 

 of this land has already been devastated by excessive cutting and 

 fires. As more and more private lands are cut over the incentive for 

 fire protection becomes less. Thus it is to be expected that damage 

 to watershed values by fire on private lands will increase unless more 

 adequate fire protection is provided. 



Large areas of cut-over land are reverting to public ownership for 

 nonpayment of taxes. On many such areas, fire control is far from 

 what it should be. Timber cutting is often severe, and where fire 

 follows cutting devastation is widespread, materially influencing the 

 watershed values. On some rather large areas still in the unreserved 

 public domain, reburns of timberlands cut over in the early days are 

 greatly adding to deforestation. 



