What is floodplain harvesting? This story was prepared by Slattery and Johnson September 2020. See referenced version.
When the rivers of the Northern Basin flow onto their lower floodplains they break up into thousands of rivers, creeks, cowals, flood runners and billabongs. The Northern Basin floodplains make up a vast interconnected network of these streams. Water taken from these floodplains and stored in private on-farm storages is important for the irrigation industry in the Northern Murray-Darling Basin.
The NSW Floodplain Harvesting Policy states that …’floodplain’ means any area of land designated as a floodplain under the WM Act [Water Management Act 2000] or the Water Act 1912 (p4).
The Policy defines floodplain harvesting as…the collection, extraction or impoundment of water flowing across floodplains, including rainfall runoff and overbank flow, but excluding the taking of:
• water under a water access licence that is not a floodplain harvesting access licence
• water under a basic landholder right, including water taken under a harvestable right
• water under an applicable water access licence exemption under the WM Act
• used irrigation water (p 4).
Measuring floodplain harvesting
Floodplain harvesting has never been licensed, measured or monitored in NSW. Helen Dalton, the Member for Farrer, asked Melinda Pavey, the Minister for Water, Property and Housing, in the NSW Parliament;
What has been the volume of water extracted through floodplain harvesting in each financial year between 1993-94 and 2018-19?
The Minister replied;
There is currently very limited data on the volume of water that has been extracted through floodplain harvesting in New South Wales because such volumes have not been required to be reported by landholders.
At a public meeting in Dubbo on 16th March 2018 an officer of the NSW water department acknowledged that the volume of water taken by floodplain harvesting had been…grossly underestimated, …there is currently no monitoring of floodplain harvesting diversions.
The NSW government intends to regulate floodplain harvesting by July 2021. Extraction will be accounted for under a water access licence, basic landholder right or licence exemption, ensuring that it is consistent with the Water Management Act 2000.
The amount of water taken by floodplain harvesting will be measured, and the volume distributed, after it is licensed. Following an amendment to the NSW Water Management Act in 2014 floodplain harvesters will be able to be compensated for these new licences, should they be reduced in future.
Licensing floodplain harvesting
NSW government policy is to licence floodplain harvesting at an historic level of extraction, infrastructure and works approvals. The Department of Planning, Industry and Environment (DPIE) has stated that floodplain harvesting licences will be based on how much water was taken at either the 1993/94 (Cap) or 1999/2000 level of development;
For most regulated rivers, it is specified as the lesser of:
• the take of water that would occur with the infrastructure and management arrangements that existed in 1999–2000, combined with the water sharing plan rules, or
• the take of water that would have occurred under the Murray– Darling Basin ‘Cap’ conditions.
NSW proposes to license floodplain harvesting at the lower of these levels of development by;
• assessing the capacity of on-farm storages at 3rd July 2008,
• assigning each landholder a notional share of the total volume of on-farm storages for each valley, and
• reducing the notional 2008 on-farm storage shares, in proportion, to the 1993/94 or 1999/2000 level of development.
DPIE has said it will use hydrological models to demonstrate that the licenced volumes do not exceed take at the lower of the 1993/94 or 1999/2000 levels of development. The models will combine gauge measurements, rainfall, irrigation development and assumptions about storage size and historical take. DPIE has not committed to providing evidence of actual take from floodplains.
A review will be undertaken by consultants commissioned by the NSW government. Government officials have said that the consultant’s report will be ‘peer reviewed’. In government water agencies the term ‘peer review’ is rarely, if ever, used in the academic sense of a properly independent review. There are concerns that the government reports might not be sufficiently independent.
Floodplain harvesting project
There are communities and groups with an interest in the Basin do not trust the NSW water agency in its implementation of the NSW floodplain harvesting policy. A project is underway to provide an alternate source of information to help communities scrutinise the implementation of the Floodplain Harvesting Policy. It will provide information about floodplain harvesting and how the NSW government plans to implement the Policy.
The project will use publicly available information to allow more informed scrutiny of the NSW position. The study area is the floodplains of the Barwon-Darling, Macquarie, Namoi, Gwydir, and NSW Border Rivers, where most floodplain harvesting occurs in NSW.
The project will be completed before December 2020.