Mr Rees has announced immediate State-wide embargos on:

* the conversion of general security to high security licences; and

* the issuing of any further groundwater entitlements in the NSW Murray-Darling Basin.

Mr Rees says these embargoes have been put in place to protect security of supply for existing users and the environment.

Climate science is now demonstrating that water systems are changing and future inflows to rivers and creeks and recharge of groundwater aquifers may differ significantly from the past, he says.

As a precautionary measure, an embargo has been placed on the conversion of all general security entitlements to high security or vice versa until the Department of Water and Energy has done further study on the effects of these conversions on both the environment and other users.

The Basin's groundwater resources have been relied upon more heavily as the drought has continued.

While there is already an embargo on new groundwater licences in the major alluvial systems in the Basin, today's announcement extends that embargo to include all the groundwater systems across the Basin.

New data has indicated that hard rock and fractured rock aquifers in the Basin contribute to the base flows of these river systems.

This embargo will apply to new licences for irrigation and other commercial uses to protect the reliability of water for existing users and for the environment, including groundwater-dependent ecosystems.

Exemptions will be allowed for water used for basic rights, town water supply and domestic and stock use, and also where failure to supply water would cause a prohibitively high social, economic or national security cost.

The use of saline groundwater for industrial purposes will be considered.