Managing flooded river flats is never easy, with each flood producing its own unique set of challenges.
For those farmers whose properties were affected by the storms and floods in June, there were some characteristics to the extreme weather that have made managing the recovery process particularly challenging.
Agriculture Victoria's Livestock extension officer John Bowman has been working with farmers for more than 30 years and has experienced an array of seasonal floods and storms. Over the past couple of weeks, Mr Bowman has been talking to farmers with flooded pastures about their management processes.
"Many of these landholders have years of experience in management of flooded river flats and many have reported that this flood has been one of the worst," Mr Bowman said.
"It's been described as a dirty flood, with the fast-flowing water carrying extra silt and debris thus making the clean-up more difficult."
Over the years Mr Bowman has collected an array of tips and recovery processes and says it's times like these that this advice needs to be shared among farmers currently dealing with recovery.
"These are some of the tips that landholders have passed onto me from their experience in managing the clean-up from previous floods, as well as some tips to reduce the damage for future floods."
First priorities
For most farmers, the initial priority was the rescue of livestock from the low-lying areas, to get them to safe ground. Ideally producers should try to do this early and certainly before nightfall, as a lot of change in river heights can occur overnight.
Once moved to high ground and provided with feed, the next priority is infrastructure, including water pumps, machinery and fodder stored on low ground.
As the flood recedes don't be too hasty to get back down on the river flats, the full flood may not have passed due to other tributaries upstream still to deliver a surge of water from upper catchments and river flats could be inundated again.
The priority is feeding your stock on the high ground, assessing the damage and working on a strategy to prioritise repairing the damage.
Take the time for some strategic planning while waiting until the soil has firmed up. This may take a day or two but it will make the job easier in the long term.
Managing the recovery
The reinstatement of boundary fences is an obvious priority. Start with the removal of the major debris such as tree trunks across fence lines. The smaller debris can often wait as much of this may break down before you can get back to it. However, if time permits, it is good to clean up the smaller debris to avoid it being washed back into the fence in future floods.
Leave the fence wires three or four days for the debris and suspended grass to dry. It is easier to remove the debris when it is semi dry, when often just a shake of the wires or tapping with a length of polly pipe dislodges most of the grass and debris. Wires can then be re-attached and strained up again.
The pastures on river flats are quite resilient and will grow up through the silt, even a covering of up to 15cm. Often a shower of rainfall after the flood helps to wash the silt off the plant leaves and aids recovery of the pastures.
If you need to reseed areas of pasture, avoid any cultivation or earthworks as any recently disturbed soil is very prone to erosion with future floods. Remember that the catchment is saturated, and the likelihood of a follow-up flood is a high possibility.
Over-sowing with a disc seeder or broadcasting onto a damp soil will be adequate to re-establish pastures on damp river flats providing there is sufficient soil temperature. In most cases it is only a portion of the area that may need reseeding.
Planning for future floods
When it comes to reducing the impact of future floods, consider the following tips:
- Install a couple of gates at the higher point of the paddock so the livestock will move to the higher point as the water rises where you can release the stock from the paddock at short notice.
- As the winter season approaches start to build up a feed wedge on some of the higher ground or hills on your farm so if a flood occurs, you have somewhere to put livestock on safe high ground which has feed available.
- Graze the river flats during the season so you do not have too much feed on the river flats that can get damaged.
- Store all your hay and silage on high ground that is accessible at short notice. Nothing is worse than watching your silage bales float down the river - yes, they float like corks. The quality of hay and silage bales, once submerged in flood water, will quickly deteriorate.
- When planning your fencing, try to run your fences parallel to the direction of flow of the flood water so the fence will collect less debris and will be less likely to be impacted by floating logs and other objects.
- If you need to fence across the potential water flow, use minimum number of wires, avoid barb wire which collects debris, and place the wires on the downstream side of the posts so the staples and insulators will detach to release the wires and hopefully leave the fence posts remaining.
- Ensure water troughs are full of water as empty water troughs can float away in flood water.
- Lastly ensure any infrastructure such as water pumps, irrigation equipment or machinery can be quickly detached and moved to high ground.
Careful preplanning and processes put in place during the offseason can reduce the damage caused by the next flood, and help manage the recovery from the next flood run a lot smoother.
