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National Water Account 2019

Daly: Water access and use

  • 93% of the region's water allocations were for agricultural purposes, mostly in the Oolloo Dolostone and Tindall Limestone groundwater allocation plan areas.
  • Around 28% of the total water allocation was used in 2018–19, similar to last year.

 

 

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

Daly River, Northern Territory (Bureau of Meteorology © Bradley Wood)

 

Surface water rights

Graph of surface water allocation for the region's key water management areas in the 2018–19 year
Figure S6 Surface water allocation for the region's key water management areas in the 2018–19 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.

 

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

 

  • 30% 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.

 

Graph of surface water allocations and diversions in the Daly region for the years ending 30 June, from 2012–2019
Figure S8 Surface water allocations and diversions in the Daly region for the years ending 30 June, from 2012–2019

 

  • Surface water allocations for the urban system increased in 2018–19 as a precautionary measure in case groundwater supply to Katherine was further limited by the presence of per- and poly-fluoroalkyl substances (PFAS) and more surface water was needed to meet the town's water supply requirements.
  • Actual diversions to the urban system were lower than the previous few years, which aligns with recent water conservation measures put in place by the Northern Territory Government (see Water restrictions) to ensure water supply in the region remains sustainable.
  • Surface water allocations for individual users were similar to the last few years. 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.
  • The estimated volume of water diverted under other statutory rights remained unchanged

 

Groundwater rights

Graph of groundwater allocation for the region's key water management areas in the 2018–19 year
Figure S9 Groundwater allocation for the region's key water management areas in the 2018–19 year

 

  • There are approximately 130 groundwater licences in the region, mostly for water sourced from the Oolloo Dolostone and Tindall Limestone (Katherine) water allocation plan 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 second successive year.

 

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

 

  • 28% 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.

 

Graph of groundwater allocations and extractions in the Daly region for the years ending 30 June, from 2012–2019
Figure S11 Groundwater allocations and extractions in the Daly region for the years ending 30 June, from 2012–2019

 

  • Groundwater allocations for individual users were similar to last year, largely based on a similar high dry season flow expected in Katherine River. Actual extractions were also similar to last year.
  • Groundwater extractions for the urban system remained relatively low, similar to last year. Groundwater supply to the town of Katherine has been limited during the last two years 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 Limestone Aquifer was filtered to remove PFAS prior to transfer to the urban system.
  • The PFAS removal process has meant that groundwater supply to the town of Katherine has been limited during the last two 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 for properties in Katherine remained in place during 2018–19. For more information, refer to the Northern Territory Power and Water's Living Water Smart Katherine website.

 

Cultural and environmental water

Kakadu wetland, Northern Territory (istock © Catherine and Simon Gidz)

 

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 Limestone Aquifer based on a minimum flow requirement in the Katherine River.

 

Graph of environmental water provisions for the Tindall Limestone Aquifer
Figure S12 Environmental water provisions for the Tindall Limestone 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 Limestone 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 Limestone Aquifer is provided in the Katherine Tindall Limestone Aquifer Water Allocation Plan.

 

Environmental water outcomes

 

Graph of environmental water outcomes for the 2018–19 year
Figure S13 Environmental water outcomes for the 2018–19 year

 

  • The environmental water provisions for the 2018–19 year for the Tindall Limestone 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 2018, groundwater discharge from the aquifer into the river was approximately 106,000 ML, lower than predicted.
  • Given the total water entitlement from the aquifer for consumptive use was 32,369 ML, the discharge reserved for environmental benefit was 69%, marginally under the required 70%.