the river had few oxbow cutoffs, consequently, mining changed the appearance 

 of the area. However, the presence of overburden and gravel stockpiles 

 detracted far more than the altered channel. 



Aquatic habitat changes at Skeetercake Creek were not as great as would 

 be expected if the channel had become braided. The narrowness of the natural 

 channel imparted a greater significance to the value of bank vegetation. 

 Loss of this cover can change the distribution of fishes. The change from an 

 incised channel to a shallow riffle area through the abandoned site caused 

 the water temperature, during the study, to be higher in the disturbed area 

 than upstream. However, changes in suspended solids were not noted. 



Summary. Scraping point bars can have little environmental effect 

 assuming that the operation is conducted in a manner that minimizes changes 

 to the hydraulic characteristics of the channel and adjacent vegetated 

 areas. If change is minimized, the effects on aquatic and terrestrial biota, 

 and water and scenic quality are greatly minimized. 



Meandering rivers provide usable deposits of gravel from point bars, in 

 inactive floodplains, and terraces. The potential effects on such a system 

 vary depending on whether only point bars are used or whether the adjacent 

 inactive f I oodp I a i n and terrace also are mined. Sites in inactive flood- 

 plains and terraces often are dug as pits while point bars in active flood- 

 plains are scraped. 



Pit sites remote from the active channel have caused some problems 

 during spring breakup at sites visited during site selection, but not 

 studied as primary sites in this project (unpublished data). When channels 

 are blocked with ice, melt water must flow over the ice and may overflow the 

 bank and spread across the entire floodplain. Pits located in these flood- 

 plains are then subject to filling which can facilitate diversion of flow 

 through the site. This diversion is particularly possible where pits are dug 

 within the inside of a meander. Depending on the size and inherent stability 

 of the undisturbed buffer between the pit and channel, the flow may cut 



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