080624 2383-01 FINAL Engineering Report for DA.pdf [As Published] · 132008.1128

BLUE CARE SUNRISE BEACH
ENGINEERING REPORT FOR DEVELOPMENT APPLICATION




The storage tanks have been sized in accordance with the requirements of the Noosa
Rainwater Tank Policy and the QDC. Each residential dwelling unit will be required to
incorporate a rainwater storage capacity of at least 3,000L. It is understood that this
requirement will be fulfilled using common storage tanks, located under the internal roads.

Stored non-potable stormwater runoff will be re-used in accordance with the QDC for the
following:

-    External Use
-    Cold Laundry Tap
-    Toilet Flushing


2.4 STORMWATER QUALITY AND QUANTITY OBJECTIVES
The aim of the stormwater management system for the proposed development is to protect
and enhance the natural water systems of the National Park and elsewhere.

Stormwater runoff from the site will be managed in accordance with the principles of Water
Sensitive Urban Design (WSUD) as expressed by the following performance criteria and
objectives (Melbourne Water, 2005):

-    Recycle stormwater for non-potable use (to reduce demand on water resources);
-    Protect and enhance natural water systems within urban developments;
-    Integrate stormwater treatment into the landscape;
-    Use stormwater infrastructure in the landscape to maximise visual and recreational
     amenity;
-    Control and improve the quality of water draining from the urban development;
-    Reduce runoff and peak flows from urban development to be no greater than the pre-
     developed case, by utilising local detention measures and the reduction of impervious
     areas; and
-    Minimise the drainage infrastructure cost of development.

Further stormwater quality objectives have been identified for this site. The Department of
Natural Resources and Water (DNRW) has recommended that the water quality for
discharges from the developed site be ‘not worse’ than for the pre-developed case. The
Healthy Waterways guidelines recommend load based reduction targets which, when met,
are generally considered to surpass the ‘not worsening’ requirement. The Healthy
Waterways load based reduction targets (Table 2.2) were adopted for this analysis.

Table 2.2, Pollutant Load Reduction Targets

    Pollutant                                  Load Reduction
    Total Suspended Solids                     80%
    Total Phosphorous                          60%
    Total Nitrogen                             45%

During the construction phase, the potential exists for significant increases in the amount of
pollutants, particularly sediment, exported from the site. During this period, an Erosion


Blue Care Property Development Unit                       Version 1.1                        24 June 2008
2008 06 24 2383-01 Engineering Report for DA         Commercial in Confidence                      Page 6