The buffer zone around the dam: is it 200m or is it 20m?  It started as 200m, then GBIP suggested it may be 20m, and now it seems it may stay at 200m after all.

When SDRC was the dam proponent, the Environmental Impact Statement (“EIS”) required a 200m wide buffer around the dam. This was in accordance with the Australian Drinking Water Guidelines and was designed to protect the water quality of Emu Swamp Dam for urban use.  When SDRC withdrew from the project, the new proponent (GBIP) proposed that the buffer zone may only be 20m wide as the water was only to be used for agricultural purposes.

Now that SDRC is again proposing to be involved in Emu Swamp Dam, the question naturally arose as to whether the original 200m buffer zone would be reinstated.  Whether the buffer zone is 20m or 200m will obviously have a significant impact on the 17 properties directly affected by the dam. Those ratepayers whose land is affected by the project would see far more of their property acquired (or compulsorily acquired) than was proposed by GBIP last December in its letters to affected landowners.

SDRC is responsible for determining the water quality requirements for all water to be used for urban purposes.  SDRC must be satisfied that the water from Emu Swamp Dam meets these requirements, and SDRC have advised that the buffer zone is being reworked to take into account the urban water component of the project.  This looks to be an acknowledgement that the buffer zone will once again be 200m rather than the earlier suggested 20m.

By way of background, the Coordinator General’s report on the EIS states that “The existing surface water quality is indicative of a slightly to moderately disturbed ecosystem, affected by surrounding agricultural development, land clearing, grazing and historic tin mining. Due to the surrounding agricultural land uses, the existing water quality does not achieve the prescribed water quality objectives for some nutrients and chemical parameters—aluminium, zinc, copper and dissolved oxygen.”

Further on:

“A 200-metre-wide vegetated buffer around the dam would be established to minimise the potential for nutrients and sediment to enter the dam. I require the buffer to be in place prior to inundation of the dam.  I am satisfied that my conditions will ensure suitable water quality is maintained during the construction and operation of the dam.”

As well as improving water quality, the 200 m buffer around the dam was also required by the Coordinator General as protection against the impact of flood events.