San Mateo Municipal Code Ch. 27.83 Slope and Hillside Development Standards

Subdivisions that result in new parcels with slopes of twenty-five (25%) percent or more are prohibited unless the following conditions are met:

(a) The parcel contains contiguous area that is less than twenty-five (25%) percent slope which equals or exceeds the minimum required parcel size for the applicable zoning district, and

(b) Any access-way to that portion of the site less than twenty-five (25%) percent slope must limit alteration of the visual character of the hillside and meet the requirements for maximum street and driveway slopes and blending of cut and fill to natural grade.

Only those areas of a site have existing slopes of less than twenty-five (25%) percent shall be considered in the calculation of allowable floor area and density limits.