24647 Seaview Tce Enviro Mgmt Plan

6.1.           ‘Clean’ Water
A clean water catchment has been identified in the Stormwater Management Plan (SMP) prepared by
Aquaintel (dated May 2016). This catchment includes the existing properties to the west of the site.
Upslope clean water will be diverted by a Clean Water Drain (CWD) around the work area, discharging via a
level spreader into the nature reserve. Sizing of the CWD has been undertaken, as detailed in Table 3. The
exact location of the drain is to be determined on site prior to the commencement of works, once the
discharge location of the external catchment into the site can be identified.
In accordance with Item 32 of the Noosa Council Decision Notice, temporary drainage has been designed
for the 1 in 5 year ARI event, assuming a 12 to 24 month construction period. The peak flow rate for the
0.286ha external catchment has been taken from Table 8 of the Aquaintel SMP
Table 3 – Clean Water Diversion Drain Design Summary


 Drain       Peak Flow          Slope         Design.          Base Width   Minimum      Horizontal Side        Proposed
  ID           (m3/s)            (%)       Velocity (m/s)         (m)       Depth (m)    Slope of Bund         Lining/Max
                                                                                                              Velocity (m/s)

CWD 1         0.153(1)           2.9                  1.5          0.6       0.27(2)          1:2             Geofabric / 1.5

NOTE:      (1) Refer Table 8 of Aquaintel SMP
           (2) Depth includes freeboard

6.2.           ‘Dirty’ Water
Runoff generated from internal disturbed areas will be conveyed primarily within dirty water diversion
bunds. These will direct runoff from those areas to the installed sediment control measures (sediment
basin). In accordance with Item 32 of the Noosa Council Decision Notice, the dirty water diversion bunds
have been designed for a 1 in 5 year event. A summary of design specifications can be seen in Table 4.

Table 4 – Dirty Water Diversion Bund Design Summary


  Diversion         Peak Flow           Design Flow           Allowable      Minimum        Horizontal Side       Proposed
  Bund ID             (m3/s)             Velocity           Flow Velocity   Depth (m)*      Slope of Bund           Lining
                                           (m/s)                (m/s)

    DB 1                 0.01                   0.3              1.5           0.23                 1:2          Geotextile

    DB 2                 0.01                   0.9              1.5           0.23                 1:2          Geotextile

    DB 3                 0.03                   0.6              1.5           0.20                 1:2          Geotextile

    DB 4                 0.01                   0.7              1.5           0.21                 1:2          Geotextile

* Depth includes freeboard

A standardised diversion bund is proposed across the site, details of which are illustrated in Figure 2.




71 Seaview Terrace, Sunshine Beach - Erosion and Sediment Control Plan                                                   Page 6

Hutchinson Builders
17SUN-0024/1600102