Licensing and Allocation
Commonly, licensing for groundwater and surface water is inconsistently defined (in terms of entitlements) and administered (in terms of institutional arrangements and asset ownership/management). Also, allocations and planning for groundwater and surface water even where high connectivity between the two is acknowledged is usually facilitated through independent planning regimes, which can have inconsistent objectives. The Rivers & Aquifers Workshop identified that for connected water resources compatible water access entitlements, common planning objectives and mechanisms are needed to identify and address over-allocation that can be hidden by the institutional separation of groundwater and surface water management. The National Water Initiative supports development of a nationally-compatible definition for water access entitlements.
Linking of the licensing and allocation arrangements for the groundwater and surface water resources in a connected system is required. Different approaches are possible to better coordinate regulation. Some examples are:
- Total Water Accounting, Taking a catchment-wide approach to the water balance that is inclusive of the inputs and outputs of groundwater and surface water resources is a pre-requisite for conjunctive water management. Estimates of the sustainable limits to water allocation should be based on budgets for the total water resource, or at the very least that there is coordination between groundwater and surface water assessments. Groundwater sustainable yield estimates are typically based on a function of recharge, with evaluation of discharge magnitude and dynamics less of a priority. Equally, surface water resource assessments tend not to directly include a groundwater interaction component. Such explicit accounting of seepage flux is required;
- Linking of Water Management Plans, Surface water and groundwater management plans for a catchment should address the same goals and their development should be coordinated. Ideally, in a highly connected system a single water plan would combine the management of the two resources, taking advantage of their inherent characteristics;
- One (or compatible) licensing systems to allow trading. Existing groundwater and surface water licenses are not compatible. Common licensing arrangements across a connected water resource would facilitate consistency of water securities and enable potential trade opportunities. A key issue in developing a single license system is investigating the transferability of groundwater and surface water securities (including supply, volumes, quality, access and reliability);
- Coordinated Embargoes, recognising that any caps placed on one component of the connected water resource will have an impact on the other. As in the case for the Murray-Darling Basin, the Cap on surface water diversions transferred water demand and stresses to the groundwater resource. When restricting entitlements, it is assumed that there is no prior hierarchy between groundwater and surface water users;
- Tiered access conditions, Consistent with security ratings of surface water allocations, tiered access conditions can also be applied to groundwater licences. Seasonally variable groundwater access could help optimise the timing of extraction of groundwater to minimise impacts on stream flow. As an example, seasonal allocations set by comparing groundwater levels to benchmark conditions are used in some Victorian groundwater management areas; and
- Triggers or Thresholds, Water access may be temporarily restricted or transferred to the other water source on the basis of triggers such as using defined thresholds for minimum stream flows or groundwater levels. This requires assessment of impacts of groundwater use on stream flow and vice-versa in terms of surface water extraction on groundwater levels. For example, in the case of streamflow depletion a robust and transparent assessment of both the magnitude of the change in groundwater discharge and the time lag for response is required.
A conjunctive allocation example
One conjunctive approach can be to:
- define conjunctive users as water users who hold a surface water license and a groundwater license to use both surface water and groundwater for irrigation. Allocation of groundwater for conjunctive use varies depending on the availability of surface water;
- allocate farmers less groundwater when the surface water allocation announced at the beginning of the season exceeds a trigger percentage of the entitlement while the allocations will remain unchanged if surface water allocation falls below this trigger;
- allow water users with a groundwater only licence to have access to their full allocation of groundwater all the time; and
- groundwater only users have an advantage over conjunctive users during reduced surface water availability and when surface water is surplus thus in the long run any perceived inequalities are expected to be even out.
This policy results in extraction levels in excess of sustainable yield in drought years, the groundwater stocks are rebuilt during wet years because of extraction levels below the sustainable yield.