B07056.W-01A Complete - Stormwater [As Published] · 132007.2398

                                                                                                               Appendix B



CONCEPT DETENTION BASIN DESIGN CALCULATIONS
File:      H:\B07\050-099\B07056 - RSL Care Cooroy.WW\Misc\[Detention Calcs MS 071009.xls]South Basin
Date:      22/10/2007
User:      MS
Note:      Storage and outlet calcs for South Basin

STAGE - STORAGE RELATIONSHIP FOR HYDROLOGICAL MODEL
Stage areas taken from ACAD model
                                       Accumulated
   RL       Area (m2)     Vol. (m3)      Vol. (m3)
 101.5        1302          0.00          0
 101.75       1465         345.88        346
  102         1632         387.13        733
 102.25       1804         429.50        1163
 102.4        1910         278.52        1441
 102.5        1980         194.48        1636
 102.75       2159         517.38        2153
  103         2344         562.88        2716

OUTLET CALCULATIONS
                        Circular Inlet Circular Inlet
Type                           1             2        INLET PIT     PIPE 1        PIPE 2         WEIR
Length                                                    2.4         30            30
Width                                                     0.9
No.                            1             5                         1             2
Dia (m)                      0.05          0.375                     0.45          0.525
         2
Area (m )                                                2.16        0.159         0.216
Invert Level (R.L)           101           101.5        102.4        101.2         101.2         102.5
Inflow Level (R.L)           101           101.5                     101.5         101.5
D/S HGL (R.L)                                                         101           101
f (Fig 1.6)                                                          0.023         0.023
Pit Loss (K)                                                          0.5           0.5
Hydraulic Conductivity (k) (m/hr)
Depth Media d (m)
Perimeter (m)                                             4.2                                     3.75
% Opening Clear *                                        50%

STAGE - DISCHARGE RELATIONSHIP FOR HYDROLOGICAL MODEL
          Accumulated Circular Inlet Circular Inlet
   RL       Vol. (m3)       1              2        INLET PIT PIPE 2              PIPE 3         WEIR          TOTAL
  101.5         0         0.004          0.000        0.000   0.000               0.000          0.000          0.004
 101.75      346          0.005          0.554        0.000   0.256               0.568          0.000          0.559
   102       733          0.006          0.857        0.000   0.324               0.865          0.000          0.863
 102.25      1163         0.007          1.106        0.000   0.385               1.026          0.000          1.113
  102.4      1441         0.008          1.241        0.000   0.418               1.116          0.000          1.248
  102.5      1636         0.008          1.326        0.220   0.440               1.174          0.000          1.554
 102.75      2153         0.009          1.526        1.444   0.492               1.311          0.778          2.581
   103       2716         0.009          1.712        2.483   0.540               1.441          2.201          4.182

Note:
The following equations have been used to calculate flow capcaties for the
outlet types for each stage:
                                                               0.5       0.87      1.63
Pipe Flow (M.J.Boyd 1972)                        Q = 0.421 x g x Dia          x HW      (where HW/Dia < 1.2)
                                                             0.5       1.87      0.63
                                                 Q = 0.53 x g x Dia         x HW      (where HW/Dia > 1.2)
                                                 where g = 9.81m/s2
Weir Equation (AR&R Equ. 14.5)                   Qi = 1.66 x P x d1.5
Orifice Equation (AR&R Equ. 14.6)                Qi = 0.67 x A x (2g x d)0.5




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