In harmony with the general purpose and intent of this Resolution and the general purposes of the Special Hillsides Preservation District, the regulations of the districts upon which this Special District is superimposed are supplemented or modified in accordance with the provisions of this Chapter. Except as modified by the express provisions of this Chapter, the regulations of the underlying districts remain in effect.

Any development, enlargement or site alteration on the buildable area of a zoning lot where the average percent of slope is less than 10 percent shall be regulated by the provisions set forth in Section 119-10 (PROVISIONS REGULATING TIER I SITES). Any development, enlargement or site alteration on the buildable area of a zoning lot having an average percent of slope equal to or greater than 10 percent shall be governed by the provisions set forth in Section 119-20 (PROVISIONS REGULATING TIER II SITES).

No development, enlargement or site alteration is permitted within any area of no disturbance on a zoning lot or other tract of land. Areas of no disturbance shall remain in their natural state, except:

(a)        for steep slopes or steep slope buffers, an authorization may be granted by the City Planning Commission, pursuant to Section 119-30 (SPECIAL REVIEW PROVISIONS);

(b)        vegetation and topsoil may be removed from a steep slope buffer during construction on a Tier I site, provided that the development, enlargement or site alteration complies with the requirements of Sections 119-215 (Landscaping controls to preserve trees, shrubs and ground cover), 119-217 (Tier II controls during construction) and 119-22 (Tier II Submission Requirements); or

(c)        in accordance with a tree protection plan.

Those portions of a zoning lot having areas of no disturbance, however, may count as lot area for the purposes of the applicable regulations on yards, floor area ratio, open space ratio or maximum number of dwelling units or rooming units.

The following uses, including enlargements to such uses, shall not be permitted within the Special Hillsides Preservation District unless an authorization is granted by the Commission pursuant to Section 119-30: community facility uses, group parking facilities of 30 cars or more, whether or not they are necessary to satisfy parking requirements.

When the Special Hillsides Preservation District is designated on a public park, or portion thereof, site alterations, the construction of new park-related facilities such as, but not limited to, roadways, parking lots, comfort stations, storage facilities, swimming pools, eating establishments, tennis courts, amphitheaters and stadiums, and improvements to existing park-related facilities, shall not be subject to the provisions of Sections 119-10 or 119-20 but shall require an authorization from the Commission, pursuant to Section 119-31 (Authorizations).

In flood zones, in the event of a conflict between the provisions of this Chapter and the provisions of Article VI, Chapter 4 (Special Regulations Applying in Flood Zones), the provisions of Article VI, Chapter 4 shall control.