Professor Russell says: "To know what size pump you'll need for your waterfall,  the width of the waterfall, and what type of stone will be used in the waterfall."

Waterfall Flow Rates

For waterfalls and streams, your pump's flow rate should be at least 100 gallons per hour for every inch of waterfall width.  For more noise and "white-water" from your falls, increase the flow rate to 200 gallons per hour per inch of waterfall width.

Waterfalls made of water falling off cut stone, 100 to 150 gallons per hour per inch wide of waterfall will work.  For waterfalls made of water falling off boulders, 200-500 gallons per hour per inch wide of waterfalls will create a nice white-water effect.

Smooth edge stone, or slate creates a "clear" waterfall.  Jagged edge stone creates more "white water" waterfall.  Clear waterfalls are more quiet then white water waterfalls.

A waterfall landing in a pool of water will have a more quiet sound than water falling onto stones.

So when designing your waterfalls, first decide what the look you are going for, then decide how quiet or loud you want it to be.  For example; if you are trying to cover up road noise - make your waterfalls from jagged stone and have most, or all the water landing on a boulder, or stones before entering a stream or pond.  If you want more quiet waterfalls, make your waterfalls clear with cut stone or slate, and have the water fall into a pool, or pond.

Next to each of our pumps will be a chart showing how many GPH (gallons per hour), GPM (gallons per minute) that pump will provide at 5' of head, 10' of head, etc.  To understand this you need to remember that water is heavy at 8 pounds per gallon - and the higher a pump has to push the water the less volume it will provide.  Important - the feet of head is the distance from the surface of the water level in the pond to the top of the waterfall. 

To create a nice "average" looking waterfall or stream,
it takes 1,800 gallons per hour (30 gallons per minute) for every 1 foot of width. 

Waterfall flow rateTo determine the GPH/GPM needed for your waterfall or stream - multiply the width in feet x 30 GPM.  Example:  To build an "average"  waterfall 3' wide and 10' high above the pond - multiply 3' (width) x 30 GPM which equals 90 GPM or 5,400 GPH at 10 feet of head.  Now look through our pumps to find the pump that achieves 5,400 GPH/90 GPM at 10 of head.  There's your pump! Its that simple!  You can double the flow rate to achieve a roaring cascade of "white-water" or scale down the flow rate for a more gentle effect. 

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