Distance ($x = \frac{qt}{k_1 D_0 + k_2 y_0}$):

Where:

• $x$ is the distance to the leading edge.
• $q$ is the unit stream size or flow per unit width of the border strip, in gallons per minute (gal/min).
• $t$ is the total time of flow, in hours.
• $D_0$ is the depth of water at the upper end, in meters (m).
• $y_0$ is the cumulative intake at the upper end, in meters (m).
• $k_1$ is the surface storage coefficient, varying from 0.5 to less than 1.0.
• $k_2$ is an additional coefficient.