169 



Kondolf: Cumulative Effects in the Sequoia National Forest 4 



contribution of roads. For example, in the CWE "analysis" for 

 the Casa-Guard Sale, many road segments were counted as only as 

 2% of their actual acreage, a gross violation of the assumptions 

 of this method. 



Deliberate Alteration of Watershed Information Used as Input to 

 the 'Analysis' 



Documents obtained from the field data binders for the Casa- 

 Guard Timber Sale illustrate the deliberate manipulation of 

 watershed data to reduce apparent potential for cumulative 

 effects. Erosion hazard ratings for soils in the sale area, 

 printed out by a word processor and evidently prepared by a 

 Forest Service soil scientist, were subsequently altered by hand. 

 Throughout the document, all erosion hazard ratings of "high" 

 were crossed out and replaced with "moderate"; all ratings of 

 "very high" were replaced with "high". Furthermore, several soil 

 description statements of "it is very difficult (or moderately 

 difficult to manage) because of the high erosion hazard", were 

 replaced with "[i]t is readily manageable". 



Moreover, examination of the field notes revealed that the 

 erosion hazard ratings were determined by comparing ratings from 

 three different methods. In every case, the lowest rating from 

 the three sources was used for the CWE "analysis" for the Casa- 

 Guard Sale. These choices of the lowest possible erosion hazard 

 rating for each soil and the subsequent, arbitrary downgrading of 

 the erosion hazard rating are part of the basis for the Forest 

 Service "analysis" that these watersheds could accommodate 

 further disturbance without experiencing cumulative effects. 

 Moreover, altering the field data and covering up the severe 

 erosion hazard of these soils opens unsuitable forest areas to 

 logging, in direct violation of Forest Service Best Management 

 Practices. 



The Forest Service's procedure also assumes that all 

 watersheds can accommodate some further watershed disturbance. 

 The most sensitive watersheds are arbitrarily assigned a 

 "threshold of concern" of 3%, meaning that the Forest Service 

 "analysis" assumes that 3% of the watershed area could be covered 

 with new logging roads without causing any impact to the channel 

 receiving the increased runoff and sediment. Such an arbitrary 

 assumption is scientifically insupportable and is contradicted by 

 the only field study of changes in erosion and sediment yield 

 conducted by the Forest Service in the Sequoia National Forest. 

 This study, conducted from 1960-1974 in the Salmon Creek 

 watershed, showed that with about 1.5% of the watershed covered 

 by roads, erosion rate increased significantly and the increased 

 sediment yield was expected to persist for many more years. 



