Flood recovery checklists

for farmsteads

BY VO THE TRUYEN REGIONAL DEVELOPMENT OFFICER, VEGETABLESWA

Carnarvon experienced substantial winds and nearly double its annual rainfall between February 4–5, 2021, which resulted in the worst flooding the region has seen since 2010.

The Gascoyne River peaked at Nine Mile Bridge at 7.2m — its previous highest peak was 7.7m in 2010. Land and farmsteads along North River Road, west of the Bibbawarra intersection, and along Robinson Road were significantly inundated.

Although the visual assessment revealed up to 80 per cent of plantations had little to no flooding from the river, all farms in the region were waterlogged.

Here are a few considerations for fruit and vegetable growers during this challenging time.

1. Living space and packing sheds

Recommendations:

• Wild animals

First, check all living spaces for wild animals. Wild animals tend to move to higher ground to avoid flooding, so carefully check in and around living spaces to make sure there are none present. If you do locate them, it is advised that you do not try to capture or repel them. Instead speak with the local incident/rescue services, for example Carnarvon Volunteer Fire and Rescue Service, 344 Robinson

Street Carnarvon, (08) 9941 1013.

Carnarvon received nearly double its annual rainfall between February 4–5, 2021.

PHOTO © THE WEST

• Pooled water

Pools of water will often remain around living spaces after flood water has receded and become ideal breeding places for mosquitoes. It is important to drain them out or encourage them to be absorbed by the soil by creating small drenches around them.

• Packing shed

Flooding may have an impact on the foundations of a shed. As running water washes away soil, it may weaken a building’s structural strength and the shed may not be safe to enter. It is important to check the foundation, sill, plate, roof and walls for damage. If severe damage is found, consult professional building services.

After water subsides from the packing shed, clean and dry out the building as much as possible.

Flooring that is covered with layers of silt and mud should be cleaned as soon as possible, as it is much easier to do before this matter has dried.

2. Electrical equipment

Some farmsteads along Robinson Street suffered from topsoil loss and soil erosion. During this process buried wiring and plumbing may have been exposed or damaged.

Recommendations:

• Inspect wiring and plumbing for damage • All breakers, breaker panel boards, fuses, switches, controllers and receptacles should be checked by an electrician.

Floodwater can leave deposits in the electric motors of irrigation systems, which may in turn cause electrical faults and create a safety hazard • Do not turn on the power to a flooded structure until it has been inspected and a licensed electrical contractor or inspector has determined it is safe.

3. Drinking water

The scheme water system reaches every farmstead in Carnarvon, so it is necessary to do the following: • Check for breaks or leaks in the supply and distribution pipes • Flush all of your water lines • Follow the local government’s update on drinking water services

3 GROWERS should conduct water and produce testing before making decisions regarding the suitability of produce.

There are withholding periods and testing requirements that must be met.

4. Food safety

Typically, during February, Carnarvon does not have large quantities of harvestable vegetable crops. However, some cash crops like pumpkin and watermelons, as well as home grown vegetables, may still be harvested. These may have come into direct contact with flood waters, which poses two major concerns: rot and food safety. Recommendations:

• Growers should conduct water and produce testing before making decisions regarding the suitability of produce • There are withholding periods and testing requirements that must be met before produce is sold. Breaches could result in prosecution under the Food Safety code so further advice should be sought.

5. Flooded or spilled oil and agrichemicals

Recommendations:

• Secure the area or building. • When surveying the flood damage, ensure you are wearing the appropriate personal protective equipment • If you suspect a major health hazard and/or you believe containment is not possible, call

Carnarvon Volunteer Fire and

Rescue Service to prevent further environmental contamination

• If you can manage the spill and/or cleanup, you still are obligated to report it to local government. When cleaning, the following is advised: • Treat all surfaces, equipment, containers, water and sludge as if they are contaminated • Avoid skin, eye and inhalation exposure by wearing the appropriate personal protective equipment • More specific information may be obtained from the Auschem course, Risk Management in Pesticide Use. For more information visit: www.dfes.

wa.gov.au/recovery/Pages/DRFA-

WA.aspx

Fuel and oil spills: • Report fuel spills to the Carnarvon

Volunteer Fire and Rescue Service • Ventilate the area to reduce vapours that are combustible and hazardous to your health • Wear rubber gloves, overshoes and use a proper respirator as exposure to fuel, oil and chemicals can cause health issues • Use absorbent materials to collect the oil or fuel • Discard porous materials that are impossible to clean. For cleanup and disposal details, contact the Waste Management Division, Carnarvon: 3 Francis Street, Carnarvon, WA 6701 p: (08) 9941 0000 e: shire@carnarvon.wa.gov.au

6. Crop fields

• Wear appropriate personal protective equipment and clothing while clearing debris from fields • Have soil tested because flooding may have affected soil nutrients and been contaminated with human pathogens, as well as heavy metals. Many farms still had plastic mulch on the field at the time of flooding and some growers were under pressure to work the soil to meet the seedling delivery time. Once saturated however, the soil can take a long time to dry out. Recommendations:

• Avoid operations on wet soil and limit load weights to reduce soil compaction • Water drainage management is very important. It is recommended to use a shank or sub-soiler between beds to help break up layers of compaction, particularly in row middles that experience heavy traffic, as it may help improve water infiltration into the soil. It is important to keep in mind that deep dripping usually doesn’t result in long-term improvements to the soil structure as it can rapidly deplete organic soil matter, which actually helps improve water infiltration.

7. Eyes out for disease

Although flooded soil may kill insect pests, such as thrips, that have life stages developed in the soil, wet conditions facilitate disease outbreaks. Phytophthora and Pythium both thrive in wet soil conditions. Root rot can also become a problem in fields that stay wet for extended periods. We encourage you to consult with your local agronomist about pest and disease management after a flood event.

MORE INFORMATION

Contact Truyen Vo, vegetablesWA Regional Development Officer, on 0457 457 559 or truyen.vo@vegetableswa.com.au.

Flooded soil may facilitate disease outbreaks.