Lawn by Season
Stage 2 + MWD Level 1 – Mandatory Conservation

Ontario Water Restrictions 2026

San Bernardino County · California

Published:

Share with your neighbors in Ontario
Sharing: “Ontario, CA water restrictions: 3 days/week. Stage 2 + MWD Level 1 – Mandatory C...”

Restrictions Active - Stage 2 + MWD Level 1 – Mandatory Conservation

3

Days/Week

Before 9:00 AM

Allowed Hours

$100 first · $250 second · $500 third+

Max Fine

Find Your Watering Day

Enter the last digit of your street address:

View full address schedule table
Address EndingWatering Day
OddMonday & Wednesday & Friday
EvenTuesday & Thursday & Saturday
Want an email when Ontario's rules change?
Reset Your Sprinkler Timer
  1. Press and hold the left arrow button for 2 seconds to enter programming mode
  2. Set current day and time first
  3. Set start time to your allowed hour (e.g. 8:00 PM)
  4. Set run time per zone (15–25 minutes for most lawns)
  5. Set watering days to your assigned day ONLY - deselect all others

Allowed Watering Hours

Before 9:00 AMAfter 6:00 PM

No sprinkler irrigation between 9:00 AM and 6:00 PM year-round. Maximum 12 minutes per spray-head zone per watering day; rotary nozzles 25 minutes. Ontario coordinates with the Inland Empire Utilities Agency (the Chino Basin wholesaler) and MWD's Level 1 framework for cross-jurisdictional consistency.

Still Allowed

💧 Hand Watering

Allowed with shut-off nozzle. Hours: Any day with a shut-off nozzle; drip and soaker hoses exempt.

🌿 Drip Irrigation

Exempt from day-of-week limits. Must follow allowed hours.

Fines & Enforcement

$100 first · $250 second · $500 third+

OMUC Water Conservation patrols neighbourhoods and responds to online complaints. First detected violation: warning. Second: $100. Third: $250. Fourth+: $500. Commercial properties (including warehousing and logistics hubs) face up to $2,000 per occurrence.

Citations begin MWD Level 1 declared March 2026

🏠 HOA Rules During Restrictions

California Water Code §10631.5 prohibits HOAs from fining residents for drought-compliant brown lawns during a declared shortage. California Civil Code §4735 prevents HOAs from penalizing homeowners who reduce irrigation under a state or local conservation order, and explicitly allows artificial turf installation notwithstanding CC&R restrictions. The MWD Level 1 declaration plus your local agency's retail stage qualify as the state-recognized triggers – document both if your HOA sends a violation letter.

If your homeowners association sends a violation notice for a dormant or brown lawn during the current restriction period, respond in writing citing the applicable law and include a copy of the current restriction order from Ontario Municipal Utilities Company. Most HOAs will rescind the notice once they are made aware of the legal protections in place. If the issue persists, contact your county’s code enforcement division for assistance.

Why These Restrictions Exist

Ontario is served by Ontario Municipal Utilities Company (OMUC), a member agency of the Metropolitan Water District of Southern California (MWD). On March 2026 MWD declared a Level 1 Water Shortage Condition for all 26 member agencies (covering roughly 19 million residents) – the first regional Level 1 since 2022. The trigger: State Water Project allocation cut to 30% for the 2026 water year, continued Colorado River shortage operating under post-2007 Interim Guidelines, and Diamond Valley Lake (MWD's largest local storage) dropping below the 65% planning threshold.

Ontario sits in the Inland Empire (San Bernardino County) and is an MWD member through the Inland Empire Utilities Agency (IEUA), the Chino Basin wholesaler. Water mix: roughly 70% local Chino Basin groundwater (managed by the Chino Basin Watermaster) and 30% imported MWD water. Ontario is the second-largest Inland Empire warehousing and logistics hub (after Riverside / Moreno Valley) – Amazon, FedEx, UPS, and dozens of e-commerce fulfillment centers operate large facilities here, with significant landscape and operational water footprints. Ontario International Airport (ONT) is a major commercial water user on its own commercial account.

MWD's Level 1 framework asks member agencies to target a 20% reduction in potable water use versus a 2020 baseline. Each retail agency translates that target into local rules – typically 2–3 days per week outdoor watering with a mid-day blackout window. California's permanent year-round baseline (no hosing hardscape, no irrigation within 48 hours of measurable rainfall, no runoff onto sidewalks, shut-off nozzle required on hoses) applies on top of MWD Level 1, regardless of conditions.

Rainfall Deficit: Inland Empire 6.0 inches below seasonal average · Chino Basin groundwater levels stable but tracking regional drought

This deficit has accumulated over the current water year and represents a significant departure from historical averages for the Ontario area. Water supply reservoirs and aquifer levels are well below seasonal targets, necessitating mandatory conservation measures.

How to Keep Your Lawn Alive During Ontario Water Restrictions

15 tips tailored for Ontario homeowners during Stage 2 + MWD Level 1 – Mandatory Conservation restrictions.

Ontario's inland summers (regularly 100–105°F July–September) make warm-season Bermuda the only Stage-2-friendly lawn grass.

Chino Basin clay sheds water in under 90 seconds – cycle-and-soak (3 min on, 20 pause, 3 min on) is essential.

Stack the IEUA $3/sq ft and SoCal Water$mart $3/sq ft turf rebates – most front-yard removals net $4–$5/sq ft total after combined rebates.

Logistics-hub landscape strips (warehouse perimeters, parking-lot islands) are high-water-loss zones – convert to drip-irrigated California-Friendly under the IEUA commercial program (up to 25,000 sq ft per parcel).

Programme your controller now for Ontario's assigned 2-day-per-week schedule (see the watering days finder above) and respect the mid-day blackout – automatic enforcement runs from smart-meter data plus neighbourhood patrols.

Bermuda is the most MWD-Level-1-friendly grass for SoCal lawns – set mower height to 1.5 inches and let summer dormancy set in rather than fight the schedule.

St. Augustine and tall fescue both brown noticeably under 2 days/week. Cut ¾ inch maximum on assigned days, raise mowing height to 3.5–4 inches, and hand-water mature trees with a shut-off nozzle on off-days.

Apply cycle-and-soak on slopes and clay soils: 3 minutes on, 20-minute pause, 3 minutes – SoCal clay sheds continuous spray inside 90 seconds.

Mulch ornamental beds 3 inches deep with arborist wood chips. Bare soil in inland SoCal loses 0.5 inch of moisture per day in May–September.

Replace overhead spray heads on narrow strips with subsurface drip – drip is exempt from day-of-week limits and uses 30–50% less water.

Fix broken or misaligned sprinkler heads within 48 hours. Visible runoff onto sidewalks and driveways is a same-day citation under California's permanent year-round baseline.

Stack rebates: SoCal Water$mart ($3/sq ft turf removal) plus your retail agency's local match brings most front-yard conversions to $4–$5/sq ft.

Install a WaterSense-labeled smart controller with a rain sensor – most SoCal retail agencies offer $80–$200 rebates and the controller pays back in one summer.

Skip your assigned cycle after 0.5 inch of rainfall in the prior 48 hours. California law requires rain sensors on any system installed after 1991.

Track weekly water use at ontarioca.gov/Utilities – Level 1's reduction target is 20% below 2020 baseline; meter-level alerts catch leaks before the bill arrives.

Ontario Water Restriction FAQs

What days can I water my lawn in Ontario?
Your watering day in Ontario depends on your street address. Addresses ending in Odd can water on Monday and Wednesday and Friday. Addresses ending in Even can water on Tuesday and Thursday and Saturday. You are limited to 3 days per week during the current Stage 2 + MWD Level 1 – Mandatory Conservation restrictions.
What hours can I run my sprinklers in Ontario?
Under the current restrictions, sprinkler irrigation in Ontario is only allowed during the following hours: Before 9:00 AM, After 6:00 PM. No sprinkler irrigation between 9:00 AM and 6:00 PM year-round. Maximum 12 minutes per spray-head zone per watering day; rotary nozzles 25 minutes. Ontario coordinates with the Inland Empire Utilities Agency (the Chino Basin wholesaler) and MWD's Level 1 framework for cross-jurisdictional consistency. Watering outside these hours, even on your scheduled day, is a violation and may result in a citation.
What are the fines for water violations in Ontario?
OMUC Water Conservation patrols neighbourhoods and responds to online complaints. First detected violation: warning. Second: $100. Third: $250. Fourth+: $500. Commercial properties (including warehousing and logistics hubs) face up to $2,000 per occurrence. The Ontario Municipal Utilities Company (OMUC) – Water Services and local San Bernardino County enforcement officers conduct patrols and respond to complaints. Keep your irrigation timer set to your assigned day and hours to avoid citations.
Can I install new sod or seed in Ontario during restrictions?
New potable-water turf installations restricted to October–April under Stage 2. Inland Empire Utilities Agency Turf Replacement Rebate ($3/sq ft up to 1,500 sq ft per residential parcel) stacks with the SoCal Water$mart $3/sq ft regional rebate where eligible.
When will water restrictions end in Ontario?
The current Stage 2 + MWD Level 1 – Mandatory Conservation restrictions in Ontario are effective from MWD Level 1 declared March 2026 Until MWD rescinds Level 1 (storage + Colorado River triggers). However, the restrictions may be extended if drought conditions persist or eased if significant rainfall improves water supply levels. Monitor the Ontario Municipal Utilities Company (OMUC) – Water Services website for updates.
Is this Ontario, California, or Ontario, Canada?
This page covers Ontario, California – population roughly 175,000, located in the Inland Empire of San Bernardino County, about 35 miles east of downtown Los Angeles. It is home to Ontario International Airport (ONT) and major logistics / warehousing hubs. Ontario, Canada is a Canadian province (population ~15 million) – entirely different jurisdiction with its own water-use rules administered by individual Ontario municipalities (Toronto Water, Region of Peel, Ottawa Water, etc.) and the provincial Ministry of the Environment. If you are looking for water restrictions in Toronto, Ottawa, Mississauga, Brampton, or any other Canadian Ontario city, search for that municipality's name on lawnbyseason.com or visit your Canadian municipal water utility directly. The page you're on applies only to Ontario, California addresses served by Ontario Municipal Utilities Company.
Ontario Airport / logistics hubs – industrial water rules?
Ontario International Airport (ONT) and the major logistics / fulfillment centers (Amazon, FedEx, UPS, and roughly 40+ million sq ft of regional warehousing) hold separate commercial water-supply accounts with OMUC. Operational water (HVAC cooling, restroom facilities, fire suppression, dust control) is governed by commercial water-use ordinances that include their own conservation conditions. Landscape irrigation at warehouse perimeters, parking-lot islands, and airport-area greenbelts follows the same Stage 2 framework as residential customers – 3 days per week, 9 AM – 6 PM blackout. Many of the larger logistics tenants have converted perimeter landscape strips to California-Friendly under the IEUA commercial turf-removal rebate (up to 25,000 sq ft per parcel).
Chino Basin groundwater – am I really under Colorado River shortage rules?
Yes. Ontario draws roughly 70% of its supply from the Chino Basin aquifer and 30% from imported MWD water. The Chino Basin is a major regional groundwater resource managed by the Chino Basin Watermaster under a 1978 court judgment that caps total annual production. Even during droughts, basin levels are relatively stable thanks to the Watermaster's management – but the basin's 'safe yield' assumes continued imported MWD water for aquifer recharge, and the SWP allocation cut to 30% directly reduces that recharge. Stage 2 reflects regional supply integration: Ontario's groundwater is healthy precisely because the city has been disciplined about not over-drafting, and the Stage 2 framework keeps it that way during dry years.

Get alerts for Ontario, California

We will email you when Ontario restrictions change – escalations, new stages, or lifted restrictions.

No spam, ever. Unsubscribe anytime.

Other California Cities with Water Restrictions

Community Reports & Questions

Share an update, ask a question, or report a change in your local restrictions.

💬

No community reports yet

Be the first to share a local update, ask a question, or report a change in your area's restrictions.

Add Your Comment

0/1000

Comments are reviewed before publishing. Your email is not collected.

Get alerted when restrictions change

Free email alerts for your city – know before you water.

No spam, ever. Unsubscribe anytime.