When Numbers Start Making Decisions · Season Four, “Things That Cannot Be Priced Directly” · Article 10
1. One megalitre is not one kind of water right
A megalitre is one million litres, about two-fifths of an Olympic swimming pool. Water rights and annual allocations in the Murray–Darling Basin are recorded in megalitres and traded in regulated markets. Irrigators buy and sell water; governments purchase entitlements for environmental recovery and First Nations programs.
There is no single Basin-wide price for one megalitre. Water can sit in different river systems and trading zones, face delivery constraints, belong to entitlements with different reliability and receive different annual allocations. The Commonwealth department states that there is no single Murray–Darling water market, but a set of related markets across products and places. DCCEEW: Introduction to water markets
Common volume makes water measurable. Market price helps move legal access towards users willing to pay. River health, town continuity, cultural responsibility and food production do not all appear as equal purchasing power.
The question is not whether markets can allocate water efficiently. It is which water government has already decided may be allocated by price.
2. Entitlement and allocation must be separated
A water access entitlement is an ongoing legal right to a share of water available in a defined system under state or territory law. It does not guarantee a fixed physical volume every year. Authorities announce allocations according to storage, inflows, rainfall and rules.
A holder of a 100 ML entitlement receiving a 40 per cent allocation generally has 40 ML available that year. High- and low-reliability entitlements follow different allocation patterns. An entitlement is a continuing asset; an allocation is the seasonal volume made available under it.
Prices therefore describe different products. A permanent entitlement price incorporates expected future reliability and rules. An allocation price reflects current scarcity and conditions. Delivery rights and irrigation rights can add other layers.
Collapsing them into “the price of water” hides legal and physical differences before the market even begins.
3. What the market solves
Trading allows irrigators to manage drought and production choices, sell unused allocation, change crops or exit. Price communicates scarcity and can move water towards higher-value economic uses. Environmental water holders can also trade under rules to improve ecological outcomes.
Compared with fixed historical allocations, markets can make adjustment more flexible. They can reward conservation if a user can sell saved water and reveal the opportunity cost of use.
These benefits depend on accurate registers, metering, enforceable rights, trading rules and physical delivery. The market is designed by institutions; it is not a natural river phenomenon.
The price also cannot decide the overall sustainable diversion limit, minimum town supply or environmental requirement. Those are prior collective decisions that define the tradable pool.
Market efficiency should be tested against the counterfactual actually available. A high-value crop may outbid a lower-value use in one season, but delivery losses, salinity, return flows and future reliability can change the social result. Price is excellent at coordinating participants within the defined product. It does not automatically calculate system-wide hydrology or the public cost of maintaining the channels and rules that make the trade possible.
4. The river cannot bid
Wetlands, fish, floodplains and water quality do not enter an auction with bank accounts. Environmental demand appears only when law reserves flows or government and environmental holders acquire rights on the community’s behalf.
If environmental needs are left to compete after most rights have been allocated, price may reflect scarcity without protecting the ecological system that makes future water possible. Markets need non-market constraints: sustainable diversion limits, environmental water, delivery rules and extraction compliance.
The Commonwealth Environmental Water Holder manages a portfolio of entitlements and allocations for environmental outcomes. Public holdings illustrate that markets can serve ecological policy, but only because government represents values the river cannot express as willingness to pay. DCCEEW: Water holdings
5. Communities experience more than one transaction
When water moves out of a district, an individual seller may gain and a buyer elsewhere may produce more value. The originating community can lose employment, processing activity, school enrolment and shared infrastructure. These effects are not fully reflected in the transaction price.
Restricting all trade to protect every existing pattern would freeze inefficient and environmentally harmful use. Ignoring adjustment would treat concentrated community loss as an externality.
Policy should assess cumulative trades, delivery constraints and regional transition. Investment, social services and economic diversification can address impacts without denying all reallocation. The relevant unit is sometimes the community trajectory, not the individual ML sale.
6. First Nations water shows the historical starting point
Markets begin from a distribution of recognised rights. First Nations peoples’ law, cultural obligations and long relationship with water were not equally represented when modern entitlements were allocated. A market can trade rights efficiently while preserving an unjust starting distribution.
The Aboriginal Water Entitlements Program uses public funding to acquire entitlements and support First Nations ownership and decisions. DCCEEW describes entitlements as legal shares in a specific system and has published a 2026–27 purchasing framework. DCCEEW: Aboriginal Water Entitlements Program
Cultural water is not merely another productive use to be ranked by price. Ownership, authority and responsibility for Country matter. Corrective programs therefore concern governance as well as volume.
7. Putting many rights into one recovery account
Government recovery programs often translate acquired entitlements into long-term diversion-limit equivalents so progress can be aggregated. This is necessary for Basin-wide targets, but rights with different reliability and location are not simply added at face volume.
Conversion methods, assumptions and progress reporting should remain transparent. A total recovered ML can conceal whether water reaches the ecosystems or communities for which it was acquired. Delivery and use matter after purchase.
The Commonwealth publishes water-recovery accounting and program dashboards. DCCEEW: Water recovery progress and accounting Aggregate progress should be paired with catchment outcomes and actual flows.
8. Transparency, correction and market integrity
Participants need reliable ownership records, timely trade prices, conflict-of-interest rules and consistent approvals. Metering and compliance ensure that a traded legal volume corresponds to lawful extraction. Market reform continues to strengthen reporting and intermediary conduct.
Errors in account balances, allocation announcements or trade approvals must be correctable. More fundamentally, evidence about ecological decline or physical constraints must be able to revise trading rules. A liquid market is not successful if it trades rights the river cannot deliver sustainably.
9. Water is not volume plus optional values
Ecological, cultural, social and productive values arise from water in a particular relationship with place and time. They are not decorations attached after the megalitre is counted. The unit isolates volume so institutions can allocate a dimension of use.
That is legitimate if law first protects the relationships the market cannot price. The market can then distribute the residual, defined tradable share.
10. A practical test for water-market decisions
Ask:
- Is the product an entitlement, allocation, delivery right or irrigation right?
- What reliability, location and trading restrictions apply?
- What environmental and town needs were secured before trade?
- Can the water be physically delivered?
- What cumulative community effects follow movement?
- How are First Nations ownership and authority addressed?
- Does recovery accounting correspond to actual ecological use?
- Can new evidence revise allocations and trading rules?
Conclusion: let markets allocate residual water, not define what is residual
Water markets help users adjust to scarcity and can move legal access towards higher-value uses. The common megalitre and transparent prices are important coordination tools.
My judgement is that markets should operate only within democratically and ecologically defined limits. Environmental flows, essential community needs, First Nations rights and physical constraints cannot be left to whichever participant can pay most.
Price can help decide among lawful uses of available water. It cannot decide how much of the river is available to sell.
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