Allocations – Bacchus Marsh & Werribee

Every year, we set allocation levels for the western irrigation business, which tells customers what percentage of their river water entitlement they can take. This is separate to any recycled water entitlements.

Southern Rural Water announces allocations every fortnight.

A season lasts 12 months, from 1 July to 30 June.

This means that we will start the new system on 1 July. As a result, any unused water in your allocation account (ABA) at the end of this season on 30 June will automatically carry over to the next season, starting on 1 July.

You need to have a water share linked to your allocation account to be able to carry over your unused water.

How can you use carryover?

Carryover gives you more flexibility to:

• hold, use or trade water when it’s of the greatest value to your business; and
• prepare for drought by holding enough water for use in the next season.
   

Will there be much change?

Carryover helps you manage your water to meet your business requirements. However, there will be small differences to allocations compared to the current system.

At the start of a new season, we will calculate the volume of water carried over from the previous season. Then if there is more water held in the reservoirs than is needed to deliver the carryover, we will announce an increase to that season’s allocation.

This means that in most years, the starting allocation may be lower than under the current system.

If you use all of your water and do not carry over, then you may have less water at the start of the year. In normal years, this will even out as the season progresses, with increases in allocations going to those who have room in their entitlements.

Trading

When you can carry over water from season to season, buying and selling water may be an important option for you to secure the right amount of water for your ongoing needs.

If you have a Facebook logon you can lodge a post on the relevant group.  If you don’t have access to Facebook, contact the Customer Service team on 1300 139 510 and they can post on your behalf.

Please note that if you want to trade water before the end of the season with the aim of carrying over any unused water, then you need to lodge your applications with us before 23 June to give us enough time to process it.

How will at affect me?

Below are a couple of examples of how carryover works.

If you want to understand how carryover might affect your circumstances, please call us and make an appointment so we can explain how it will work in your business.

Carryover:  Farmer A

• Farmer A has a high reliability water share of 20ML and low reliability water share of 10ML
• Allocation this season is 100% high-reliability and 15% low-reliability. This equals 21.5ML of water for farmer A (20ML of high reliability and 1.5ML of low reliability)
• Farmer A uses 11.5ML of water in the season and so there is 10 ML of unused water
• Farmer A carries over 8.5 ML of water to the next season. This is the 10 ML unused water minus 15% for evaporation loss, which is 1.5ML
• Starting allocation for the following season is 40% high-reliability
• Farmer A has 16.5 ML of water available for the start of the next season, made up of 8.5ML carried over from previous year, and 8ML of new season allocation (40% of their 20 ML high-reliability share)
• As the reservoirs fill, Farmer A will receive further allocation increases up to a maximum of 13.5 ML – when he will have 30 ML of water which is the maximum under his water shares (20 ML high-reliability and 10 ML low-reliability).
   

Carryover: Farmer B

• Farmer B has 200ML high reliability water share and 100ML low reliability water share.
• Farmer B uses 200ML of water in the season and so there is 15ML of unused water
• Farmer B carries over 12.75ML of water to the next season. This is the 15ML unused water minus 15% for evaporation loss, which is 2.25ML
• Starting allocation for the following season is 40% high-reliability
• Farmer B has 92.75ML of water available for the start of the next season, made up of 12.75 ML carried over from previous year, and 80ML of new season allocation (40% of their 200ML high-reliability share)
• As the reservoirs fill, Farmer B will receive further allocation increases up to a maximum of 207.5ML – when he will have 300ML of water which is the maximum under his water shares (200 ML high-reliability and 100 ML low-reliability)

We use a range of data to work out the amount of water we can allocate. Some of this is actual data and some of it is assumed data.

Actual data

Volumes:

High and Low Reliability Water Shares

The figures for these are in the Victorian Water Register and our Irrigation Planning Module (IPM).

Total usage to date

This figure comes from the IPM system. It includes data from meter readings, usage estimates since last meter readings, and orders lodged in the system.

Inflows

We assume that we are able to harvest all flows into both Pykes Creek and Melton Reservoirs, other than the legal passing flows.

Flows into Merrimu are shared between Southern Rural Water, Greater Western Water and the State Government.

Evaporation

We use a model to work out evaporation, based on average evaporation, area of storage and a 12-month period.

Delivery and river transfer losses

Delivery and river transfer losses can vary considerably, depending on weather, leakage and demand.

Unused entitlement

At the end of the season, any unused water is either carried over by an entitlement holder or forms part of the opening allocation at the start of the new season.

Guaranteed inflows

Guaranteed inflows are estimated by skilled staff.