An infinity pool, also called a vanishing-edge pool, has one or more edges set right at water level. Water spills over that edge into a hidden catch basin below, and a pump sends it back up. From the house or patio, the water seems to run straight into the view. In Tucson, they work best on hillside and view lots in places like the Catalina Foothills, Oro Valley, Dove Mountain and Tanque Verde. They take more engineering, more pumping and more water than a standard pool, so it pays to know the trade-offs before you commit.
Here is how they work, what makes a lot a good fit, and when a simpler feature gives you a similar look.
How does an infinity pool work?
A vanishing-edge pool has three main parts:
- The weir wall. This is the edge the water flows over. Its top has to be set very level, because even a small dip changes how evenly the water spills.
- The catch basin. A trough or small pool below the edge collects the water. It has to hold enough water to cover what is flowing over the edge, what swimmers push out, and what the pool loses between top-offs.
- The return system. A pump pulls water from the catch basin, sends it through the filter, and returns it to the main pool so it can flow over the edge again.
When the edge is off, the pool behaves like a normal pool. When it is on, water moves constantly from the pool to the basin and back. That constant movement is what creates the look, and it is also where the extra cost and upkeep come from.
Which Tucson lots are good for an infinity pool?
The vanishing-edge effect depends on what lies beyond the edge. It works best when:
- The land drops away past the pool, so you look out over the slope instead of at a wall.
- There is a view to borrow, like the Santa Catalina, Tortolita, Rincon or Tucson Mountains, city lights, or open desert.
- The main viewing spot is set up right. The illusion works from certain angles, usually from the house or a main patio. We plan sight lines so the edge lines up with the view from where you will actually sit.
That is why vanishing edges show up most often on hillside lots. If you live in one of these areas, our local pages have more on building there:
- Catalina Foothills, with steep lots and wide city and mountain views
- Oro Valley, with views of Pusch Ridge and the Catalinas
- Dove Mountain, on the slopes of the Tortolitas
- Tanque Verde, on the east side near the Rincons
On a flat lot with a block wall, a vanishing edge usually just looks into the wall. In that case, other features often look better and cost less.
One of our infinity-edge pools in the Oro Valley area: the water spills over the curved edge into a catch basin below, and dark tile finishes the edge wall.
What engineering goes into a vanishing-edge pool?
An infinity pool on a slope is a bigger structural job than a pool on flat ground. Part of the pool may sit on fill or hang out over the slope, and the weir wall and catch basin are often well below deck level.
Things we plan for:
- Soils and slope. Steep lots in the foothills can have rock, caliche or fill. The shell has to be designed for what is under it. Our post on building a pool in caliche covers how rock affects a dig.
- Structural design. The shell, weir wall and catch basin are engineered as one structure, and the plans go into the permit. Concrete (gunite or shotcrete) is well suited to this kind of custom shape.
- Access. Hillside lots can be hard to reach with equipment. We own our excavation equipment, which helps us plan the dig around tight or steep access.
- Local rules. In unincorporated Pima County, which includes much of the Catalina Foothills, the county’s Hillside Development Overlay Zone can apply to parcels with slopes of 15 percent or more. Dove Mountain is in the Town of Marana and Oro Valley has its own town rules. We handle permits with the right agency for your address.
- Safety barrier. A pool on a slope still needs a proper barrier, and the drop on the low side changes how it is laid out. See our pool barrier guide.
How much more does an infinity pool cost to run?
There are no exact numbers that fit every pool, but the extra costs come from the same few places.
| Running cost | Why it’s higher with a vanishing edge |
|---|---|
| Electricity | A pump has to move water up from the catch basin whenever the edge is flowing |
| Water | Falling water and wind on an exposed hill add to evaporation and splash-out |
| Chemicals | More moving water and surface area can burn off chlorine faster |
| Cleaning | The catch basin collects leaves and dust and needs regular cleaning |
| Scale | Tucson’s hard water can leave white mineral lines on the weir wall |
On evaporation: the EPA’s WaterSense guide says the turbulence from water features increases evaporation and can lose water to wind and splashing. It also recommends windbreaks to cut evaporation. On a breezy ridge, that matters. A cover helps when the pool is not in use, but a cover does not stop water moving through the catch basin while the edge is running.
How we keep running costs in check:
- Pentair variable-speed pumps sized for the edge flow.
- Automation, so the edge runs when you are home and enjoying it.
- Careful weir design, so the edge flows evenly at a lower flow rate.
- Tile or a durable finish on the weir face, which is easier to clean than plaster.
For a bigger picture of yearly costs, see our post on what it costs to run a pool in Tucson.
When does a sheer descent or spillover make more sense?
A vanishing edge is not the only way to get the look of moving water. On many lots, especially flat ones, these features give you much of the same feel with less complexity:
| Feature | How it works | Good for |
|---|---|---|
| Vanishing edge | Pool edge at water level spills into a hidden basin | Hillside lots with a real view |
| Sheer descent | Thin sheet of water falls from a raised wall into the pool | Flat lots, modern designs, privacy walls |
| Spillover spa | Raised spa overflows into the pool | Pool and spa combos |
| Scuppers | Water pours from openings in a raised wall | Classic or rustic looks |
These features return water straight into the main pool, so there is no separate catch basin to build, fill or clean. They still add evaporation when they run, so put them on a schedule. Our pool water features guide goes deeper on each.
The same pool as a shotcrete shell: you can see the curved vanishing edge, the catch basin beside it and the raised spa.
How do we design an infinity pool at Meraki Pools AZ?
Every vanishing-edge pool is custom, so the process starts with your lot.
- Site visit. We look at the slope, the view, access and where the water and power will come from.
- 3D and VR design. You see the pool on your lot and can walk it in VR, including the view over the edge from your patio. We use this to fine-tune where the edge goes. See how our design process works.
- Engineering and permits. The shell, weir and catch basin are designed together, and we handle the permit.
- Build. Our in-house crew digs with our own equipment and builds the shell, weir, tile and finish.
- Startup. We set up the pumps and automation so the edge runs the way you want.
Most new custom pools we build run about $40,000 to $120,000 or more. A vanishing edge, a hillside site and the extra engineering usually put a project toward the higher end. Our pool cost guide explains the main cost drivers.
Tiling the vanishing-edge wall. This face is visible from the yard, so the tile and its joints need to be perfect.
Planning a high-end backyard? See what goes into our luxury custom pools in Tucson.
Have a view worth building around?
We are a family-owned Tucson builder of concrete pools and spas, licensed under AZ ROC #342505 and #352797. Whether a vanishing edge or a sheer descent is the better fit, we will show you both in 3D before you decide. Learn more about our custom pool construction, then contact us or call (520) 342-8335.
Sources
- U.S. EPA WaterSense: Jump Into Pool Water Efficiency (PDF)
- Pima County GIS: Hillside Development Overlay Zone layer (Pima County Code Chapter 18.61)
- City of Tucson: Hard Water
Put this guide to work
Planning your own project? See our Luxury Custom Pools in Tucson and Custom Pool Construction in Tucson, or read about building a pool in Marana.
Frequently asked questions
What is the difference between an infinity pool and a vanishing-edge pool?
They are the same thing. Infinity, vanishing-edge and negative-edge all describe a pool where one or more edges sit at water level, so water spills over into a hidden catch basin below. From the right angle, the water seems to meet the view.
Do you need a hillside lot for an infinity pool?
Not strictly, but the effect works best when the land drops away beyond the edge and there is a view to borrow. On a flat lot, the edge often just looks into a fence or wall, which loses most of the effect.
Do infinity pools use more water in Tucson?
Usually, yes. Water falling over the edge and moving through the catch basin adds surface turbulence, and the EPA notes that features like that increase evaporation. Exposed hillside lots also tend to get more wind, which carries water off the edge.
Do infinity pools cost more to run?
Yes. A pump has to lift water from the catch basin back to the pool whenever the edge is flowing. With a variable-speed pump and automation, you can run the edge when you are enjoying it and keep it slower or off at other times.
What is a cheaper alternative to an infinity pool?
A raised wall with sheer descents, a spillover spa or scuppers gives you moving water and a high-end look without a catch basin or the same structural work. On a flat or modest lot, these often make more sense.
Do infinity pools need special permits around Tucson?
They go through the same pool permit process as any pool, but the plans include more engineering. Steep lots can also bring extra rules. In unincorporated Pima County, for example, the county's Hillside Development Overlay Zone can apply to slopes of 15 percent or more.
