Water restrictions are always a possibility. Review our Frequently Asked Questions below to better understand the Water Use Rules and Guidelines. Contact us for additional information.

Residential Irrigation and Landscaping

How often should I water my lawn?
You can have a healthy green lawn watering only TWO days per week during most of the irrigation season. With automatic sprinkler systems, the best way to water is to run each zone in short cycles. For example, if you normally run a zone for 15 minutes on a watering day, split the time into three 5-minute cycles with an hour in between cycles. Most sprinkler system timers have a cycle function. Download a recommended 2 day per week watering guide.

To learn more about programming your irrigation controller check out this factsheet.
What do I do if water runs into the gutter during my watering cycle?
Watering one zone for too long results in wasted water and storm water pollution. When watering, once the soil is saturated, it's like a wet sponge. It can't take in any more water. The excess water flows down into the ground or over sidewalks and gutters into the storm drain. The most efficient way to water is to cycle and soak.
For example, using the watering guide for August, we recommend scheduling fixed pop- up spray heads for 20 minutes on each watering day (2 day/week watering schedule). After 10 minutes, the clay soil will be saturated and the rest of the water will probably run off into the street. To avoid wasting water and to get the full benefit from water you are applying, split up and shorten your watering times by programming 2 cycles on your watering day. For example, in August, schedule the fixed pop-up spray heads for 10 minutes at time, with 2 different start times about an hour apart. If water is still running off, try 3 different start times and set the spray zones to run for 6 minutes. See how cycle and soak works.
What is a zone?
A zone refers to all sprinkler heads controlled by one valve (and all the turf area covered by the water spray from those sprinkler heads).
Can I haul water in from another location to water my lawn?
No. The City prohibits the use of water supplied from sources other than the City of Thornton.
Can I capture rainwater at home to save for personal use like gardens?
Most homeowners in Colorado are now allowed to use rain barrels to collect rainwater. A maximum of two rain barrels with a combined storage of 110 gallons or less are allowed at each household. Collected rainwater may be used to irrigate outdoor lawns, plants or gardens.
For more information on this topic: CSU Rainwater Collection in Colorado
How much and how often should I water my trees?
In general, water trees once or twice a month in the winter, three or four times a month in the summer, using a soaker hose or deep root probe. For each inch of the tree's diameter, apply 10 gallons of water. A three-inch diameter tree will need 30 gallons of water applied at least once a month. Water slowly so that it will reach a depth of 12 inches into the soil. Most of a tree's absorbing roots are located in the top 12 inches of soil. If you use a deep root probe, insert it no more than eight inches into the soil. Apply the water at many locations around the tree's dripline, but not too close to the trunk. Deep root probes can be purchased at home improvement stores. Check out the Thornton Forestry page for more information on trees in Thornton.

If you have specific questions related to how much water a particular plant needs, please call a local nursery or the Adams County Cooperative Extension office at 303-637-8100. Colorado State University's Cooperative Extension has a website that gives useful information on plant care. Follow this link to ask a Colorado Master Gardner.
When should I fertilize my lawn and landscaping?
Colorado State University Cooperative Extension recommends that lawns be fertilized according to manufacturers' instructions in the fall using a fertilizer with a combination of nitrogen sources that will be available immediately and released slowly. If you have a new lawn with compacted soils, you may need to fertilize in the spring too.

Looking for an inexpensive way to fertilize? Try returning your lawn clippings back on the lawn while mowing. Clippings contain nitrogen and other nutrients that will be recycled back into your lawn, promoting healthy grass growth. Clippings on the lawn also mean no bagging or hauling which saves both human and fuel energy.

Is Xeriscaping allowed?
Xeriscaping is allowed and encouraged in the City of Thornton. There is no minimum amount of lawn required for existing residential properties, however regular maintenance is required regardless of the landscape design. All areas of your lot that are not covered by buildings, sidewalks, decks, patios or driveways must be landscaped or mulched. Weeds and bare ground are not considered landscaping. Landscaping includes living plant materials such as trees, shrubs, grass, groundcovers, flowers, etc. and other features such as fountains, pools and benches. Mulch includes rock, stone, bark and other organic or inorganic materials typically used to retain soil moisture and hinder weed growth. Artificial turf is allowed in limited applications. Artificial turf reqires a permit and is allowed in side yards that are not visable from the public right of way and back yards. Click here for more information on artificial turf. The use of artificial trees, shrubs, vines or other plants is prohibited.

Water-wise Landscaping City Code
(a) Water-wise landscaping is required on all development, private or public, in recognition of our semi-arid climate and limited amount of water available for outdoor uses. This approach to landscaping shall be done by incorporating water-wise landscape principles into development permit landscape requirements.
(b) Water-wise landscape principles include:
(1) Promoting the use of low water-demand turf and plants and a balance of landscape materials.
(2) Promoting practical turf areas by limiting the use of high water-demand turf and plants to areas of high visibility or functional needs.
(3) Grouping plants with similar water and environmental requirements together on the same irrigation zone.
(4) Use of efficient irrigation systems.
(5) Use of soil amendments and mulches, generally organic and biodegradable.
(c) No person, organization, or association may create or impose restrictive covenants, conditions, restrictions, deed clauses or other agreements between the parties that prevent the use of water-wise landscaping.
For the full City Code click on this link, http://library.municode.com/index.aspx?clientID=15041&stateID=6&statename=Colorado.
If you have questions about City Landscape Code, please call 303-538-7295
Check out additional water-wise landscape information on the tips and resources page.
Is artificial turf allowed?
Artificial turf is allowed in limited applications. Artificial turf reqires a permit and is allowed in side yards that are not visable from the public right of way and back yards. Click here for more information on artificial turf. The use of artificial trees, shrubs, vines or other plants is prohibited. If you have questions about City Landscape Code, please call 303-538-7295

Check out additional water-wise landscape information on the tips and resources page.
Can large outdoor fountains, waterfalls or ornamental ponds be operated?
If Thornton is in a drought warning, the City asks customers to shut down ornamental fountains and ponds that do not recycle water.
Can I use graywater (water from my washing machine, tubs, or sinks) to water my outdoor vegetation?
No. The use of graywater is regulated by the Tri-County Health Department. Graywater use is a public health issue because it contains harmful bacteria and viruses. Both graywater and black water (water from toilets) are regarded as wastewater. Tri-County Health Department regulations state that for any home serviced by a public sewer system, all wastewater must go down the drain. Since Thornton residents are serviced by a public sewer system, graywater use in Thornton is prohibited. Please visit CSU's website and Tri-County's Water website for more information on using graywater and harvesting rainwater.

Water Conservation Programs

What rebates are available?
The City of Thornton offers residential and commercial rebates to help customers upgrade to water efficient fixtures. Please go to Rebates and Free Services or call 720-977-6600 for information on rebates and to obtain the program rules before you purchase your water saving fixture.
Can I receive a rebate, even if I pay my HOA for water?
Yes, if you are in the Thornton water service area, but you pay an HOA for water you can still qualify for water rebates. Please go to Rebates and Free Services or call 720-977-6600 for information on rebates and to obtain the program rules before you purchase your water saving fixture.
Are there other ways to save water indoors?
Yes, residential water customers can bring their old, water-wasting showerhead (delivers more than 2.0 gallons of water per minute) and exchange it for a free, highly-rated, Earth Massage Showerhead by Niagara Conservation Corporation. Customers may exchange showerheads at the Water Resources Division located at 12450 Washington Street. Proof of Thornton residency (or proof that the residence receives water from the City of Thornton) is required at the time of exchange. Limit of two showerheads per residence. For more information, please call 720-977-6600.

Free indoor water use consultations are offered on a first come, first served basis to Thornton water customers. The consulations are similar to energy audits, only for the purpose of saving water. Water customers may call Center for ReSource Conservation at 303-999-3824 or go to www.conservationcenter.org for more information or to schedule an indoor water use consultation.
Does Thornton offer any programs to help save water outdoors?
Yes, the city partners with the Center for ReSource Conservation to offer a limited number of FREE sprinkler consultations to residential water customers with automatic irrigation systems. Participants schedule an appointment to meet with a trained water conservation technician at their home and learn how to save water and money while keeping their lawn healthy and green! The consultations are offered on a first come, first served basis from June through August. Residents can call CRC at 303-999-3824 or go to www.conservationcenter.org to schedule an appointment.
Does Thornton offer any programs to help with my water bill?
Yes, the city has resources to help customers with their water bills. Visit the Utility Billing webpage to learn about bill payment options and budget billing. You can also check out the Thornton Water Assistance Program to see if you qualify. To speak with someone about your bill and payment options call Utility Billing at 303-538-7370.


Can I wash my sidewalks, driveway or patio?
We recommend using a broom instead of a hose to clean impervious surfaces such as sidewalks, driveways and patios. Try to minimize non-essential uses of water, when possible.
Can I wash my car in my driveway this summer?
Yes, vehicles may be washed on any day at residences with the use of a bucket or a hand-held hose equipped with a positive shutoff nozzle. The City encourages customers to limit car washing to no more than once a week.
Can I fill my pool this summer?
Pools can be filled, refilled or topped off as long as water is not being wasted. Use of a pool cover is encouraged to reduce water loss.
Is it water conscious to use automatic car washes?
Yes, automatic car washes will remain open. Many automatic car washes use recycling water systems for their operations.
Why do I see water shooting out of hydrants?
The City of Thornton is committed to providing a safe and reliable water supply to its customers. It's standard procedure for water utilities to use a certain amount of water to ensure that the city's infrastructure is maintained. You may see City of Thornton Utilities crews working in the community, allowing water to run into the street. Periodic flushing of fire hydrants and testing of water meters are important preventative maintenance activities that ensure the integrity of the water system, the accuracy of the meter system and the delivery of the highest quality water to our customers.


What are the irrigation practices in City parks?
The City of Thornton Parks & Forestry Division is responsible for maintenance of over 960 acres of parks and public lands. We use a variety of water delivery methods from overhead spray irrigation to subsurface drip irrigation. The City follows a practice called Cycle and Soak when we apply the water to our landscapes. Our maintenance staff will determine water needed for each area based on the location, slope, soil type, sun exposure and vegetation. The water needed is delivered in 2 or 3 watering cycles for a given time-frame. This practice allows for the soil to take in more water over a given period of time and helps to promote deeper roots.

Given the number of acres we have to water, it is not always possible to complete the watering schedules between 10 p.m. and 7 a.m. We also have to give high-use sport turf areas different watering schedules to keep the sites safe for play while maintaining a viable green lawn.

If you have any questions about our watering practices, or want to report a broken sprinkler system component in a park, please call the Parks division at 303-255-7833 or fill out a service request on Thornton Connected.
Will Eastlake 3 and Hunter's Glen Lakes be refilled in the spring?
The lakes will be refilled as the water supply allows.

Water Waste

What is considered water waste?
Wasting water is prohibited by the Water Use Rules. Water waste is defined in the Thornton City Code as the intentional, unintentional, or excessive use of water that is not considered reasonable, prudent or a wise use of water for an authorized purpose, but not limited to, by way of example, the following: Allowing water to be applied in any manner, rate or quantity such that the water is allowed to pool or flow across the ground or into any drainage way, such as gutters, streets, sidewalks, alleys or storm drains is prohibited. Incidental runoff from an irrigation system operated in a reasonable and prudent manner is excepted. Failing to repair, for a period of more than 10 days after notice, leaking or damaged pipe, hose, or irrigation components is prohibited.
How will notification of violations for water waste be handled?
A water customer may be issued a warning first to ensure understanding of the water waste ordinance. If the waste continues, a written notice of violation will be personally served, posted on a structure on the property, or mailed by regular mail to the violator or the owner of the property. The penalty for the first violation is $100, $250 for the second, and $500 for the third violation. The penalty will be added to the violator's utility bill for the property. If the third violation charge is not paid within five days following written notice of violation, the water service will be suspended. At all times, representatives of the City will attempt to talk to the owner of the property to discuss the cause of the violation and to offer information on how to correct the cause of the violation. Our primary goal is to have citizens help us save water.
Is there an appeal process for violations?
Yes, an appeal may be started by requesting a conference with an Infrastructure Department Representative. The request must be made within 10 days of receiving notice of a violation. Contact the Water Resources Division at 720-977-6600.
Reporting Water Waste
When you observe water being wasted, we need to know the exact address, the nature of the problem, and what time it occurs. A representative of the City must witness the water waste. There are many ways you can report issues. You can call the Water Resources Division at 720-977-6600 or email info@thorntonwater.com to report the problem. You can also fill out a service request on Thornton Connected . If you have access to a camera, pictures are a great way to document and help us locate the issue.
Want to report issues using our Thornton Connected iPhone and Android application? The app can be downloaded free.The process is quick and easy. When a resident spots a problem, or needs an issue resolved, they simply open the app, select an issue, take a picture if applicable, and tap submit . If a photo is submitted, the app uses GPS to detect the exact location of the reported problem, and then include the location with the service request. The request will then go directly to the City staff member who is most qualified to address it. You can use this app for water waste or any other issue you would like to report to City staff.

Commercial / Industrial

Are there any restrictions for restaurants?

Restaurants are encouraged to serve water only upon customer request.