Why Longmont Isn't Under Mandatory Restrictions
While Denver Water declared Stage 1 mandatory restrictions in late March 2026 and cities like Aurora, Thornton, and Arvada followed suit, Longmont is operating under different rules — because it gets its water from a different source.
Longmont sits within the St. Vrain Creek watershed and holds some of the most senior water rights in the entire South Platte River Basin. Senior water rights, under Colorado water law, are the last to be cut during a shortage. The city has spent decades building a diversified portfolio that includes several of these senior rights, which gives it significantly more resilience than communities that depend more heavily on Denver Water's South Platte and Colorado River basin collection systems.
Denver Water's primary watersheds came in at 42–55% of normal snowpack as of late March — both at record lows for those basins. Longmont's situation is different. Ralph Price Reservoir (Button Rock Preserve), the city's primary drinking water source, was near 79% full as of February. Union Reservoir was around 62% full. Those numbers are below normal, but not at crisis levels.
That said, Longmont's water staff have noted that reservoir storage is expected to finish the season below average after runoff. The St. Vrain Creek was running at about 13 cfs in February, well below its 125-year average of around 15 cfs. Snowpack concerns are real here too — just not as acute as the Denver Water system.
What "Drought Watch" Means for Your Yard
Longmont's Sustainable Conservation Level — Drought Watch designation isn't a formal restriction stage. It's the city's baseline conservation posture, which remains in effect year-round. Under this level, the city asks residents to follow voluntary best practices and stay mindful of water use. No assigned watering days. No time-of-day restrictions. No enforcement action.
However, the city does have a Water Supply and Drought Management Plan with formal shortage stages that can be activated if conditions warrant. That plan has been in place since before 2020, when the state's Drought Task Force was last activated. Longmont's April and May runoff data will drive any decisions about moving into a higher response level this season.
The city's water staff have said publicly that they believe Longmont has sufficient supply for 2026 and 2027 under normal operations — but that policy choices about how conservatively to manage that supply will depend on spring runoff data. April is historically one of Longmont's most important months for snowmelt and streamflow; what comes off the mountains in the next few weeks will significantly shape the city's outlook for summer.
Voluntary Practices the City Is Recommending
Even without mandatory restrictions, Longmont officials are encouraging residents to pull back on outdoor water use. The specific guidance being promoted during Drought Watch includes watering no more than twice per week, watering only before 10 a.m. or after 6 p.m. to reduce evaporation, and not turning on automatic sprinkler systems until May — consistent with the broader Front Range guidance that April irrigation is premature and wastes water that lawns don't yet need.
Longmont has seen significant voluntary conservation success over the past three decades. Daily per-person water use dropped from about 215 gallons in 1996 to roughly 115 gallons in 2023, even as the city's population grew. The city is actively expanding a public awareness campaign this season and offering conservation rebates for turf removal and native landscaping. The regional rebate portal launched earlier this year and includes a Garden in a Box program and lawn replacement incentives that can offset some of the cost of transitioning away from water-intensive grass.
When Could Mandatory Restrictions Be Triggered?
Longmont's formal shortage response plan has multiple levels. A moderate water shortage triggers additional conservation messaging and rebates. A severe shortage moves into more formal demand reduction programs. An emergency level — which Erie reached this spring due to infrastructure constraints, not supply — would mean mandatory restrictions similar to what Denver is imposing.
The city's Water Advisory Board receives monthly supply and drought updates through the spring. The formal water supply and shortage implementation plan for the season is typically finalized in April or May based on updated runoff forecasts from the St. Vrain watershed. If streamflow projections drop significantly or reservoir levels fall faster than expected, a move into moderate shortage designation — and the public messaging and voluntary reduction programs that come with it — becomes more likely.
The Governor activated Phase 2 of Colorado's Drought Response Plan statewide in March 2026, the earliest activation in the history of the plan. Button Rock Preserve, Longmont's primary watershed, is facing elevated wildfire risk this season due to low snowpack and wind events. Staff increased ranger presence there and have treated over 1,100 acres since 2024 to reduce fire fuel. A wildfire affecting the preserve would have direct water supply implications — that's a risk Longmont is actively managing.
Longmont Watering Best Practices Right Now
Hold off on automatic sprinklers until May. The city and every Front Range water utility are giving the same advice: don't activate your irrigation system until at least May 1, and mid-to-late May is better. April soil in Colorado still holds winter moisture, lawn roots are just breaking dormancy, and there's meaningful freeze risk through May 5 on average. Turning on systems in April wastes water and risks freeze damage to pipes and heads.
Hand-water trees and shrubs if needed. Established trees don't need irrigation in April unless conditions are unusually warm and dry for an extended stretch. Newly planted trees and shrubs are more vulnerable — a few gallons of hand watering every week or two during a dry April stretch is sufficient and keeps you from pressurizing the system early.
Water no more than twice a week when you do start. The voluntary guidance from Longmont aligns with CSU Extension's standard recommendation: two to three deep sessions per week rather than daily light watering. Deep watering builds the root depth that helps lawns tolerate heat and reduced irrigation frequency later in summer.
Water before 10 a.m. or after 6 p.m. This applies whether restrictions are mandatory or voluntary. Watering during peak heat loses a significant portion of water to evaporation before it reaches the root zone. Morning is preferable — blades dry before evening, reducing fungal disease pressure.
How to Check Longmont's Current Status
Longmont updates its current water shortage and drought status on the city's water resources page at longmontcolorado.gov/water. The Water Advisory Board meets monthly and publishes summaries; the Longmont Ledger (longmontledger.com) has been covering the board's meetings in detail and is the best local source for supply and restriction updates through the spring. Any change to mandatory restrictions would be communicated broadly through city channels, but checking the city's water page periodically is the most direct way to stay current.
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Frequently Asked Questions
Does Longmont have watering restrictions in 2026?
No mandatory restrictions as of April 2026. Longmont is at a Sustainable Conservation Level — Drought Watch, which is voluntary. The city encourages residents to water no more than twice a week and to delay sprinkler startup until May, but there are no enforced limits, assigned watering days, or fines.
Why doesn't Longmont have restrictions when Denver does?
Longmont gets its water primarily from the St. Vrain Creek watershed and holds senior water rights in the South Platte River Basin, which are the last to be affected in a shortage under Colorado water law. Denver Water's supply basins — the Colorado River and South Platte — hit record-low snowpack in 2026. Longmont's supply situation is below normal but not at the same crisis level, so mandatory restrictions haven't been triggered.
When should Longmont residents turn on their sprinklers in 2026?
May at the earliest. The city's guidance, consistent with Denver Water and CSU Extension, is to delay automatic sprinkler activation until at least May 1 and ideally mid-to-late May. April soil still holds winter moisture, frost risk persists through early May, and early startup wastes water during a drought year when every week of delay saves meaningful reservoir storage.
Could Longmont move to mandatory restrictions this summer?
It's possible. The city's formal Water Supply and Drought Management Plan has several shortage stages, and the final decision for 2026 will be based on April and May runoff data from the St. Vrain watershed. If streamflow projections come in significantly below average, Longmont could move to a moderate shortage designation with more formal conservation programming. Any change would be announced through the city's water page and public communications.
Are Longmont's rebates for turf removal still available?
Yes. Longmont participates in regional conservation rebate programs and is actively encouraging turf removal and native landscaping transitions in 2026. The city's regional rebate portal includes the Garden in a Box program and lawn replacement incentives. Check longmontcolorado.gov/water for current program details and eligibility.