Catch Rain Water from Shed Roof
Rainwater collected off the dairy shed roof is usually of good quality and the volume over the year can be substantial. Calculate this from the annual rainfall (mm) X roof surface area (M2) = litres collected per year.
Most sheds could capture enough rainwater to supply the plant wash and / or plate cooler if combined with re-use systems. Size the storage tanks according to the expected period of days without rain and the daily water use. Tank costs generally vary from $3,000 - $8,000.
Rainwater from the yard can be collected for re-use in yard wash.
Tips on Getting the Best Result
Covered tanks with ‘initial flush’ diverters give the best quality water. Concrete is more thermally efficient if the water will be used for milk cooling.
Pros and Cons
Subsidies for tanks are available and reduces load on effluent system. Back-up supply is needed as rainfall varies substantially throughout year. Water quality can suffer in dusty environments.
Issues in Making it Happen
Can use rainwater to make up teat dip (preferably after it has passed through the hot water service or been boiled).
Rainwater is often the cleanest water available on the farm and so is suited to plant washing.
Reduce size of effluent storage, especially if capture stormwater from yard.