Resource Development
The nature and extent of resource development in the catchment needs to be defined. This includes aspects of:
- the level of groundwater and surface water extraction and allocation compared to any sustainable limits set for the resource;
- the infrastructure associated with water storage, delivery, drainage and use; and
- the intensity and nature of land use.
The extent of the use and development of water resources dictates how conjunctive management can be applied. There tends to be greater flexibility in changing water management and policy in relatively undeveloped catchments. In catchments with high levels of water extraction, existing property rights and infrastructure can limit management change. Alternatively, there may be opportunities where existing infrastructure can be retrofitted in a cost-effective manner to achieve conjunctive management. Any investment in on-ground conjunctive technologies would need to fit in with existing infrastructure used to manage water quantity and quality.
In terms of water quantity, the policy tools to implement conjunctive water management will vary with the degree of water regulation in the catchment. Different approaches may be taken for regulated catchments where water flow is controlled by infrastructure such as dams, locks or weirs, compared to unregulated catchments where such infrastructure does not exist. The tools applied will also vary depending on development levels, measured by comparing water allocation (and use) with the defined sustainable extraction limit for surface water and groundwater resources. So-called greenfield catchments have low levels of water use compared to the resource available for extraction. In brownfield catchments, levels of water allocation (and use) are close to or exceed the defined sustainable limits for either or both of the groundwater and surface water resources.
The intensity and value of land use activities in the catchment can be an important factor, particularly in terms of response and take up of conjunctive water policies. For example, conjunctive water trading established in catchments with high-value permanent horticulture will have a different market response to catchments dominated by land uses with lower $/ML returns such as irrigated pasture.