I never had much luck raising fish in our pond, at least enough to consider it a dependable source of food for our family. On the other hand the kingfishers, herons, and otters dined happily and often on our rainbow trout.
My disappointment over growing pond food disappeared, however, when I started using the pond for garden irrigation. We raised potatoes, carrots, beets, greens, and more, with irrigation flowing by gravity from pond to garden. Not to mention an annual pig whose garden side water trough was supplied by the pond. You don't have to grow fish to harvest food from a pond.
This spring I encountered a couple of growers with ponds in their food production plans (also sans fish). At Sweetland Farm www.sweetlandfarmvt.com in Norwich, Vermont, the pond is rigged to supply drip or overhead spray. Sweetland is a diversified family farm that grows and sells vegetables and meat using sustainable practices. I know a bunch of other farms, local and national, commercial and private, with long established pond irrigation systems.
As far as new pond irrigation systems go, over on the other side of the state in Rutland County, I worked on a new pond project for a commercial grower looking to expand production acreage. That means more water. Their household well won't provide enough water for the increased planting, so the owners are planning on digging a pond and using a combination of well water and pond water to take care of irrigation needs.
There's not much of a contest between wells and ponds for irrigation. Wells are expensive to drill, and you never know how good the yield will be until you drill. Irrigation potential will depend on a combination of well depth (storage) and gallons-per-minute flow.
On the other hand it's clear that, for instance, a 1/8 acre pond about 8 ft deep holding over 100,000 gallons looks more reliable than an average capacity 5 gpm well. Naturally, meeting water needs will depend on acreage in production, crop varieties, and the weather. And of course overtaxed ponds can go dry, or fail for other reasons (leaks, etc).
It's true that even a weak well supply can be stretched out by using drip irrigation rather than overhead spray. But spray, which uses more water, may be more plant productive than drip on leafy crops. And when it comes to frost protection, spray rules. In other words, for spray needs, you may be able to count on a pond more than a well. What's a grower to do? Many farms solve the dilemma by using a combination of pond water and well water.
If you're thinking of building or using a pond for irrigation, check out the many sources of equipment on the net. You'll want to research pumps, filters, tubing, and spray devices. And keep in mind that if your pond is uphill from the crops, you may be able to irrigate using gravity flow, without electricity. Off-the-grid growers also may use wind power, or solar powered pumps, to irrigate.
And after a hot day hoeing the cabbage, there's nothing better than a dive in the pond to cool off. That's something you don't get with a well.
Topics vary from month to month and provide great information when researching where you want to build a pond, or how to keep it clean. Other areas of interest are pond use for more than swimming, and how to keep fish happy in your pond.