Once you’re prepared for the permit process and you’ve picked a site for your pond, you can move on to designing its size, shape, layout, and special features. Regardless of the type of farm pond you choose, you’ll need to design a way for it to drain during heavy rainfall and runoff. You’ll also need to size the pond properly based on its intended uses.
Embankment vs Excavated Ponds
Excavating a pond completely from scratch on a level surface requires more heavy machinery work than an embankment pond built into an existing valley or depression. However, excavated ponds are more flexible; they are easily built in almost any part of the landscape that can support weight and supply water. Excavated ponds are easily connected to streams or built over wetlands, but they’re more limited in their ability to trap runoff from sloped areas. For the lowest possible permit complications, choose a completely excavated pond design that doesn’t connect to a wetland or stream or empty into one.
Soil composition affects both types of ponds, but differently. Excavated ponds made with built-up artificial levees will still require a high-clay soil or the levees will allow water to leak out. Wrapping constructed levees in pond liner is costly and doesn’t always work as designed. If you have low-clay soil, you’ll need to bring in clay to construct either your dam or levees, regardless of whether you choose an embankment or excavated style. Generally, most natural resource organizations recommend excavation over dam-building since it’s more flexible and less likely to fail catastrophically in a storm event. It’s also possible to build an excavated pond in low-clay soil without buying clay if you use a flexible liner and skip levee building, while dams for embankment ponds always require some amount of clay.