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]North Basin
Date:      22/10/2007
User:      MS
Note:      Storage and outlet calcs for North Basin

STAGE - STORAGE RELATIONSHIP FOR HYDROLOGICAL MODEL
Stage areas taken from ACAD model
                                      Accumulated
                    2            3             3
   RL       Area (m )     Vol. (m )     Vol. (m )
  99.6        1334          0.00          0
 99.75        1492         211.95        212
  100         1642         391.75        604
 100.25       1821         432.81        1037
 100.5        1999         477.44        1514
 100.7        2203         420.24        1934
  101         2510         707.01        2641

OUTLET CALCULATIONS
                        Circular Inlet Circular Inlet
Type                          1              2        INLET PIT   PIPE 1        PIPE 2       WEIR
Length                                                    2.4       15            15
Width                                                     0.9
No.                           1              5                       1            1
Dia (m)                      0.05          0.375                   0.75         0.825
         2
Area (m )                                                2.16      0.442        0.535
Invert Level (R.L)           99.2          99.6         100.25     99.15        99.15        100.7
Inflow Level (R.L)           99.2          99.6                    99.6         99.6
D/S HGL (R.L)                                                       99           99
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                                  4
% Opening Clear *                                        50%

STAGE - DISCHARGE RELATIONSHIP FOR HYDROLOGICAL MODEL
          Accumulated Circular Inlet Circular Inlet
                   3
   RL       Vol. (m )       1              2        INLET PIT PIPE 1            PIPE 2       WEIR       TOTAL
  99.6          0         0.003          0.000        0.000   0.000             0.000        0.000       0.003
  99.75      212          0.004          0.401        0.000   0.446             0.485        0.000       0.405
   100       604          0.005          0.744        0.000   0.788             0.856        0.000       0.750
 100.25      1037         0.006          1.011        0.000   1.029             1.230        0.000       1.017
  100.5      1514         0.007          1.241        0.872   1.171             1.400        0.000       2.119
  100.7      1934         0.008          1.408        2.105   1.278             1.527        0.000       2.804
   101       2641         0.009          1.639        2.776   1.428             1.707        1.091       4.226

Note:
The following equations have been used to calculate flow capcaties for the
outlet types for each stage:
Pipe Flow (M.J.Boyd 1972)                        Q = 0.421 x g0.5 x Dia0.87 x HW 1.63 (where HW/Dia < 1.2)
                                                 Q = 0.53 x g0.5 x Dia1.87 x HW 0.63 (where HW/Dia > 1.2)
                                                 where g = 9.81m/s2
                                                                   1.5
Weir Equation (AR&R Equ. 14.5)                   Qi = 1.66 x P x d
Orifice Equation (AR&R Equ. 14.6)                Qi = 0.67 x A x (2g x d)0.5




H:\B07\050-099\B07056 - RSL Care Cooroy.WW\Misc\Detention Calcs MS 071009