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Sheer Descent Technical Information

Waterfall Height Specification

Waterfalls naturally narrow as they fall. Waterfalls should not be installed more than 3 1/2 feet above the water surface or the sheet will start to break up.

Hydraulic Guideline Chart


Pipe Size Max SUC Flow* Max DIS Flow**
1 1/2" 37 GPM 50 GPM
2" 62 GPM 82 GPM
2 1/2" 88 GPM 117 GPM
3" 136 GPM 180 GPM
4" 234 GPM 313 GPM

*Based on 6' per second velocity. **Based on 8' per second velocity.

Pump Sizing and Installation Options

One of the advantages of the Sheer Descent Waterfall is the ability to provide a continuous sheet of water with a minimum of water flow. A standard 4 ft. model, for example, requires only 48 gallons per minute to operate. In order to size your pump properly, refer to the Water Flow Requirement Chart. In most cases, a properly sized standard swimming pool pump will operate the Sheer Descent Waterfall and filter the pool with little loss of total water turnover. As a general rule, the Sheer Descent Waterfall requires approximately 12 gallons per minute per foot with a little head loss. For a more dramatic effect, more water gallonage can be applied to project the waterfall away from the wall.

NOTE: When plumbing multiple falls, add the total length of waterfalls together to determine GPM required. Example: when plumbing two (2) 6' units, you now have 12 feet of waterfall, which requires 144 gallons per minute.

The installation of the Sheer Descent Waterfall using the main pool filter pump is the most common plumbing system due to the unique low flow aspect of the waterfall system. Simply plumb a 3-way valve on the return line, after the filter, and plumb the waterfall feed line in a minimum of 1 1/2" PVC schedule 40 pipe. Units above 5' in length need a minimum of 2" plumbing.

If multiple waterfalls are being installed, or a Sheer Descent Waterfall 6' or longer is being installed, we recommend installing a separate pump. When plumbing a pump dedicated for use by the Sheer Decent, a separate suction line to the pool must be plumbed. This should be plumbed in a minimum of 2" schedule 40 pipe.

Install at least two (2) (anti-entrapment) suction outlets provided with covers which are listed/certified as complying with ANSI/ASME A112.19.8–2007. Suction outlets (drains) should be installed in accordance with ANSI/APSP–7, the American National Standard for Suction Entrapment Avoidance in Swimming Pools, Wadding Pools, Spas, Hot Tubs, and Catch Basins. The anti-entrapment suction cover is recommended to be positioned 18" above the floor of the pool.

Next, a Sheer Descent filter/strainer (part# 3456), or equivalent, must be installed on the return side of the pump, between the pump and the Sheer Descent Waterfall. A FILTER IS REQUIRED for separate pump installation, as debris (hair and lint) must not be allowed to enter the Sheer Descent unit. For installations requiring up to 60 gallons per minute, use one Sheer Descent filter. For higher water requirements, use two (2) or more filters plumbed in parallel. A separate return line, with a 3-way valve plumbed in such a way that water can be balanced between the Sheer Descent Waterfall and return back to the pool, is also required. See plumbing diagram below.

ALL Zodiac® Water Features (Sheer Descent, Laminar Jets, and Aqua Accents®) MUST HAVE FILTERED WATER.

Recommended Pump

Water Feature
Jandy Water Feature Pump (WFTR80, WFTR120, WFTR160)