S25-107-Stormwater Report

Erosion and sediment control plans are based on three sets of control measures:
    1. Drainage control
    2. Erosion control
    3. Sediment control
These control measures must be maintained in an effective operational condition. Sediment disposal from site is to
occur to the satisfaction of NC. Defects in erosion and sediment control devices, such as sediment fences and baskets,
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 (if applicable) 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.
The effectiveness of the erosion and sediment control devices can be monitored by visual audits. All ESC measures are
to be inspected:
    •      at least daily (when work is occurring on site) or weekly (when work is not occurring on site)
    •      within 24 hours of expected rain
    •      within 18 hours of a rainfall event (i.e. an event of sufficient intensity and duration to mobilise sediment on
           site)
Drainage paths are to be inspected to ensure the sediment fences are not being bypassed as a result of soil erosion.
Sediment laden run-off shall be prevented from entering neighbouring properties. This shall be achieved by
landscaping disturbed areas immediately and prior to a rainfall event.
The proposed development has scored a 16 on the IECA erosion hazard assessment with no trigger score values
exceeded (refer Appendix A for details). Further details of proposed on site erosion and sediment control measures
will be required at the detailed design phase of the development.

4.2.2      Maintenance and Monitoring Requirements

Periodic maintenance and monitoring of stormwater devices proposed in this report is crucial to ensure effective
operation and design life.
Inspect field inlet grates, pits and underground pipes for blockage or damage at least 6 monthly or after significant
rainfall event. The filter baskets shall be inspected and maintained preferably by the manufacturer to avoid damage
to units and to ensure adequate cleaning and record keeping. For the first 12 months routine inspections of filter
baskets shall be carried out monthly with routine clean out at alternate months. Results of the initial 12 months
maintenance program shall be used to determine future maintenance intervals. Refer manufactures maintenance and
monitoring methodology for specific details.
Maintenance of ESC measures must occur in accordance with Table 2.




 S25-107                                        Stormwater Management Report                                   Page 4 of 6
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