Mersey Water Management Plan

​​​​​The Mersey Water Management Plan was adopted, under section 28 of the Water Management Act 1999, on 18 August 2005 and took effect on 31 August 2005.

The purpose of the Plan is to provide a framework for managing the water resources of the Mersey River Catchment in accordance with the objectives of the Water Management Act 1999

Mersey Water Management Plan (1003 KB)


Please note: Due to its size, 'Figure One - Catchment of the Mersey River' is not included in the above Plan document.

  Catchment of the Mersey River   (2Mb)

 

Review of the Mersey Water Management Plan

The Mersey Water Management Plan is currently under review.  

As a part of the review a trial of changes to water management in the Mersey River catchment was  undertaken over the last two years.

For more details of the review process see the link below;
 

Rules under the Mersey Water Management Plan from 1 November 2022 to 31 May 2023

The access rules that will apply under the Mersey Water Management Plan from 1 November 2022 to 31 May 2023 are similar to those tested under trial over the last two irrigation seasons, except the 1 December to 31 May cease-to-take will not be reduced when inflow to Lake Parangana fall to low levels, as trialled previously.

The reduced cease-to-take was previously applied to account for Hydro Tasmania reducing environmental releases below 160 ML/day during dry periods. Now that Hydro Tasmania are applying a constant minimum environmental release the reduced cease-to-take is not necessary. Assessments undertaken since the end of last season, as part of the Plan review process, have shown that this change will maintain highly reliable access, similar to that experienced in dry periods under the previous trial arrangements.  The arrangements for this season will be:

  1. Hydro Tasmania will continue to maintain a constant environmental release of 160 ML/day from Lake Parangana with the flow release measured at the dam outlet.

  2. The cease-to-take measured at Mersey River at Shale Road stream flow gauging station will remain at 260 ML/day for November; and be 195 ML/day for 1 December to 31 May.

  3. The four-stage restriction protocol that has been applied in the past two seasons will remain in place with no change, as described in the Table below. The restriction protocol progressively restricts access based on surety levels (priority of access) when flow available above the Cease-to-take is not able to meet 100% of demand.
Staged restriction thresholds for the Mersey River catchment for 1 November to 31 May, as measured at the Mersey River at Shale Road stream flow gauging station.

A general warning will be issued within 10 ML/day of the Stage 1 restriction.

​Restriction
Stage
​Protocol​Flow thresholds (ML/day) for November
​Flow thresholds (ML/day) for 1 December to 31 May
​Restrictions - Percent (%) of Maximum Daily Take
​Stage 1
​Cease-to-take plus 30 ML/day
​290​225​50% Ban on Surety Level 6 takes
Surety Level 5 limited to no more than the Maximum Daily Take
Stage 2
​Cease-to-take plus 20 ML/day
​280​215Ban on all Surety Level 6 takes
Surety Level 5  limited to no more than the Maximum Daily Take
Stage 3
​Cease-to-take plus 10 ML/day
​270​205​50% ban on all Surety Level 5 takes
​Stage 4
​Cease-to-take​260​195Ban on all Surety Level 5 and 6 takes*
*All flows into a dam must be passed downstream (where dam outlet structures permit).

Contact

Water Management Planning
Lands Building
HOBART TAS 7000
Phone: 03 6165 3221
Email: Water.Enquiries@nre.tas.gov.au