Drought Response
Staying more than a few drops ahead.
Because we live in a semi-arid climate, we must expect and prepare for periods of drought. The city continuously monitors water supply and balances storage levels with demand. Storage levels are affected by weather, the amount of snowpack and rainfall, stream flow levels, and other factors.
Drought status:
Stage 1 Restrictions
Effective March 15, 2026
Dry winter conditions have led to historically low snowpack in Colorado, the lowest recorded in 20 years. Snowpack in the Upper South Platte and Clear Creek watersheds that supply Thornton’s Water is critically low, which impacts the amount of water delivered to Thornton. To maintain city water supplies, Thornton City Council voted on March 10 to declare Drought Stage 1.
Outdoor Watering Rules
- Wait to turn on irrigation systems until May. Turf is naturally dormant while nights are still cool, and frost is frequent. Even though it looks brown and dry, the roots are alive under the soil. Bringing lawns out of dormancy too early is unnecessary and will create early demands on our reservoirs and water treatment systems.
- Continue watering trees, shrubs and other non-turf established landscaping.
- Limit turf watering to two days/week and water between 6 p.m. and 10 a.m. Most turf can survive and even thrive with two days of watering per week. Less frequent watering will both save water and deepen lawn roots, making your turf more drought tolerant. Use the Cycle and Soak method of breaking watering times into 2 or 3 smaller cycles to get the most out of your watering
- Water vegetable gardens and other gardens as needed.
- The city is discouraging installing new sod or grass seed during drought. If it cannot be avoided, you can apply for a 21-day watering permit if you are laying new sod, seeding, or reseeding lawns to increase watering for a short time in May, June, September and October. Permit fees will apply and will be available on May 1. Check back for a link at that time. Permits will not be issued for July and August.
2-Day Watering Guide | Minutes Per Zone, Per Watering Day:
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| Fixed Spray Nozzles | Rotors | Rotary Nozzles | Manual Sprinklers | |
| Minutes | Minutes | Minutes | Minutes | |
| January – April | Water trees and shrubs as needed | |||
| May | 15 | 33 | 42 | 23 |
| June | 22 | 48 | 61 | 34 |
| July | 24 | 52 | 65 | 36 |
| August | 20 | 44 | 55 | 31 |
| September | 14 | 31 | 39 | 22 |
| October | Water trees and shrubs as needed | |||
Businesses & Large Properties
- Properties over an acre in size that can demonstrate they are unable to water within two days a week can contact Thornton Water at Water@ThorntonWater.com to set a 10% reduction water budget instead. If approved, an administrative fee of $400 will be required.
- Business owners can help limit their water use where possible by:
- Only serving water upon request in restaurants and bars.
- Reducing the frequency of washing hotel linens.
- Recycling water and optimizing the efficiency of car washes.
- Signing up for a free non-residential sprinkler evaluation for actionable steps to improve your watering efficiency and reduce waste.
- Looking for and fixing leaks quickly.
Violations & Fines
Customers who violate water-use restrictions will receive a courtesy warning for a first occurrence.
Water leaks and waste must be addressed or repaired within 10 days from the date of notice.
If leaks or water waste are not remedied within 10 days, Thornton may impose fines starting at $100 for residential customers, $250 for commercial customers, and $1,000 for construction customers; fines will increase with each violation. For more information about water waste fines, refer to the Thornton City Code.
What Customers Can Do Now
Reducing outdoor water use is the easiest way to cut back on your overall water use during drought. Visit the Saving Outdoors page for more resources and recommendations, or explore our Residential, Commercial, and HOA &Multifamily rebates and services.
City of Thornton Actions – Reducing City Water Use
- The city of Thornton is joining customers to reduce city-wide water use by 10% across all city-owned properties.
- Thornton’s Parks and Recreation is actively working to reduce water use, while strategically maintaining public landscapes.
- The city will continue to water areas with high-use turf grasses, including popular parks and the Thorncreek golf course, with changes to watering time, frequency, operations, and capacity to help decrease overall usage.
- You may see watering in parks during the day. Staff will be running regular water efficiency system checks and identifying priority areas that require additional attention due to high traffic. These exemptions allow for water efficiency and safety on Thornton’s many recreational sports and festival areas. To compensate, the Parks Division will be decreasing watering times and frequency in lower-traffic areas and allowing low-use areas to become drier than normal during the warmer months.
- At the Thorncreek Golf Course, steps are being taken to preserve turf health by delaying starting tee-times, increasing the time between tee-times, and closing putting greens as needed to prevent heavy wear and tear. For updates, visit the Thorncreek Golf Course website.
- Many parks are able to water with non-potable water to decrease the demand on Thornton’s drinking water supply.
Understanding Water Supply and Demand
Thornton Water is continuously balancing supply and demand to ensure the consistent delivery of water to customers. Demand is affected by weather; it’s lower in cool, wet years and higher in hot, dry years. Thornton’s Drought Management Plan helps manage the demand side of the equation.
Our water comes from the Upper South Platte and Clear Creek river basins and is stored in several reservoirs along the South Platte River and in Standley Lake. We are constantly evaluating Thornton’s current and projected water supply by tracking reservoir levels, stream flows, snowpack and customer water demand.
How is Thornton Water typically used?
Thornton Water delivers thousands of gallons of water throughout the city every day for single and multifamily residences; commercial businesses and schools; irrigation at parks, open spaces and HOAs; system uses for hydrant flushing and water quality; and non-account uses for water breaks and fire fighting.
The demand for water also fluctuates dramatically throughout the year.
- Winter: Customers use as little as 9.6 million gallons per day.
- Summer: Customers use as much as 46.3 million gallons per day.
Outdoor watering in the summer months causes city water usage to spike dramatically. When conditions are hot and dry during times of drought, customers are more inclined to water more as well, making irrigation efficiency critical.
Residential Conservation Progress
Over time, the Thornton community has made a conscious effort in partnership with city conservation efforts to be waterwise and take steps to conserve. As a result, Residential Gallons Per Capita Per Day (GPDC) decreased from 103 in 2002 to 73 in 2025. GPDC is calculated by dividing the number of gallons used in a year by the population and then dividing by 365 days.
Thornton’s Drought Management Plan:
Securing our water now, and for years to come
Thornton’s Drought Management Plan provides action-based guidance to respond to drought in ways that equal the severity of conditions. During droughts, Thornton can experience a water shortage that could require the community to reduce its water use. The plan also includes additional steps for reducing water demand and acquiring additional water supplies. Read the Drought Management Plan.
Water Use Rules and Watering Guide:
Water lean and still green
Effective March 15, 2026, Thornton City Council has declared a Stage 1 Drought. Wait to turn on sprinkler systems until May 1. Our new Watering Guide contains some of the new rules and provides a guide for watering up to two days per week. For complete Water Use Rules visit our Saving Outdoors page and get your Watering Guide.
Additional Drought Resources:
