§ 9.4.2. Standards

A.

Definition For purposes of this Division, "slope" means the ratio of elevation change to horizontal distance, expressed as a percentage. Slope is computed by dividing the vertical distance ("rise") by the horizontal distance ("run"). For example, a 3-foot rise in a 20-foot run results in a 15% slope.

B.

Applicability All construction, including renovations and additions, must comply with the requirements of this Division.

C.

Designation on Plans Moderate and steep slopes of 1,000 square feet and greater in area must be designated on any Land Disturbance Permit or Building Permit application.

D.

Moderate Slopes of 15% and Up to 35% Building and site preparation may occur upon demonstration of specialized site design techniques and approaches that meet the requirements in F. below.

E.

Steep Slopes of 35% or Greater These areas are generally unsuitable for development. Land disturbance must not exceed ¼ of the area containing slopes of 35% or greater in areas of 1,000 square feet or more, except that where an existing lot of record does not have a reasonable building site with less than 35% slope or natural grade, the Director may approve the site, subject to any necessary mitigation measures.

F.

Construction Techniques Construction activities on slopes of 15% or greater must comply with the following:

1.

All plans must show provisions for reducing and minimizing stormwater runoff during construction on steep slopes and cut and fill slopes.

2.

All swales and all slopes must be provided temporary or permanent stabilization with ground cover sufficient to restrain erosion as soon as practicable, but in any event, within 7 calendar days of any phase of grading.

3.

All other disturbed areas must be provided temporary or permanent stabilization with ground cover sufficient to restrain erosion as soon as practicable, but in any event, within 14 calendar days of termination or completion of any phase of grading.

4.

Prior to issuance of a certificate of occupancy, vegetation must be reestablished.

5.

Where irrigation is not provided, the exposed soil must be planted with species that survive without irrigation.

6.

Vegetative ground cover or any alternative cover (rock, masonry, or similar materials) must be maintained in perpetuity.

G.

Grading In order to protect trees and vegetation on sites, and to protect the character of the neighborhood, the following limits on grading are required.

1.

Mitigation measures Any grading in side and rear building setbacks in RE-, RD- and RU- districts, must be mitigated following the measures listed below.

a.

For each tree of 10 inches DBH or greater removed or damaged by grading in the side setback, one tree must be planted;

b.

If no tree of 10 inches DBH or greater is removed or damaged, at least one large canopy shade tree must be planted for every 1,000 square feet of area disturbed in the side setback;

c.

Replacement tree species must be of comparable canopy size at maturity as those of the trees removed or damaged;

d.

Replacement trees must be at least 2 inches caliper at time of planting;

e.

Planting must take place in the graded area. If this is not possible, the replacement trees may be located elsewhere on the property. If this is not possible, recompense provisions (see Sec. 9.3.8) of the Tree Ordinance apply;

f.

This mitigation is required in addition to any other provisions of the Tree Ordinance, including those that apply to Setback Trees (see Sec. 9.3.5).

2.

In the side building setbacks  

a.

In all RE- districts, grading may encroach up to 10 feet into the required side building setbacks.

b.

In all RD- and RU- districts, grading may encroach into the required side building setbacks.

3.

In the rear building setbacks  

a.

In all RE- districts, no grading is allowed within 20 feet of the rear lot line.

b.

In the RD-27, RD-18, and RD-15 districts, no grading is allowed within 15 feet of the rear lot line.

c.

In the RD-12, RD-9, RD-7.5, and RU- districts, no grading is allowed within 10 feet of the rear lot line.

4.

In all districts, resulting graded slopes must not exceed 3 feet (horizontal) to 1 foot (vertical). Steeper slopes may be approved by the Director upon certification of stability by a soils engineer or geologist.

H.

Variance from Standards In granting a variance from the standards of this Section, the Board of Appeals may determine that some features or areas may not be disturbed. These include, but are not limited to:

1.

Large stands of trees;

2.

Areas containing state waters, floodplain, or wetlands or in the Nancy Creek Declared Sensitive Area;

3.

Rock outcroppings; and

4.

Slopes of 35% or greater.

( Ord. of 4-17-2018(7) , §§ 9-34—9-40)