- The top of the berm should be minimum six (6) feet in height and held level along its entire length except at the entrance drives. An undulating ridgeline on the berm within the restricted height of six feet would tend to destroy the visual unity and would create a “forced” appearance to the berm.
- The sides of the berm must not exceed a 3:1 slope ratio.
- The ridge of the berm must have an approximate two (2) foot wide area at the top that is rounded (i.e., neither flat nor meeting at the peak).
- The ridge of the berm must have an approximate two (2) feet wide area at the top, which is, rounded (i.e., neither flat nor meeting at a peak).
- The ground surface on the berm should be covered primarily with lawn. If other types of ground covers are used, they should be planted in areas large enough to be in scale with the overall length of the berm, thus avoiding a "spotty" effect.
- If evergreens are used, they should generally be planted in groups of six or more of the same species. Widely spaced evergreens create a “spotty” effect on the landscape. This is especially true during the winter.
- Continuous planting along the ridgeline of the berm and an even spacing of trees along the strip should be avoided except where deciduous trees are required. Random spacing of trees and shrubs creates a less formal and more naturalistic effect.
- Planting on berms should consist of species, which naturally grow in high, well drained situations. Plants such as aborvitae, birch, cedar, hemlock and cypress, which are indigenous to low, moist situations, should not be used. In addition, plants such as dogwood and redbud should not be used in a berm area where there is much exposure to the elements.
These General Design Principles for Berm Planting and Design Plan were adopted as guidelines by the City of Farmington Hills Planning Commission August 22, 1974.