Section R. 247.261 - DrainageRule 61.
(1) A driveway shall be constructed so that it does not adversely affect the highway drainage. The drainage and the stability of the highway subgrade shall not be altered by driveway construction or roadside development.(2) Drainage from adjacent parking or storage areas on private property in excess of existing drainage shall not be discharged into the highway drainage system.(3) Culvert pipe shall be of a size adequate to carry the anticipated natural flow of the ditch. The culvert shall be no smaller than the nearest upstream culvert nor less than 12 inches inside diameter. A culvert, catch basin, drainage channel and other drainage structure required within the highway right-of-way shall be manufactured or constructed and installed in accordance with the current department standard specifications for highway construction. The minimum length of the culvert may be determined as the sum of the distance between driveway edges, measured along the ditch line, plus the distances needed to accommodate an embankment slope not to exceed 1 foot vertical for 6 feet horizontal on both sides of the driveway.Mich. Admin. Code R. 247.261