Slope is determined by objective geometry—not by arbitrary definitional preference.

To allow more building where the General Plan prohibits it, the City claims it can ignore the classic definition of “slope” (i.e., vertical rise over horizontal run) and instead use an artificial definition from the City’s zoning code that’s based on what the City decides are a property’s front and back yard lot lines, thereby minimizing slope calculations and allowing buildings where the General Plan prohibits them. But this artificial definition ignores the physical steepness of terrain: the homes on Lombard Street would be on flat 0% slope lots if it was applied to them! But, averaging does not change the physical steepness of terrain. A mountain does not become less steep because you measure it along a winding path instead of directly upward.

The General Plan prohibits development on steep slopes—not lots that can be made to appear compliant through selective measurement techniques.

The trial court recognized the City’s ploy to skirt the General Plan prohibition and ruled that slope under the General Plan must be based on the classic “slope” definition using objective engineering standards.

The City is now asking the appellate court to grant “deference” to redefine slope measurement—effectively allowing subjective interpretation to override mathematical fact.