Get to know your pond: basins

Learn About Pond Basins

This is the first in our series Get to Know Your Pond. We’re taking a deep dive into the key components that make up healthy water features.

The basin is the thing that holds the water in your pond. So, it’s basically the pond, right?

Right. But you can’t just dig a hole, call it a basin, and call it good. Whether you’re planning a new pond or working to understand the pond you have, here are the factors that make a basin work well.

A pond is the right size and shape when it works for your space and how you want to use the pond. If you want large koi, they need plenty of room to swim. If you want to add a stream and waterfalls, the surface area of the pond must be large enough to fluctuate with the loss of water due to splash and evaporation.

Most people want a pond that looks natural. So, that means irregular shapes. Think about peanut or kidney shapes. Round off any angular edges and add some curves to make your pond look like it’s been there forever.

In the Midwest, we live in zone 5 or 6. Two feet is the standard depth of ponds here. Even in our coldest winters, ice will only freeze around eight or 10 inches thick. Two feet give fish plenty of room to swim.

Ideally, your pond will have shelves that create different layers of depth. At Good Earth Water Gardens, we usually make two shelves in a pond. The outer layer is about 10 to 12 inches deep. Then, the middle is about 20 to 24 inches deep. This helps many different aquatic plants thrive in the pond. Marginal plants like pickerel, sweet flag and iris do well in the shallow areas. Water lilies can thrive in the deeper sections.

These layers of depth make ponds safer, too. Shelves make it easy for folks to climb out of a pond.

If you fill a hole with water, the water seeps into the ground. A liner helps your pond retain water and keep its shape. And many homeowners have learned the hard way that the right liner can make or break a pond.

We recommend high-quality liner material. A 45 mil EPDM rubber liner is standard. Other liners, like what you can find at a hardware store, will hold water. But these liners aren’t usually as durable and there’s a noticeable difference in thickness.

If you’re going to have fish, it’s important to have a liner that’s rated fish safe. EPDM liners are often used in roofing. However, some roofing liners can contain traces of metals that can be toxic to fish. Make sure your liner is designed for ponds and is fish safe.

Before you install a liner, add a layer of underlayment fabric. It’s a protective barrier between the earth and the rubber liner. Underlayment comes in a variety of thicknesses. You’ll find everything from nonwoven fabric to a concreate cloth that hardens when it’s put into the ground. Think of underlayment fabric as inexpensive insurance that can prevent holes in the liner.

Rocks do a lot of heavy lifting in pond basins. Large rocks help give the pond form, providing an attractive perimeter and defining shelves and ledges. Small rounded rocks at the bottom of the basin protect the pond liner from foreign objects and UV rays. They also hold the liner in place and prevent the ground from shifting.

Rock is also an important part of a balanced pond ecosystem. Beneficial bacterial live on and around the small rocks at the bottom of the basin. These bacteria eat up fish waste and leaves that fall to the bottom of the pond. When they chow down, bacteria help keep water clear.

All these factors set your pond up for success. Taking the time to get them right can help your pond flourish.

Good Earth Water Gardens is here to help. If you have questions about your pond or need a professional to make it right, email us or give us a call at 913-749-8090.