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(d) Stormwater ponds must be designed to provide: (1) Water quality features consistent with NURP criteria and accepted design standards for average and maximum depth; (2) A permanent wet pool with dead storage at least equal to the runoff volume from a 2.5 -inch rainfall over the area tributary to the pond; (3) An outlet structure capable of preventing migration of floating debris and oils for at least the one-year storm; (4) An identified emergency overflow spillway sufficiently stabilized to convey flows greater than the 100 -year critical storm event; and (5) An outlet structure to control the 2 -year, 10 -year & 100 -year frequency events. (e) Soil borings (utilizing ASTM D5921 and D5879, as amended) shall be considered for design purposes, and provided to the District, for each proposed BMP. The soil borings must be taken to a depth of at least 5 feet below the bottom of the proposed feature. (f) An outfall structure discharging directly to a wetland, public water or public water wetland must incorporate a stilling -basin, surge -basin, energy dissipater, placement of ungrouted natural rock riprap or other feature to minimize disturbance and erosion of natural shoreline and bed resulting from stormwater discharges. Where feasible, outfall structures are to be located outside of the natural feature. TABLE C6. LOW FLOOR AND LOW ENTRY FREEBOARD REQUIREMENTS. (g) All new residential, commercial, industrial and other habitable or non -habitable structures, and all stormwater BMPs, must be constructed so that the lowest floor and lowest entry elevations comply with Table C6. The low entry freeboard criterion of Table C6 may be deemed met when the structure does not have the required vertical separation, but is protected from surface flooding to the required elevation by a berm or other natural or constructed topographic feature capable of providing flood protection. Within a landlocked basin, minimum low floor elevations must be at least one foot above the surveyed basin run out elevation. Where a structure is proposed below the run out elevation of a land -locked basin, the low floor elevation will be a minimum of two feet above the highest water level of either the 10 -day snowmelt event or back-to-back 100 -year, 24- hour rainfalls. Aerial photos, vegetation, soils, and topography may be used to derive a "normal" water elevation for the purpose of computing the basin's 100 -year elevation. 23