Longmont CO Water Restrictions 2026

Current water restrictions in Longmont, Colorado

Longmont is currently under a Drought Watch (Voluntary) designation, encouraging residents to limit outdoor watering to no more than 3 days per week while avoiding irrigation between 10 a.m. and 6 p.m.

The City of Longmont declared the Drought Watch status as part of its Sustainable Conservation Level framework, responding to declining water supplies and regional drought conditions across northern Colorado. No mandatory restrictions are currently in effect — compliance is voluntary, and no fines are being issued. The City of Longmont Water Resources division is the governing authority, reachable through longmontcolorado.gov.

The Drought Watch was triggered by a combination of reduced snowpack runoff into the St. Vrain Creek watershed, below-average storage in Union and Button Rock reservoirs, and the broader emergency drought conditions affecting the entire Front Range. Colorado is currently experiencing a Stage 1–4 drought emergency statewide, with neighboring communities under far stricter rules — Erie has banned all outdoor irrigation under a Level 4 Emergency declaration, and Denver Water entered Stage 1 mandatory restrictions in March 2025.

Longmont's position at the Sustainable Conservation Level means the city is managing supplies carefully but has not yet crossed into mandatory scheduling. Residents are specifically encouraged to reduce outdoor watering voluntarily before conditions force a mandatory trigger.

Practically speaking: yes, a Longmont resident can water their garden on a Wednesday morning — but the City asks that you do so before 10 a.m. or after 6 p.m., limit yourself to roughly 3 days per week, and avoid any runoff onto sidewalks or streets. There is no enforcement action for watering on a Wednesday at 11 a.m., but following the recommended guidelines helps Longmont avoid escalating to mandatory Stage 1 or Stage 2 restrictions under its Water Shortage Ordinance.

Watering schedule and allowed days

Rule	Details
Days per week	3 (voluntary guideline)
Day assignment	No mandatory address-based schedule; residents voluntarily limit outdoor watering
Allowed hours	Before 10 a.m. or after 6 p.m. recommended to reduce evaporation
Hand watering	Exempt; shut-off nozzle strongly recommended
Drip irrigation	Exempt; encouraged as most efficient method
New sod/seed	Typically a 30-day establishment window — contact City of Longmont Water Resources to register

Because Longmont is currently at the voluntary Drought Watch level rather than a mandatory stage, there is no address-based odd/even day assignment in effect. Residents are simply asked to self-select up to 3 watering days per week. If Longmont escalates to a mandatory Stage 1 or Stage 2 under its Water Shortage Ordinance, address-based scheduling would likely be triggered, with odd-numbered addresses watering on certain days and even-numbered addresses on others — consistent with how neighboring Front Range utilities structure mandatory schedules.

Multi-family residential properties and commercial accounts managed through Longmont Power & Communications are subject to the same voluntary guidelines. Homeowners associations managing shared irrigation systems on common areas are encouraged to program controllers to no more than 3 run days per week and to audit spray heads for misting or overspray onto hardscape — a particular concern in Longmont's older subdivisions west of Airport Road where aging Hunter and Rain Bird rotors are common.

Longmont's urban tree canopy deserves special attention during Drought Watch periods. Cottonwood trees (Populus fremontii) along the St. Vrain Creek corridor and in older residential yards are shallow-rooted and show stress quickly in dry summers. Bur oak (Quercus macrocarpa), widely planted in Longmont's newer developments near Sunset Street, and honeylocust (Gleditsia triacanthos), common as street trees along Main Street and in the Prospect New Town neighborhood, both benefit from deep, infrequent watering at the dripline rather than frequent shallow sprinkler coverage. Trees are a long-term investment; during Drought Watch conditions, prioritize deep tree watering over lawn coverage if you must choose.

What happens if you violate restrictions in Longmont?

Offense	Penalty
First violation	None — voluntary restrictions only
Second violation	None — voluntary restrictions only
Commercial	No fines currently; same voluntary guidelines apply

Because Longmont is operating under voluntary Drought Watch rather than a mandatory restriction stage, there are no fines or penalties currently in effect for any property type — residential, commercial, or industrial. The City of Longmont's Water Resources division has authority under its Water Shortage Ordinance to begin issuing warnings and escalating fines if conditions worsen and a mandatory Stage 1 is declared, but that enforcement mechanism has not been activated. Longmont Power & Communications handles billing and can flag unusually high irrigation consumption to the Water Resources team, effectively acting as a passive monitoring layer even without formal enforcement.

If Longmont advances to mandatory restrictions, enforcement historically involves a combination of utility billing data analysis, staff patrols in high-consumption zones, and neighbor complaint intake through the city's non-emergency reporting system. There is an administrative appeals process available through the City of Longmont's utility services office for any notices issued once mandatory stages are active. Response times to reported violations during past mandatory periods have typically been 3–5 business days for a first inspection visit.

Other outdoor water rules

Beyond lawn irrigation, the following outdoor water uses carry voluntary guidelines or ongoing baseline rules under Longmont's municipal code during the current Drought Watch period:

• Vehicle washing: Residents are asked to use a bucket or a hose with a shut-off nozzle. Commercial car washes that recirculate water are considered more efficient and are not restricted.
• Pool and hot tub filling: Initial fills and top-offs to offset evaporation are permitted but should be minimized. Longmont sits at approximately 4,979 feet elevation, where lower humidity accelerates pool evaporation — covering pools when not in use can reduce water loss by up to 90%.
• Decorative fountains: Voluntary guidance asks residents to turn off decorative water features that do not recirculate. Recirculating fountains are not subject to this guidance.
• Pressure washing: No formal restriction, but voluntary conservation guidelines suggest using the minimum water necessary and avoiding washing impervious surfaces like driveways unless there is a health or safety reason.
• Landscape water features and water walls: Commercial properties along Main Street and in the Village at the Peaks area with non-recirculating water features are encouraged to shut them off during Drought Watch.
• Construction water: Dust suppression and concrete curing for active construction sites are considered essential uses and are not restricted under voluntary guidelines.
• Restaurant table water: Longmont follows standard Colorado voluntary practice — water served only upon request, though not formally mandated at current restriction levels.

Water source and infrastructure

Longmont's municipal water supply comes primarily from two sources: Button Rock Reservoir (also known as Ralph Price Reservoir) on the North St. Vrain Creek in the foothills west of Lyons, and Union Reservoir east of Longmont near Weld County Road 1. Together these two reservoirs form the core of Longmont's storage system, with a combined capacity of roughly 35,000 acre-feet.

Raw water from Button Rock and Union Reservoir is treated at the Longmont Water Treatment Plant on Pike Road, which is capable of processing up to approximately 40 million gallons per day. The city also holds water rights in the Colorado-Big Thompson Project (CBT), a federal transmountain diversion project operated by the Northern Colorado Water Conservancy District that moves water from the Colorado River headwaters through the Alva B. Adams Tunnel under the Continental Divide to the South Platte Basin — Longmont's CBT allocation is a critical buffer in dry years.

The St. Vrain Creek itself is both a source and a routing corridor; Longmont holds direct-flow water rights on the creek, though these rights are junior and are often curtailed during drought years when senior downstream appropriators call for water under Colorado's prior appropriation doctrine. This legal reality is part of why Drought Watch declarations are taken seriously — curtailment of St. Vrain direct-flow rights concentrates pressure on reservoir storage.

Longmont also participates in the Northern Integrated Supply Project (NISP) planning process, a long-range regional water supply project proposed by the Northern Colorado Water Conservancy District that would add additional storage capacity via a proposed Glade Reservoir near Fort Collins. However, NISP infrastructure is not yet operational and does not affect current supply conditions.

In dry years like the current cycle, Button Rock storage levels become the most closely watched indicator. When Button Rock drops below certain storage thresholds, the City of Longmont's Water Resources team typically escalates from Drought Watch toward mandatory Stage 1 restrictions under the Water Shortage Ordinance.

Brown lawn protections in Colorado

Colorado homeowners are protected from HOA fines for brown or drought-stressed lawns under Colorado Revised Statute § 37-60-126. This statute prohibits homeowners associations from fining, penalizing, or taking enforcement action against a property owner who reduces or temporarily eliminates landscape irrigation in response to a government-declared drought or water restriction. Because Longmont's Drought Watch is an official City of Longmont declaration, it qualifies as the triggering condition under CRS § 37-60-126.

If your HOA in a Longmont community — such as Prospect New Town, Renaissance, Quail Crossing, or any other covenant-controlled neighborhood — sends a violation notice about a browning lawn during the current Drought Watch, you have a statutory defense. Document that the City of Longmont has issued a Drought Watch and that you are reducing irrigation in compliance with city guidance.

Use this template when responding to your HOA:

"Dear [HOA Name] Board of Directors: I am writing in response to your notice dated [date] regarding lawn appearance at [address]. The City of Longmont has declared a Drought Watch under its Water Shortage Ordinance and is actively encouraging residents to reduce outdoor irrigation. I am complying with City of Longmont voluntary conservation guidelines. Under Colorado Revised Statute § 37-60-126, a homeowners association may not impose fines or penalties on a property owner for reducing or eliminating landscape water use in response to a government-issued drought declaration or water restriction. I respectfully request that this violation notice be withdrawn. Please contact me if you have any questions."

Lawn care during restrictions

Grass Type	Drought Tolerance	Min. Water (inches/week)	Notes for Longmont
Kentucky Bluegrass	Low–Moderate	1.0–1.5	Most common in Longmont; goes dormant (tan) under drought — will recover
Tall Fescue	Moderate	0.75–1.0	Deeper roots than bluegrass; handles Longmont's clay-loam soils better in dry spells
Buffalograss	Very High	0.25–0.5	Native to Colorado's Front Range plains; ideal for water-wise conversions in Longmont
Blue Grama	Very High	0.25–0.5	Native grass; low-maintenance, thrives in Longmont's semi-arid climate

Longmont sits at just under 5,000 feet elevation, which means UV intensity is higher than at sea level and evapotranspiration rates are elevated even when temperatures feel moderate. During Drought Watch, raise your mower deck to at least 3–3.5 inches for Kentucky Bluegrass and 3.5–4 inches for Tall Fescue — taller grass blades shade the soil surface, slow moisture loss, and reduce the frequency of required irrigation. Avoid fertilizing cool-season grasses with nitrogen during drought stress; fertilizer applied to a drought-stressed lawn encourages top growth that demands more water and can burn already-stressed turf on Longmont's predominantly clay-heavy soils.

Longmont's Water Resources division and the City's partnership with Colorado State University Extension offer guidance on converting Kentucky Bluegrass lawns to native Buffalograss or Blue Grama through Longmont's WaterSmart program. These native grasses evolved on the shortgrass prairie that once covered this part of Weld and Boulder counties and require a fraction of the irrigation bluegrass demands once established. If you're maintaining an existing bluegrass lawn through the Drought Watch, allow it to go semi-dormant rather than applying enough water to keep it dark green — the grass will recover when fall rains arrive, and drought-induced dormancy does not kill healthy bluegrass.

Common questions about Longmont water restrictions

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

Under the current voluntary Drought Watch, there are no assigned watering days based on your address. The City of Longmont asks that you voluntarily limit outdoor irrigation to 3 days per week of your choosing, and that you water before 10 a.m. or after 6 p.m. to minimize evaporation. No permit or registration is needed to follow this schedule — it's a recommendation, not a mandate.

Will I get a fine if I water my lawn every day in Longmont?

Not currently. Because Longmont is at the voluntary Drought Watch level, there are no fines or enforcement actions in place. However, if conditions worsen and the City of Longmont escalates to a mandatory Stage 1 or Stage 2 under its Water Shortage Ordinance, violations could result in written warnings followed by financial penalties. Watering every day is strongly discouraged given regional emergency drought conditions across the Front Range.

Is Button Rock Reservoir at a critically low level right now?

The City of Longmont monitors storage at Button Rock (Ralph Price) Reservoir and Union Reservoir closely and publishes reservoir status updates through the Water Resources section of longmontcolorado.gov. The Drought Watch declaration signals that storage and supply conditions are below normal seasonal levels, though not yet at the emergency thresholds that would trigger mandatory Stage 1 restrictions. Checking the city's water dashboard during summer months gives the most current picture.

Does the City of Longmont offer rebates for replacing grass with drought-tolerant landscaping?

Yes. Longmont's WaterSmart program offers rebates for turf replacement with water-wise plants, native grasses like Buffalograss or Blue Grama, and xeriscaping. Rebate amounts and program availability are updated seasonally — visit longmontcolorado.gov or contact Longmont Water Resources directly for current incentive levels. The program has historically offered per-square-foot rebates for removing Kentucky Bluegrass and replacing it with approved low-water alternatives.

Can I wash my car at home in Longmont right now?

Yes, but the City asks that you use a bucket or a hose fitted with a shut-off nozzle to minimize runoff. There is no restriction or fine for home car washing under the current voluntary Drought Watch. If you use a commercial car wash, facilities that recirculate wash water are considered significantly more water-efficient than a standard driveway wash.

Can I fill my swimming pool or hot tub in Longmont during Drought Watch?

Initial pool fills and evaporation top-offs are permitted under current voluntary guidelines. The City encourages pool owners to keep pools covered when not in use — at Longmont's elevation and with Colorado's characteristically low relative humidity, an uncovered pool can lose an inch or more of water per week to evaporation alone. There is no fill permit required at the current restriction level, but this may change if Longmont moves to mandatory stages.

My HOA sent me a warning about my brown lawn — what do I do?

Colorado Revised Statute § 37-60-126 protects you. The City of Longmont's Drought Watch is an official government-issued water restriction, which means your HOA cannot legally fine you for allowing your lawn to go dormant or brown in compliance with city conservation guidance. Send your HOA a written response citing CRS § 37-60-126 and referencing the City of Longmont's current Drought Watch declaration. Keep copies of all correspondence in case escalation is needed.

How does Longmont's water situation compare to other Front Range cities right now?

Longmont is in a relatively stable position compared to several neighbors. Erie is under a Level 4 Emergency with all outdoor irrigation prohibited. Denver Water declared Stage 1 mandatory restrictions in March 2025. The Eagle River service area near Vail is at Stage 3. Longmont's access to Colorado-Big Thompson Project water through the Northern Colorado Water Conservancy District, combined with storage in Button Rock and Union reservoirs, has provided more buffer than communities relying more heavily on direct-flow river rights — but the situation remains dynamic and residents should check longmontcolorado.gov for any escalation announcements through the summer.

What time can I water in Longmont?

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

When will water restrictions end in Longmont?

Current Drought Watch (Voluntary) restrictions are in effect through Until conditions improve. Monitor https://www.longmontcolorado.gov for the latest status.

Can I hand water during Longmont water restrictions?

Yes. Hand watering with a hose fitted with a shut-off nozzle is generally allowed on any day during permitted hours. Drip irrigation and soaker hoses are also typically exempt from the day-of-week schedule. Confirm specifics with City of Longmont.

How do I report a water waste violation in Longmont?

Contact City of Longmont or visit https://www.longmontcolorado.gov. Most utilities accept online reports and respond within 48 hours.