Negotiated - Compiled Reference Document - RAL25 0011 (As Published)

LINDSAY CONSULTING PTY LTD
STRUCTURAL AND CIVIL ENGINEERS
ACN 079 744 808 ABN 61 478 386 385 GST REGISTERED

AS TRUSTEE FOR THE LINDSAY FAMILY TRUST




Table 4 – SPP Appendix 2: Part 3 Construction Phase – Stormwater Management Design Objectives
for Emergency Spillways on Temporary Sediment Basins

                  Drainage Structure                            Anticipated Operation Design Life and Minimum
                                                                             Design Storm Event


                                                                 <3 Months      3-12 Months       >12 Months

 Emergency      spillways                 on        temporary    1 in 10 year    1 in 20 year     1 in 50 year
 sediment basins                                                ARI/10% AEP      ARI/5% AEP       ARI/2% AEP


Best practice erosion and sediment controls must be installed to minimise the discharge of sediment
laden runoff during construction and to achieve the objectives outlined in Tables 2-5. This is discussed
in the following section.
   4.2.2        Erosion and Sediment Control

Management of stormwater runoff during construction is necessary to avoid pollution of downstream
waterways from sediment and gross pollutant loading. Impacts of inadequate erosion and sediment
control downstream from the site include:
     •     traffic safety problems;

     •     blocked drains;
     •     local flooding problems;
     •     aesthetic pollution of drainage paths; and
     •     damage to local ecosystems.

Best practice erosion and sediment controls must be installed to minimise the discharge of sediment
laden runoff during construction. Erosion and sediment control plans shall be developed during detailed
design phase and must be continually maintained and amended as required to minimise environmental
harm.
Erosion and sediment control plans are based on three sets of control measures:

     •     drainage control;
     •     erosion control; and

     •     sediment control.
These control measures must be maintained in an effective operational condition. Sediment disposal
from site is to occur to the satisfaction of Sunshine Coast Council. Defects in erosion and sediment
control devices, such as sediment fences, are to be inspected and documented. Upon Inspection, the
Contractor is to determine whether the device should be replaced or repaired. Documentation is to
include how the damage was caused and what measures can be implemented to reduce the possibility
of repeat occurrences. Any damage to either permanent or temporary water quality control structures
or devices is to be immediately rectified at the contractor’s expense.




Off. 2C/82 Parker St, Maroochydore 4558
                                                                                                                 5
OFFICE: (07) 54 792 118 MOBILE: 0412 313 645 FAX: (07) 54 510 118
E-MAIL: [email protected]