Interception
June 2010
Commitments on interception under the National Water Initiative
The National Water Initiative (NWI) explicitly recognises that water interception activities such as farm dams, plantation forestry, capture of overland flows and groundwater extraction, can reduce water availability.
In the NWI, governments committed that by 2011, significant interception activities will be identified for all water systems so that:
- in water systems that are fully allocated, over-allocated, or approaching full allocation, significant interception activities should be recorded (e.g. via a licensing system) - with any proposals for additional interception activities requiring a water access entitlement
- in water systems that are neither fully allocated or approaching full allocation, estimates are made of the amount of water likely to be intercepted over the life of the relevant water plan, and a threshold level of interception calculated, above which a water access entitlement would be required for additional significant interception activities.
All parties to the NWI recognised that activities which use unaccounted water present a risk to the security of water access entitlements and the achievement of environmental objectives for water systems. These activities therefore urgently need to be accounted for in planning and regulation regimes. This includes jurisdictions having an agreed view on concepts fundamental to managing interception (e.g. 'sustainable levels of extraction' and 'over-allocation').
Progress on interception
The Australian Water Reform 2009 report (2009 Biennial) - the Commission's major assessment on how all Australian governments are tracking on their reform commitments - found that progress by governments to meet their NWI interception commitments has been limited. Aside from South Australia's process for dealing with forestry water use, there has been no evidence that states and territories have formally identified significant interception activities, or have established NWI-compliant policy responses.
The Commission acknowledges that major deficiencies in data make it difficult to quantify the impact of interception activities on water systems. These information gaps therefore need to be redressed urgently. However, imperfect data and information should not be an excuse for failing to act on the available knowledge or for developing policy and administration measures to account for significant water use by interception activities.
National Water Commission activities on interception
The National Water Commission has produced a Waterlines report titled Surface and/or groundwater interception activities :initial estimates This is the first national baseline assessment of unaccounted water use across the nation to assist governments to:
- understand the extent of water use that is unaccounted to provide a basis for further work to measure water use by these activities
- identify the key interception activities in their respective jurisdictions
- prioritise their investments to better manage interception activities.
The first-cut national estimate of total unaccounted water use on average per year as a result of interception activities is in the order of 5600 GL/yr comprised of: forestry plantations using approximately 2000 gigalitres a year (GL/yr), farm dams 1600 GL/yr, stock and domestic activities 1100 GL/yr, and overland flows (floodplain harvesting) on average 900 GL/yr. In a wet year, interception volumes are estimated to be even greater, for example overland flows (floodplain harvesting) may potentially use up to 2600 GL. The total volume of unaccounted water is equivalent to roughly one quarter of all entitled water on issue (~25 000 GL/yr: Australia Water Markets Report 2008-09).
Future reform priorities
The report findings provide further evidence of the urgency to the recommendations in the Australian Water Reform 2009 report. The Commission considers that the NWI interception commitments can only be addressed by paying greater attention to the following priority activities:
Quantifying unaccounted water use
- Develop a nationally-aligned science agenda of research to remedy deficiencies in knowledge and data on interception activities and to improve the quality of information available for decision making.
- Invest in the development of nationally consistent models, tools and collection of data in association with catchment planners and managers and promote adoption across all jurisdictions.
- Identify and quantify immediately all interception activities that have a potentially significant effect on the security of water access entitlements and achievement of environmental objectives, with activities prioritised according to catchments at, or approaching, full allocation and peri-urban areas.
- Identify possible future interception impacts, including increases in interception water use from expanding forestry plantings as a result of future climate change responses policies and programs.
Accounting for unaccounted water use
Prepare an overarching work program to address interception activities, including:
- Establish planning and regulatory frameworks for dealing with unaccounted water use within the next six months, including processes to trigger management response before a water access entitlement is required. This is an urgent requirement for addressing forestry water use, given the possible significant expansion of forestry as a response to future climate change response policies and programs.
- Harmonise principles and approaches for dealing with interception activities across all jurisdictions to allow more effective implementation.
- Ensure any current, or possible future, interception actions are explicitly identified in all water plans.
o Strengthen monitoring, compliance and enforcement efforts in relation to interception activities identified in water plans. - Ensure frameworks are in place to allow time for all interception activities to be accounted for by 2011 (committed timeline under the NWI).
The National Water Commission continues to support targeted investments to improve both the quantification of water use by interception activities, and to encourage the proactive development of planning and regulatory frameworks to address all unaccounted water use.
Position statement to download
Interception: National Water Commission position statement (96KB)