Attachment 8 - Interim Stormwater Management Plan - TOPO · 132005.638.06

R5304: NOOSA RESOURCE RECOVERY CENTRE - STORMWATER MANAGEMENT PLAN




Figure 5 – Existing Drainage Features

3.1.             PREVIOUS DESIGNS & UPGRADES

3.1.1.           SW5 HES BASIN
Previous modelling and designs were undertaken by Topo for a Type A HES for the southern catchment, being directed
to the SW5 outlet. The basin was designed for a 4.5 ha catchment, with a clean water diversion drain sized for a maximum
6.2 ha catchment to divert clean water flows around the basin. Drains were sized for the 1 in 10 year ARI critical storm.

The basin was assessed using a MUSIC water-balance model against the EA requirement to treat 90 % of annual runoff.
The modelling demonstrated 90.3 % annual runoff treatment is achieved, exceeding the performance of a 10 year 24
hour traditional basin (85.2 %). The basin includes automatic flocculant dosing and a monitoring system reading
turbidity, pH, electrical conductivity and dissolved oxygen, linked to a power-actuated outlet valve that closes when
readings fall outside the EA release limits.

Refer to Appendix B – Design Report & Maintenance and Inspection Plan: Noosa Landfill – Clean Water Drain & High-
Efficiency Sediment Basin (SW5) for further details.




Environment. Engineering. Education.                                                                              PAGE 10