1209 SWQMP Report_3 2013

                                                                                  Callaghan & Toth

APPENDIX 8                 -         SEDIMENT BASIN CALCULATION




                                         V=10 x CV x A x Rx-day, y-%ile

Where:

10 = a unit conversion factor

CV = the volumetric runoff coefficient defined as that portion of rainfall that runs off as
stormwater over the x-day period

Rx-day, y-%ile = is the x-day total rainfall depth (mm) that is not exceeded in y percent of rainfall
events.

A = total catchment area (Ha)




Sediment storage zone design parameters used here:

    •    50% of setting zone capacity


AREA OF   SITE                  CV          RX-day,y-   TOTAL       SETTING   SEDIMENT     TOTAL
TREATMENT                                   %ile        CMT         ZONE      STORAGE      BASIN
                                                        (Ha)        VOLUME    VOLUME       VOLUME
                                                                    (m3)      (m3)         (m3)
150x21 A                           0.3        43.4       0.315        41.0       20.5        61.50
70x21 B                            0.3        43.4       0.147        19.1       9.55        28.65


Basin A: 13.7m x 3m x 1.5m D, setting depth 1m, storage 0.5m

Basin B: 9.55m x 2m x 1.5m D, setting depth 1m, storage 0.5m




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1209 Animal Husbandry – Top Forestry Rd, Ridgewood                               SWQMP_REV_3
SEPTEMBER 2013