Depth and width criteria could also be developed and used in conjunction with 

 the WACD option of the WETP program to formulate flow recommendations for 

 nesting. 



Maintenance of Spawning and Rearing Habitats in Side Channels 



Side channels provide important and sometimes critical spawning and rearing 

 habitats for many cold and warm water fish species. The maintenance of tbese 

 habitats is dependent on adequate side channel flows. 



The wetted perimeter/inflection point method, when applied to the riffle areas 

 of critical side channels, will provide a measure of the side channel flow 

 that is needed to maintain the spawning and rearing habitats at acceptable 

 levels. When this side channel recommendation is used in conjunction with a 

 rurve correlating the side channel flow to the total river flow, the total 

 river flow that would maintain adequate side channel flow can be determined. 



This method is applied to a series of side channels and the final 



recommendation derived by averaging the recommendations for each or choosing 



the river flow that would maintain at least the inflection point flow in all 

 the sampled side channels. The latter method is again preferred. 



Recreational Floating Requirement 



Minimum depth and width criteria have been developed for various types of 

 boating craft by the Cooperative Instream Flow Service Group of the U.S. Fish 

 and Wildlife Service (Hyra, 1978). These are listed in Table 3. 



Table 3. Required stream width and depth for various recreation craft. 



Recreation Craft Required Depth (ft) Required Width (ft) 

 Canoe-kayak 0.5 A 



Drift boat, row boat-raft 1.0 6 



Tube 1.0 4 



Power boat 3.0 6 



Sail boat 3.0 25 



These criteria are minimal and would not provide a satisfactory experience if 

 the entire river was at this level. However, if the required depths and 

 widths are maintained in riffles and other shallow areas, then these minimum 

 conditions will only be encountered a short time during the float and the 

 remainder of the trip will be over water of greater depths. 



Cross-sections are placed in the shallowest area along the waterway. The WACD 

 option of the WETP program is used to determine the flow that will satisfy the 

 minimum criteria for the craft of interest. For example, if deriving a 

 recommendation for power boats, the flow providing depths ° 3.0 ft for at 



7-3 



