If you’re still at the planning stages of a backyard or neighborhood pond, you have plenty of design options while keeping winter protection in mind. A well-designed pond will only freeze as much as expected, even when temperatures drop lower than predicted. This is essential for keeping fish or just maintaining a healthy pond year-round. Anyone building a pond in a cold climate should incorporate the following features for a better, winter, pond-keeping experience.
Choosing a Depth
An absolute minimum depth of 18 inches in required, to ensure a pond does not freeze solid, in any areas that experience freezing temperatures. Ponds that are shallower won’t provide enough liquid water at the bottom for fish like koi or goldfish. If you live in an area where temperatures drop far below freezing regularly, you’ll likely need extra depth to avoid a solidly frozen pond. General temperature and depth recommendations are:
- 24 inches if temperatures drop into the 10s and 20s regularly
- 36 inches or more if temperatures reach 0 and below regularly
- 48 inches or more for the coldest areas, which still may not be enough without supplemental heating.
Surface Area Considerations
The surface area of the pond less directly controls the amount of freezing that occurs than the depth. However, surface area does affect how much you’ll spend on equipment to keep ice under control on the surface. If you need to keep holes in the ice open for fish that are hibernating at the bottom, a large pond can cost far more than you expect just for de-icing equipment. Add in the cost of warming and circulating the entire body of water for sensitive species and you’ll see why many fish-keepers build the smallest ponds possible. Ponds with a lot of surface area tend to develop ice in the center slower than those with a smaller area, but this is also largely affected by wind and other conditions.
Access to Equipment
Winterizing involves both maintaining the equipment that stays in place and removing some elements of pond treatment systems. If it’s hard to get to the pumps and filters, they’re likely to incur damage due to being overlooked each fall. Don’t forget that some elements, including UV classifier and active bio-filters, are best removed and kept warm over the winter. Install these devices with fittings designed to make them easy to remove and reinstall as needed since it will be a seasonal chore.
Protection from Predators
Fish are particularly vulnerable and easy for predators to spot during the winter. Since they’re slow moving and barely using oxygen, they typically don’t react to the shadows or vibrations that would usually send them scattering. An enterprising raccoon or crane may return over and over to scoop up any fish they can reach through the ice. Some larger predators can even break through the ice to get at your fish. If this is a concern in your pond, include permanent posts or hooks to hang protective netting over the surface. A durable net will let snow fall through while keeping predators of all sizes from reaching the fish. This is especially recommended in areas where ice cover is scattered but temperatures are cold enough to slow the fish.
Power for De-Icing Equipment
If you are planning an all-natural pond, without any pumps, filters, or other electrical devices, don’t forget about the need for temporary power to de-ice the water in the winter. Heavy duty insulated power cords will work, but they may cost more than you expect if the pond is located far from a power source. Remember that damage to the power cord could leave the pond icing over unexpectedly. Check the pond regularly to ensure it is staying properly de-iced if you can’t permanently wire in power for the deicer over the winter.
What starts out as a large and shallow pond may become a deeper and more compact design once you take into account de-icing and netting costs. Balance your need for aesthetics, winter protection, and general function when laying out design features. All ponds, regardless of their winter conditions or intended purposes, will last longer and perform better when properly lined with the help of BTL Liners.
