§ 3-12. Fill.
(a) In general.
(1) In the Coastal High Hazard Area:
(i) fill is prohibited for structural support; but
(ii) placement of nonstructural fill is allowed to the extent provided in this section and in ASCE 24, § 4.5.4 {"Use of Fill"}.
(2) In the Coastal Floodplain:
(i) fill material must meet the requirements of this section; and
(ii) structural fill must comply with all applicable provisions of ASCE 24.
(b) Maximum fill amount.
The placement of more than 600 cubic yards of fill per acre in the floodplain is prohibited except by variance.
(c) Required alternate consideration.
(1) Elevating a structure by other methods must be considered unless 600 cubic yards or less of fill are required.
(2) An applicant must demonstrate that:
(i) fill is the only alternative to raising the structure to at least the flood- protection elevation; and
(ii) the amount of fill used will not affect the flood storage capacity or increase flooding onto neighboring properties.
(d) Affect on adjacent properties.
Fill may be used only to the extent to which it does not adversely affect adjacent properties.
(e) Materials.
(1) Fill may consist of soil or rock materials only.
(2) Landfills, dumps, and sanitary soil fills are not permitted.
(f) Compacting standards.
Fill material must be compacted in accordance with the standard proctor test method issued by the American Society for Testing and Materials (ASTM Standard D-698) to provide the necessary stability and resistance to erosion, scouring, or settling.
(g) Slopes.
Fill slopes may be no steeper than 1 vertical to 2 horizontal, unless substantiating data justifying steeper slopes are submitted to and approved by the Department of Public Works.
(h) Hydrologic and hydraulic analyses.
(1) If structures on adjacent properties are known or determined to be subject to flooding under current conditions, the Floodplain Manager may require submission of hydrologic and hydraulic analyses to adequately demonstrate the effects of the proposed fill.
(2) A hydrologic and hydraulic analysis requirement does not apply to projects located in the Coastal Floodplain or tidal portion of the Flood Resilience Area.