Calle del Norte, Catalina Foothills.

Site & client

The lot is on Calle del Norte in the Catalina Foothills, half a mile west of Sabino Canyon Road and three minutes drive to the trailhead at Sabino Canyon Recreation Area. 0.6 acres on a north-facing 5% slope; soil is the bajada profile (gravelly sandy loam over decomposed granite, with a 12-foot-deep caliche fragment layer). The clients are a retired hydrologist (formerly with the USGS Arizona Water Science Center) and a museum curator. They contacted us in November 2023 with the explicit goal of "putting our roof's water on our trees and not on the city's storm sewer."

The site walk

December 7, 2023. Three hours, both clients on hand, hydrologist with a topographic map. We mapped 4,180 sf of contiguous roof catchment with eight downspouts, three of them at the high end of the slope (rear of house) and five at the low end (front, facing the wash). AC handler in a mechanical closet on the north elevation, dripping at 21 gal/day measured. Two existing 35-foot mesquites on the lot showed obvious water stress (drought of 2020–2022). Foundation drainage was non-functional on the rear elevation, where the original 1972 grade had been disturbed during a 2008 pool installation.

The defining constraint was the Catalina Foothills HOA, which (correctly) prohibits visible cisterns from the street. Our solution put the tank array along the north property line, behind a 6-foot coyote-fence wall the clients agreed to install as part of the project, with the tanks finished in mocha to match the existing wall paint.

What we built

The build ran nine crew-days plus two days for the coyote-fence subcontract. The major elements:

• CIS-1 · 8,400-gal linked tank array. Three Bushman SLI2800 mocha tanks linked at the bottom via 2″ PVC manifolds, fed by the rear and side downspouts via two Wisy WFF-150 first-flush filters. Suction line runs 60 feet underground in 1.5″ PEX with a small booster pump (Grundfos MQ3-45) at the foothill end to overcome static head to the upper irrigation zone.
• EARTH-1 · five basins. Two large basins under the mature mesquites at the back of the lot (each ~150 ft³), three smaller basins along the front entry walk for new ironwood and palo verde plantings.
• COND-1 · AC condensate to the front-yard mesquite. 1/2″ PEX with UV jacket from the AC closet, 35-foot run under the side-yard hardscape.
• FNDN-1 · rear-elevation re-grade and French drain. Pulled out 14 cubic yards of soil that had piled up against the slab over fifty years, installed a 4″ corrugated French drain at the rear elevation, daylighted to a sediment basin downhill of the property line.
• Telemetry. Adafruit IO dashboard reporting tank levels, pump runtimes, and individual zone valve states. The hydrologist insisted on the data and rebuilt our default dashboard within a week.

By the numbers · 2024-04 to 2026-04

The dashboard is published privately for the clients and not for us. With permission, summary numbers below.

The HOA letter

The Catalina Foothills HOA — like most Pima County HOAs — has approval clauses that predate residential rainwater harvesting being common. The clients' original architectural review committee submission was rejected in February 2024 over a generic "no above-ground tanks" clause from the 1985 covenants. We worked with them to write a four-page letter citing Arizona Revised Statutes § 33-1806.01 (which preempts HOA prohibitions on rainwater harvesting equipment that is "not visible from neighboring property or the public street"), referencing the proposed coyote-fence screening, and including drawings of the tank pad. Approved at the next ARC meeting on March 14, 2024.

We send roughly four such letters a year. The template is on the rebates & HOA page if you want to crib it.