Constant Tailwater Method
The Constant Water Surface Method is useful where tailwater elevation does not change with changes in discharge. This method requires the least amount of site information and may be appropriate for preliminary culvert assessments.
Pool Surface Elevation - Enter the water surface elevation of the outlet pool.
Outlet Pool Bottom Elevation – Enter the elevation of the lowest point in the outlet pool. The Pool Bottom Elevation will be used to calculate the pool depth at the culvert outlet and to determine if there is sufficient depth for leaping when required.
Note: All elevations should be tied to the surveyed elevation of the culvert inlet and outlet by use of a common datum.
See also: Pool Depth and Leaping Calculations