This is the water committed for ecosystem health or other environmental purposes and managed through rules in water sharing plans established under the Water Management Act 2000 (WMA 2000). Environmental water rules are established for both surface water and groundwater sources.

This water is also known as rules based environmental water and can be ‘discretionary’ (which means it can be ordered for use by environmental water managers) or “non-discretionary” (which means it is automatically scheduled for release from a water storage, or protected from extraction, when the WSP rules are met).