WATER CORPORATION —
GRASS PATCH DAM
1453. Hon COLIN de GRUSSA to the minister representing the
Minister for Water:
I refer to answers to questions
without notice 1363 and 1324 asked last week about Grass Patch Dam.
(1) On what basis or criteria is a minimum
water level designated for a dam?
(2) Why does the
dam no longer meet the quality standards required for supply of drinking water
by the Water Corporation?
(3) What danger occurs when the
water level in the dam is below ''its minimum safe level''?
(4) Given the
water in the dam is simply being left to evaporate, will the minister now make
the dam available for locals in desperate need of stock water?
Hon
ALANNAH MacTIERNAN replied:
I thank the member for the question.
The Minister for Water has provided the following answer.
(1) The minimum
water level is set by the Water Corporation on a dam-by-dam basis, giving
consideration to the construction
methodology of the dam. Grass Patch Dam has been constructed utilising a natural
clay lining that is impervious to
water, and this is how the dam retains water. In order to protect this lining
from damage, the Water Corporation has estimated a minimum volume that
is required in order to ensure that the dam retains some water, taking into
account likely evaporation losses over coming months.
Hon Colin Holt
interjected.
Hon ALANNAH
MacTIERNAN: It is a very good answer, actually. The answer continues —
(2) In March
2013, under a Liberal–National government, the decision was made to
cease using the dam to supply local drinking
water due to water quality concerns by the Water Corporation. The Water
Corporation is required to ensure that any water that it supplies to its
customers meets the very stringent standards determined by the Department of
Health. These standards closely reflect the Australian drinking water
guidelines, which are generally accepted as the minimum standard for Australian
water utilities. The Water Corporation has determined that the water provided
by Grass Patch Dam is no longer able to meet the Department of Health's
standards due to the difficulty in protecting the source from contamination.
(3) The risk is
that the current dry conditions continue to prevail in the Grass Patch area and
the remaining water will evaporate completely. This would leave the dam lining
exposed, causing it to dry out and crack, rendering it ineffective and
preventing it from holding water effectively in the future.
(4) No. This
would prevent the dam from holding water effectively in the future. If farmers
in the Grass Patch area are concerned about water availability for stock, they
should liaise with the shire and the Department of Water and Environmental
Regulation.
Several members
interjected.
The PRESIDENT: Order! If
members do not like the length of the response, perhaps they might rethink the
length of their questions.