Site Based Stormwater Managment Plan

                                                                                 20169 - SBSMP/2
                                                                                            Page 7




4.2 Existing Drainage Patterns
Data obtained from Noosa Council’s records and detailed site survey indicate that the site has
the following drainage patterns:

Roofwater Runoff
    1. The existing commercial building roofwater within Lot 1 on RP230931 appears to travel
       underground and connect into the existing structure located within the driveway access of
       Lot 61 on RP69404. Hence, the roofwater from the existing commercial building was
       discharged to the Eumundi Noosa Road kerb and channel.
    2. A review of the street frontage of the site along Eumundi Noosa Road indicated that there
       is no kerb outlet for Lot 1 on RP849431. Hence, it is assumed that roofwater from the
       existing residential building is discharged to the ground or to the existing underground
       stormwater infrastructure at the rear of the site via downpipes.

    3. The existing building roofwater within Lot 61 on RP69404 appears to travel underground
       and connect into the existing structure located within the north eastern corner of the site.
       Hence, the roofwater from the existing building was discharged to the 300mm dia. pipe
       within Lot 79 on SP138388.

Surface Runoff
    1. Surface runoff from the rear portion of Lot 1 on RP230931 generally sheet flows towards
       the adjacent site on Lot 61 on RP69404, north and east of the site.
    2. Surface runoff from the front portion of Lot 1 on RP230931 generally sheet flows towards
       the Eumundi Noosa Road kerb and channel.
    3. Surface runoff from Lot 1 on RP849431 generally sheet flows south east towards Lot 46 and
       62 on SP132578.

External Catchment
    1. There appears to be no external catchment entering the site.

4.3 Lawful Point of Discharge
If the proposed development maintains pre-development flow conditions, the lawful point of
discharge for the proposed development is the existing stormwater drainage infrastructure within
Lot 46 and 62 on SP132578, southeast of the site, the existing stormwater infrastructure within
Lot 79 on SP138388, northeast of the site, and the Eumundi Noosa Road kerb and channel.

In consideration of the site characteristics, surrounding topology and stormwater drainage
infrastructure, the aforementioned proposed lawful point of discharge is considered to be
compliant with the criteria for lawful point of discharge outlined in Section 3.9.1. of QUDM 2017
as per below:
    i) The location of the proposed discharge point is under the lawful control of the local
       government or other statutory authority from whom permission to discharge has been
       received.

    ii) The post development discharge will not cause an actionable nuisance, nor environmental
        or property damage, as it is intended to implement measures to account for any change to
        the existing flow characteristics.




Site Based Stormwater Management Plan
Proposed Townhouse Development at 99, 101 & 105 Eumundi Noosa Road, Noosaville