Water Trading Zones and Rules — Australia
Every water trading zone in the Murray-Darling Basin operates under its own register, carryover rules, and inter-valley or interstate transfer limits. This page is a reference for irrigators, accountants, and advisers who need to understand how the rules work before trading.
MDB trading zones — quick reference
| Zone | State | Register | Carryover | IVT / interstate | Key industries |
|---|---|---|---|---|---|
| Zone 1A | VIC | Victorian Water Register | 100% up to volume cap | Goulburn-to-Murray cap applies | Dairy, stone fruit, pears, mixed cropping |
| Zone 2 | VIC | Victorian Water Register | 100% up to volume cap | 1,500 ML IVT cap; no trade out after 31 March | Dairy, mixed farming |
| Zone 3 | VIC | Victorian Water Register | 100% up to volume cap | Part of Goulburn system; trades freely with 1A/1B | Dairy, mixed cropping |
| Zone 4A/4C | VIC | Victorian Water Register | 100% up to volume cap | Campaspe-to-Murray cap applies | Dairy, mixed cropping |
| Zone 5A | VIC | Victorian Water Register | 100% up to volume cap | Loddon-to-Murray cap applies; 8,000 ML entitlement cap with 1B | Dairy, mixed cropping |
| Zone 6 | VIC | Victorian Water Register | 100% up to volume cap | Above Barmah Choke — local delivery unconstrained | Dairy, horticulture, broadacre |
| Zone MIL | NSW | WaterNSW | Partial — varies by licence class | Cross-valley transfer to Murray applies | Rice, wine grapes, horticulture, cotton |
| Zone 7 | VIC | Victorian Water Register | 100% up to volume cap | Below Barmah Choke — downstream delivery constraint | Almonds, wine grapes, citrus, dairy |
Source: MDBA Water Trading Rules, Victorian Water Register, WaterNSW, DEW SA. Carryover rules may change annually — confirm current rules with the relevant register before trading.
Carryover rules by state
Victoria
Victoria's carryover system is the most generous in the MDB. Entitlement holders can carry over 100% of unused seasonal allocation to the next water year, up to an individual volume cap tied to their entitlement class. Any allocation above the cap at 30 June is forfeited. This rule applies across all Victorian zones including Zone 1A, 2, 3, 4, and 7 VIC.
Victorian Water Register →New South Wales
NSW carryover is more restrictive and varies by licence class and valley. General security holders typically receive a partial carryover allowance announced by WaterNSW in late June based on storage conditions. High security entitlements generally have more reliable carryover. NSW carryover rules can change year-to-year — do not assume last year's rules apply. Check with WaterNSW or Integra before the end of the water year.
WaterNSW →South Australia
SA carryover is established in the SA Murray Water Allocation Plan. Entitlement holders have a defined carryover allowance based on their licence class. SA's downstream position means storage and flow availability strongly influence what DEW SA announces as carryover for each season. Surplus allocation above the cap is forfeited at 30 June. See DEW SA for your specific licence conditions.
DEW SA WaterConnect →Inter-valley and interstate transfer rules
Moving water between valleys or across state lines introduces additional rules and constraints. Here is a practical overview:
Victorian inter-valley transfers (IVTs)
Victorian IVTs allow allocation to move between the Goulburn, Campaspe, or Loddon systems and the Victorian Murray system. Each valley-to-Murray pair has its own annual cap set under the MDBA Water Trading Rules. Caps reset on 1 July. During years when the Murray is short of water, IVT caps fill quickly — often by October or November. Once the cap is reached, Goulburn water cannot enter the Murray regardless of how much capacity is available on the register.
Cross-state (interstate) trades
Interstate trades are governed by the MDBA and bilateral state agreements under the Murray-Darling Basin Agreement. Practically, interstate trades involve: (1) lodging a departure notice on the source state register, (2) lodging a receipt application on the destination register, and (3) both parties having accounts in both states. Processing time is typically 3–7 business days for a straightforward interstate trade.
The Barmah Choke — physical constraint
The Barmah Choke is a natural restriction in the Murray near Barmah, Victoria. Maximum daily flow through the Choke is approximately 8,000 megalitres per day. Zone 6 (Vic Murray) sits above the Choke and Zone 7 (Vic Murray) sits below it. When total river flow approaches this limit, no additional water can physically travel downstream from above the Choke to Zone 7 and other below-Choke zones. This physical constraint is separate from the regulatory caps and can apply even when the register shows available IVT capacity. Integra monitors Choke flows daily and can advise on current downstream transfer feasibility.
Rules and trading zones — frequently asked questions
How many water trading zones are there in the Murray-Darling Basin?
The Murray-Darling Basin has multiple trading zones across Victoria, NSW, South Australia, and Queensland. Victoria alone has zones covering the Greater Goulburn (1A), Broken (2), Lower Goulburn (3), Campaspe (4A/4C), Loddon (5A), Vic Murray above Choke (6), and Vic Murray below Choke (7). NSW has several river valley zones including the Murrumbidgee, Macquarie, Border Rivers, and Murray. The MDBA publishes the definitive zone map. This page focuses on the major actively-traded zones where Integra operates.
What is an inter-valley transfer (IVT) limit?
An inter-valley transfer moves water allocation from one river valley to another within the same state. IVT caps are set annually by the MDBA and state authorities to protect the ecological function and supply security of the source valley. Once the cap is reached for a water year, no further inter-valley transfers are possible until 1 July. Key caps include Goulburn-to-Murray (Zone 1A to Zone 7 VIC), Campaspe-to-Murray, and Loddon-to-Murray transfers.
How do cross-state (interstate) trades work?
Interstate trades move water between state registers — for example, VIC to SA or NSW to VIC. These trades require approval under the MDBA Water Trading Rules and must comply with interstate trade caps. Each state register records the departure and receipt of the allocation. Interstate trades also require both parties to have accounts in the relevant state registers. The Barmah Choke is a physical constraint that limits how much water can move from upstream zones to Zone 7 SA regardless of the regulatory cap.
What is the Barmah Choke and how does it affect trading?
The Barmah Choke is a narrow section of the Murray River near Barmah, Victoria, where the river's floodplain constricts and limits flow to approximately 8,000 megalitres per day. Zone 6 (Vic Murray) sits above the Choke and Zone 7 (Vic Murray) sits below it. When total river flow at this point reaches the limit, no additional water can physically travel downstream from Zone 6 to Zone 7. This creates price disconnects between upstream and downstream zones during high-demand periods.
Which water register do I use for my zone?
Victorian zones (1A, 2, 3, 4, 6, 7) use the Victorian Water Register at waterregister.vic.gov.au. Zone 6 covers the Vic Murray above the Barmah Choke and Zone 7 covers below the Choke. NSW zones (Murrumbidgee, Macquarie, Border Rivers) use WaterNSW at waternsw.com.au. SA uses the DEW SA WaterConnect portal at waterconnect.sa.gov.au. Queensland irrigation areas have their own register managed by DRDMW. All interstate trades require accounts on both the source and destination state's register.
Can I trade water between different entitlement classes within the same zone?
In general, allocation trades within the same zone and the same entitlement class are straightforward. Trading between entitlement classes (e.g., selling high security allocation to a general security buyer) may be restricted or subject to specific conditions on the state register. Victoria, NSW, and SA each have their own rules on this. Integra will confirm whether a cross-class trade is possible for your specific entitlement before proceeding.
Ready to trade?
Integra trades across Zone 1A, Zone 6, Zone 7, and the full MDB. Contact us for a current market price or to discuss a cross-zone strategy.
Zone guides and pricing
Liz Johnston
Senior Water Broker
Indicative only. Not financial advice. Water trade involves risk of principal loss. Rules and caps described are subject to annual revision by the MDBA and state authorities. Confirm current rules with the relevant water register before trading.