

APPENDIX »l 

 DETERMINING STREAMSIDE ZONE WIDTH 



The prescribed width for a streamside management zone (SMZ) is dependent 

 on stream status, terrain, landforms, and water use. A perennial stream 

 generally requires a wider SMZ than an intermittent stream. Steep slopes 

 along the channel banks dictate the need for a wider SMZ than gentle slopes. 

 Erosive landforms should have wider SMZs than less erosive landforms. A 

 downstream domestic or irrigation use may require a wider SMZ than if there 

 were no adjudicated use. 



Guidelines for determining SMZ width should be used only as guidelines. 

 Results should be tempered with the factors listed above, and others, such as 

 the niimber on-the-ground obstructions, and personal judgement. 



For sensitive streams (from SCS) 



SMZ width (slope distance in ft.) = 100 + 4 (% slope) 



For less sensitive streams 



SMZ width (slope distance in ft.) = 50 + 3 (% slope) 



Other guidelines are available, such as Guidelines For Controlling 

 Sediment From Secondary Logging Roads by Packer and Christiansen. 



This guideline incorporates, among other items, the amount of debris on 

 the ground. For example, in topography composed of gravelly material, with 

 log obstructions every 9 feet, this guideline suggests a 72 foot wide protec- 

 tive strip. 



The Bureau of Land Management recently published guidelines in their 

 Garnet Resource Area Management Plan/EIS. It calls for "buffer zones" in 

 their General Forest Management Area based on land slope as follows: 



