minor losses in storm sewer junctions

A standard equation for determining minor headloss at a 45 degree wye junction "hj=(v out squared - 0.75 x velocity in squared) / 64.4" results in a negative headloss if the upstream velocity is high. Example: inflow velocity = 20.3 fps and outflow velocity = 10.2 fps results in a -3.17 ft loss. How should this result be used in determining headloss?

The general equation for fluid flow loss due to elbows, tees, valves and so on is:

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Where:

K = Coefficient of minor loss
V = Fluid velocity
g = gravity as given
A = Area of pipe or channel
h[SUB]m[/SUB] = Minor Loss (Unit of energy/ fluid weight) or Head Loss

Thanks, but my question relates to junctions.

[QUOTE=lazlo;4660]Thanks, but my question relates to junctions.[/QUOTE]

See:

[URL]http://www.engineersedge.com/civil_engineering/storm_drains_junctions_losses_calculation_10161.htm[/URL]