requirements of the SMZ Law and 

 have a low risk of affecting 

 recruitment of large woody material 

 to Dog Creek or its tributaries. 

 The SMZ law, rules, and all 

 applicable BMPs would be applied to 

 all harvesting activities, which 

 would minimize the risk of sediment 

 delivery to draws and streams. 



Cumulative Effects 



• Cumiilatice J^ecttf qfJVo-wlction »1tternative 

 »1 on Sediment Delivery 



The cumulative effects of No-Action 

 Alternative A on sediment delivery 

 would be very similar to those 

 described in the existing condition 

 portion of this analysis. All 

 existing sources of sediment would 

 continue to recover or degrade as 

 dictated by natural and preexisting 

 conditions until a source of 

 funding became available to repair 

 them. Sediment loads would remain 

 at or near present levels. 



• C'limulatice fyjecbi qf, Iction ^lUernatice Ji on 

 Sediment Delicery 



Cumulative effects to sediment 

 delivery under the action 

 alternative would be primarily 

 related to roadwork and stream- 

 crossing replacements. The 

 sediment generated from replacement 

 of existing culverts would increase 

 the total sediment load in Dog 

 Creek for the duration of the 

 activity. These increases would 

 not exceed any State water-quality 

 laws and would follow all 

 applicable recommendations given in 

 124 and 318 permit applications. 

 In the long term, the cumulative 

 effects to sediment delivery would 

 be similar to existing levels. As 

 the sites stabilize and revegetate, 

 sediment levels resulting from 

 culvert replacements would return 

 to preactivity levels. Over the 

 long term, cumulative sediment 

 loads may be reduced due to 

 improved design on the crossings. 

 Improved design would reduce the 

 risk of structure failures, which 

 would reduce the risk of sediment 



delivery to the outlet of Dog 

 Creek. 



The installation and improvement 

 of erosion-control and surface- 

 drainage features on existing 

 roads would also affect the 

 cumulative sediment delivery in 

 Dog Creek. In the short term, 

 the installation and improvement 

 of surface drainage features 

 would expose bare soil. This 

 would increase the risk of 

 sediment delivery to Dog Creek. 

 An increase in sediment load to 

 Dog Creek is possible as a result 

 of this work. The application of 

 all applicable BMPs during this 

 work would make increased 

 sediment loads unlikely. Over 

 the long term, cumulative 

 sediment delivery to Dog Creek 

 would likely be lower than 

 existing conditions with the 

 installation of more effective 

 surface-drainage and erosion- 

 control features on the existing 

 road system. 



Harvesting of trees within 

 selected SMZs would have a low 

 risk of adverse cumulative 

 effects to downed woody material 

 in Dog Creek or its tributaries. 

 Tree retention requirements of 

 the SMZ Law would ensure a future 

 supply of woody material to the 

 creeks . 



None of the cumulative impacts 

 described above are expected to 

 adversely affect downstream 

 beneficial uses. All activities 

 would comply with applicable 

 laws, rules, and regulations. 



TfiKTER YIELD 



Direct and Indirect Effect 



• Direct and Indirect I^'ectit qfj\o-,lction 

 ,Hternntive*1on IVater Yield 



No-Action Alternative A would 

 have no direct or indirect 

 effects on water yield. Water 

 quantity would not be changed 

 from present levels. 



Appendix D-Hydrology Analysis 



Page D-5 



