STEP 4: Measuring for Liner

Liner size is calculated based on the width, length and depth of the excavation, the size and number of plant shelves, and the amount of edge overhang, so the sizing will be more accurate if done after the excavation is complete.

To measure, use a sewing or construction measuring tape. Start by measuring the length at the widest point. Place one end of the measuring tape at a point 12-18" outside the perimeter of the excavated hole, or 12-18" beyond the base of a berm. Press the measuring tape against the ground, going over berms and down through the excavated hole and back up over the other side to a point 12-18" beyond the perimeter of the excavation or base of a berm. Make sure measuring tape is always contacting the soil over any shelves and levels. Write this measurement down. Do the same for the width. You may want to add an extra foot or so to both the legth and width, just in case.

Take several measurements of the various depths of your pond. Note the width and length of the areas at the various depths as well. Write these measurements down on your design if you did one. Also measue the height of your waterfall. These measurements will allow a pond store professional to determine what size of pump will be necessary for your waterfall.

NOTE: If you will be constructing a tall waterfall additional measurements will need to be taken. Measure height of waterful so that your waterfall liner will extend from a point beneath the waterfall, to a point where your liner will drape over the back and down to ground level.

Calculating Water Volume

This is not absolutely necessary for you to do, but the measurements in the equation will be useful to your pond store professional. He or she can then determine what size pump and filter will be required.

Use the equations below to calculate water volume.

Rectangular Pond: Length in feet x width in feet x depth in feet =cubic feet. Example: 10' L x 6' W x 2' D = 120 cubic feet x 7.5 gallons = 900 gallons

Circular Pond: 3.14 (1/2 diameter in feet x 1/2 diameter in feet) x depth in feet = cubic feet. Example: If your the diameter of your circular pond (from one side to the other) is 10 feet, and the depth is 2 feet, the equation would look like this: 5' W x 5' L x 3.14 = 78.5 x 2' D = 157 cubic feet x 7.5 gallons = 1,177 gallons.

Free Form Shapes: Break the pond down into a series of rectangles and circles and figure the volume of each area separately, then add the volumes together.

NOTE: Each cubic foot contains 7.5 gallons of water, so always multiply the total number of cubic feet times 7.5 to determine the total number of gallons. Write down the total volume of water your pond contains. And remember, you don't have to calculate water volume. If you have the basic measurements as to width, length and depth of your pond, this will be enough information for your pond store professional.

STEP 5: Purchasing Materials & Supplies

The reason to wait until this point to purchase supplies is that you never know how wide or deep you will actually go when it comes to the excavation process. What if you prepurchased a custom-cut liner that ended up to be too small? You want to wait until the excavation is completed to measure and then purchase the pond liner, pump, filter, and other supplies.