Allowable water use limits
What are the limits and why are they important?
NSW Water sharing plans include long-term average annual extraction limits (LTAAEL). In the Murray Darling Basin this includes the Murray-Darling Basin Cap and in future will also include the Sustainable Diversion Limit (SDL). These limits are designed to protect water resources, dependent ecosystems and communities from the impacts of over-extraction in the longer term. They reinforce the value of water, support the water market and the integrity of tradeable water entitlements.
Have we checked for compliance with the limits?
Department of Planning, Industry and Environment have been completing these assessments for groundwater and have been completing Cap and provisional SDL compliance assessments for surface water systems. Previous assessments for LTAAEL compliance have been limited for surface water systems due to a lack of data availability. New data sets, for example through the healthy floodplains project, will address these issues and the department is committed to ongoing implementation of LTAAEL compliance assessments.
LTAAELs apply to a total rather than a separate limit for each category of water use. The amount that can be extracted by all water users varies each year and may be above or below the long-term average limits. The plans specify how the limits are to be calculated and how compliance is to be assessed. Action is required if there is growth and each water sharing plan specifies the triggers for action.
In most regulated surface water plans, action is required if the average current water use is more than 3 percent above the LTAAEL. In these systems we use river system models which reflect current conditions to assess the average current water use. Some plans have additional triggers.