DRIVEWAY & DRAINAGE REQUIREMENTS
November 21, 2022
All driveways connecting to main roads must be constructed and maintained to comply with the following requirements. The requirements maintain and protect our private roads and drainage systems. Requests for variations must be addressed to the MMPOA Building and Plans Committee. Property owners are responsible for correcting any damage that results from failure to comply with these requirements.
DRIVEWAY PROFILE (see Figure 1)
All driveways shall have a grade that slopes away from the main road entrance at a rate not greater than the slope of the existing, or proposed, shoulder at the main road. The slope shall continue for a distance equal to the prevailing shoulder width, or longer, so as not to cause a hump or a depression in the shoulder area (either could cause drainage issues). Beyond the shoulder, it is recommended that the grade of the driveway within the main road right of way (30 feet from the road centerline) should not exceed 15 percent if reasonably attainable.
DRAINAGE (see Figure 1)
Driveways must be constructed so they do not adversely affect the main road drainage or the drainage of /onto adjacent properties. The drainage and stability of the main road sub grade must not be impaired by driveway construction, or any owner associated roadside developments. In no case, should the driveway construction cause water to flow across the main road, to pond on the shoulders or in the ditch, or result in erosion within the main road right of way (30 feet from the main road centerline). The property owner may be required to submit a drainage study to the Building Plans Committee justifying the proposed drainage system and the type of culvert pipe to be used. Natural drainage laws and practice must be observed.
When driveway construction requires crossing a main road ditch, a culvert pipe must be installed in the ditch. The driveway profile’s low point shall be at or close to the ditch line (see Figure 1). Under no circumstances, will existing ditches or gutters be filled without adequate alternate drainage provisions being made.
Culvert pipe size will be adequate to carry the maximum flow in the ditch and not smaller than 12 inches, inside diameter. Culvert pipe structural material and gauge (thickness) must be adequate to support loads of anticipated traffic across the driveway. Culvert material will be either corrugated metal or concrete and meet or exceed the North Carolina Department of Transportation Standard Specifications for Roads and Structures. The culvert length is the sum of the driveway width (surface width and shoulder) at the ditch line and the length needed to accommodate a side slope of at least 1 foot vertical to three feet horizontal from the driveway grade to the ditch. The property owner is responsible to immediately repair, and pay for, any damage to the main road, shoulders, or ditch, due to improper culvert pipe size or installation, now or in the future.
If headwalls or wing walls are constructed with drainage facilities, they will be installed a minimum distance of 30 feet (measured from the road centerline), unless protected by a guardrail. Flared end sections are encouraged.
PREPARED BY: Wayne M Barth
DATE OF BOARD OF DIRECTORS APPROVAL: December 10, 2022
