In Goodyear, most new development keeps its stormwater on site. The city's Engineering Design Standards and Policies Manual (Chapter 3, 2017) sets how much, how deep, and how fast it has to drain.
The numbers
| Item | Goodyear standard |
|---|---|
| Storm to retain | 100% of the 100-year, 6-hour storm |
| Average high-water depth | No more than 3 feet |
| Within 10 feet of right-of-way | No more than 1.5 feet, unless the basin is fenced |
| Without a positive disposal method | No more than 1 foot deep and 1,000 cubic yards |
| Side slopes by public areas | 6:1 or flatter |
| Side slopes by walls or fences with limited access | Up to 4:1 |
| Time to drain | Within 36 hours |
Retained stormwater can't be discharged onto a city street, gutter or alley.
Custom lots are different
Goodyear's custom-lot grading checklist says no on-lot retention is allowed on lots under one acre. Those lots drain to the street at a minimum 1% slope instead. See custom lot grading.
Who signs off
Drainage reports are signed and sealed by a registered professional engineer, and as-built drawings by a qualified professional registered in Arizona. The excavation contractor builds to those plans.
Cost
Angi's Phoenix guide lists grading and leveling at $415 to $6,720, leveling at $5 to $15 per cubic yard and machine time at $105 to $260 an hour. Engineering, drywells and landscaping are extra.
Sources
- City of Goodyear: Engineering Design Standards and Policies Manual, Chapter 3, Stormwater Management (2017)
- City of Goodyear: Grading & Drainage, Custom Lots review checklist (revised July 23, 2018)
- Angi: Excavation costs in Phoenix, AZ (updated June 16, 2026)
Reviewed October 20, 2026. Rules, prices and contacts change, so check the source before relying on it.
Questions and answers
What storm does a Goodyear retention basin have to hold?
Goodyear's stormwater manual calls for on-site retention sufficient to hold 100% of the 100-year, 6-hour storm.
How fast must a retention basin drain in Goodyear?
The manual says retained or detained stormwater must be disposed of within 36 hours.
Get your basin quoted
Send the details or call, and a local excavation contractor will follow up with you. Quote requests are free.
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