APPENDIX H 



STANDARD FORMULA AND CONVERSION FACTORS 



CONTINUITY OF FLOW 



^^ = V2 



where = discharge 



A = cross sectional area of the flow at I 



V = mean flow velocity at I 



A = cross sectional area of the flow at 2 



V = mean flow velocity at 2 



VELOCITY OF CULVERT FLOW 



Culvert Flowing Full (Outlet Control) 



A 



where V = mean flow velocity in culvert 

 = discharge through culvert 

 A = cross sectional area of culvert 



Cross sectional areas of plate steel arch, pipe-arch, and circular culverts 

 of various sizes are listed in Tables H-l, H-2, and H-5. Estimates of cross 

 sectional areas of circular culverts whose inverts are buried below the stream 

 bed can be obtained from Tables H-l or H-2, using measured or estimated span 

 and r i se va I ues. 



Culvert Flowing Partially Full (Inlet Control) 



Outlet velocity may be approximated by computing the mean velocity for the 

 culvert cross section using Manning's equation. Manning's equation can be 

 wr i t ten : 



145 



