Michigan Administrative Code
Department - Transportation
Bureau of Highway Development
Drainage Assessments
Section R. 280.8 - Pro rata share of runoff for county roads and state highways; computation examples
Current through Vol. 24-04, March 15, 2024
Rule 8. The computations hereinafter set forth are included to clarify the method by which the pro rata share of runoff for county roads and state highways may be determined.
Formula: Q=ciA Q = runoff c = runoff coefficient i = rainfall intensity
A = area
Rainfall intensity is assumed to be constant throughout the drainage district, according to R 280.2(2), and since the apportionment is based on the pro rata share of the runoff, the rainfall intensity has been deleted from these computations.
(a) Computation No. 1:
(b) Computation No. 2:
(c) Utilities, railroads, or streets may also be subtracted from the total entitled "remaining lands," and computed on an equitable "c" factor at the discretion of the assessing authority.