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National Water Account 2018

Daly: Water access and use

  • 95% of the allocations were for agricultural purposes; mostly from the Oolloo Dolostone and Tindall Limestone aquifers.
  • Allocations in the Tindall Limestone water allocation plan area were 100% of the full entitlement for the first time in 4 years.

 

 

 

For further information on water rights and water use within the region during the year scroll down this page or click on the links below:

 

Water rights and use

 

Surface water rights

Figure S6 Graph of surface water allocation for the region's key water management areas in the 2017–18 year
Figure S6 Surface water allocation for the region's key water management areas in the 2017–18 year

 

  • There are approximately 30 surface water licences in the region, mostly for water sourced from the Katherine River. More information is available on the Bureau's Water Markets Dashboard.

 

Figure S7 Graph of allocated surface water diversions for each licence purpose in the region
Figure S7 Allocated surface water diversions for each licence purpose in the region

 

  • 40% of the allocated surface water was used. Most of the surface water diverted in the region was for town supply.
  • The remaining allocated diversions were mainly to individual users for agricultural purposes.

 

Figure S8 Graph of surface water allocations and diversions in the Daly region for the years ending 30 June, from 2012–2018
Figure S8 Surface water allocations and diversions in the Daly region for the years ending 30 June, from 2012–2018

 

  • Surface water allocations for individual users and the urban system were similar to last year.
  • Actual diversions to the urban system were higher than last year. The limited groundwater supply to the town of Katherine in 2017–18 (see Water restrictions) meant more surface water was needed to meet the town's water supply requirements. Actual diversions for individual users also increased, but this is likely to represent an increase in metered data available.
  • The estimated volume of water diverted under other statutory rights remained unchanged.
  • The relatively large increase in surface water allocation in 2014–15 was due to a number of new licences being granted for the Katherine River, primarily for agricultural purposes.

 

Groundwater rights

Figure S9 Graph of groundwater allocation for the region's key water management areas in the 2017–18 year
Figure S9 Groundwater allocation for the region's key water management areas in the 2017–18 year

 

  • There are approximately 130 groundwater licences in the region, mostly for water sourced from the Oolloo Dolostone, Tindall Limestone (Katherine) and Jinduckin groundwater areas. More information is available on the Bureau's Water Markets Dashboard.
  • Allocations in the Tindall Limestone (Katherine) water allocation plan area were 100% of the full entitlement for all licences for the first time in 4 years.

 

Figure S10 Graph of allocated groundwater extractions for each licence purpose in the region
Figure S10 Allocated groundwater extractions for each licence purpose in the region

 

  • 30% of the allocated groundwater was used. Most of the groundwater extracted in the region was for agricultural purposes.
  • About 1% of the region's allocated groundwater extraction was for town supply.

 

Figure S11 Graph of groundwater allocations and extractions in the Daly region for the years ending 30 June, from 2012–2018
Figure S11 Groundwater allocations and extractions in the Daly region for the years ending 30 June, from 2012–2018

 

  • Groundwater allocations for individual users slightly increased from last year, largely based on a similar high dry season flow expected in Katherine River. Actual extractions were also marginally higher than last year, but this is likely to represent an increase in metered data available.
  • Allocations for the urban system remained unchanged from last year; however, actual extractions were about 60% less than previous years. Groundwater supply to the town of Katherine was limited this year due to a requirement for groundwater to be filtered to remove per- and poly-fluoroalkyl substances (PFAS) before transfer to the urban system (see Water restrictions for more detail).
  • The estimated volume of water extracted under other statutory rights remained unchanged.

 

Water restrictions

 

  • A per- and poly-fluoroalkyl substances (PFAS) treatment plant commenced operation in the region in October 2017 to remove higher levels of PFAS identified in the town of Katherine's groundwater supply. Groundwater extracted from the Tindall aquifer was filtered to remove PFAS prior to transfer to the urban system.
  • The PFAS removal process meant that groundwater supply to the town of Katherine was limited and much less than previous years. Although most of the town water supply for Katherine comes from surface water, the drop in groundwater contribution meant total water usage in Katherine needed to reduce by 20% to ensure a sustainable water supply. 
  • A 3-day a week sprinkler roster was introduced for properties in Katherine in 2017–18, including no watering of hard surfaces. For more information, refer to the Northern Territory Power and Water's Living Water Smart Katherine website.

 

Cultural and environmental water

Katherine Gorge, Katherine River (NT tourism © Shaana McNaught)

 

Cultural benefit

  • The water allocation plans for the Daly region recognise Aboriginal rights and interests in water and provide for Aboriginal interests through measures to limit extraction of groundwater (see the Cultural water management section in the 'Region description').
  • The cultural water provisions are strongly linked to the environmental water requirements in the plans (see  Environmental benefit below).

 

Environmental benefit

Environmental water provisions

  • Environmental water provisions have been established for the Tindall aquifer based on a minimum flow requirement in the Katherine River.

 

Figure S12  Graph of environmental water provisions for the Tindall aquifer
Figure S12 Environmental water provisions for the Tindall aquifer

 

  • Water provisions are defined based on a model-predicted flow rate at the end of the dry season on 1 November along the Katherine River.
  • The flow on 1 November is equated to an annual groundwater discharge volume from the Tindall aquifer into the river. The proportion of discharge reserved for environmental benefit is based on this volume. The remainder of the annual groundwater discharge is allocated for extraction for consumptive use.
  • A more detailed description of the environmental water provisions for the Tindall aquifer is provided in Part 4 of the Water Allocation Plan: Tindall Limestone Aquifer (Katherine) .

 

Environmental water outcomes

 

Figure S13  Graph of environmental water outcomes for the 2017–18 year
Figure S13 Environmental water outcomes for the 2017–18 year

 

  • The environmental water provisions for the 2017–18 year for the Tindall aquifer were based on a normal-to-wet year classification and a predicted annual groundwater discharge of 127,970 ML.
  • Based on the observed flow on 1 November 2017, groundwater discharge from the aquifer into the river was approximately 112,000 ML, slightly lower than predicted.
  • Given the total allocation from the aquifer for consumptive use was 33,628 ML, the discharge reserved for environmental benefit was still above the required 70%.