Pond for a Small Patio

Despite a small patio and sharp hillside, there's still room for a water feature.

A do-it-yourself homeowner can complete the project in about three weekends for around $2500. A professional would charge around $6500 (neither estimate includes plants). There's a lot of heavy lifting involved, and the concrete framework that forms the fountain must be lined up just right, making it important to pay attention to detail: Egger rates this project a 4 on a difficulty scale of 1 to 5, with 5 being the hardest. (Enlist the help of a friend or two to lift the heavy stones.)

Figure A

Building the Forms

Begin by building the 18"-high wall that will be the outside form of the seating area, then create a smaller box inside as the inside wall. Cement poured between the two forms will create an area wide enough to support the flagstone seats around the 8' x 6' pond.

Concrete mason Jim Ray uses 2x12 planks to create the outer form. He stakes the form in place at the edges of the patio, then tops the form with 2x6s. The rebar grid he builds on the floor adds strength to the pond. Use a rebar bender to form 90-degree angles (figure A.)

Figure B

The rebar bender will allow you to form a square inside the pond with rebar placed vertically and horizontally (figure B). Connect the grid with tie wire and be sure to leave the middle of the grid open so you can set in a smaller box.

Figure C

Use plywood to create the 3.5' x 5' form that fits in the larger box. Top it with 2x4s (figure C) to help suspend it above the ground so that concrete can go beneath it. Move it into place and check to see that you have a gap of twelve inches on all sides.

Figure D

Don't forget to install PVC tubing to run the pump's electrical cord through (figure D).

Figure E

Pouring the Concrete

Egger is using colored concrete to create warm, serene feeling--shades of violet and taupe are in the mixture. She rented a pump and truck for this job but says that you could probably just rent a concrete mixer for smaller areas. Get some friends to help with the pour--while one of you fills the forms with concrete, another should tap the forms with a hammer to prevent air pockets from forming between the boxes and the concrete.

Smooth the surface with a hand trowel. Let the walls cure for at least three to four days, then remove the forms from the concrete (figure E).

Adding the Stones

Landscape contractor Sergio Tostado is using large pieces of water-washed stone cut in half to face the front of the concrete pond walls. You can have the rock cut at a rock supply store or you can use veneer rock for this project. Crew starts by cutting large water-washed stone into a variety of shapes and sizes with a circular saw.

The stone Tostado is using costs about $80 per ton. Crew mixes mortar mix that costs about $3 a sack and adds liquid concrete tint to mortar--it costs $4 per bottle at home supply store. They use tint because it helps the mortar blend and become less noticeable.

Stones are set to look as if they've been dry-set--the crew applies only a thin layer of mortar on each stone and sets them against each other. They vary size, shape and color for a more rustic appearance. To finish, they scrape out any excess mortar left in gaps and clean the rocks with a damp sponge, then let it set at least 24 hours.

Planting Plan

Egger is treating the plants as sculptures, using color, texture and size as the main focus in the garden. She also uses a few water plants.

Japanese maple (Acer palmatum) 'Sango-kaku', Zones 6-8
Gardenia (Gardenia augusta) 'Veitchii', Zones 8-10
Japanese bloodgrass (Imperata cylindrica) 'Rubra', Zones 4-9

Figure F

Completing the Pond

Egger creates three spouts from bamboo poles to allow water to flow into the pond. She wants to add sound and motion to the pond. They'll come out of a wall behind the pond--it's made from the same stone used in the seat wall. She places larger rocks on the bottom and smaller ones at the top to make it look natural.

She says to be sure to get some help moving the larger stones. Set them right on the wall towards the back.

Install the PVC piping that will run behind the wall and re-circulate the water from the pond and up the spouts.To make the spouts, hollow out the bamboo by poking a stick through the stalks. Use rubber L-joints (figure F) to connect the PVC piping to the stalk.

Figure G

Attach a shutoff valve to one of the spouts (figure G) to make it easier to control the water pressure. Set the spouts so they overhang the pond.

Figure H

Use temporary braces to keep them in place while you dry-stack the rest of the stones around them (figure H). Using a handsaw, cut the ends of the bamboo at an angle.

Figure I

Egger chooses Connecticut Lilac stone to cover the seat wall because she likes the flat surface. To cap the walls, set pre-cut pieces of stone in a bed of mortar. Leave 1.5 inches of overhang on each side (figure I). Check the level between the stones as you go to ensure a comfortable seating surface and fill in the gaps between stones with grout. Wipe away any excess.

Figure J

Let the stones set overnight, then seal the inside of the pond with the same rubber topcoat often used inside pools to protect it against any cracks or leaks. After it dries (overnight), it's time for the pump. You need one that can pump at least 900 gallons of water per hour, but tostado is using one that can pump 1800 gallons an hour (figure J). It costs about $150 at the home supply store.

Set the pump on one side of the pond to recirculate the water back through the spouts. Fill the pond with water, give it a test run and enjoy!