Murray-Darling Basin Agreement (Schedule D - Calculating Cap Adjustments) Protocol 2010

“Cap” means the annual diversion target for a designated river valley under the Murray‑Darling Basin Agreement. It is the volume of water that may be taken in a year. When water entitlements or allocations are permanently traded between valleys, the caps must be adjusted so that the total water taken in the Basin does not exceed the sum of the original caps (adjusted for trade). The Protocol is the rule‑book for how that adjustment is calculated.

“Designated river valley” refers to the nine geographical units listed in Table 1: three in New South Wales (NSW Murray, NSW Murrumbidgee, NSW Lower Darling), four in Victoria (Victorian Murray/Kiewa/Ovens, Victorian Goulburn/Broken/Loddon, Victorian Campaspe, and the combined Victorian Murray/Kiewa/Ovens appears as valley 4), and three in South Australia (SA Country Towns, SA Lower Murray Swamps, SA Other). These valleys are the units of cap management.

“Exchange rate trade” and “tagged trade” are the two forms of water trade to which the Protocol applies (clause 4). The Protocol does not define these terms; they have the meanings given by the Act or the Agreement. In context, exchange rate trade involves a conversion factor applied to the water title, while tagged trade likely involves water that is delivered under the seller’s entitlement but accounted against the buyer’s cap. The Protocol’s tables supply the specific exchange rates.

“Cap transfer rate” is the factor by which the cap in the selling valley is reduced and the cap in the buying valley is increased per unit of water traded. Table 1 (allocations) and Table 2 (pre‑2007 entitlements) set these rates. A rate of 1.0 means 1:1 adjustment; a rate of 0.9 means the cap moves by only 0.9 units per unit of trade; a rate of 0.0 means the caps of the two valleys are not directly adjusted at all (instead, a third valley’s cap is adjusted, as with Campaspe/Goulburn).

“Cap factor” is the conversion factor from a unit of entitlement to the volume of the cap. It is used to determine the net change in cap required when entitlements are traded or converted within a valley. Table 3 lists cap factors for various entitlement types; where “not applicable” appears, the cap is not calculated under this Protocol for that type - presumably because other mechanisms apply.

“Stage 1 adjustment” matches increases and decreases between pairs of valleys that arise from trades. The lesser of the increase and decrease is the “valley adjustment” - thus, if Valley A’s cap needs to increase by 100 and Valley B’s cap needs to decrease by 150, the Stage 1 adjustment is only 100 (the lesser). The remaining 50 of Valley B’s decrease becomes a shortfall (if the decrease is not yet matched) and is carried forward.

“Stage 2 adjustment” pools all shortfalls and surpluses valley‑wide and then shares them using a ratio derived from the total pooled shortfall vs. total pooled surplus. This ensures that if there is excess surplus overall, it is allocated proportionally to valleys with shortfalls, and if there is excess shortfall, each valley’s shortfall is reduced proportionally. The ratio is capped at 1.

“Stage 3 adjustment” handles any surplus that remains after Stage 2 that is attributable to interstate trades. It reduces the cap in the surplus valley by that amount. The note suggests that this surplus is not available to offset deficits in other states; it is effectively forfeited from the cap.

“Stage 4 adjustment” simply sums the three previous stages to produce the net change to each valley’s annual diversion target. This is the final, operational adjustment.

“Pooled cap surplus” and “pooled cap shortfall” are the aggregate surpluses and shortfalls across all valleys after Stage 1. The “shortfall ratio” is the pooled surplus divided by pooled shortfall (capped at 1), which determines how much of each valley’s shortfall is actually filled. The “surplus ratio” is the pooled shortfall divided by pooled surplus (capped at 1), which determines how much of each valley’s surplus is actually shared.

The Protocol directly imposes obligations on the Murray‑Darling Basin Authority. The Authority must maintain the Transfer Register, collate valley‑level data, perform the multi‑step calculations each year, and determine the adjustment to each valley’s annual diversion target. The Authority is the sole entity responsible for the arithmetic; no other party is required to compute or verify the adjustments.

The Basin Officials Committee must be consulted before the Authority makes a protocol (see the preamble), but the Protocol itself does not impose duties on that Committee.

Contracting Governments - the Commonwealth, New South Wales, Victoria, South Australia, and the Australian Capital Territory (likely via the Agreement) - are affected because the adjusted diversion targets become binding on state water‑management agencies. Those agencies must ensure that actual diversions in each valley do not exceed the adjusted cap. If a state fails to enforce the cap, it may be in breach of the Murray‑Darling Basin Agreement and the Water Act.

Individual water entitlement holders are indirectly affected. When a holder trades water from one valley to another, the cap adjustments reduce the volume available for future diversions by other entitlement holders in the selling valley. The rate at which the cap changes may not be 1:1 for some valleys (especially SA), meaning that water sold out of SA reduces the remaining SA cap by more than the increase in the receiving valley’s cap - effectively a tax on leaving the SA system. Similarly, trades into the Goulburn system from the Murray may be subject to a 1.29 rate, but only if matched by a prior back trade. For holders moving water from Victorian Goulburn to Victorian Murray, the cap factor is 1.29, increasing the Murray cap by more than a unit per unit of entitlement traded, but only on the condition of a back trade.

Environmental water holders are affected indirectly because adjustments to the cap affect how much water can be diverted for consumptive use, influencing the residual flow available for the environment. However, the Protocol does not address environmental water directly; it only moves the cap between valleys when water rights are traded.

The Campaspe valley is uniquely treated. Trades to or from Campaspe do not adjust Campaspe’s cap; instead, the Goulburn/Broken/Loddon valley’s cap is adjusted. This affects water users in both valleys: those in Campaspe may not see a direct cap impact from their trades, while those in Goulburn may find that trades originating in Campaspe affect the Goulburn cap, potentially reducing the water available for existing Goulburn users.

Businesses relying on irrigation in each valley bear the compliance risk associated with cap uncertainty. The multi‑stage calculation, with its pooling and ratios, means that the net adjustment for a valley may not be obvious at the time of trade - it depends on the profile of all trades across all valleys. This uncertainty may deter trade or increase the cost of due diligence.

The only explicit duty created by the Protocol lies on the Murray‑Darling Basin Authority. Under clause 9, the Authority “must” implement the stages in accordance with the method statements. This includes:

• Determining the net increase in cap required for each valley by collating information from the Transfer Register for every type of entitlement, from the effective date to the beginning of the year for which the adjustment is made (Step 1).
• Calculating Stage 1 valley adjustments for every pair of valleys (Step 2).
• Computing net deficits, shortfalls, surpluses, maximum cap commitments, and interstate cap surpluses (Steps 3-8).
• Determining entitlement conversion cap surpluses for conversions within a valley (Step 9).
• Calculating total cap shortfalls, total cap surpluses, shareable surpluses, pooled surpluses, and pooled shortfalls (Steps 10-13).
• Computing the surplus ratio and shortfall ratio (Steps 14-16).
• Determining the total Stage 2 cap adjustment for each valley (Step 17).
• Calculating the Stage 2 cap surplus and total Stage 3 cap adjustment (Steps 18-19).
• Summing all adjustments to produce the Stage 4 adjustment (Step 20).

No other party is required to perform any computation. However, the Authority’s duty is contingent on the accuracy and completeness of the Transfer Register. If a state or water‑holder fails to record a trade, the calculation may be wrong.

The Protocol does not confer any rights on individuals. Water entitlement holders have no statutory right to have a trade result in a particular cap adjustment; the adjustment is purely a mechanical consequence of the tables and method. Holders in SA, for instance, may find that trading water out of their valley reduces the SA cap by 0.9 per unit but increases the receiving valley’s cap by only 0.81, thereby reducing the total combined cap. This is a feature, not a bug - it returns some water to the Commonwealth environmental water holder or to the system. But the Protocol itself does not explain the policy; it simply sets the rates.

The Protocol recognises a limited right of the Authority to adjust caps using the specified rates. It does not permit the Authority to depart from the tables or the method. This rigidity may be desirable for predictability but can produce perverse outcomes if hydrological conditions change or if trades occur that are not captured by the tables.

The Campaspe note qualifies the duty: for allocations transferred to or from Campaspe, the Authority must alter the Goulburn/Broken/Loddon annual diversion targets rather than the Campaspe target. The same applies for entitlements under Table 2. This overrides the normal pairing of valleys.

The Protocol revokes all earlier protocols made under paragraph 6(1)(a) of Schedule D. This means that any prior rates or methods no longer apply, and the Authority must use only this document for trades occurring after its commencement.

The Protocol itself does not create any penalties. It is a legislative instrument under the Water Act 2007 and the Murray‑Darling Basin Agreement. Contravention of the Protocol as such is not a separate offence. Instead, the Protocol sets the binding cap adjustments; if a state or entity takes more water than the adjusted cap, it may be in breach of the Agreement or the Water Act, which carry their own enforcement provisions.

Under the Water Act, the Authority may issue directions to a Contracting Government to comply with the cap. Failure to comply could lead to civil proceedings, including injunctions or orders for specific performance. No monetary penalties are specified in the source. The Murray‑Darling Basin Agreement itself contains dispute‑resolution mechanisms, but these are outside the scope of this Protocol.

Enforcement risk falls primarily on state water‑management agencies. They must keep diversions within the adjusted targets. Because the Protocol’s calculation is complex and involves multiple steps, there is a risk of human error. If the Authority miscalculates the adjustment, a state might inadvertently exceed the cap and face enforcement action. The Authority is protected by its statutory functions, but the practical consequence is that states must monitor both the Authority’s calculations and their own diversions.

The revocation of prior protocols (clause 3) removes any ambiguity about which rates apply. However, transitional issues may arise: trades that occurred before the Protocol’s commencement but under earlier protocols may need to be reconciled. The Protocol does not address this explicitly, which could lead to disputes.

No private right of action is created. An irrigator whose water allocation is reduced because a trade altered the cap cannot sue the Authority or the trading parties under this Protocol. The remedy, if any, lies in the broader statutory framework.

The Legislative Instruments Act 2003 applies: the Protocol is a legislative instrument and must be registered on the Federal Register of Legislative Instruments. Failure to register would affect its enforceability, but the Protocol notes it was authenticated and registered.

This Protocol is made under clause 6 of Schedule D to the Murray‑Darling Basin Agreement and section 18E of the Water Act 2007. It is therefore part of a hierarchy of instruments: the Water Act is the primary legislation, then the Agreement (as amended and scheduled to the Act), then Schedule D, then Appendix 3 to Schedule D, and finally this Protocol. The Protocol fills the specific technical details left open by paragraph 6(1)(a) of Schedule D.

The Protocol must be read together with the other provisions of Schedule D. For example, clause 2 of Appendix 3 (which references Table 1) and paragraph 5(a) (which references Table 2) are the enabling provisions. The Protocol does not duplicate those provisions; it merely supplies the tables.

The Protocol interacts with the Murray‑Darling Basin Plan (made under Part 2 of the Water Act). The Basin Plan sets the overall sustainable diversion limits (SDLs) for each valley. The cap adjustments calculated under this Protocol affect the annual diversion targets, which must be within the SDL for each valley. However, the Protocol does not reference the Basin Plan, as the Protocol predates the Basin Plan? Actually the Protocol was made in 2010, while the Basin Plan was finalised in 2012. So the Protocol may have been superseded by later instruments under the Basin Plan. But the source does not indicate any amendments or repeal. For the purpose of this deep dive, we treat the Protocol as currently in force unless otherwise noted.

The Protocol also interacts with state water laws. Each Contracting Government must give effect to the cap adjustments through its own licensing and water‑allocation systems. For example, New South Wales must ensure that its water‑sharing plans prescribe diversion limits consistent with the adjusted targets. Victoria must manage its bulk water entitlements accordingly. South Australia must apply the adjusted cap for its Country Towns and Lower Murray Swamps valleys.

The Campaspe note and the note on back trades in Table 2 show that the Protocol coordinates with physical infrastructure realities. The Campaspe valley does not have its own cap adjustment because its water is supplied via the Goulburn system. This cross‑reference to infrastructure is not found in the primary legislation; it is a protocol‑level operational detail.

The Legislative Instruments Act 2003 governs registration and scrutiny. The Protocol is exempt from disallowance? Not stated, but as a legislative instrument it is subject to tabling unless exempt.

The Protocol revokes all previous protocols made under paragraph 6(1)(a). This creates a clear hierarchy: only this instrument is current for trades subject to clause 6. There is no mention of transitional arrangements, so any trade that was recorded under an earlier protocol must be recalculated? Possibly, because the Authority must collate data from the “effective date” to the beginning of the current year (Step 1). The “effective date” is not defined in the Protocol, but likely refers to the commencement of Schedule D. Therefore, earlier protocol rates may have been used for past years, but future adjustments would use the current Protocol’s rates. The source does not clarify.

The Protocol was made on 30 August 2010 by the Murray‑Darling Basin Authority, authenticated by the Chief Executive Rob Freeman, and commences the day after registration. It revokes “all previous protocols made under paragraph 6(1)(a) of Schedule D to the Agreement” (clause 3). This indicates that there were earlier protocols with different tables or methods. The source does not list what those earlier protocols were or their content. No subsequent amendments to this Protocol are recorded in the text provided. It is possible that later protocols have superseded this one, but the user’s source appears to be the original instrument as registered. The Federal Register of Legislative Instruments note at the end of the document (Note 1) suggests that compilations are available on that register; the user has provided only the original text.

Because the Protocol deals with highly technical matters (swap rates and cap factors), and because hydrological knowledge and trade patterns evolve, it is likely that the Authority has since updated these tables. However, the source does not show any amendment history beyond the initial revocation of prior protocols. The deep dive therefore must rely on the instrument as presented. It is plausible that a successor protocol exists under the Basin Plan (such as the Murray‑Darling Basin Plan 2012 and its own schedules), but that would not be part of this document.

The instrument itself has been subject to the Legislative Instruments Act registration. No other amendment history is available from the text.

The source does not refer to any court or tribunal proceedings interpreting or applying this Protocol. No cases are named. Because the Protocol is a technical, mathematical instrument, litigation is unlikely unless the Authority or a state disputes the calculation or the rates are challenged as beyond power. The Protocol’s terms are prescriptive; the main risk of litigation would be on jurisdictional grounds (whether the Protocol is a valid legislative instrument) or on administrative law grounds (whether the Authority followed the method correctly). However, without any case law in the source, we cannot comment on actual disputes.

The broader Murray‑Darling Basin Plan has been subject to extensive litigation, including in the High Court (e.g., ICM Agriculture v Commonwealth [2009] HCA 51). But that case concerned the validity of water‑buyback arrangements under the Water Act, not this Protocol directly. Because this Protocol predates the Basin Plan, it may not have been tested in court.

Practitioners should be aware that the Protocol’s rates and method could be challenged if they are inconsistent with the enabling provisions of Schedule D or the Water Act. However, the Protocol appears to be squarely within the rule‑making power: paragraph 6(1)(a) expressly allows a protocol “prescribing a matter required or permitted by this Schedule to be prescribed by a protocol”. The Protocol supplies exactly the tables and method that Appendix 3 calls for.

No litigation history is present in the source material, so this heading is necessarily brief. The absence of litigation should not be read as endorsement of its clarity; the complexity may have deterred challenges or simply not arisen.

The Campaspe treatment is a significant trap. Under Table 1, transfers to or from the Victorian Campaspe valley are assigned a rate of 0.0 with both the Goulburn/Broken/Loddon valley. The note explains that allocations transferred to or from Campaspe are supplied through the Goulburn system, so the Goulburn annual diversion targets, not Campaspe’s, must be altered. A trader buying water into Campaspe may be unaware that the cap adjustment occurs in a different valley. If Goulburn already has a binding cap, trades into Campaspe might effectively be constrained by Goulburn’s limit. Similarly, a seller moving water out of Campaspe reduces Goulburn’s cap, potentially harming other Goulburn users.

The cap factors in Table 3 show “not applicable” for several entitlement types: all NSW entitlements (High and General Security in Murray and Murrumbidgee) and SA Metropolitan Adelaide. This means that for those entitlements, the Authority does not use a cap factor to convert entitlement units to cap volume. The Protocol does not explain what method is used instead. It likely relies on other provisions of the Agreement or state‑specific baseline data. A water‑holder relying on Table 3 might be misled if they assume a factor exists for their type.

The split in Table 2 for SA “Other” is noteworthy. The table has two sub‑rows: “(a) reduction in SA” and “(b) increase in other valleys”. The rate for reduction in SA is 0.90; for increase in other valleys it is 0.81. This asymmetry means that when water entitlement is transferred from SA Other to another valley, the SA cap is reduced by 0.9 per unit, but the receiving valley’s cap increases by only 0.81 per unit. The net effect is a 0.09 per unit reduction in the system‑wide cap. This looks like a deliberate policy to reduce total entitlements originating from SA, perhaps to account for lower reliability or transmission losses. A SA water‑holder trading out may expect the receiving valley’s cap to increase 1:1, but it does not. Conversely, if water is traded into SA Other, the receiving valley’s cap (SA) increases by 0.9 and the selling valley’s cap decreases by 0.90 (or possibly 0.81 depending on direction), which could be disadvantageous.

The back‑trade requirement in Table 2 (notes for Goulburn/Broken/Loddon and Victorian Murray Water Right + Sales) adds another layer of complexity. A 1.29 rate is available only if the trade is a “back trade”, meaning water must first have moved in the opposite direction. This restricts flexibility: a trade from Goulburn to Murray at the favourable 1.29 rate is conditional on a prior trade from Murray to Goulburn. Without that back trade, the rate may be different (the table does not give an alternative rate - presumably it reverts to a default like 1.0, but the Protocol is silent). This conditional rate is a trap for traders who are unaware of the entire trade history.

The multi‑stage method itself is a compliance minefield. The Authority must follow 20 steps in a fixed order. Any error in an earlier step cascades through later steps. For example, a mistake in calculating the Stage 1 net cap deficit (Step 4) affects the Stage 1 cap shortfall (Step 5), which feeds into Stage 2 total cap shortfall (Step 10), which then affects the surplus ratio (Step 15) and the Stage 2 cap adjustment (Step 17). There is no fallback or discretion. A small data error can produce large, counter‑intuitive adjustments.

The lack of a definition for “effective date” (used in Step 1) introduces ambiguity. The Authority must collate information from the effective date to the beginning of the year for which the adjustment is made. If the effective date is not clearly defined in the Agreement, different interpretations could lead to different results. The Protocol does not define it, relying on the definition in the Act or Agreement. This is a gotcha for anyone trying to verify the Authority’s work.

The Protocol uses the term “designated river valley” but does not list which waterways constitute each valley. For instance, “Victorian Murray/Kiewa/Ovens” lumps three rivers together. A trade on one of these rivers might affect the cap of the whole group. Similarly, “SA Other” is a residual category; it is not clear which catchments fall under it. This may create disputes about where a trade was actually made.

Compliance with this Protocol is primarily the responsibility of the Murray‑Darling Basin Authority. For the Authority, compliance means:

• Maintaining a complete and accurate Transfer Register. All trades of allocations and pre‑2007 entitlements must be recorded in a way that identifies the source valley and receiving valley, the type of entitlement or allocation, and the date of trade.
• Annually (or as specified in the Agreement) performing the calculations in the order prescribed by clause 9. This requires careful record‑keeping: the Authority must know, for each valley, the net increase in cap required from every trade, the conversion surplus within the valley, and the interstate cap surplus.
• Applying the correct table. Table 1 applies to allocations; Table 2 applies only to entitlements transferred before 1 July 2007. Any entitlement trade after that date is not covered by Table 2 - the Protocol does not specify what rate applies for post‑2007 entitlement trades. This gap is a potential compliance risk. The Authority may need to treat such trades under a later protocol or under other provisions.
• Using the cap factors from Table 3 where applicable. For entitlement types listed as “not applicable”, the Authority cannot use Table 3 and must refer to other provisions in the Agreement or other sources.
• Understanding the Campaspe anomaly: the Authority must ensure that trades involving Campaspe are attributed to the Goulburn/Broken/Loddon valley for cap adjustment purposes.
• Following the Stage 2 pooling carefully. The Authority must compute the shareable cap surplus for each valley, then the pooled surplus and pooled shortfall across all valleys, then the ratios, then the Stage 2 adjustment. This requires aggregating data across valley pairs, not just a simple total.
• Documenting each step to allow verification by states or the Basin Officials Committee. The method statement is detailed enough that an external auditor could replicate the calculation if given the raw data.
• Ensuring the final Stage 4 adjustment is communicated to each Contracting Government so state agencies can enforce the modified annual diversion targets.

For state water agencies, compliance involves:

• Providing accurate trade data to the Authority in a timely manner. If a state fails to report a trade, the cap adjustment will be wrong, potentially leading to over‑diversion.
• Monitoring the Authority’s published adjustments and updating their own water‑allocation systems accordingly.
• Making sure that the annual diversions in each valley do not exceed the adjusted target. This may require curtailment of licences if the cap is reduced.
• Being aware of the asymmetry: for trades out of SA, the cap reduction in SA may be larger than the increase in the receiving valley. State officials should inform water‑holders of this impact.

For water‑holders, compliance is indirect but important. When entering a trade between valleys, the holder should assess how the cap transfer rate will affect the future availability of water in both source and destination valleys. For example, a holder selling water from SA Other to Victoria will reduce the SA cap by 0.9 per unit but increase the Victorian cap by only 0.81 per unit. This may mean less water available for remaining SA users, potentially affecting the market value of remaining entitlements. The holder should also check if a back‑trade condition applies (Table 2). If the trade is not a back trade, the expected cap adjustment may not be available, and the trade might not proceed as anticipated.

For compliance professionals, the key is to verify that the Authority has followed the method exactly. Common errors could include:

• Using Table 2 for post‑2007 trades (the Protocol only covers pre‑1 July 2007 trades; later trades are not covered by this instrument - this is a serious gap).
• Misreading the Campaspe note and adjusting the wrong valley.
• Miscalculating the Stage 1 valley adjustment by not taking the lesser of the increase and decrease.
• Incorrectly computing the surplus ratio by mixing up the denominator or not capping it at 1.
• Forgetting to multiply by -1 in Step 19 for Stage 3.

The absence of a sunset clause or review requirement means the Protocol may remain in force indefinitely unless replaced. Those relying on it should check the Federal Register for any later versions. Given the Protocol’s level of detail, any amendment to the tables would significantly change cap adjustments, so water users should monitor for new protocols. The instrument itself is thin on compliance guidance; practical compliance requires cross‑referencing the Water Act, the Agreement, Schedule D, and state water regulations.