Pond excavation in Boise, Idaho

If you've marked where the pond should go and now you're staring at the lawn wondering how deep, how steep and what to do with all that dirt, pond excavation in Boise is where those answers count. It's the step that decides whether a pond works for years or fights you every season. Dig it too shallow and fish can't make it through winter. Dig the edges uneven and you'll see liner on one side. Dig it in the wrong spot and runoff will turn it green.

I handle pond excavation as part of building the whole pond. I don't dig a hole and leave. The person digging is the person who'll set the liner, the stone and the plants, so every shelf is shaped for what goes on it next.

Before the first shovel

• Design. I paint the shape on the ground so you can see it from the patio and from inside the house. If you're not that far along, start with custom pond design.
• Utilities. I call 811 so buried power, gas, water and cable lines get marked.
• Sprinklers. Irrigation lines run all over most Boise yards. I find them and reroute them around the pond.
• Drainage. I check where water flows when it rains or the sprinklers run. The pond edge should sit a little higher than the ground around it, so lawn runoff and fertilizer don't wash in and feed algae.
• Access. I check gates and paths to plan how soil comes out and materials go in.

Shelves and depth zones

A good pond isn't a bowl. I dig it in steps:

• Top shelf, about 8 to 10 inches deep, for marginal plants like rushes and iris
• Middle shelf, deeper, for water lilies and more plants
• Deep zone, at least 2 feet for goldfish and 3 feet for koi in our climate, so fish have water below the ice in winter and cooler water in summer

Shelves also hold the rock that covers the liner, and steep walls between them keep herons from wading in. I dig a flat, level pad for the skimmer and a solid base at the top of the waterfall for the filter.

Digging in Treasure Valley soil

What's under your grass changes the job:

• Clay. Much of the valley sits on heavy clay. It holds steep shelf walls well, but it's slow and sticky to dig when wet, and it swells and shrinks with moisture. I avoid digging it soaking wet.
• Builder fill. Newer subdivisions often have compacted fill with rocks and construction scraps mixed in. I clear out anything sharp so it can't poke the liner.
• Slopes and rocky ground. In the Boise foothills, Hidden Springs and the Eagle foothills, the ground can be steep and rocky. A slope is great for a waterfall, but the pond itself has to sit level, so I cut into the hill and sometimes add a small retaining wall on the downhill side.

How I dig depends on access. A tight side yard means more hand digging. A yard with a wide gate opens up more options. I choose the method that fits the site and protects the rest of your yard.

Getting the edge level

Water always sits flat. If the ground around the pond doesn't, the liner shows on the low side. I check the edge with a level all the way around and fix it before anything else goes in. Then I pull out rocks and roots and lay underlayment, so the liner rests on a smooth, padded surface.

What happens to the soil

A pond turns out more soil than people expect. I usually reuse it on site: building a berm behind the waterfall, shaping a mound for plants or filling low spots. Extra soil can be hauled away. Reusing it saves money and gives a flat yard some shape.

Digging out an existing pond

Excavation isn't only for new ponds. I also dig to make an old pond deeper so fish can winter safely, enlarge a pond that's too small, or reshape the shelves before a pond liner replacement.

What drives the cost of pond excavation

• The size and depth of the pond
• Soil type, and how much rock or debris is in it
• Yard access, and how much has to be dug by hand
• How far the soil has to move, and whether it stays or gets hauled
• Sprinkler lines to reroute
• Slope work or walls

Excavation is one stage of a full pond construction project, and you'll find every other stage on my pond contractor page.

Where I dig ponds

I dig and build ponds in Boise, Eagle, Meridian, Star, Kuna, Garden City, Hidden Springs, Nampa, Caldwell, Middleton, Sun Valley and Ketchum.

Planning a pond? Schedule a consultation for pond excavation in Boise, and I'll look at your soil, slope and access before anyone picks up a shovel.