Flood Investigation & Stormwater Quantity Management Plan

Flood Investigation & Stormwater Quantity Management Plan
Proposed Residential Development at Doonella - Stage C


2.0 SITE CHARACTERISTICS
2.1      Location
The site is located in Noosaville, within the Doonella Lake Catchment of the Sunshine Coast Regional Council - Noosa
Shire District local government area. The proposed Stage C subdivision is bounded by Beckmans Road to the south,
Sea Eagle Drive to the west, a conversation reserve to the north and north east, and a new residential subdivision to
the east.
The subdivision proposal is for 185 residential Lots and 43 Group title lots, occupying a total area of 28.64ha. Stage C
of the development entails the creation of 61 residential allotments, road and open space. The location of the site is
indicated in Figure 2.1 below. The environmental corridor through the site is highlighted in blue.


                                                                                                         N




                                                                    SITE

                                    SEA EAGLE DRIVE


                                        ENVIRONMENTAL CORRIDOR

                               Figure 1: Approximate Location of Site (source UBD).

2.2      Existing Topography and Drainage.
The site is relatively steep and undulating with several high points and gullies. Currently the site is densely vegetated
and the proposal is to maintain some of this existing vegetation within the environmental corridor.
At the southern end, close to Beckmans Road, the environmental corridor has an average slope of approximately 6%.
Towards the eastern site boundary the average slope reduces to 3%. Flows in the environmental corridor continuing
past the eastern boundary pass through two 1.2m dia. RCP culverts under Shire Drive. Downstream of these culverts
is a detention basin constructed to mitigate flows from the newly completed adjacent subdivision. For further details of
the detention basin refer to the JF&P Site Based Stormwater Management Plan (2008).
Two external catchments contribute to the flow in the proposed environmental corridor. These catchments are to the
south of Beckmans Road and a small proportion of Sea Eagle Drive.
Apart from the Dodonaea Close road crossing and culverts only minimal works are proposed within the environmental
corridor. This involves minor invert works with retaining walls/batters to adjacent lots/roads. At the downstream end
(near Lot 146) the proposed retaining walls along the environmental corridor are higher than the proposed lot and road
levels, effectively forming a levee.

B09182.W-02A                                                                                                        Page 2