17 GRADING, RETAINING WALLS, AND HARDSCAPE STANDARDS
Exhibit 7-13. Allowable Maximum Permanent Graded and Hardscape Areas | |
ALLOWABLE MAXIMUM PERMANENT GRADED AND HARDSCAPE AREAS | |
MAXIMUM GRADED AREA | |
Less than 0.5 acre = | 10,000 sq. ft. |
Greater than 0.5 acres = | If footprint is over 4,000 square feet: 12,000 sq. ft. + (4,000 sq. ft. * (area in acres -1)) + (footprint - 4,000) |
If footprint is less 4,000 square feet: 10,000 sq. ft. | |
MAXIMUM HARDSCAPE AREA | |
Less than 0.5 acre = | Maximum graded area minus 4,000 square feet |
Greater than 0.5 = | Maximum graded area minus 4,000 square feet |
Table 7-10 Cut Slopes, Fill Slopes and Retaining Walls Height, Length and Other Limits | ||||
|---|---|---|---|---|
Use/Type | Cut Slopes | Fill Slopes | Retaining Wall (cut) | Retaining Wall (fill) |
Retaining Wall or Slope Creating Area for Primary Structure (refer to Exhibits 7-14 and 7-15) | ||||
Maximum total height of all walls and slopes for primary structure | Lesser of height of structure or 20 ft.1. | Lesser of height of structure or 20 ft.1. | Lesser of height of structure or 20 ft.1. | Lesser of height of structure or 20 ft. |
Maximum total length of all walls and slopes for primary structure | Total width of structure parallel to slope plus 40 ft. | Total width of structure parallel to slope plus 40 ft. | Total width of structure parallel to wall plus 40 ft. | Total width of structure parallel to wall plus 40 ft. |
Retaining Wall or Slope Creating Area for Accessory Structure (refer to Exhibits 7-14 and 7-15) | ||||
Maximum total height of all walls and slopes for accessory structures | Lesser of height of structure or 12 ft.1. | Lesser of height of structure or 12 ft.1. | Lesser of height of structure or 12 ft.1. | Lesser of height of structure or 12 ft.1. |
Maximum total length of all walls and slopes for accessory structures | Total width of structure parallel to slope plus 20 ft. | Total width of structure parallel to slope plus 20 ft. | Total width of structure parallel to wall plus 20 ft. | Total width of structure parallel to wall plus 20 ft. |
Retaining Wall or Slope Creating Area for Accessory Use (refer to Exhibits 7-14 and 7-15)4. | ||||
Maximum total height of all walls and slopes for accessory uses | Eight (8) feet | Eight (8) feet | Eight (8) feet | Eight (8) feet |
Maximum total length of all walls and slopes for accessory uses | Total width of use parallel to slope plus 12 ft. | Total width of use parallel to slope plus 12 ft. | Total width of structure parallel to wall plus 12 ft. | Total width of structure parallel to wall plus 12 ft. |
Slope Steepness Limits (refer to Exhibit 7-16) | ||||
Maximum slope. | Maximum of 2 to 1. | Maximum of 2 to 1. | Maximum of 2 to 1 between walls | Maximum of 2 to 1 between walls |
Minimum Slope Boundary Radii (refer to Exhibit 7-17) | ||||
Minimum top of slope curvature radius: | Five (5) feet | Five (5) feet | NA | NA |
Minimum bottom of slope curvature radius: | Five (5) feet | Twenty Five (25) feet | NA | NA |
Minimum edge of slope curvature radius: | Five (5) feet | Twenty Five (25) feet | Five (5) feet | NA |
Landscaping Requirements for Erosion Control and Screening of Slopes and Walls | ||||
Erosion control measures required upon completion of wall or slope. | 100% of surface | 100% of surface | 100% of disturbed area | 100% of disturbed area |
Landscape screening standards to achieve within three years following completion of project.3. | 75% of visible surface. | 75% of surface area. | 75% of visible surface. | 75% of visible surface. |
Notes: |
|---|
1. Measured to the double plate or top of full-width wall section. |
2. Modification allowed per UBC. |
3. Landscape planting must be installed over the entire slope. |
4. For purposes of this Chapter, guest houses are considered accessory structures. |
![]() Exhibit 7-14. Measurement of Wall and Slope Heights |
![]() Exhibit 7-15. Measurement and Limits on Wall and Slope Lengths |
![]() Exhibit 7.16 Limitations on Maximum Slope Angles |
![]() Exhibit 7-17. Minimum Slope Boundary Radii |
![]() Exhibit 7-18. Contour Grading Concept |
![]() Exhibit 7-19. Fences on Top of Retaining Walls |
![]() Exhibit 7-20. Minimum Distances Between walls |