The Act establishes a web of duties and entitlements that fall primarily on a narrow, identifiable set of actors and impose obligations that travel with land, not primarily with operators.
Owners of irrigated properties. Owners are the primary financially liable class. Membership of the Trust is defined by ownership of irrigated properties with an attached risk management allocation, s 5(2). Owners at midnight on the first day of the contribution year are primarily liable for the shares determined under s 48 and amounts for unauthorised use, s 55(1). A subsequent owner remains liable for amounts unpaid and can seek recovery from the person primarily liable, s 55(3)-(5). Owners must provide irrigation declarations, comply with meter rules, supply information at the Trust’s request, and permit entry for inspections, ss 54, 73, 76, 71.
Occupiers of irrigated properties. Occupiers share joint and several liability with owners under s 55(1). They are also subject to obligations to maintain meters and allow testing, s 73. Occupiers can be subject to notices to rectify unauthorised well activity s 64, and to enforcement actions, including debt recovery and sale of land where instalments remain unpaid, ss 56, 59.
Irrigation authorities and irrigation districts. The Act treats irrigation districts under the Irrigation Act 1994 as special cases. Depending on whether water allocations exist under that Act the irrigation authority may be a member and the district may be taken as an irrigated property owned by the authority, with owners of parcels in the district treated as occupiers, s 4. The Act also provides for division of risk management allocations in accordance with irrigation allocations where subsection (2) applies, s 4(4).
The Trust and its officers. The Trust is the implementing body, empowered to construct, maintain, operate and insure Scheme infrastructure, manage allocations, issue permits for wells, and levy and recover funds, ss 19-27, 61-66, 46-59. The Trust can appoint a board, delegate functions, and must keep records and submit audited financial statements, ss 12-16. The Minister may appoint an administrator where the Trust persistently fails to perform, s 18.
The Minister and Treasurer. The Minister has a range of powers and responsibilities, including approving specifications for construction, approving sales or mortgaging of infrastructure, granting certificates of zero impact, and making determinations where the Minister and Trust cannot agree on models or allocation matters, ss 19(2), 27(2)(k),(l), 33(9), 42(6), 36. The Treasurer provides initial funding to the Trust under s 47 and is the payee of money recovered under s 60.
Water users and market participants. The Act affects the ability of landholders to use water taken under water licences and allocations under the Landscape South Australia Act 2019, because risk management allocations, and the Act’s rules about what counts as authorised use, interface with licensing under that other Act, ss 3 definitions, 40(4), Part 9 (ss 66-69). The Trust can sell water pumped into the Scheme infrastructure while that water is in the infrastructure, s 72, and with Ministerial approval it can enter agreements to produce or sell salinity credits under the Murray‑Darling Basin Agreement, s 26 and s 27(2)(k).
Service providers and trades. Licensed well drillers are the default required class to carry out certain well works under s 62(6). Auditors must be independent and qualified under s 16(2) and cannot be members of the Trust or owners of irrigated properties, s 16(3). Builders and equipment suppliers may be engaged by the Trust for construction and maintenance, but the Trust must comply with Ministerial specification approvals if required, s 19(2).
Local government and other creditors. The Act provides for a first charge on land for unpaid instalments and interest, s 58. The Minister’s recovery process prioritises the Crown and local government debts in the sale proceeds waterfall, s 59(9)(b)-(d). Registered mortgagees must be notified of intended sales under s 59(3).
Entities operating outside the Scheme Area are not directly subject to its core provisions, but the Act may affect wider water markets because it conditions certain water management authorisations and provides for the production, transfer and sale of salinity credits, s 26. Overall, the statutory design attaches obligations and entitlements to land and its registered ownership, while operational discretion rests mainly with the Trust and the Minister, subject to defined appeal rights to the ERD Court in respect of permits and certificates, ss 38, 65.