Lachlan River rises as enviro flows pass through dam

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Lachlan River rises as enviro flows pass through dam
25 August 2012 - State Water Corp

Water users on the Lachlan River downstream of Wyangala Dam, Gooloogong and Jemalong are advised of ongoing rises in river levels due to increased environmental water releases from the dam.

Environmental flows announced last week increased further from Saturday (25 August) as inflows increased due to recent rain. An environmental release of 2300ML per day from Wyangala Dam commenced on Sunday, 19 August.

Environmental releases from Wyangala Dam are triggered by rainfall, as well as inflows into the dam and tributaries below the dam wall. The translucent environmental flow period which commenced on 15 May 2012, will close on 15 November 2012.

The rules in the water sharing plan for the Lachlan River provide for a more natural flow regime within the river system by allowing a portion of dam inflows to pass into the river system for environmental benefit.

Water Delivery Manager, Central valleys, Sri Sritharan again urged water users in the area to monitor their stock and equipment.

This current event commenced on 19 August 2012 at Wyangala Dam. Current predictions are:
 
Estimated total dam inflow                 48,000 ML
Total dam release                                 43,000 ML
Estimated total tributary inflow          14,000 ML
Estimated peak flow @ Cowra            10,500 ML/day
Estimated peak flow @ Forbes              11,500 ML/day
Estimated peak flow @ Condobolin       8,000 ML/day    
Estimated peak flow @ Brewster Weir  7,500 ML/day

This event is expected to last for another 5 days, depending on follow-up rainfall in the catchment.

Storage information in relation to this event is summarised in the following table:
                    Wyangala Dam                Lake Cargelligo           Lake Brewster
Start event    97.9%                           112%                       92%
Finish event    98%                           112%                       92%


 Image: Wyangla Dam outlet valves