St. Louis River - River Watch Discharge Calculations?? Fall 2003
School Name _____________________________________ Site Name ________________________________? Date ___________________
Where
DISCHARGE =? A L C A = Avg. cross sectional area of stream C = Coefficient or correction factor
T ???? L = Length of stream reach measured_ T = Time for float to travel length L
               
           
  ?"A" AVERAGE CROSS-SECTIONAL AREA  
   
   
  Transect #1 (upstream) Transect #2 (downstream)  
   
  Stream width (ft):?   Stream width (ft):?    
   
  Interval Depth (inches) Interval Depth (inches)  
   
  A to B   (at B) A to B   (at B)  
  B to C   (at C) B to C   (at C)  
  C to D   (at D) C to D   (at D)  
  D to E 0 (at shoreline) D to E 0 (at shoreline)  
   
  Total   ? 4? =   ? 12? =   Total?   ? 4?? =?   ? 12? =    
  Convert to ft. Average? Convert to ft. Average?
  depth (ft) depth (ft)
  Cross-sectional area of Transect #1: Cross-sectional area of Transect #2:  
   
    x   =   ft2   x   =   ft2  
  Width (ft) Avg. depth (ft) (a) Width (ft) Avg. depth (ft) (b)  
   
  Average Cross-sectional Area:??  
    +   =   ? 2?? =?   ft2  
  (a) (b) (A)  
                             
                             
  "L" LENGTH OF STREAM REACH (usually 20 ft.) "T" TRAVEL TIME FROM TRANSECT #1 TO #2
      travel time of float  
    ft     Trial #1 sec.  
  (L)     Trial #2   sec.  
                  Trial #3   sec.  
                   
  "C" COEFFICIENT      
  0.8 for rocky-bottom streams     Total?   ? 3?? =?    
  0.9 for soft-bottom streams       Avg. time (sec.)  
  (C)     (T)  
                             
                             
    x   x      
Discharge? = A   L   C =  
?ft3/sec  
    Volunteer Stream Monitoring: A Methods Manual, USEPA  
            T       source: