Full effluent ponds and irrigation
At any time of the year soils may be saturated and not suitable for irrigation. Overflowing ponds or spreading effluent onto saturated soils can result in surface ponding or run-off to waterways.
If this ponding or run-off could reach a waterway then you’ll be non-compliant with your consent.
Non-compliance can result in significantly degraded waterways and anyone found breaching the effluent management rules in the Southland Water and Land Plan will face enforcement action.
If I’m facing this issue what can I do?
If your effluent storage is full, or above normal levels, and you are facing saturated soil conditions, there are some options.
Understand your soil moisture deficit and how much you can irrigate
- Environment Southland soil moisture sites may be red but are indicative of an area only. Your farm might be different due to location, rainfall and soil drainage.
- If you think that your soils may be able to handle irrigation, you can actively monitor a test first to see how much effluent you could apply before ponding or runoff occurs. This can be done with a 15-minute test of your irrigation to see if any ponding occurs.
- You can adjust your effluent irrigation depths to be low (below 5mm) during periods of higher soil saturation. This can be achieved by setting your irrigator to its fastest setting or lowering your run time on your pod system to allow for less application depth.
- Record any effluent irrigation events to show that they were actively monitored. You can also look at testing the nutrient content of the effluent, as rain entering the effluent system may have diluted it, allowing for more applications in the year.
- Keep a close eye on weather forecasts and be ready to start or stop applications when the weather conditions change.
- Where possible use the technology available to try to measure this soil moisture deficit. Ask your neighbours if they have soil moisture tapes or probes you could use and consider investing in these for your own farm in the future.
Understand the regulations on your consent conditions
- Read the conditions of your resource consent to understand where and when you can irrigate effluent. Make sure you stay inside your application area when looking for a place to irrigate.
- Within your effluent irrigation area be selective, look for the most free-draining or low risk soils to irrigate to. To do this you could look for low risk areas on your farm in the effluent soil classification map on the Environment Southland website.
- Avoid tile-drained areas to prevent discharges to water. Also avoid areas that are close to waterways as they could lead to effluent entering it.
- Actively monitor your irrigation to avoid ponding or over application. If a problem does arise with your irrigation, you should contact Environment Southland as soon as possible to help mitigate the issue.
- If unsure of your conditions, contact Environment Southland for a copy of your consent conditions.
Reduce water entering your effluent system
- Optimise efficient water use in the dairy shed. Look at repairing leaks, use scrapers to remove effluent, check the nozzles on hoses and their performance and train your staff to use minimal water when washing the yard.
- Stormwater diversions will reduce the amount of effluent you will have to manage, especially during periods of heavy rain. Ensure all rainwater collected from the dairy shed roof and other sheds are diverted away from the effluent system. If you are using them between milkings on your farm, ensure the yard is clean and devise a fail-safe system that gets your team to check the diversion before each milking.
Have excess effluent removed from your pond and property
- Contact an effluent spreading contractor to help reduce effluent in your pond if soil and weather conditions allow.
- Make sure the contractors are aware of the consent conditions in terms of areas to apply to, depth, ponding and runoff.
- If they are using slurry tankers farmers need to be aware of the compaction issues that these machines could place on the farm and the time between application events and cows returning to grazing that pasture.
- If contractors are using an umbilical system ensure they are aware of tile drains, distance to waterways, boundaries and dwellings
Get everyone on board
Ensure your employees understand the issues and have adequate training on managing your system. They should know where the high and low risk areas are on your farm and within your system. Talk to them about your consent conditions, your plans for effluent management in wet weather and who is in charge of monitoring irrigation events.
