Water shares, bulk entitlements and environmental entitlements give entitlement holders a share of space in the dams used to supply their water in regulated surface water systems. These entitlements provide the right to carry over unused allocation  in the dams.

These dams are there to capture inflows to support the reliability of existing entitlements, including full allocations to high and low-reliability water shares and reserves for future seasons.

Carryover rules are necessary to make sure that water carried over does not lock up space in the dams that is needed for the inflows to support allocations to all entitlements.

Two types of rules are used to prevent carryover having any adverse impact on entitlement holders:

1) The 100 per cent rule

The 100 per cent rule is used to regulate carryover in the smaller Broken, Loddon, Bullarook and Werribee water systems. This rule prevents entitlement holders from using more space in the dams than they are entitled to by limiting carryover plus new allocations to 100 per cent of their entitlement volume.

What does the 100 per cent rule mean for me?

If you carry over water in these systems, you will have water in your allocation account at the start of the new season, but your carryover will limit the volume of new season allocations that can be made to your water share. You still cannot use more water than your full water share volume unless you trade water into your account.

In these systems, there are also limits on how much water can be carried over. Rules differ between slightly between systems to match the specific entitlements and hydrology of each system.

You can use the carryover calculator to help understand how the rules work for you in your system


2) Spillable water accounts

In the larger regulated Murray, Goulburn and Campaspe water systems of northern Victoria, water entitlement holders can carry over unused allocation up to their full entitlement volume, and are allowed to store more than their full water entitlement volume in the new season when there is there is space available in the dams.

Spillable water accounts are used to keep track of the carryover and allocation stored above 100 per cent of entitlement. This water spills if the dams fill up and the storage space is needed for inflows to support allocations.

Spillable water accounts also apply to bulk and environmental entitlements in the Wimmera-Mallee system of western Victoria.

What do spillable water accounts mean for me?

If you carry over water, you will only lose water if the dams actually spill.

However there is no guarantee of access to water above your full entitlement. This water is recorded in your allocation account as spillable water. It will spill to make room for inflows for new allocations if the dams fill up. You cannot use or trade your spillable water until the Resource Manager makes a low risk of spill declaration.

This fact sheet  gives more detail on how carryover works in the Murray, Goulburn and Campasp

Carryover in these systems was the subject of the recent carryover review in 2012. You can find out more about how carryover works on the carryover fact sheets page, and about the outcomes of the review on the carryover review 2012 page.

You can also use the carryover calculator to help understand how the rules work for you.


Carryover declarations and determinations made by the Minister for Water

Copies of the formal rules set by the Minister for Water for each water system are available here.

Carryover is also allowed for bulk and environmental entitlements in the regulated Wimmera-Mallee water system, and for licence holders in some groundwater systems. Copies of the formal rules set by the Minister for Water for these systems are available here.