Pool water features: sheer descents, bubblers and waterfalls

Anything that moves water above the surface for the look or the sound of it. On the pools we build around Northeast Ohio, four types cover almost every request.

• Sheer descents. A slot fixture set into a raised wall or seat wall that lets a clean sheet of water drop into the pool. Sheer Descent is Jandy's product name, and the trade uses it loosely for any sheet waterfall.
• Bubblers. Small fittings in the floor of a tanning ledge or step that push a short dome of water up through the surface.
• Deck jets and laminars. Nozzles set in the deck that throw an arc of water into the pool. Laminar jets make a glassy, rod-like stream that can carry light at night.
• Waterfalls and cascades. Stone or boulder falls, or the preformed cascades that fiberglass manufacturers offer to sit behind the shell.

Spillover spas are a water feature too, but they come with a heater, a second body of water and their own set of choices. We cover them in a separate guide.

A sheer descent is a long, shallow box with a lip on the front. Water comes into the back of the box from a return line, spreads out, and spills over the lip as a flat sheet. Jandy makes them in lengths from 8 inches to 8 feet, and the sheet can be set up to fall close to the wall or to throw farther out.

The flow number is what drives the rest of the design. Jandy's technical sheet gives a rule of thumb of about 10 gallons per minute per foot of waterfall. A 4 ft unit needs around 40 gallons per minute, and two 6 ft units side by side need about 120. The same sheet says that in most cases a properly sized pool pump can run the waterfall and still filter the pool, but it recommends a separate pump once you have more than one fall or a single unit 6 ft or longer.

Height matters as well. The sheet of water narrows as it drops, and a fall set too high breaks up into streams instead of staying glassy. The manufacturer publishes a recommended height for each length, and we build the raised wall to hit it.

On a fiberglass pool, the sheer descent sits in a raised wall or bond beam built behind the shell on its own footing. The shell does not carry the wall. On an ICF concrete pool, the wall can rise straight out of the pool structure. Jandy also makes arc-style units that mount just above the waterline without a raised wall, which suits vinyl liner pools.

For most families, yes, and they are the cheapest way to get moving water. Liberty Composites, which makes the fiberglass shells we install, says bubblers are available on all of its fiberglass pool models, tanning ledges and fountain pans, and that they need very little water to run.

Bubblers belong on a tanning ledge or a wide entry step, where the water is shallow enough that the dome breaks the surface. Kids love sitting on them. Adults tend to like the sound more than they expected. A pair on a ledge is common, and some people put a third on the top step.

Two things to decide early. First, bubbler height changes with water level and flow, so we put them on their own valve or circuit to turn them up, down or off. Second, a bubbler sitting under a lounge chair on the ledge is annoying, so we lay out the ledge furniture in the 3D design before we place the fittings.

Deck jets are set into the concrete around the pool and shoot an arc of water into it. The better ones sit nearly flush, so the stream seems to come straight out of the patio. Pentair's MagicStream laminars go one step further: a clear, uniform arc that an LED lights up at night, adjustable left and right up to 60 degrees in total.

Jets need to be placed with the deck layout in mind. They sit in the walking area, so we keep them out of the main path from the house and away from where chairs will go. They also need to land in water deep enough that nobody is standing where the stream comes down, which usually means aiming them at the deep end or the middle of the pool.

A natural stone waterfall can look great on a sloped lot, and a lot of Northeast Ohio yards slope. Where the grade already rises behind the pool, as it does on many lots around Hudson, Aurora and Chagrin Falls, the fall can sit into the hill instead of looking like a pile of rocks dropped on a flat lawn.

We are careful with these for two reasons. Stone falls are built on the ground behind the pool, so they need a proper base below frost depth and good drainage, or freeze-thaw will shift the rocks over a few winters. And a big fall moves a lot of water, which usually means its own pump. If you want a waterfall, tell us early so we can plan the grading and the footing as part of the dig, not as a patch-on after the deck is poured.

If you like the idea but not the size, the preformed cascades that Liberty sells for its fiberglass pools are a tidier option. They give you the sound of falling water without a stone mountain in the yard.

Moving water loses heat. The U.S. Department of Energy says evaporation is by far the largest source of energy loss from a pool, and evaporation rises with water temperature, wind and low humidity. A sheet of water falling through the air, or spray from a deck jet, gives that water more contact with the air. If you heat the pool in May or September, run the features when you are out there to enjoy them and turn them off the rest of the time.

Aeration also pushes pH upward. AQUA Magazine explains that pool water carries more carbon dioxide than it would at balance with the air, and as moving water lets that carbon dioxide escape, pH rises while total alkalinity stays the same. A pool with a big waterfall running all day will usually need a little more acid through the week than the same pool without it. It is not a reason to skip a feature, just something to expect when you test.

A feature that runs all day costs electricity too. Our packages include a Pentair variable-speed pump, and when a feature shares that pump, the pump has to run faster while the feature is on. Automation makes this easy: the feature runs on a schedule or at the tap of an app, and the pump drops back to its low filtration speed afterward.

Every feature adds a pipe that holds water, and water left in a pipe over a Northeast Ohio winter will freeze and crack it. That is the main local difference between putting a waterfall in Ohio and putting one in Florida.

At closing, every feature line gets blown out with air and plugged, just like the returns and skimmer lines. Sheer descents have a lip that should be protected, and deck jet and laminar nozzles either come out or get sealed. Stone waterfalls need their basin drained if they have one. Our closing service handles this. It also helps to have every feature line labeled at the equipment pad, so whoever closes the pool knows which valve serves what.

Snowbelt owners in Geauga, Lake and northern Portage counties should think about the raised wall as well. A seat wall with a sheer descent sits in the middle of the snow load and gets hit by freeze-thaw on both faces. Those walls need a stone or concrete cap that sheds water, and no feature fixture should be left open where snowmelt can sit in it.

Water features are a design decision, not an accessory. They touch the plumbing, the pump, the equipment pad, the deck and sometimes the retaining walls, and they are far cheaper to include before we dig than to add once the concrete is poured.

1. Decide what you want to hear and see. A quiet sheet over a seat wall, kids on bubblers, or a loud rock fall are three different builds.
2. See it in 3D. We model the feature in the same 3D design as the pool, so you can check the view from the kitchen window and the patio before anything is built.
3. Size the flow. We add up the gallons per minute and decide whether the package pump handles it or the feature needs its own.
4. Plumb and wire it. Separate lines, valves and circuits go in during the build, with automation if you want app control.
5. Build the structure. Raised walls and stone falls get their own footing and drainage.

If you are not sure yet, we can stub in a line to a future wall location during the build. It costs a little now and saves cutting the deck later.