Pond & Waterfall Construction Formulas

How to calculate liner size.

Measure the maximum length and the maximum width of the pond.  Add the maximum depth x 2 to each dimension then add another two feet of liner to each dimension for your anchor trench.

How to calculate approximately how many gallons of water are in a pond.

Maximum length x Maximum width x 0.8 (unless your pond is completely square, if so use the whole number) x Average depth x 7.48 = Total gallons.

How to calculate approximately how many gallons of water are in the stream.

Maximum length x Average width x 0.25 x 7.48 = Total gallons. (This would be water in transition. Water that has to be supplied by the lower pond is water in transition. Upper ponds, streams or multiple streams all contribute to this total number.)

How to calculate approximately how many gallons of water are required to overflow an upper pond.

Maximum length x Maximum width x 0.8 x 0.25 x 7.48 = Total gallons required to overflow upper pond. (This would be water in transition.)

How to calculate how many gallons of water are available to put in transition, before the water level in the lower pond, is drawn down below the skimmer opening.

Maximum length x Maximum width x 0.8 (unless your pond is completely square) x 0.33 x 7.48 = Total gallons available at the skimmer faceplate. (It is recommended that no more than half of the volume of water available at the faceplate is put in transition. If power is interrupted the lower pond will have to receive all the water in transition, or the pond will overflow.)

How to calculate how many gallons of water are in a Just-A-Falls reservoir.

Maximum length x Maximum width x Maximum depth x 7.48 x 0.40 = Total gallons. (60% of the reservoir is mass / rock and 40% is water.)

How to calculate how many inches of draw down there will be in a Just-A-Falls reservoir to fill the stream.

Total gallons contained in reservoir / Depth of reservoir in inches = gallons per inch. (Calculate how many gallons of water your stream requires using the stream formula)

Total gallons required for the stream / Gallons per inch in reservoir = Total inches the water level will be drawn down in reservoir. (Make sure  that there will be enough water remaining in your reservoir to keep the pump completely submersed in water. This is required so that the pump will cool properly.)

How to calculate how much it will cost to run the pump.

Volts x Amps x 24 (hours of operation) / 1000 x .09 = Cost for a 24 hour period of time.