The methodology used to determine the appropriate mitigation fee shall be:
M = Vt x C where
M = Mitigation fee
Vt = Total volume of sand required to replace losses due to the structure, through loss of available beach area (cubic yards). Derived from calculations provided below.
C = Cost, per cubic yard of sand, of purchasing and transporting beach quality material to the project vicinity ($ per cubic yard). Derived from the average of three written estimates from sand supply companies within the project vicinity that would be capable of transporting beach quality material to the subject beach, and placing it on the beach or in the near shore area.
Vt = Ve where
Ve= Volume of sand necessary to replace the area of beach lost due to encroachment by the seawall; based on the seawall design and beach and near shore profiles (cubic yards)
Ve = E x W x v where
E = Encroachment by seawall, measured from the toe of the bluff or back beach (ft.)
W = Wide of property to be armored (ft.)
v = Volume of material required, per unit width of beach; to replace or reestablish one foot of beach seaward of the seawall; based on the vertical distance from the top of the beach berm to the seaward limit of reversible sediment movement (cubic yards/ft of width and ft. of retreat). The value of v is often taken to be 1 cubic yard per square foot of beach. In the report, "Oceanside Littoral Cell Preliminary Sediment Budget Report" (December 1987, part of the Coast of California Storm and Tide Wave Study, Document #87-4), a value for v of 0.9 cubic yards/square foot was suggested. If a vertical distance of 40 feet is used for the range of reversible sediment movement, v would have a value of 1.5 cubic yards/square foot (40 feet x 1 foot x 1 foot / 27 cubic feet per cubic yard). These different approaches yield a range of values for v from 0.9 to 1.5 cubic yards per square foot. The value for v would be valid for a region, and would not vary from one property to the adjoining one. Until further technical information is available for a more exact value of v, any value within the range of 0.9 to 1.5 cubic yards per square foot could be used by the applicant without additional documentation. Values below or above this range would require additional technical support.