Boulder CO Water Restrictions 2026

Current water restrictions in Boulder, Colorado

Boulder is under Stage 1 Mandatory restrictions, limiting outdoor irrigation to 2 days per week as declared by City of Boulder Utilities. These restrictions are in effect until conditions improve — there is no fixed end date tied to a calendar month or season.

City of Boulder Utilities activated Stage 1 in response to tightening water supply conditions driven by ongoing drought across Colorado's Front Range. Boulder's water system depends heavily on mountain snowpack runoff feeding the South Boulder Creek and North Boulder Creek watersheds, and below-average precipitation has reduced yield into storage. The restrictions apply to all residential, commercial, and institutional accounts served by the city's municipal system.

The broader state context is significant: Colorado is experiencing a Stage 1–4 drought emergency across the Front Range, with over 20 municipalities under mandatory schedules. Denver Water declared its own Stage 1 drought on March 25, the Eagle River area is at Stage 3, and Erie has gone to Level 4 Emergency with all irrigation prohibited. Boulder's Stage 1 is currently less severe than those neighboring situations, but conditions remain dynamic.

Practically speaking: a resident cannot simply water their garden on a Wednesday morning whenever they choose. You must water on your two assigned days per week, and you may not run sprinklers or irrigation systems between 10 a.m. and 6 p.m. on any day — even your assigned days. Watering a garden by hand with a shut-off nozzle is permitted outside those restricted hours on any day. If you are unsure of your assigned days, contact City of Boulder Utilities directly or check your account online.

Boulder's watering days and hours

Rule	Details
Days per week	2
Day assignment	2 assigned days/week (based on address)
Allowed hours	Not between 10 a.m. and 6 p.m.
Hand watering	Exempt — shut-off nozzle required at all times
Drip irrigation	Exempt from day restrictions
New sod/seed	Usually a 30-day establishment window — register with City of Boulder Utilities before installation

In Boulder, outdoor irrigation day assignments are typically based on the last digit of your street address. Odd-numbered addresses are assigned one pair of days, even-numbered addresses another. City of Boulder Utilities publishes the specific day pairings on their water restrictions page at bouldercolorado.gov/water — check there for the exact combination currently in effect under Stage 1, as assignments can shift when the stage level changes.

Multi-family residential properties and commercial accounts follow the same two-day-per-week framework, but property managers are responsible for ensuring all shared irrigation systems, including common-area turf and landscaped medians, comply. Large commercial properties with separate irrigation meters should verify their assigned days independently, as a single billing account may cover multiple meter addresses.

Boulder's urban tree canopy includes species that are particularly vulnerable during summer drought stress: Plains Cottonwood (Populus deltoides), Green Ash (Fraxinus pennsylvanica), and Bur Oak (Quercus macrocarpa) all have deep but water-demanding root systems that can suffer irreversible damage during extended dry spells. City of Boulder Utilities allows targeted deep-root watering of established trees with a drip system or soaker hose without counting against your two-day schedule, provided the water is applied slowly at the drip line rather than broadcast across lawn areas.

Violation fines and enforcement

Offense	Penalty
First violation	Written warning — no monetary fine
Second violation	Monetary fine issued by City of Boulder Utilities
Subsequent violations	Escalating fines; potential flow restrictor installed on meter

City of Boulder Utilities enforces the Stage 1 restrictions through a combination of field patrols by utility staff and a neighbor-complaint reporting system. Boulder has deployed advanced metering infrastructure (AMI) across much of the city, meaning smart meter data can flag accounts with consumption patterns inconsistent with their assigned watering days — unusually high flow on off-days, for example, can trigger a follow-up inspection without any complaint being filed. Enforcement staff also patrol neighborhoods during the restricted midday window (10 a.m.–6 p.m.) to observe active irrigation violations directly.

If you receive a warning or fine and believe it was issued in error — for example, because you were using exempt drip irrigation or hand-watering with a shut-off nozzle — City of Boulder Utilities has an administrative appeals process. Contact the utility in writing within the timeframe stated on your notice. Response times for complaints submitted through the city's online reporting portal are generally within one to three business days during active restriction periods.

Other outdoor water rules

Stage 1 in Boulder extends beyond lawn irrigation. The following rules apply to other outdoor water uses:

• Vehicle washing: Permitted only with a hand-held hose equipped with a self-closing nozzle. Commercial car washes that recycle water are fully permitted.
• Pressure washing: Restricted to health and safety purposes only — cleaning a driveway for cosmetic reasons is not permitted.
• Swimming pools and hot tubs: Filling a new pool or topping off an existing pool is restricted; covers are strongly encouraged to reduce evaporation, which is significant at Boulder's elevation of 5,430 feet. Pools that already have water may maintain current levels with minimal top-off using a hand-held nozzle with shut-off.
• Decorative fountains: Recirculating fountains are permitted. Fountains that discharge water to a drain without recirculation must be shut off.
• Construction water: Dust suppression and concrete curing use must use the minimum quantity necessary; contractors should confirm requirements with City of Boulder Utilities before project start.
• Restaurant outdoor water features: Ornamental water features at restaurants and hotels follow the same recirculating rule as residential fountains.
• Sidewalk and patio rinsing: Hosing down hard surfaces for cleaning is not allowed; a broom must be used instead.

How Boulder gets its water

Boulder's municipal water supply comes primarily from two mountain watersheds: Boulder Creek and its tributaries fed by the Indian Peaks Wilderness area, and diversions from the Colorado-Big Thompson (C-BT) Project, which transports water from the Colorado River's headwaters on the Western Slope through the Alva B. Adams Tunnel beneath Rocky Mountain National Park and into the Big Thompson River system on the Front Range.

The city's primary storage is Barker Reservoir, located in Boulder Canyon on Middle Boulder Creek, with a capacity of approximately 3,200 acre-feet. Boulder also holds C-BT Project allotment units managed through the Northern Colorado Water Conservancy District (Northern Water), which gives the city a share of water stored in Horsetooth Reservoir near Fort Collins and Carter Lake near Loveland. In dry years, these C-BT deliveries become critical because natural Boulder Creek flows drop sharply by midsummer.

Raw water is treated at the Boulder Water Treatment Plant on Iris Avenue before distribution. The city also operates the Betasso Water Treatment Plant in Boulder Canyon as a secondary facility. Together, these plants serve roughly 66,000 Boulder residents plus some surrounding service area customers.

The Colorado-Big Thompson Project itself is under pressure: C-BT allotments are tied to snowpack and runoff in the upper Colorado River basin above Grand Lake. When the Western Slope runs dry, Front Range cities including Boulder receive reduced C-BT deliveries, compounding the stress already felt from low local creek flows. This is the structural vulnerability behind Boulder's Stage 1 restrictions — not just a single dry month, but cumulative deficit across both its local and imported supply systems.

HOA and brown lawn protections

Colorado law protects Boulder homeowners from HOA enforcement actions related to brown or dormant lawns during declared drought restrictions. Colorado Revised Statutes § 37-60-126 prohibits homeowners associations from fining or penalizing a property owner for allowing their lawn to go brown, become dormant, or die when the local water provider has declared mandatory water restrictions. Because City of Boulder Utilities has declared Stage 1 Mandatory restrictions, this statute is currently in effect for all Boulder homeowners subject to an HOA.

The protection applies specifically when the restriction is mandatory — voluntary conservation requests do not trigger the statute. Stage 1 in Boulder is classified as mandatory, so you are fully covered. Some HOAs have attempted to distinguish between "brown from drought" and "unmaintained landscaping," so document your compliance with City of Boulder Utilities' schedule and keep records of your watering days.

If your HOA issues a fine or violation notice related to your lawn during the current Stage 1 Mandatory restrictions, use the following template response:

"Dear [HOA Board/Management Company]: I am writing in response to the violation notice dated [date] regarding the condition of my lawn at [address]. City of Boulder Utilities has declared Stage 1 Mandatory water restrictions currently in effect for all properties in Boulder. Under Colorado Revised Statutes § 37-60-126, a homeowners association may not impose fines or penalties on a homeowner for allowing landscaping to brown or go dormant during a period of mandatory water restrictions declared by the applicable water provider. I am in full compliance with City of Boulder Utilities' Stage 1 restrictions. I respectfully request that this violation notice be rescinded immediately. Please confirm in writing. [Your name, address, date]"

Keeping your lawn alive on restricted water

Grass Type	Drought Tolerance	Survives Dormancy?	Minimum Water Needed
Kentucky Bluegrass	Low–Moderate	Yes, up to 4–6 weeks	~1 inch/week to stay green
Tall Fescue	Moderate	Yes, more resilient than bluegrass	~0.75 inch/week
Buffalograss	Very High	Yes — native to Colorado plains	~0.25 inch/week once established
Blue Grama	Very High	Yes — native shortgrass prairie species	~0.2 inch/week once established

Most Boulder lawns are seeded or sodded with Kentucky Bluegrass, which is the dominant turf in Colorado's Front Range. Under Stage 1 restrictions with only two watering days per week, bluegrass will likely enter partial or full dormancy by mid-to-late summer if temperatures are high — this is normal and not permanent death. Apply your water early morning or after 6 p.m. on your assigned days, and set sprinkler run times to deliver approximately 0.5 inch per session rather than shallow daily sprinkles. Boulder's average summer evapotranspiration rate exceeds 0.25 inches per day at peak heat, so prioritizing deep, infrequent watering on your two allowed days is more effective than splitting short cycles.

Boulder's altitude — 5,430 feet — means UV intensity is higher than sea-level cities, which stresses turf more quickly during drought. Raise your mowing height to at least 3 to 3.5 inches for Kentucky Bluegrass and Tall Fescue; taller grass blades shade the soil, reduce evaporation, and keep root zones cooler. Avoid fertilizing cool-season grasses during active drought stress — nitrogen pushes top growth that the plant cannot support without adequate water, worsening die-off. Homeowners with Buffalograss or Blue Grama lawns, both native to Colorado's shortgrass prairie, will find these grasses remain green on significantly less water and are well-matched to Boulder's semi-arid climate.

Boulder water restriction FAQ

What days can I water my lawn in Boulder right now?

Under Stage 1 Mandatory restrictions, you are assigned two specific days per week based on your street address. Odd and even address numbers are assigned different day pairings, which City of Boulder Utilities publishes at bouldercolorado.gov/water. On your assigned days, you may not run irrigation between 10 a.m. and 6 p.m. Watering is permitted in the early morning (before 10 a.m.) or evening (after 6 p.m.) on those days only.

Can I water by hand on days that aren't my assigned days?

Yes. Hand watering with a hose fitted with a self-closing, shut-off nozzle is exempt from the two-day-per-week schedule. You can use a hand-held hose or a watering can on any day, as long as you are not between 10 a.m. and 6 p.m. This exemption is specifically designed to allow targeted care of garden beds, containers, and trees without triggering the schedule restriction.

Does City of Boulder Utilities use smart meters to catch violations?

Yes. Boulder has deployed advanced metering infrastructure (AMI) across its service area. Smart meters transmit consumption data at regular intervals, giving City of Boulder Utilities the ability to identify accounts that show high water flow on non-assigned days. Meter data flagging an apparent violation can initiate an inspection or enforcement action without a neighbor complaint being filed.

What rebates or programs does City of Boulder Utilities offer for replacing grass?

City of Boulder Utilities operates a Water Smart Landscapes Rebate program that pays qualifying homeowners per square foot of irrigated turf converted to low-water or xeric landscaping. The program also offers rebates on high-efficiency sprinkler nozzles (such as rotary nozzles replacing fixed spray heads) and smart irrigation controllers. Check bouldercolorado.gov/water for current rebate amounts and eligibility requirements, as funding availability changes seasonally.

Can I fill my swimming pool during Stage 1 restrictions?

Filling a new pool is restricted under Stage 1. Topping off an existing pool to replace evaporation is permitted in minimal amounts. At Boulder's elevation, pool evaporation rates are notable due to low humidity and high UV exposure — using a pool cover when the pool is not in use is strongly encouraged and will significantly reduce the volume of makeup water needed.

My HOA sent me a fine for a brown lawn. What can I do?

Colorado Revised Statutes § 37-60-126 prohibits HOAs from fining homeowners for dormant or brown lawns during mandatory water restrictions. Because City of Boulder Utilities has declared Stage 1 Mandatory restrictions, your HOA cannot legally penalize you for a lawn that has browned due to restricted watering. Send the HOA a written response citing CRS § 37-60-126 and referencing the current City of Boulder Utilities Stage 1 declaration. See the template letter in the HOA section above.

Is drip irrigation exempt from the two-day schedule?

Yes. Drip irrigation systems that apply water slowly and directly to root zones — rather than broadcasting water across turf — are exempt from the two-day-per-week assignment under Boulder's Stage 1 rules. This exemption exists because drip systems are far more efficient than spray irrigation. If you currently have spray heads watering shrub beds or perennial borders, converting to drip emitters qualifies you for the exemption and may also be eligible for City of Boulder Utilities' efficiency rebate program.

What happens if I water on the wrong day and get a second violation?

A first violation results in a written warning from City of Boulder Utilities with no monetary fine. A second violation triggers a fine. Subsequent violations carry escalating penalties, and the city has authority to install a flow restrictor on your water meter — a physical device that limits the flow rate entering your home — until compliance is achieved. Flow restrictors significantly affect household water pressure and can make normal indoor use inconvenient, making it one of the more impactful enforcement tools available to the utility.

What time can I water in Boulder?

Watering is allowed Not 10am-6pm. Watering outside these hours is a violation even on your assigned day.

When will water restrictions end in Boulder?

Current Stage 1 Mandatory restrictions are in effect through Until conditions improve. Monitor https://bouldercolorado.gov/water for the latest status.

How do I report a water waste violation in Boulder?

Contact City of Boulder Utilities or visit https://bouldercolorado.gov/water. Most utilities accept online reports and respond within 48 hours.