East 5th Street, Sam Hughes.

Site & client

The lot is on East 5th Street between Tucson Boulevard and Campbell Avenue, in the platted center of Sam Hughes — the 1925-developed streetcar suburb that holds the densest concentration of pre-war housing in central Tucson. The 1948 brick ranch is on the third pour of slab; the original 1948 footprint was extended in 1962 and again in 1989, with mismatched grade transitions at each addition. The owners are an architect and an emergency-medicine physician who bought the house in 2018 and contacted us in July 2022 after the kitchen flooded during a single 1.7-inch monsoon event.

Soil is the predictable Sam Hughes profile: 8 inches of fine silty topsoil over a coarse caliche-pebble layer at 18–24 inches, then a denser caliche pan around 4 feet. Drainage was poor along the south elevation where seventy years of leaf litter had built grade above the slab edge.

The site walk

September 14, 2022. Two hours, the architect on hand. We mapped the roof catchment, identified six downspouts (three on the long elevation, two on the rear, one over the kitchen), measured AC condensate dripping from the air handler at 14 gal/day at 95°F outdoor, and noted three potential basin sites: the right-of-way under an existing 4-foot mesquite (visible from the street, low political risk), the south side yard between the house and the alley fence, and a corner of the back yard that historically pooled. We took 41 photographs.

The clients had two non-negotiables: don't lose any of the existing trees and don't visibly change the front of the house. We agreed; the right-of-way basin is invisible from the front because it sits in the curb cutout that already existed for street drainage.

What we built

The build ran four crew-days plus one half-day for commissioning. The major elements:

• EARTH-1 · three basins. Right-of-way curb cut feeding a 50-ft³ basin under the existing mesquite (now 18 feet tall, full canopy). Two side-yard basins receiving the rear downspouts after their first flush.
• CIS-1 · 3,000-gal Bushman SLI3000 mocha tucked between the south wall and the alley fence, fed by the two long-elevation downspouts via a Wisy WFF-150 first-flush filter. Pump is a Grundfos SCALA1, controller a Hunter X-Core 4-zone with Solar Sync.
• GWY-1 · branched-drain laundry to four basins. Brass three-way diverter at the standpipe behind the washer, 1″ HDPE distribution to four citrus and one mesquite under the alley fence. Owner switched to Oasis Biocompatible detergent at install.
• COND-1 · AC condensate to existing pomegranate. 1/2″ PEX from the air handler under the slab to a basin at the foundation of an established pomegranate twelve feet from the house.
• FNDN-1 · south-elevation re-grade. Hand-dig and re-grade six linear feet of slab edge, replacing piled-up leaf litter with screened decomposed granite at proper slope.

By the numbers · 2022-09 to 2026-04

The cistern's tipping-bucket rain gauge has logged 47 distinct rainfall events since install. Total roof catchment delivered to the cistern is 158,400 gallons; total supplied to drip irrigation from the cistern is 132,800 gallons (the 25,600 difference is largely overflow during the extreme TS Lorena event of Sep 2025, plus an inflow leak we repaired in May 2024). The basins captured a separate 71,200 gallons we did not measure directly. Branched-drain greywater contributed an estimated 38,400 gallons over 43 months (≈ 893 gal/month). AC condensate measured at the meter contributes 1,200–1,800 gal/year.

Follow-ups & service calls

Annual maintenance walks May 2023, May 2024, and May 2025. Findings:

• 2023-05. First-flush filter mesh replaced (clogged with ash from a March prescribed burn at Tucson Mountain Park). Cost: $24, no labor.
• 2024-05. Discovered a slow leak at the tank-to-pump union (UV-degraded gasket on a non-original fitting we'd installed before realizing the spec mismatch). Replaced gasket. Cost: $32 in materials, 1 hour.
• 2024-09. After TS Lorena, basin under the mesquite had filled with road sediment (4 inches deep). Crew of three cleared it in two hours. Cost: included in callback warranty.
• 2025-05. Pump bearings noisier than spec. Replaced under Grundfos warranty (no charge).
• 2026-04. Greywater outlet to citrus #2 had backed up — root intrusion into the 1″ HDPE line. Cleared and repositioned the outlet 18 inches farther from the trunk. Cost: $48, 1.5 hours.