Having degraded their own rivers and failed to adequately plan their own water security for times of drought, local governments in the Murray-Darling Basin are calling for damming and diversion of water from the Northern NSW Clarence River system.
Thus far the Maryland River and the Aberfoyle River have been identified as desirable options by these wannabee water raiders.
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This is the Clarence River Catchment.
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| via Blicks River Guardians
The Aberfolye River is shown in the left hand lower curve of the catchment boundary.
The river is approximately 115km in length with an annual average water flow of 19,482 ML.
The Aberfoyle River* empties into the Guy Fawkes River which in turn runs into the Boyd River which is a tributary of the Nymbodia River which itself is the greatest contributor of water to the Clarence River system and the source of at least 95 per cent of Clarence Valley drinking water.
The Nymboida River is also the source for water storage held in the 30,000Ml Shannon Creek side dam which supplies water security for a combined total of 128,198 residents (as well as local businesses and over 5 million tourists annually) in Clarence Valley and Coffs Harbour City local government areas.
Ten years ago the Nymboida was supplying water for a population of 95,000 - in forty years time it is conservatively expected to supply 220,000. |
Currently WaterNSW, a NSW Government agency, is investigating a proposal to extract water from the Aberfoyle River and send it south-west to the Gwydir River and Copeton Dam at an estimated cost of $1.8 billion.
This proposal appears to be based on one of fourteen Clarence River diversion schemes 'desktop' investigated in the early 1980s - specifically a proposed dam on the Aberfoyle diverting water to either Happy Valley, Boorolong or Teatree creeks to feed the Gwydir River, or alternatively an Aberfoyle dam to feed the Gara River.
Drawing more water from the Upper Nymboida sub-catchment will in all probability raise hydrological and environmental stress on the entire Nymboida River and, may result in water levels at the Nymboida Weir falling below the 225Ml/D low flow level pumping cutoff up to est. 80 per cent of the time.
At the time of writing the Nymboida flow was 200Ml/D.
At the time of writing the Nymboida flow was 200Ml/D.
Indeed, given that rainfall decline has been occurring in the Northern Rivers region for around five decades, any further decline in available river water to supply daily use and long-term water storage has the potential to see intractable water scarcity develop in Clarence Valley and Coffs Harbour City local government areas, as well as a sharp decline in the health of the Nymboida River.
The rest of eastern Australia needs to realise that the Clarence River system is not filled to the brim with harvestable water. The 500,000,000Ml of water annually discharging into the Pacific Ocean at the mouth of the Clarence River was a myth from the first time it was calculated.
Even Clarence Valley and Coffs Harbour City councils will have to curb their desire for continuous development, as they probably have less than twenty years of water security remaining even if the wall of Shannon Creek Dam were to be raised.
Since the Millennium Drought Clarence Valley households have been on permanent low level water use restrictions as a precautionary measure, but as this current drought** may indicate that severe drought is no longer an anomaly but an everyday fact of life, we may be facing a higher level of permanent water restrictions very soon.
The rest of eastern Australia needs to realise that the Clarence River system is not filled to the brim with harvestable water. The 500,000,000Ml of water annually discharging into the Pacific Ocean at the mouth of the Clarence River was a myth from the first time it was calculated.
Even Clarence Valley and Coffs Harbour City councils will have to curb their desire for continuous development, as they probably have less than twenty years of water security remaining even if the wall of Shannon Creek Dam were to be raised.
Since the Millennium Drought Clarence Valley households have been on permanent low level water use restrictions as a precautionary measure, but as this current drought** may indicate that severe drought is no longer an anomaly but an everyday fact of life, we may be facing a higher level of permanent water restrictions very soon.
Note
* The Devils Chimney in the Aberfoyle River gorge was declared an Aboriginal Place on 8 August 1980. It is protected under under Section 90 of the NSW National Parks & Wildlife Act 1974 and can not be damaged, defaced or destroyed without the consent of the NPW Director-General. Unfortunately the NSW Berejiklian Government does allow for damage and destruction of such sites.
** The NSW DPI Clarence Valley Drought Map as of 24 September 2019:
CDI = Combined Drought Indicator. RI = Rainfall Index. SWI = Soil Water Index. PGI = Pasture Growth Index. DDI = Drought Direction Index
Data current to 24/9/2019 (AEST)
* The Devils Chimney in the Aberfoyle River gorge was declared an Aboriginal Place on 8 August 1980. It is protected under under Section 90 of the NSW National Parks & Wildlife Act 1974 and can not be damaged, defaced or destroyed without the consent of the NPW Director-General. Unfortunately the NSW Berejiklian Government does allow for damage and destruction of such sites.
** The NSW DPI Clarence Valley Drought Map as of 24 September 2019:
Data current to 24/9/2019 (AEST)
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