Hydro Tasmania has cut back the discharge to the river Mersey from Lake Parangana over problems with plant outages and low rainfall in a bid to maintain continuous flow.
Low rainfall over recent months have resulted in progressive reductions in discharge and further cut backs may happen, according to the company’s energy resources manager David Marshall.
He added that water resource management in the reservoir should enable the discharge, albeit at restricted levels, to be maintained until the end of March when it is expected that the restrictions will be lifted.
Complicating factors for the company have been the recent forced outage of the Rowallan power plant which affected inflow to the reservoir. The Fisher plant was shut down for scheduled maintenance, which also affects inflows but the company had filled the lake prior to the planned outage.
Hydro Tasmania’s reservoir storage levels are at the lowest ever for the beginning of February due to the ongoing drought, it has reported. The storage levels were at 22.4% at the start of the month compared to 27.6% at the same time last year.
Over the last decade the inflows to the company’s reservoirs have been down by 5%-10% on average, the worst year having been 2006. Hydro Tasmania is drawing upon electricity imports via the Basslink connector, which has enabled it to optimise the drawdown of water levels. The link was commissioned almost two years ago.