# How to Build Your Own DIY Waterfall – Pump, Plumbing & Waterway Basics

Building your own waterfall can be a rewarding experience however dealing with water can be tricky so you must arm yourself with as much information as possible in order to build something that you will be happy with.

Minimum flow rates

For every inch of width of your waterfall you should have a minimum of 100 to 150 gph (gallons per hour) of water supplied by your pump. Example waterfall: if you want the top bowl in your waterfall to have a 10 inch wide area where the water rolls over and down your waterfall, you would need a pump that can supply 1000gph. Additionally you need to understand how pumps are rated to ensure that you get the desired effect that you are looking for. There is an efficiency loss in the movement of water through pipes and you will need to account for this to make sure that your waterfall receives the water flow it needs.

The maximum rating for your pump, say 1000gph, refers to a pump with zero head pressure. Head pressure refers to the weight of the water that the pump is lifting and pushing. If the pump has to lift the water a long way it will produce less gph. Simplified, the pump will have a rating that refers to the amount of vertical climb the water will need to make. It will supply a chart in the pump specifications which states the zero head pressure gph, but also the gph to expect with one foot of vertical lift, or two feet of vertical lift, or five feet of vertical lift and so on.

Another factor in this equation is fittings such as ninety degree elbows, forty five degree elbows, and bends in the pipe or valves also will increase the head pressure. A pump that has to lift the water one foot, but also through a series of four or five 90 degree elbow fittings will have significantly less gph than a pump pushing through a straight run of pipe.

The height and width of your waterfall will determine your pump requirements

For this reason you need to determine how high your pump will need to push the water to reach your top bowl and also how wide you want the spillway in your top bowl to be. This will give you an idea of what size pump you need. Assuming the same 10 inch wide spillway and a vertical climb of five feet to reach the top bowl, you would need to find a pump that can produce a minimum of 1000gph with a head of 5 feet. This means that the label on the pump would likely be around 1250 gph referring to the zero head pressure rating for the pump with a performance of about 1000gph with five feet of head.

Calculating head pressure from pipe fittings