Ponds can be filled by rainfall and can be beneficial to irrigation water supply security on the farm. Ponds are commonly sited at a natural low point in the landscape to also collect runoff water. Ponds can be lined or un-lined.
Lindencroft Farm captures rainwater in farm ponds and uses these man-made reservoirs to ensure that they have a secure supply of irrigation water for their specialty crops, especially during the end of the dry season when their well output decreases.
At Lindencroft Farm, Linda and Steven Butler use drip irrigation on the two acres that they farm, pulling primarily from a well that, according to Steven, “has maybe enough capacity for the farm and nothing to spare.” To ensure that there is always ample water, they put in a 250,000 gallon plastic-lined pond. This pond usually fills up with the first rain of the season and provides them with about “one year’s worth of irrigation insurance.”
The Butlers also have a second pond that handles the run off from the first. The ponds receive water from their produce wash station, but are filled primarily from rainwater and by rain run-off from the buildings on their property. The plastic liners for the ponds are about $6,000 each, but the rental of the excavator was the biggest expense—about $10,000, and Steven adds, “if you can avoid that cost, you can save a lot of money”.
A half-horsepower submersible pump is set-up to send the water up a hill to several 5,000 gallon holding tanks. Steven can control the flow of water from the pump house. The plumbing for this system is “very straightforward,” utilizing components that just about every farmer would be familiar with, such as PVC piping.
Steven says, “the one thing I would do differently is put in an automatic, or semi-automatic backwashing filter.” The ponds themselves need virtually zero maintenance, but the filters can get clogged easily. Without the automatic type, it is manual labor that does this easily avoidable job.
Ecological sustainability and good systems planning is evident on Lindencroft Farm by their photovoltaic panels, farm ponds and efficient irrigation systems. Steven reflects that Ben Lomond is a good place to be a farmer and only wishes that he had gotten into agriculture sooner!
2012 EcoFarm Conference Audio: Ecological Pond Design and Management
CAWSI’s Agricultural Water Stewardship Center: http://agwaterstewards.org/index.php/practices/farm_ponds_for_irrigation/
Lindencroft Farm: http://www.lindencroft.com/
This project is funded in part by a water stewardship grant from the California Department of Food & Agriculture.