<< Peninsula New 18 September 2006 - Endangered bushland is groundwater-dependent >>

Endangered bushland is groundwater-dependent

While we are endeavouring to conserve and reduce our water use, unfortunately our nearby Endangered Ecological Communities (EEC) - Umina Coastal Sandplain Woodland and Sydney Freshwater Wetlands - have no such ability.

The Woy Woy-Umina sandplain aquifer is being targetted by Gosford Council to supply up to five per cent of our drinking water through a proposed borefield of 20 sites, seven of which will be located adjacent or near the two EECs.

The endangered Umina Coastal Sandplain Woodland (UCSW) is particularly at risk as only between 10 and 40 hectares remain (Bell, 2004 - Native Vegetation of Gosford Council LGA; DEC-NPWS Scientific Committee 2003) and none is conserved within NPWS reserves, State Forests or Local Government reserves (Bell, 2004).

The UCSW community is recognised by the Department of Environment and Conservation, the National Parks & Wildlife Service and the Scientific Committee set up under the Threatened Species Act, 1995.

We believe that the proposed seven bores within the larger Umina-Woy Woy borefield is a "key threatening process".

Gosford Council also recognises that these communities are endangered and vulnerable (GCC 2006, Draft Biodiversity Strategy) and has acknowledged that existing private bores will be affected by the proposed draw-down.

Yet the council still proposes to locate and pump from the seven bores adjacent to these EECs, relying on monitoring bores to check for saltwater incursion - and four tiny vegetation monitoring plots.

The importance of groundwater to certain ecosystems has been identified by CSIRO in the Australian Journal of Botany, April 2006, where a whole issue was devoted to Groundwater Dependent Ecosystems.

As a sandplain woodland, the UCSW is dependent on groundwater during times of drought (O'Grady, 2006).

The modelling of responses of these ecosystems to groundwater extraction is identified by Professor Eamus as being 'conceptual only' and that additional research is required (Australian Journal of Botany April, 2006) to understand these responses.

By extracting groundwater during drought, the magnitude and rate of draw-down are sufficient to collapse the water flow through plant xylems, leading to the death of plants such as Banksias - one of the 'positive' species in the Umina EEC.

In the recent National Parks Association Journal, Environment Minister Debus wrote that Climate Change is a key threatening process and that ".. action must be taken to enhance the resilience of ecosystems and reduce the impacts on biodiversity" (Debus, Jun-Jul, 2006).

We totally agree, and believe intervention is required to prevent potential eradication of these EECs on the Umina-Woy Woy sandplain.

We know that our water shortage is dire, but such a tiny percentage (1.5 per cent) of drinking water from seven bores in environmentally sensitive areas will not make a significant difference to the Central Coast's water supplies.

Rod Craig, Pearl Beach Pearl Beach Progress Association