Determination outlooks 2018/19

15 May 2018

This post was originally published on 15 May 2018. Additional charts and updates were made 21 May 2018.

Both Victorian and NSW authorities updated their seasonal determinations for the 2018/19 irrigation season today.

Unfortunately the dry conditions experienced to date have done nothing to help the previous outlooks. But all in all, the projections are very similar to the previous ones.

The chart below shows the forecast seasonal determinations against the various entitlement under different inflow scenarios. The outlooks for the NSW valleys assume “very dry” inflows for the remainder of the 2017/18 season.

water availability outlooks for 2018/19

The following charts compare the various scenarios with the water availability this season (2017-18).

The first chart shows the combined sMDB water availability for the 2017-18 season (5,550GL) represented by the outline compared to the scenarios projected by the authorities. Under an extreme dry scenario, water availability will be ~60%, factoring in an estimated 1,355GL of carryover across the sMDB.

Chart of 2018-19 predicted sMDB water availability under various inflow scenarios

Naturally there is a lot of difference in water availability between the various catchments. The following charts show the estimated water availability (solid bars) compared to the 2017-18 water availability (outlines) for each of the major catchments under “Extreme Dry”, “Dry” and “Average” inflow scenarios.

Even under an “Average” inflow scenario, water availability will be lower than this season due to the reduced volume of water available for carryover (dotted lines). Having said that, carryover will be a significant resource should it remain dry.

Chart of 2018-19 water availability under extreme dry inflow scenarios Chart of 2018-19 water availability under dry inflow scenarios Chart of 2018-19 water availability under average inflow scenarios

In Victoria, inflows have been tracking dry-average. H2OX expects that both Murray and Goulburn will get to 100% next season but it may be slightly later if streamflows don’t start to improve over the coming months.

Predicted determinations in NSW are likely to match this seasons if the storages receive average inflows. Inflows this season have been very dry and significant rainfall events will be required to turn this around.  At this stage, H2OX are estimating determinations to be somewhere between the average and dry scenarios in both NSW Murray and Murrumbidgee.

With NSW Murray expecting slow increases, irrigators will be relying on carryover and the allocation market. If it remains dry, H2OX expects increased demand for allocation early in the season.

Now that the authorities have provided theses outlooks it is a perfect time to sit down and consider what water you may have available under the various scenarios.

Contact H2OX on 1800 988 118 to discuss your options for securing water in the 2018/19 irrigation season.