How Phoenix funded and built a water-recycling splash pad at Encanto Park in a drought-state climate
A composite case study of a recirculating, UV-treated, evaporation-managed splash pad in metro Phoenix — water-budget math, climate-resilient design, and parks-department politics in a Colorado River basin city.
Summary
Phoenix replaced an aging flow-through splash pad with a $1.4M recirculating, UV-treated, evaporation-managed design at Encanto Park, cutting annual potable-water consumption by roughly 84% versus the legacy pad. First-summer use logged about 105,000 visits across a 240-day operating season, the project survived a contested council debate over drought optics, and the design now anchors the city's 'climate-resilient parks' framework with three additional retrofits in flight.
Key metrics
Background: a flow-through pad in a Colorado River city
Encanto Park is one of metro Phoenix's signature urban parks, with deep historical resonance and heavy weekend use. The park's existing splash pad — built in 2008 — was a flow-through design, meaning it pulled potable city water, sprayed it through pad features once, and sent it to the storm-drain system. Year-on-year, the pad consumed roughly 4.6 million gallons of potable water across a March-through-October operating season. By 2022, with the Colorado River basin in continued drought stress and the city's water-conservation framework tightening, the pad had become a politically visible water-use line item. A small group of council members and environmental advocates had begun publicly questioning whether the city should operate splash pads at all during a sustained drought, while parks staff and family advocates pushed back hard, citing heat-illness mitigation, equity, and the absence of comparable cooling resources in many neighborhoods.
The water-budget conversation: not a yes-or-no question
The parks department's response was deliberately not a defense of the existing flow-through pad — staff agreed that the legacy water consumption was indefensible at the city's current drought posture. Instead, the department proposed a redesign-and-retrofit framework with three pillars. First, replace the flow-through pad with a recirculating, UV-treated, evaporation-managed design that would cut annual potable consumption by an estimated 80%+. Second, integrate the pad's mechanical building with a separate non-potable greywater pre-treatment loop that could in theory be tied into a future municipal greywater system. Third, publish quarterly water-use transparency reports that gave council members and advocates the data needed to confirm the savings actually materialized. The reframed conversation moved the council debate from 'should we have splash pads' to 'how should our splash pads work,' which was a meaningfully more solvable question.
Design choices: recirculation, UV, and evaporation management
The design firm — selected for prior arid-climate aquatic experience — proposed a 5,200-square-foot recirculating pad with three engineering layers stacked specifically for water efficiency. First, a closed-loop recirculation system with a 22,000-gallon reservoir, sand-and-DE filtration, and a 250-mJ UV treatment skid sized for high-bather-load conditions. Second, an evaporation-management overlay including partial pad shade structures over roughly 35% of the surface footprint, scheduled feature operation that throttles spray volume during peak heat hours, and a covered nighttime reservoir that prevents the largest single source of evaporative loss. Third, a feature-selection palette weighted toward low-spray, high-engagement features — bubblers and ground sprays use dramatically less water than tipping buckets and high-arc cannons, so the design intentionally limited high-volume features and over-supplied gentle features. Initial water-budget modeling estimated annual potable consumption at roughly 720,000 gallons across the operating season — an 84% reduction from the legacy flow-through pad.
Construction timeline and the council-vote moment
Council approved the $1.4M capital line in November 2022 by a 6–3 vote, with the dissenting members preferring no splash pad at all rather than a more efficient one. Procurement and design ran December 2022 through April 2023, demolition of the legacy pad ran May–June, mechanical-building construction ran July–October, feature installation ran November–January 2024, and commissioning and water-quality verification ran February. The pad opened on March 15, 2024 — slightly ahead of the early-spring Phoenix swim-season demand peak. The council vote moment was politically delicate; the parks department brought a published water-budget model with sensitivity analysis to the council hearing, and the modeling work plus the quarterly transparency commitment was widely credited with moving two undecided council members into the yes column.
Opening reception and the water-bill receipt
Opening weekend drew strong neighborhood and citywide attendance, with roughly 6,200 visits across the first three days. The political payoff came in the first quarterly water-use transparency report, published in June 2024: across the March–May operating window, the pad had consumed approximately 187,000 gallons of potable water versus the legacy flow-through pad's same-period consumption of roughly 1.1 million gallons. The 83% reduction was within one percentage point of the design model, and the published data effectively closed the political debate. The transparency report became a quarterly staple in council parks-committee meetings and was picked up by regional press as a positive example of climate-resilient parks design. The pad's first-summer attendance ran approximately 105,000 visits across a 240-day operating season, averaging roughly 440 visits per day.
Operating costs in an arid-climate recirculation regime
Year-one operating costs settled at approximately $96,000, broken down as $14,000 water and sewer (the dramatic potable-consumption reduction is the headline savings, although evaporation-makeup water remains a meaningful line), $13,000 chemistry (UV reduces but does not eliminate chlorine and pH-adjuster needs, and arid-climate evaporation drives concentration creep that requires more frequent partial drain-and-refill), $22,000 electricity (continuous filtration plus UV plus higher-than-typical pump pressures for a larger pad), $26,000 in dedicated labor (one full-time pad attendant across the long operating season, plus shared mechanical-systems maintenance technician hours), $14,000 supplies and minor repairs, and $7,000 in insurance and risk allocation. The operating-cost profile is meaningfully different from a Midwest pad — labor is the largest line item because of the long season, and electricity is high because the mechanical systems run 240 days a year. The water-bill savings versus the legacy pad — approximately $48,000 per year — partially offset the higher recirculation operating costs.
Climate resilience and the future-greywater hook
The Encanto Park retrofit also included a forward-looking climate-resilience design choice: the mechanical building was sized and plumbed to accept a future non-potable greywater feed if the city ever rolls out municipal greywater infrastructure to the surrounding district. The hook adds roughly $40,000 to the construction cost but preserves the option to cut potable water consumption another 60–70% on top of the recirculation savings, without requiring a future mechanical-building rebuild. The design also includes a dedicated water-quality monitoring telemetry stack with continuous chlorine, pH, ORP, and turbidity readings published in real time on a public-facing dashboard, which has become a popular education tool for school field trips and an unexpected source of community engagement.
Lessons learned and the climate-resilient parks framework
Three lessons defined the Encanto Park project. First, in a drought-state political environment, the parks department's defensible posture is engineering credibility, not advocacy — bringing a water-budget model with sensitivity analysis to the council hearing was more persuasive than any number of community comment cards. Second, the recirculation-vs-flow-through decision is unambiguous in arid climates — flow-through pads are no longer politically viable in Colorado River basin cities and any new pad must be recirculating from day one. Third, the future-greywater hook is cheap insurance — adding $40,000 to construction to preserve a future option that could cut another 60% of potable consumption is the kind of forward-leaning design choice that moves the city's climate-resilient parks framework from rhetoric to specifics.
Replicability for other drought-state cities
The Encanto Park playbook is highly replicable for cities across the Colorado River basin and broader arid Southwest. The single biggest replicability filter is the existence of an aging flow-through pad inventory — many drought-state cities have one or two legacy pads in the same political position as the original Encanto Park pad, and the retrofit framework moves the political conversation from 'should we have pads' to 'how should our pads work.' The second filter is council water-conservation appetite — cities with weak water-conservation political will may not approve the higher capital cost of a recirculating pad, even though the water savings clearly justify the spend on a 15-year life-cycle basis. The third filter is mechanical-systems labor availability — recirculating pads require more sophisticated mechanical-systems maintenance than flow-through pads, and cities without internal expertise need to build a contracted maintenance relationship before opening day, not after.
Voices from the project
“We stopped trying to defend the old pad and started designing the next one. That reframe moved the whole council conversation.”
“The quarterly water-use report did more for community trust than any press release we put out. Show the receipt.”
“Adding the greywater hook now is the cheapest fifty thousand dollars we'll spend on this pad in the next twenty years.”
Lessons learned
- Reframe drought-state pad debates from 'should we have pads' to 'how should our pads work.'
- Bring a published water-budget model with sensitivity analysis to the approving council hearing.
- Commit to quarterly water-use transparency reports as part of the project approval.
- Recirculating + UV + evaporation management can cut potable consumption by 80%+ versus flow-through.
- Add a future-greywater plumbing hook during construction; it's cheap insurance.
- Weight the feature palette toward bubblers and ground sprays over high-volume buckets and cannons.
- Build the contracted mechanical-systems maintenance relationship before opening day, not after.
FAQ
How much water does a recirculating splash pad use?
A well-designed recirculating pad in an arid climate typically uses 600,000–900,000 gallons of potable water per season for evaporative makeup and periodic partial refills — roughly 80–90% less than a comparable flow-through design.
Are splash pads appropriate during a drought?
Recirculating splash pads consume far less water per visit than most outdoor home water uses (lawns, pools, washing) and can be defensible during drought when paired with engineering and transparency. Flow-through pads are not defensible in modern drought conditions.
What is the typical capital premium for a recirculating versus flow-through pad?
Recirculating designs typically add $250,000–$450,000 to construction cost for the mechanical building, filtration, UV treatment, and reservoir. The water-bill savings usually pay back the premium in 8–12 years, faster in high-water-cost cities.
Related reports & data
Pair this case study with our original-data reports for citation and benchmarking.