The Constant Loss/Gain method uses a simple relationship to calculate channel loss. A fixed flow rate is subtracted from the routed flow, then the remainder is multiplied by a fraction. This method can be used with any channel routing method.
For each subreach: Q_{out}=\left(Q_{in}-lossRate / n\right)\cdot\left(1-lossFraction / n\right)where n is the number of routing steps or subreaches in a reach.
Required Parameters
This method requires two parameters: a loss rate expressed in ft3/s or m3/s, and a loss fraction in the range 0 to 1.