If you’re thinking of building a pond on your land, the soil has to be able to hold water. You also need a consistent water source to rapidly fill the pond and maintain a relatively constant water level throughout the year. Dry spells and evaporation will take a toll, so without water flowing in, your pond can slowly dry down to a mud puddle.
Ron Duvall is a Natural Resources engineer in South Dakota and says there are two options to tap into: surface water from rainfall and ground water.
“If you happen to be building the pond on a drainage way, you can catch some surface runoff,” Duvall says. “Just be aware of who’s downstream of you, and what the drainage area is compared with the size of pond you want to build. Make sure there’s enough runoff to fill your pond up and take care of your neighbors downstream.” It’s helpful to look at a topographic map of the area that drains into your pond.
Most farm ponds are dependent on runoff from a watershed area to fill and maintain water levels. Unfortunately, when there’s no rainfall to provide the surface water, a pond dries up, and you may need an alternative to fill it.
Drill a well
Bob Lusk is a fisheries biologist with Pond Boss Magazine. He says one plan is to drill a well and pump water into the pond, but you may need a permit depending on local regulations.
He advises asking the well driller what kind of volume you can expect from the well. For example, he says, a rate of 50 gallons per minute will support a pond around two acres in size, and it takes 27,000 gallons to add one inch of water to a one-acre pond.
It’s also important to consider the chemistry of the well water. Lusk says minerals that are dissolved in underground well water oxidize when they are exposed to air, causing dirt particles to cling to them, which makes the pond muddy.
No pumping will be necessary if your ground water comes from a spring.
“If you’re fortunate enough to have a spring, you’ve probably got a boggy area already,” Duvall says. “Sometimes you can get a little more flow out of a spring if you clean it out, which you would in effect be doing by digging your pond, if it happens to be located right where the spring is at.”
Dam it up
If there’s a stream running through the property, damming it up may be one option, but Duvall says a water-right permit will likely be required. It’s also important to consider the drainage area, who else is downstream, and their water rights. If the stream is small enough that it only fills after a heavy rain, he suggests finding a different water source.
Lusk says pumping water from a nearby creek or river can cause unwanted fish could hitch a ride into your pond.
Some landowners build small retention ponds upstream in the watershed to help rough-proof the main pond. “When their main pond begins to drop, they can open a valve from those retention ponds,” says Lusk.
When the retention ponds are down, Lusk says that’s a good time to check for leaks and do additional digging to make the ponds deeper.