g. When required, active channels should be crossed via temporary 

 bridges, low-water crossings, or properly cul verted access road. 

 Refer to Appendix E on fish passage. 



h. Floodplain travel to and from the work area should occur only 

 on designated access roads 



3. Buffers are areas of undisturbed ground surface that are designed to 

 maintain the integrity of active channels . In general, low- flow or 

 flood-flow buffers are recommended at a site. Low-flow buffers are 

 recommended for scraping operations on unvegetated gravel bars adja - 

 cent to active channels . Flood -flow buffers should be used for scrap - 

 ing or pit-mining operations that are separated from active channels . 

 Operators of gravel removal activities may desire to use buffers wider 

 or higher than those recommended in order to protect the site from 

 inundation while it is being worked, since water levels at the time of 

 ining may exceed those for which the buffer is designed. 



mi I 



a. The low-flow buffer is a strip of undisturbed ground surface 



extending up the bank and beneath the water surface from the low 

 summer flow water's edge (Figure 4). Its purposes are: 



• To maintain the integrity of the channel configuration and 



• To minimize change to the aquatic habitat 



The boundaries of the low-flow buffer are defined as follows 

 (F i gure 5) : 



i) The upper limit at any location along the channel is that 

 point on the bank that is the lesser of the following: 



• having an elevation that is 0.5 m above the low summer 

 flow water surface elevation 



35 V. SITE PREPARATION 



