Distribution flows and water quality

Water balance

We have prepared a simplified water balance for the period 1 February to 28 April 2020 as shown in the table below. We used measured flow data and estimated the unmeasured inflows for each regulated water source (downstream of the major dams) and in the unregulated Barwon-Darling water source.

This water balance below shows estimated inflows, licenced extractions, system replenishments and flows out from each river system to the downstream water sources. System replenishment includes evapotranspiration, groundwater seepage, instream and wetland replenishment, as well as any measurement error. We also corrected measurements of the end of system outflows if they were affected by water backing up into the tributaries from the high flows in the Barwon-Darling River.

^{1 Estimated total inflow to the regulated river systems downstream of major storages, 1st February to April 28th.}

^{2 Provides consumptive extraction volumes from the rivers including supplementary water take. Held environmental water usage was 3.7 GL in Gwydir and 4.6 GL in the Macquarie and is included in the system replenishments. The water balance excludes floodplain harvesting activities. That is, any water that was captured on-farm or on the floodplain and did not flow into a river.}

^{3 Queensland extractions for the period 14th to 24th February 2020.}

^{4 Inflows and direct outflows to the Barwon Darling are for the regulated river downstream of Burrendong Dam. The system replenishments presented for the regulated balance are inclusive of flows in Gunningbar Creek (8 GL) and Duck Creek (6 GL) which connect to the unregulated Bogan River system.}

^{5 Marthaguy Creek cumulative flows recorded at Carinda 421011.}

^{6 Bogan River cumulative flows recorded at Gongolgon 421023.}

^{7 Barwon-Darling River inflow estimate includes the outflows from the regulated Border Rivers, Gwydir, Namoi, Macquarie Rivers together with an estimate of the contribution from all other unregulated inflow sources such as the Culgoa, Warrego, Castlereagh, Paroo and Bogan Rivers. The estimate will be refined when further information on extraction volumes is available.}

^{8 The final extraction volumes for the Barwon-Darling were not available at time of publication, due to A class extractions continuing, and the timing of meter reads being scheduled for the end of the water year. The preliminary extraction volume is 230 GL. This table will be updated and republished when the final information is available.}

^{9 Barwon Darling River water balance outflows at Wilcannia Main Channel 425008. This volume will be refined as the Wilcannia and upstream gauges are checked in the field.}

Supplementary water

Supplementary water licence holders in the Border Rivers, Gwydir and Lower Namoi valleys had limited periods during February when access was allowed. For more information on each supplementary flow announcements visit the WaterNSW website. The table below shows the impact of the pumping restrictions applied in February, comparing the actual supplementary event extractions against an estimate of what could have been made available for supplementary extractions under standard water sharing plan rule operation.

^{1 Includes 3,448 ML held environmental water}

^{2 Includes 1,375 ML held environmental water}