LMDIP - Wimmers Carpark Site Planning Assessment

proposed work area will remain exposed for a full year. In reality the proposed earthworks will be opened up for approximately
1 week during the lowest risk months of the year (July / August) before being capped and sealed with roadbase material –
reducing the soil loss risk even further.

The total disturbed area is estimated at 2100m2.

Based on this Type 3 ESCs would be considered suitable to control sediment loss from the site.


5.1.2    Erosion and Sediment Control Plan (ESCP)
The ESCP is shown below along with eth standard drawings indicating how to install the specified ESCs.

The carpark area will be worked with some minor cut & fill to ensure a level surface that slopes gently 1-2% towards the
existing road table drain.

Sediment fence will line the downslope side of the works area. Returns and spill-through weirs to be installed as required.

Sheet flows will be captured in the drain which will require reprofiling into a trapezoidal / spoon drain. It will then be topsoiled
and lined with turf placed down in an interlocking pattern as seen in the standard drawing below. A rock check dam will be
installed at the end of the swale to slow water before it enters the rock mattress where it gets diverted into the existing
culvert under the road.

A Rock outlet structure will be installed at the final discharge location at the culvert outlet where water will then be dispersed
towards the creek.


5.1.3    Stockpiles
Topsoil will be stripped from the work area at a depth of approx. 100-150mm. Topsoil will be stockpiled at the locations
shown on the ESCP. Topsoil height should not exceed 1.5m. Once stockpiling is completed topsoil stockpiles will be hand-
seeded to ensure faster stabilisation.



6. Community Engagement
Seqwater and John Holland will be undertaking communication and engagement activities to notify for the works including:
    Doorknock to immediate neighbours
    Works notification emailed to the project database
    Project webpage update.



7. Conclusion

Seqwater and John Holland are proposing to use an undeveloped area on the Wimmer’s industrial property located on land at
271 Lake Macdonald Drive, Lake Macdonald (Lot 2 SP108094) to construct a temporary gravel carpark and laydown area
which will be used for an upcoming increased workforce required for the LMDIP project.

JHG have entered into a written agreement with the landowner and the relevant signed lease agreement is attached to this
submission. The temporary carpark will accommodate approximately 60 cars and will be used by John Holland contractors
for approximately 34 months from August 2026 to May 2029. A temporary laydown area is also proposed, for the purpose of
storing building materials and machinery as needed from time to time. There is no storage of hazardous or dangerous goods
proposed within the laydown area.

In terms of construction works, only minor earthworks are required, however they fall partially within the riparian buffer zone.
Therefore, appropriate erosion and sediment controls and waterway protection measures need to be deployed. No




REX# D26/127335 Wimmers Carpark Planning Assessment, 20 July 2026                                                       Page 7 of 13