Why would a pond project stall because it rained too much? Anyone who has walked past the construction fencing north of Vistoso Highlands Drive this fall has seen it happen. The answer says a good deal about what is being built in the middle of the preserve. It is not the old golf-course water hazard brought back. It is an engineered, sealed, sensor-monitored part of Oro Valley's reclaimed-water system, and that design shapes both the construction schedule and how the finished pond will behave.
What Is Behind the Fence Right Now
Contractor KE&G started on Aug. 10, 2026, according to the Town of Oro Valley's pond project page. The first weeks were demolition. Crews pulled out the old bulkhead, broke up the concrete walls and the old liner, and dug out the bottom of the basin. September was grading and compaction, plus the "penetrations," the openings where pipes will pass through the liner. Late in the month, trees around the pond's edge came out and aeration sleeving went in.
The Town's Oct. 7 update said the pump skid had arrived, with the wet well expected the following week. The wet well has its own story. It was built ahead of schedule in September, and the plan was to install it before the liner. So the order on site is fixed. The pumping hardware goes in first, and the waterproof skin follows.
Why Rain Keeps Winning
The rain delays follow from that order. The liner cannot go down until the subgrade is dry, compacted and inspected. After the heavy rains in early October, crews had to pump standing water out of the basin, then use equipment to spread the mud so the site would dry more evenly. The liner consultant's inspection is waiting on dry ground.
The weekly log shows how often that has happened since summer:
- Week of Aug. 19: grading resumes "after last week's rain delays."
- Week of Sept. 2: work "began with a rain delay."
- Week of Sept. 30: recent rain causes "a brief delay while crews allow the ground to dry."
- Week of Oct. 7: heavy rains force pumping and mud-spreading before grading can continue.
The rest of the preserve has felt the same storms. The Town's general preserve page reports staff clearing trail debris after heavy rains in October, and major pruning on a large storm-damaged tree in September.
A Pond Built to Stay Sealed
The liner gets this much care because it does two jobs. The design calls for a reinforced linear low-density polyethylene liner between layers of geotextile, with every pipe sealed where it passes through using specialized boots. Tucson Local Media reported that the product is a Titan R45 polyethylene geomembrane. In the same article, Town Manager Jeff Wilkins said the liner will hold water in and also "basically acts as a cap" on the soil underneath. That report also says KE&G has a "no-discharge" permit from the Arizona Department of Environmental Quality, and that as of Aug. 6, the Town was awaiting results of analyses by environmental consulting contractor Ninyo & Moore.
The Town's project page describes the rest of the system:
- Water source: reclaimed water from an existing connection, run through an enclosed pumping setup with a wet well, intake screening, and a skid-mounted pump with filtration and controls.
- Circulation: recirculation keeps the water moving, and diffusers on the bottom of the pond add air from equipment inside the enclosure.
- Storm handling: an overflow structure sealed to the liner sends excess water into an adjacent wash.
- Landscape: drip irrigation for trees, shrubs and planting beds, plus sprinklers for future turf areas, all drawing on the pond. A flow sensor and master valve can shut the system down if a mainline breaks.
Filling Slowly, Sharing the Supply
Filling the pond will take a while, and that is by design. The first water will go in slowly until it covers the discharge point, which sits on a reinforced pad set with cobbles so the inflow does not scour the liner. Only then will the flow pick up. A water-level sensor will track the pond and time its filling around other reclaimed-water demands across town so the system is not overloaded.
As for size, Oro Valley Water Utility Director Peter Abraham told Tucson Local Media that the finished pond can hold up to 6.2 million gallons of reclaimed water, worth about $15,000, with electricity for the recirculating pumps as an added cost. That works out to a million gallons for every mile of the preserve's 6.2-mile concrete path.
How the Basin Got Here
The pond's history explains why it is being rebuilt so carefully. The golf course opened in 1995 and closed in June 2018. Preserve Vistoso, a community nonprofit, formed in February 2019, and the group says neighbors raised $1.8 million toward saving the land. The Conservation Fund bought 202 acres on Feb. 16, 2022, and donated them to Oro Valley under a conservation easement on July 8, 2022, according to Preserve Vistoso's background page. The Arizona Daily Star covered the Town's ribbon cutting on July 15, 2022.
After that, the 2.5-acre basin sat empty, and Town Council changed its mind about it more than once:
| Date | Council action |
|---|---|
| April 17, 2024 | Unanimous vote to turn the basin into a "Desert Garden" node: remove the bulkheads, fill and reshape the basin |
| Sept. 18, 2024 | Keeps the desert garden concept in a restoration plan |
| Dec. 4, 2024 | Directs staff to add a pond concept and cost estimate to the Kimley-Horn contract |
| April 16, 2025 | Votes 4–2 to restore the pond with reclaimed water, in phases |
| April 8, 2026 | Votes 6–1 to add $461,399, bringing the project total to $2,033,939 |
The $2,033,939 figure covers the pond and memorial garden plus an add-on for a parking lot and an ADA connection to the existing path. Tucson Local Media's August story gave a $1.88 million figure, which probably reflects a narrower scope.
Not everyone supports the decision. Archaeology Southwest, which oversees the preserve's conservation easement, has stayed critical. In Tucson Local Media's coverage, vice president John Welch called it "an expensive and unnecessary project." In the same report, Wilkins noted that the easement allows a pond to be restored on the site and said, "We're trying to do it the best way, to build it to a technology that's best for the community, given that it's going to be a pond."
What the Center of the Preserve Gains
Along with the water, the project adds an 8-foot concrete trail around the pond and a small parking lot. A grant announced in September 2025 helps pay for path repairs, safety signage and an ADA-compliant loop around the pond. The Town says it wants the pond area to become a gathering place that works year-round for visitors of all ages and abilities.
KE&G is also building the Adam Zimerman Memorial Garden near the pond. Tucson Local Media reported that the garden is funded by a donation to the Town, with $50,000 set aside for it and the rest of the gift going to improvements elsewhere in the preserve.
The Town has not announced an opening date. Tucson Local Media reported that the contract was awarded May 12 with a one-year completion deadline. With the liner still waiting on dry ground in October, the finished pond is reasonably expected sometime in 2027, not this winter.
Walking the Preserve This Fall
Most of the preserve is open as usual. It is open dawn to dusk, with temporary parking at 945 W. Vistoso Highlands Drive and views of the Catalina and Tortolita mountains from the 6.2-mile path. The Town's park rules require pets to be leashed and under control, and they bar motorized vehicles other than accessibility and official vehicles.
The trails right around the worksite will stay closed for the whole project. Detour signs are posted, and the current route is on the map on the pond project page. It is worth checking before a long loop.
The next scheduled group outing is a Tucson Bird Alliance walk with Gerry Hodge on Monday, Nov. 23, at 8 a.m. The Tucson Bird Alliance listing describes an easy 1.25-mile route on flat pavement lasting about two and a half hours, meeting at the large lot off Vistoso Highlands Drive. It is free for members and $5 for nonmembers. By then the basin may finally have its liner in, depending on the weather.
I'm Nancy Mancuso, and I enjoy following how Oro Valley takes care of the open spaces near its homes. If you live near the preserve and would like to talk about what the pond's return could mean for your corner of Rancho Vistoso, I'd be glad to hear from you. Let's Connect at Nancy Mancuso.
