Zone 1A Water Trading Explained: Greater Goulburn

Zone 1A is the Greater Goulburn irrigation system. It covers the regulated Goulburn River from Lake Eildon through the channel network servicing Shepparton, Tatura, Kyabram, Rochester and Cobram. It is the largest and most liquid water trading zone in Australia, consistently recording the highest number of allocation trades of any zone in the Murray-Darling Basin — 350 to 500 GL per year on the temporary market alone.

If you are buying or selling water anywhere in northern Victoria, Zone 1A is almost certainly where the action is.

The system

Goulburn-Murray Water (GMW) manages the delivery infrastructure. Water is stored in Lake Eildon (3,334 GL capacity), with Waranga Basin (432 GL) and Nagambie Weir Pool providing distribution capacity. The channel network feeds one of Australia's oldest and most developed irrigation districts.

The Northern Victorian Resource Manager (NVRM) announces allocations fortnightly during the irrigation season based on Eildon's storage level, modelled inflows, environmental obligations and system losses. Everything starts with Eildon. When Eildon is above 60% on 1 July, the season typically runs smoothly. When it opens below 40%, prices run hot.

In WY2025/26, Eildon entered the season around 38% full. Goulburn HRWS opened at 31% and crawled to 80% by March. LRWS received 0% all year. The result: Zone 1A allocation averaged $258/ML — the highest since the 2019-20 drought.

As of April 2026, Eildon sits at 42.4% and is falling at approximately 18,000 ML per week. It will likely enter WY2026/27 below 40%.

Who uses this water

Dairy dominates Zone 1A water demand. The Shepparton-Tatura-Kyabram corridor is one of Australia's largest milk-producing regions. Dairy operations run pasture irrigation from September through April, consuming 8-12 ML/ha. A 450-cow operation on 280 hectares might need 1,800 ML per season. Dairy provides enormous, consistent base demand.

Stone fruit and pears — the Greater Goulburn is stone fruit capital. Peaches, nectarines, apricots, cherries. SPC Ardmona is based here. These are permanent plantings: 6-10 ML/ha, cannot be fallowed without killing the orchard.

Almonds — expanding rapidly in the Cobram-Moama corridor. At 10-14 ML/ha and $30,000-50,000/ha establishment costs, almond growers buy water at almost any price before losing trees. This creates a structural price floor in dry years.

Processing tomatoes — Kagome and SPC both procure from the region. Summer cropping, 4-6 ML/ha.

Environmental holders — the Commonwealth Environmental Water Holder (CEWH) and Victorian Environmental Water Holder (VEWH) hold significant entitlements in Zone 1A. Their carryover decisions and trading activity influence market dynamics.

What trades in Zone 1A

High-reliability water shares (HRWS): The premium permanent entitlement. HRWS receive allocation first. In most years they reach 100%. In WY2025/26 they reached 80% — still well above LRWS. Prices for Zone 1A HRWS have ranged from $2,000/ML (wet years) to $5,000+/ML (drought). HRWS are the backbone of permanent crop operations and dairy farms.

Low-reliability water shares (LRWS): Only receive allocation after all HRWS holders reach 100%. In average or dry years, LRWS gets zero. In big wet years, LRWS can receive 100%+. Cheap to buy ($200-800/unit) but unreliable. Used by opportunistic irrigators and water traders.

Temporary allocation: The bread and butter. Allocation trades account for the vast majority of Zone 1A market activity. Prices move with the season — averaging $128/ML in June (trough) and $217/ML in January (peak) across all years in the dataset.

For the full distinction, read our guide on how water trading works.

Carryover rules

Victoria allows carryover of up to 100% of your water share volume. If you hold 200 ML HRWS and have 150 ML unused at 30 June, you carry all 150 ML into next season. You do not need to apply — it is automatic.

The catch: carried water is spillable. If Eildon fills and spills during winter or spring, a proportion of all spillable carryover is forfeited system-wide. The VWR calculates a spillable water account balance and publishes it.

In dry years (like now), spill risk is minimal and carryover is extremely valuable — you enter July with water already in your account before a single allocation is announced. In wet years, carrying large volumes exposes you to spill losses.

LROS (Low Risk of Spill) declaration: By approximately 1 June each year, entitlement holders must complete their LROS declaration confirming carryover intention. Miss the deadline and your unused allocation may expire on 30 June. This is a costly administrative error — worth tens of thousands on a large holding.

Strategic carryover is one of the most powerful tools available. Buy allocation cheaply in April-June (seasonal trough), carry it into the following season, and use or sell it when prices run 70% higher in January. The cross-season arbitrage from La Nina troughs ($36/ML in WY2022/23) to the current dry-year pricing ($258/ML) shows why institutional holders treat carryover as a core income strategy.

The Goulburn-to-Murray IVT constraint

The single biggest trading constraint affecting Zone 1A.

Water from the Goulburn enters the Murray River downstream of Shepparton. The MDBA sets an annual limit on net transfers — approximately 200 GL per season after reserves — released across three windows: 1 July, 15 October, 15 December. After December 15, only back-trades create new capacity.

When IVT exhausts, Zone 1A sellers lose access to Murray buyers. The zone becomes an isolated market. Prices can drop relative to Murray zones by $50-150/ML because supply is effectively trapped in the Goulburn system.

In dry years (WY2018/19, WY2019/20), IVT exhausted before mid-season. Murray irrigators were trying to source cheaper Goulburn water; demand overwhelmed the quota.

If your strategy involves selling Zone 1A allocation to downstream buyers, monitor the VWR's published IVT balance weekly from October onwards.

Seasonal price patterns

Zone 1A allocation prices follow a broadly consistent seasonal curve:

• July-September: Season opens. Prices set by opening allocation and seasonal expectations. If Eildon is below 40%, prices start elevated.
• October-January: Peak irrigation demand. Dairy and horticulture both pulling hard. Prices reach their annual high. January is the peak month on average ($217/ML).
• February-April: Demand eases as autumn arrives. Irrigators with surplus sell. Prices soften.
• May-June: Season trough. Low demand, carryover decisions dominate. Prices bottom ($128/ML average in June).

In drought years, prices can stay elevated through autumn. In flood years, they stay low all season. The pattern is directional, not guaranteed.

Current season context: WY2025/26 peaked at $300-320/ML in January-February. With Eildon entering WY2026/27 likely below 40%, and IOD positive, next season's pricing is expected to firm further. Base case: $250-350/ML. If El Nino confirms: $350-450/ML.

Check our water pricing guide for live Zone 1A market levels.

How to trade

You need a water trading account with the Victorian Water Register and, if you hold water shares, an account with Goulburn-Murray Water.

Contact a broker with the volume you need and your preferred price. We find a counterparty, prepare the transfer application, lodge with the VWR. Allocation transfers within Zone 1A settle in 1-3 business days. Entitlement transfers take 4-8 weeks.

Zone 1A trades freely with Zones 1B, 3, 6, 6B, and 7. Back-trade only to Zones 2, 4A, 4C, 5A. Interstate trade to NSW Murray is subject to the 200 GL net cap.

Indicative only. Not financial advice. Water trade involves risk of principal loss.

Frequently asked questions

How much does Zone 1A allocation cost right now?

Zone 1A averaged $258/ML through WY2025/26 (9-month VWAP to March 2026). Prices fluctuate daily. Contact a broker for a live quote or check our Zone 1A prices page.

Can I transfer water from Zone 1A to the Murray?

Yes, subject to the Goulburn-to-Murray IVT limit. The annual cap is released in three windows (July, October, December). Once exhausted, no further transfers until 1 July. Your broker checks IVT status before every cross-zone trade.

What is the difference between HRWS and LRWS in Zone 1A?

HRWS receives allocation first and typically reaches 100% in all but dry years. LRWS only receives allocation after all HRWS holders are fully satisfied — it received 0% in WY2025/26. HRWS costs 5-10x more but delivers water when it matters.

How does carryover work?

Carry over up to 100% of your water share volume. Automatic — no application needed, but you must complete the LROS declaration by approximately 1 June. Carried water is spillable: if Eildon fills, a proportion is forfeited. In dry years (current conditions), spill risk is negligible and carryover is extremely valuable.

When is the best time to buy?

No single answer. Buying early (July-September) captures lower prices but means committing before the season unfolds. Buying mid-season (October-December) gives more certainty from allocation announcements. Late-season (March onwards) can be cheaper but supply may not be available at volume. Spread purchases across the season to average your cost.

Who manages Zone 1A?

Goulburn-Murray Water (GMW) delivers water. The Victorian Water Register processes trades. NVRM announces allocations. The MDBA oversees Basin-wide arrangements including IVT limits.