Expanded Comments for Braided Rivers 



Comment- I. Generally, the bed of an active channel should not be dis- 

 turbed. If bed deposits are the only available source, the gravel should 

 be taken only under strict work plans and stipulations. 



• It is recommended that side channel (s) be mined rather than the main 

 channel. Select side channel (s) that carry less than approximately 

 one third of the total flow during the mining period; block off up- 

 stream ends and mine by scraping operations. Refer to Scraping Guide- 

 I ines (VI B 2) . 



• If the main channel must be mined, dredging may be an appropriate 

 method. Refer to Dredging Guidelines (VI B 4). 



Comment 2. Gravel is available by scraping gravel deposits to near the 

 low summer flow, maintaining appropriate buffers, or no lower than the water 

 level present during the mining operation. Refer to Scraping Guidelines (VI B 

 2). 



Comment 3. Gravel is available by scraping such that the configuration 

 of the channel is not greatly changed and there is not a high probability 

 of channel diversion through the mined area. Refer to Scraping Guidelines 

 (VI B 2). 



Comment 4. Vegetated islands are often a limited habitat in these systems 

 and should generally be excluded from the work plan. Exposed deposits should 

 be considered before vegetated island deposits. If deposits in feasible alter- 

 native locations are not sufficient, and vegetated islands are abundant in the 

 particular reach in question, up to about 10 to 20 percent of this habitat may 

 be removed from about a given 5-km length of the floodplain. Refer to Scraping 

 Guidelines (VI B 2) or Pit Guidelines (VI B 3). 



Comment 5. Vegetated river banks of both active and high-water channels 

 should not be disturbed because of biological and hydraulic alterations. 

 These should be removed from work plans. 



58 



VI . SITE OPERATION 



