The General Manager
Eurobodalla Shire Council 10 March, 2005
PO Box 521
MORUYA NSW 2537

DESIGNATED DEVELOPMENT PROPOSAL -- EARTH WATER STORAGE AND IRRIGATION DAM, HAXSTEAD RD, CENTRAL TILBA
Application No 747/05 Ref no. 02.9111.D

Our Association is concerned by several aspects of this proposal:
1. The cumulative impact, together with other dams in the catchment of Tilba Tilba Lake, on the flows into the Lake;
2. The potential for greatly increased nutrient run-off into the Lake from irrigated areas; and
3. The potential for huge amounts of sediment to enter the Lake during and after construction.

We object to this proposal unless it can avoid all these problems.

We would also like to be advised if and when it comes before the EPAS committee.

As the advertisement in the newspaper did not say where to send submissions we would appreciate it if you would copy this submission to the relevant parties in the Dept of Infrastructure Planning and Natural Resources.

Cumulative Impact
From topographic maps it appears there are already over 90 dams along the Tilba Tilba Lake/Victoria Creek catchment drainage lines. This additional huge dam could be the final nail in the coffin of the Lake which already suffers from eutrophication and extremely poor flushing.

Nutrient Run-off
While the dam will capture some nutrients it is likely to generate much larger amounts if the water is used for irrigation of such activities as improved pasture and denser stocking with dairy cattle. How can run-off with elevated nutrients be kept out of the Lake? Even if the irrigated areas drain back into the dam, and not into the Lake, there is still the potential for high nutrient input when the dam overflows.

Sediment Input
The DA says a total volume of 27,000 cubic metres of earth will be moved during construction and the earth embankment will use 24,890 cubic metres. Earth moving will take some time and it will be even longer before erosion of the embankment is prevented by vegetation growth. Sediment control will need to be much more effective than on road works and most building sites to ensure that large amounts do not end up in the Lake.

Will the spillways be made of erodible earth or concrete? What measures will be taken to prevent gully erosion downstream of the spillways?

Jenny Edwards
Secretary,
The Coastwatchers Assoc Inc
Phone (02) 4471 5032