Conjunctive water management and New South Wales water policy
The New South Wales Water Act is about managing water sources through water sharing plans. These can be surface water, groundwater or both in the one plan. Mostly, the plans deal separately with surface water and groundwater but a few are combined surface and groundwater plans. It is State policy to manage water in an integrated way through linkages between the different plans. In practice, the linkages are not all there and opportunities are missed. An example is the surface water cap in the Murray Darling Basin. Groundwater plans do not address this issue and yet groundwater extraction obviously impacts on river flows.
The NSW Department of Natural Resources (DNR) have developed a draft policy: Management of Highly Connected Unregulated River-Aquifer Systems. Because of the diversity of highly connected systems in NSW, the draft policy proposes three management approaches depending on the system type:
- manage to groundwater (groundwater dominant system) - where river flow is mainly absent during the irrigation season and most use is from groundwater;
- manage to unregulated surface water (surface water dominant system) - where river flow is reliable during the irrigation season and groundwater abstraction from narrow aquifers impacts on surface water; and
- integrated approach - where surface water is reliable and groundwater is productive during the irrigation season and groundwater abstraction occurs at a range of distances from the river.
This is a new approach to the conjunctive management issue and in practice surface water and groundwater are mostly still managed as separate entities. As new water sharing plans are developed the uptake of the policy should be greater.
Although a surface water license was swapped for an equivalent groundwater license in the Murrumbidgee in the late 1980s, there are no recorded trades between surface and groundwater sources. It has been spoken about and it is the intent to be able to do this in systems that are highly connected.
Relevant Links
Department of Natural Resources (NSW)
New South Wales Water Legislation
References
NGC, 2004. Surface water-groundwater integration and legislative constraints. National Groundwater Committee