B. For a minimum mean depth with a maximum littoral area 



Mean of depth Percent of 



interval (m) pit area 



0.5 35 



1.5 10 



2.5 10 



3.5 15 



4.5 25 



5.5 5 



Maximum depth: 6.0 m 

 Mean depth: 2.5 m 



A pit with greater littoral area generally allows greater productivity 

 and is preferred for waterfowl, shorebirds, and fish. In both of the above 

 examples an increased mean depth will decrease the probability of fish winter 

 mortality. If more gravel is required, increasing depth is preferred over 

 increasing the surface area of disturbance. 



METHOD FOR CALCULATING MEAN DEPTH OF P I T 



To obtain an estimate of the mean depth of a designed pit, the following 

 procedures can be used. 



A. Determine the l-m (or other unit of measure) contour intervals for the 

 pit. 



B. Determine the percent of surface area(s) consisting of a particular 

 l-m depth interval [i.e., 0-1 = 0.35; 

 where n = number of depth intervals], 



l-m depth interval [i.e., 0-1 = 0.35; 1-2 = 0.10; ;(n-l)-n = s , 



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