Mitta Mitta River flow advice: Harmony transfers to continue
21 February 2013 - MDBA
'Harmony' transfers from Dartmouth Reservoir to Lake Hume are expected to continue for at least the next 4 weeks due to continued hot, dry conditions and a high demand on water held in Hume Reservoir.
Download PDF (http://www.mdba.gov.au/files/Flow-advice-Mitta-Mitta-River-Dartmouth-Dam-21-February-2013.pdf)
The flow rates over the coming weeks will be varied as described below (see Figure 1), if conditions remain dry.
(http://www.mdba.gov.au/files/image/Proposed-flow-and-river-depth.jpg)
Figure 1. Proposed flow and river depth at Colemans gauge.
The flow in the Mitta Mitta River will be gradually reduced at Colemans from the current flow of about 4,700 ML/day (2.2 m gauge height) to about 800 ML/day (1.3 m gauge height) by 22 March 2013. If inflows from Snowy Creek remain low, the flow at Tallandoon is expected to decrease from the current flow of about 4,500 ML/day (2.5 m gauge height) to about 900 ML/day (1.6 m gauge height).
It is currently planned to increase the flow again at Colemans, after midday on Sunday 24 March, to about 1,500 ML/day (1.55 m gauge height). However, another flow advice will be issued prior to this date with further information.
Rates of rise in the river at Colemans will follow operational guidelines, with the rate of fall being about 10 mm/hour.
These continuing harmony transfers aim to provide additional flood mitigation capacity at Dartmouth Reservoir for the coming winter and spring without impinging upon the security of supply to downstream water users. Harmony transfers benefit the operations of the Dartmouth power station, reduce the rate of fall of Hume Reservoir and provide higher in‐channel flows in the Mitta Mitta River.
The transfers will also reduce the need for very large volumes to be transferred in 2013‐14 should dry conditions be seen next season. This in turn will reduce the risks of channel erosion from prolonged high flow rates in the Mitta Mitta River.
If there is substantial rainfall during the next 4 weeks, it is possible that this planned release may be reduced or cancelled. A further flow advice will be issued if these plans are significantly changed.
The transfer of significant volumes of water from Dartmouth to Hume Reservoir is likely to continue during the next few months if conditions remain dry. The flow rates will aim to benefit the local communities and the environment of the Mitta Mitta River without significantly impacting on river users.
MDBA provides a flow forecast each Wednesday for the following week on the MDBA website at http://www.mdba.gov.au/water/river_info/storage_volumes. (http://www.mdba.gov.au/water/river_info/storage_volumes.)
Landholders and river users, including pumpers, should take in to account the changing flow rates along the Mitta Mitta River and make any necessary adjustments to their river activities.