Engineering

                                              LINDSAY CONSULTING PTY LTD
                                                                                RAINFALL VOLUME CALCULATIONS
Project                                       WILLIAMS ST, NOOSAVILLE                                                                                                                                                                            Project Number                                    201343OW
                                                                                                                                                                                                                                                 Client

                                                                                                                                                                                                                  SITE INFORMATION

                                                                                                                                                                                    Total Site Area                      594                     sqm
                                                                 RAINFALL INTENSITIES (FROM BOM, ARR 2016)                                                                          Limiting runoff from Site (Dia 450) 999                      m3/sec        (999 voids this check)
                                                                                                                                                                                    Pavement area to Detention Tank       0                      sqm
                                                                             Annual Exceedance Probability (AEP)                                                                    Storage in bio-retention basins       0                      cbm
                                            Duration   63.20%            50%# 20%*        10%     5%          2%                                        1%                          Roof Area into Detention Tank         0                      sqm
                                              1 min      171              192     257     301     343         398                                       440                         Site Area                            594                     sqm
                                              2 min      144              161     219     260     300         357                                       402                         Travel length                         30                     m
                                              3 min      135              152     206     244     281         332                                       372                         Site Slope                          0.007
                                              4 min      129              145     196     231     265         311                                       347                         Surface Roughness                    0.03
                                              5 min      123              139     187     220     252         294                                       326                         Land Description                      L                      L/M/D
                                             10 min      101              114     152     177     201         232                                       255                         Soil Permeability                     M                      High/Medium/Low (H/M/L)
                                             15 min     85.7              96.2    128     150     170         196                                       215                         L ==> Light cover bushland, or poor grass cover, or low density pasture, or low cover bare fallows
                                             30 min     60.1              67.5   90.4     106     120         140                                       154                         M ==> Medium Density Bush, or good grass cover, or high density pasture, or zero tilling cropping
                                             1 hour     39.7              44.8   60.7     71.6    82.4       96.9                                       108                         H ==> Dense Bushland
                                             2 hour     25.7              29.2   40.4     48.2    56.1       66.9                                       75.5                        Un-Developed Fraction Impervious 0.1                                       From Fig. 4.05.1 in QUDM (2007)
                                             3 hour       20              22.8     32     38.6    45.1       54.2                                       61.4                        Developed Fraction Impervious        0.9                                   From Fig. 4.05.1 in QUDM (2007)
                                             6 hour     13.2              15.2   21.9     26.7    31.6       38.3                                       43.5                        One Hr rainfall Intensity for Q10 71.53598 mm/hr
                                            12 hour     8.82              10.3   15.2     18.8    22.4       27.2                                       31.1                        Calculated Travel Time                9    Min                             Must equal time selected for intensity
                                            24 hour      5.9              6.95   10.4      13     15.6       19.1                                       21.9                        Adopted Storm Time                    9    min
                                            48 hour     3.82               4.5    6.8     8.52    10.3       12.8                                       14.9
                                            72 hour     2.88              3.39   5.13     6.44    7.83       9.82                                       11.5



                                                                                                                                                   Return interval (ARI)
                                                              63.20%                        50%#                                  20%*                         10%                            5%                            2%                             1%
Intensity (for Return Interval)                               127.00                        143.00                               193.00                       227.00                         260.00                        304.00                         337.00
                                                       Undeveloped       Developed   Undeveloped       Developed   Undeveloped         Developed      Undeveloped       Developed   Undeveloped       Developed    Undeveloped       Developed   Undeveloped       Developed
C10 value                                                0.720            0.880        0.720            0.880        0.720              0.880           0.720            0.880         0.720           0.880         0.720            0.880        0.720            0.880
Fy Factor                                                1.200            1.200        1.200            1.200        1.200              1.200           1.200            1.200         1.200           1.200         1.200            1.200        1.200            1.200
Cy                                                       0.864            1.056        0.864            1.056        0.864              1.056           0.864            1.056         0.864           1.056         0.864            1.056        0.864            1.056
Q (m3/sec)                                               0.018            0.022        0.020            0.025        0.028              0.034           0.032            0.040         0.037           0.045         0.043            0.053        0.048            0.059
Total Rainfall for event (m3)                                    12                            14                                 19                            22                             25                            29                            32
Total Non-Worsening Volume for Storm (m3)                            3                             3                               4                                4                             5                              6                             6