Union City, CA Landscaping Rules: Water Restrictions (2026)
Water restrictions in Union City, CA, also called the watering schedule, outdoor irrigation rules, or drought ordinance, set which days and hours you can run sprinklers or irrigation.
Key Facts
- Watering window
- 8:00 p.m.–10:00 a.m.
- Governing section
- UCMC § 18.112.110
- Stricter rule controls
- City or ACWD hours
- Maintenance exception
- auditing/repair allowed anytime
Summary
Covered new and rehabilitated landscapes in Union City must run overhead sprinklers only between 8 p.m. and 10 a.m., with the stricter of the City's or Alameda County Water District's hours controlling.
Overhead irrigation shall be scheduled between 8:00 p.m. and 10:00 a.m. unless weather conditions prevent it. If allowable hours of irrigation differ from those stipulated by the Alameda County Water District, the stricter of the two shall apply. Operation of the irrigation system outside the normal watering window is allowed for auditing and system maintenance.
3. For implementation of the irrigation schedule, particular attention must be paid to irrigation run times, emission device, flow rate, and current reference evapotranspiration, so that applied water meets the estimated total water use. Total annual applied water shall be less than or equal to maximum applied water allowance (MAWA). Actual irrigation schedules shall be regulated by automatic irrigation controllers using current reference evapotranspiration data (e.g., CIMIS) or soil moisture sensor data.
4. Parameters used to set the automatic controller shall be developed and submitted for each of the following:
a. The plant establishment period;
b. The established landscape; and
c. Temporarily irrigated areas.
5. Each irrigation schedule shall consider for each station all of the following that apply:
a. Irrigation interval (days between irrigation);
b. Irrigation run times (hours or minutes per irrigation event to avoid runoff);
c. Number of cycle starts required for each irrigation event to avoid runoff;
d. Amount of applied water scheduled to be applied on a monthly basis;
e.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4940544; v16 updated 2026-06-23).
Full Breakdown
Section 18.112.110 sets irrigation-scheduling rules for landscape projects covered by Chapter 18.112 (new construction of 500+ square feet, rehabilitated landscapes of 2,500+ square feet). Overhead spray irrigation is confined to an 8:00 p.m.-to-10:00 a.m. watering window unless weather prevents it, automatic controllers must regulate scheduling, and if the local water purveyor, Alameda County Water District, sets different allowable hours, whichever schedule is stricter applies. Running the system outside the window for auditing or maintenance is allowed.
Violations & Fines
Scheduling overhead irrigation outside the 8 p.m.-to-10 a.m. window on a covered project violates Chapter 18.112 and can block certificate-of-completion sign-off or draw code enforcement action.
Frequently Asked Questions
Does this apply to drip irrigation?
Who enforces the watering window?
Sources & Official References
Other rules in Union City
How Union City compares: Cities with the Strictest Water Restrictions·California rules heatmap·Compare Union City to another location·View the California landscaping rules overview
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Water Restrictions in Nearby Cities
How other cities in Alameda County handle water restrictions.