Ploughmans Creek Stormwater Harvesting Scheme

The Ploughmans Creek Stormwater Harvesting Scheme follows on the heels of the multi award winning Blackmans Swamp Creek Stormwater Harvesting Scheme. This scheme will transfer a portion of the storm flows from the Ploughmans Creek catchment into Suma Park Dam, via pipelines, where it will supplement the City's raw water supplies.

Urban development, through the creation of impervious surfaces (such as roads, car-parks and footpaths), provides a valuable resource of predictable stormwater generation. Urban development in the Ploughmans Creek catchment has increased the average volume of run off by 880ML per year.

A drier future, albeit with more extreme storm events, makes stormwater harvesting from an urbanised catchment a sensible option to consider. The challenge is to adaptively manage the scheme's use so that the downstream impact is not significant and that the needs of downstream users and the aquatic environment are not compromised.

The urbanisation of the Ploughmans Creek catchment, compared to its natural condition, has generated additional stormwater runoff. The harvesting scheme has been designed and will be operated to capture and use this extra runoff.

The Ploughmans Creek stormwater harvesting scheme was constructed and will operate without risk of serious or irreversible damage; without degrading the health, diversity and productivity of the environment for future generations; and without jeopardising biological diversity or ecological integrity.

The Ploughmans Creek Stormwater Harvesting Scheme comprises four (4) wetlands to provide stormwater quality and quantity-controls and two (2) small V-notch weirs and associated pumps to pool and harvest stormwater flows. The average volume harvested by the scheme under current catchment conditions is estimated at 700ML/year however, when the catchment is fully developed this is estimated to increase to an average of 800ML/year.

Wetlands

There are four wetlands making up this scheme. These are Somerset Park wetlands, Cargo Road wetlands, Burrendong Way wetlands and The Escort Way wetlands.

This program has been assisted by the New South Wales Government through its Environmental Trust.

There has been an extensive planting of aquatic vegetation in these wetlands to suit the local environment.

Here is a list of aquatic vegetation planted in the wetlands:

Ecotone Zone 1

Lomandra longifolia, Pennisetum alopercuroides

Ecotone Zone 2

Gahnia sieberiana, Juncus usitatus, Juncus aridicola, Poa labillardieri

Fringing Zone

Baumea articulata, Bolboschoenus fluviatilis, Phragmites australis

Mudflat Zone

Carex appressa, Carex fascicularis, Juncus aridcola, Juncus usitatus

Deep Water Zone

Ottelia ovalifolia, Eleocharis sphacelata

Downstream Impacts

The Ploughmans Creek Storm Water Harvesting Scheme has been designed to minimise the impact on the environment and downstream users. It needs to be remembered that there are agricultural properties and communities which rely on flows from this creek.

The Council has designed the scheme so it will take slightly less than the extra water generated by the urban development within Orange City.