By Christine Freak, Jim Cush, Linda Christesen
This week a number of our Members took part in our Floodplain Harvesting Tour. The Members travelled throughout the Gwydir and Namoi Valleys to look at a range of irrigation farms and river systems, and also heard from the Government about the Healthy Floodplains Project.
The tour was a huge success, and we are very thankful to our Members Gwydir Valley Irrigators Association and Namoi Water for hosting the group, and for Coleambally Irrigation, Murray Irrigation and Ricegrowers Association for taking part.
Some of the take-home messages from the trip included:
- FPH is a very infrequent and irregular event, with events happening only 1 in 5 years (estimated average) or for many farms further from a waterway, only 1 in 8 years.
- Farmers have invested significantly to develop structures to store flood water in these wet years, in order to have a water supply for a number of years into the future when it’s dry. This prevents the need to take water from rivers during these dry periods. These structures also allow water to be recycled on the farm.
- The geography and hydrology of the Northern Basin is unique, as water moves through small creek systems and floodplains.
- FPH is just part of a portfolio of water sources which irrigation farmers have to manage risk.
- The current licensing process is about regulating an existing historic practice – it will not allow any more water to be taken.
- The volume of take during a floodplain event is often very small in comparison to the total volume of floodplain flows at the time.
The tour started in the Gwydir Valley at Moree, where we heard that the valley is characterised by low water reliability, but is also currently facing serious drought conditions – on par with the worst drought on record. The below maps shows the extent of the floodplain areas in the Gwydir. As you can see, the flood extent map covers a significant amount of the area.
Our first visit was to Peter’s property west of Moree. Peter explained how his family have developed their land and built infrastructure to carefully manage the extreme climatic fluctuations between floods and droughts, which are typical in the area. This has involved significantly investing in infrastructure to prevent floodwater from damaging crops, and having the storage capacity so that when it does flood on to his farm, his family can use that water in future years. Peter is pictured below at their pump site where the water is metered, with the NSWIC Chair Jim Cush.
Peter also showed us a creek at the back of his property where the force of the extreme floods in this area can be seen.
We then went to see the farm of the NSWIC Chair, Jim, and we saw how the farm is designed to manage and recycle water. Jim explained that his farm has been designed around managing floodwater effectively. Jim explained:
“the ability to store floodwater takes the pressure off
both farmers and the river system in dry years.”
We then headed into Narrabri where we met with a representative of the Department of Industry who gave a presentation on the Healthy Floodplains Project.
The Healthy Floodplains project aims to improve on this system of regulation by implementing a new three-fold compliance approach, including monitoring of actual take at an individual and valley-scale rather than using modelled estimates, and monitoring of storages to determine volumes of take. Currently floodplain harvesting is controlled through work approvals process under the NSW Water Act 1912. This process provides regulation of floodplain protection structures.
Note – The NSWIC is supportive of the need to licence floodplain harvesting activities and to issue the appropriate water access licences to bring a recognised and accepted practice into line with the requirements of the Water Management Act 2000.
Day 2 started with a visit to a cotton farm in the Namoi Valley. The farmer explained that a large focus of theirs over the previous few years has been gaining the ability to determine the sources of water used on the farm, particularly when the water is recycled to be used multiple on the farm. He explained that the use of telemetry has been a huge benefit to recording the volumes of water on farm more easily. The dam storage has been surveyed, including all the internal curvature, so that a reading of the water level can accurately indicate the volume of water in the storage, which can then be communicated directly using telemetry.
Groundwater is used to provide the baseline amount of water, with the bore deeply sunk so that smaller nearby farms and graziers can use shallower bores for their water access. Floodplain water is used occasionally on this farm as part of the water portfolio.
We then headed to Namoi Water, where we learnt of the history of FPH management and policy development. This included how irrigation farmers have actively participated in the process in good-faith, such as through Irrigator Behavior Surveys. We also heard some more technical information regarding the modelling of FPH, and asked whether the model can generate an entitlement that will accurately reflect historical use, as is intended.
We discussed the challenge of including rainfall runoff within a FPH licence. The group discussed that rainfall runoff is a ‘created water’ rather than a form of take, as farmers have invested significantly in ensuring the runoff from their properties can be recycled and reused to maximise water efficiency – and thus this recycled water is not a form of take.
The next stop was Waverley, near Wee Waa. This property is located a larger distance from the major waterways, so there is significantly less opportunity to store floodwaters. Here the reliability of flood water is about 12.5% (1 in 8 years). We got to see a cotton harvest (grown from groundwater and supplementary), as well as a new system of irrigation using a double channel to reduce labor time.
Overall, the tour was a great success and clearly demonstrated two of the core values of NSWIC under our 2019-2024 Strategic Plan: Collaboration and Leadership. It is so important that our community of irrigation farmers in NSW work together to understand and discuss the challenges we face.
Moving forward, we must continue our efforts to ensure that FPH is licensed appropriately in a way which supports public confidence and trust, and recognises this highly valued form of water security for farmers in these areas who face climatic extremes of droughts and floods.
For more information on FPH – see our video: https://www.nswic.org.au/factsheets/