Layout the location, size and shape of your new pond. Look for a place where you & your family can enjoy & access it easily. Preferably away from trees as to avoid falling leaves and tree roots. (That was a bit unavoidable for us, but we worked around them as much as possible).
Make all of your adjustments now before you dig. We used a couple of extension cords to layout our pond. You could also use a garden hose.
Use a straight shovel to edge around your layout (careful not to cut into your cord or hose). Remove Sod and if possible, set it aside to decompose. You can then add it to your garden. Most of the soil nutrients is in this top layer and it is invaluable in our garden once decomposed. Dig from the center out and dig straight sides as you begin to excavate your pond. Note: We saved our heavy clay soil to create that raised vegetable garden we discussed and to plant our pond plants.
Level the area. As you dig, use two 2″ x 4″ wood planks and a level to check the sides of your hole. Level sides will ensure your pond will not leak when you are done and provide a nice finished edge.
In our case, we had to build up the back of our pond because the yard slopes slightly downward. We accomplished this with some of the removed soil and some concrete blocks. It was also very helpful to use two string levels and scrap pieces of wood so we could get a sense of where the top of the water would be once the pond was filled. This ensured that all of our borders were sufficiently high enough.
Lining the hole for protection from sharp rocks and roots. Once the hole is dug to the correct shape, size and depth and the sides are level, it should be inspected for pointy rocks and/or roots that could potentially rip the liner. Then, the sides should be covered with an underlayment to protect the liner along the sides of the pond. In our case, we used extra carpet from our attic. The carpet strips were cut so that they would not buckle under the liner.
Once the underlayment is in place, we covered the bottom of the hole with 1″ of sand to protect the liner at the bottom of the pond.
Installing the pond liner. Carefully unfold the liner and avoid dragging it across the ground. We placed ours in the middle of the hole and gently unfolded it. Let the liner loosely drape over the edges of the hole. Adjust the liner if necessary to be sure it is centered in the hole and there is sufficient overlap on all sides.
You can hold it in place by carefully placing bricks or rocks along the edge. Bricks can be used to hold the folds as you fit your liner into place. They can be eased off as necessary to adjust the fold during the filling process or at the end when you put your final edging in place.
Fill the pond with water. This can take some time depending on the size of your pond. The kids love this job but try to keep them out of the pond during this process.
Once your pond is full, you can begin placing your edging material. We used large thin flat rocks of various sizes. Putting it together was like working a jigsaw puzzle except the pieces were very heavy and moving them was exhausting. In the end, we are very happy with the final look.
When you are happy with the edging, you can trim your liner to 6″-12″ around the entire pond. Then you can plant in the ground outside of the edging for a more natural look.
Add your pump and waterfall (if using). The pump goes at the opposite end of the waterfall or outlet in order to provide good circulation. Here, I reused the waterfall we had on our small pond. I hid the tube as best I could by bending it gently and hiding it between two of the rocks that edge the pond. I then ran it behind the rock edge and under other plantings until it reached the waterfall.
Now that your pond is complete, you can stock it with water plants and goldfish. As I mentioned, I split several of the pond plants that I already had and used them in the new pond. I also inherited some pond plants from friends. Thank you Lily Bruch for sharing some of your pond plants. Giving and receiving pond plants is a perfect use for our Plant Share.
I also stocked the pond with Shubunkin and Comet Goldfish. Thought they are small, I felt that it was worth the cost savings to purchase small fish and be patient. They school very nicely already and we all enjoy seeing them float together under the water. This will also be the new home for our baby fish mentioned in the Surprise Update (5/6/13).
Lessons Learned on this Project
- Black plastic milk crates make perfect underwater plant stands as well as provide a safe place for fish to hide. This will come in handy if any predators come lurking, especially Great Blue Herons. Thanks to Dee Lertora, Montgomery County Master Gardener, for the suggestion and the donation of the crates.
- I learned from Kevin White, Owner of The Wild Bird Center, Gaithersburg, that you can create a shelf in the center of the pond that will provide a safe and shallow place for birds to land, drink & bathe. This is essential since the pond edges are straight in order to dissuade predators. It was created by using a cement block which provides holes for the fish to hide and a shelf made of a slate piece. Kevin explained that herons will not look under the shelf for the fish. So, this will also serve as another way to protect the fish.
- Even level ponds overflow in heavy rainfall. I learned along the way that although the pond is great and holds water effectively, recent heavy rains (3-4″) caused it to overflow it’s banks. Ironically, the same is true for container gardens. Just keep this in mind when you plan your project. Luckily, our pond drained conveniently away from our house and down the hill behind it. Our containers are placed in an area where the overflow also drains to the yard. But. I wanted to share this information with you if you are putting your container garden on a patio for example or if your pond is designed in a way that it might drain toward your home. If you have questions about drainage or overflow, you may want to consult with a pond professional before installation.
- It is normal for a pond to go through a “green phase” after initial construction. This is caused due to a water imbalance. It takes a few weeks for the pond to “mature” and for the plants to begin working efficiently as filters. I added Ponsparkle (a product from Lilypons) and a barley product to help clear it up. Both are beneficial bacteria that help hasten the process of balancing the pond. It cleared up after one week and one application.