The League of Water Savers

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Water Restriction Information

Living in a semi-arid climate, drought and water restrictions have been a reality for Colorado residents in the past. With your help, we can conserve our water supply and possibly avoid the need to impose mandatory water restrictions. Our goal is to conserve year-round by using water wisely. Due to the naturally occurring cycles of drought, there may be times when the City of Thornton will need to observe voluntary or mandatory water restrictions. City residents will be notified of a change in restriction level, but can always visit this Web page to find the most current drought status.

drought status key

South Platte River Basin Snowpack

Colorado's Drought Response Portal

Lawn Care Tips

Colorado Water 101 - Drought

To view Thornton's Drought Management Plan click here.

Frequently Asked Questions

Water restrictions are always a possiblity. To help you understand the Water Use Rules and Guidelines, take a look at our Frequently Asked Questions below. Contact us if you need additional information.

Residential Irrigation Questions
Other Residential Questions
Water Conservation Program Questions
General Questions
Recreation Questions
Violation/Notification/Penalty Questions
Commercial/Industrial Questions
Reporting Water Waste

Residential Irrigation:

Q. How often should I water my lawn?
A. You can have a healthy lawn and only water TWO days per week during most of the irrigation season. For those 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. Modern sprinkler system timers have a cycle function. Click here to download a recommended 2 day per week watering guide.


Q. How do I know if the sprinkler heads in my irrigation system are spray, rotor or impact heads?
A. Spray heads do not rotate and will emit a continuous flow of water. The entire area of ground they cover will receive water for the full amount of time the spray heads are running. Rotor and impact heads will move the spray of water in an arc pattern. Therefore, only a portion of the spray area will receive water as the rotor or impact head rotates. Rotor heads have slower precipitation rates than spray heads.


Q. When I water, after about 10 minutes water runs off and flows down the gutter. Is there a better way to water?
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. Click here to see how cycle and soak watering works.


Q. What exactly is a zone?
A. 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).

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Q. Can I haul water in from another location to water my lawn?
A. No. The City prohibits the use of water supplied from sources other than the City of Thornton.

Q.Can I capture rainwater at home to save for personal use like gardens?
A. Although it is permissible to direct your residential property roof downspouts toward landscaped areas, unless you own a specific type of exempt well permit, you cannot collect rainwater in any other manner, such as storage in a cistern or tank, for later use.

For more information on this topic:


Q. How much and how often should I water my trees?
A. 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 for about $20.00. 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 web site that gives useful information on plant care. Try out their question and answer forum.


Q. When should I fertilize my lawn and landscaping?
A. 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 nurtients 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.

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Other Residential Questions:

Q. Is Xeriscaping allowed?
A. Xeriscaping is allowed and encouraged in the City of Thornton. Here are some highlights from the City Code that might be of interest to you:

  • 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.
  • The use of artificial trees, shrubs, turf, vines or other plants is prohibited.
  • Plants may not intrude onto or overhang sidewalks or other pedestrian areas.
  • Water-wise landscaping.

  • (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,

For questions about City Landscape Code, please call 303-538-7295

Check out our water-wise landscape resources at


Q. Can large outdoor fountains, waterfalls or ornamental ponds be operated?
A.While we are in a drought warning, the City asks customers to shut down ornamental fountains and ponds that do not recycle water.


Q. Can I use graywater (water from my washing machine, tubs, or sinks) to water my outdoor vegetation?
A. 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 Web site for more information on using graywater and harvesting rainwater.

Q. Can I install artificial turf?
Maybe.  Artificial turf is allowed in some residential areas of the City.  In areas where it is allowed, artificial turf may be installed in side yards that are not visible from the public rights-of-way, and in rear yards.  Artificial turf is not allowed in front yards or in nonresidential areas.  There are additional installation, maintenance, appearance, and other standards included in the City Code, and a permit is required prior to installation.   For more information on artificial turf permits or requirements, contact the Current Planning Division staff at or 303-538-7295.


Water Conservation Programs:

Q. Is the City of Thornton offering any water conservation rebates?
A. Yes, the City of Thornton offers residential water customers the chance to receive $100 credit on their water bill for purchasing a new water-efficient washing machine, and a credit of $75 for replacing a 3.5+ GPF toilet with an EPA WaterSense certified toilet. The City also offers a WaterSense irrigation controller rebate. Please go to Rebates and Free Stuff or call 720-977-6600 to obtain the program rules before you purchase your water saving fixture. Other restrictions apply to these programs.

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Q. Are there other ways to save water indoors?
A. 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-checks are offered on a first come, first served basis to Thornton water customers. Water Check-ups are similar to energy audits, only for the purpose of saving water. Water customer may call Center for ReSource Conservation at 303-999-3820, ext. 217 or go to and click on Slow the Flow Indoors for more information or to schedule a water check-up.


Q. Does the City offer any programs to help save water outdoors?
A. Yes, the City has teamed up with the Center for ReSource Conservation to offer a limited number of FREE irrigation inspections to a residential water customers with automatic irrigation systems. Irrigation inspections provide valuable information that can help improve a system's efficiency, save water, and improve lawn appearance. Free inspections are offered on a first come, first served basis from June through the first week of August. Residents may call CRC at 303-999-3820, ext. 217 or go to to schedule in irrigation inspection.


General Questions:

Q. Can I wash my sidewalks, driveway or patio?
A. We recommend using a broom intead of a hose to clean impervious surfaces such as sidewalks, driveways and patios. Try to minimize non-essential uses of water, when possible.


Q. Can I wash my car in my driveway this summer?
A. 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.

Q. Can I fill my pool this summer?
A. 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 through evaporation.

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Q. Can I pull my car onto my lawn to wash it?
A. City Code prohibits residents from parking their cars on landscaped areas; however, temporarily parking your car on your lawn to wash it is okay.


Q. Will automatic car washes remain open?
A. Yes, automatic car washes will remain open. Many automatic car washes use recycling water systems for their operations.


Q. Why do I see water shooting out of hydrants?
A. There are two reasons water might be flowing from a hydrant. The first is that the City of Thornton has to occasionally flush certain hydrants to meet water quality standards. The City will monitor the quality of water in the distribution lines to determine if a once-a-year flushing program will suffice to meet standards and also conserve water. The second is that during construction and repairs on the pipes in our distribution system, hydrants sometimes have to be turned on. During these operations, it is usually not possible to capture this water for later use.


Recreation Questions:

Q.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. It is our intent to replace the loss of ET, evapotranspiration, when possible; however, site conditions dictate what final adjustments are made to watering schedules. ET is the loss of water from evaporation of water from the soil and transpiration by the plant. This ET rating is generally given on local weather reports.

The City follows a practice called Cycle and Soak when we apply the water to our landscapes. Our maintenance staff will determine what the infiltration rate is for the soil, this is how much water the soil can take in before the water begins to puddle or run off. This infiltration rate is different throughout the City as well as throughout any given park. Slope areas have a different rate than flat areas; clay soils have different rates than amended soils or sandy loam soils. High-use compacted areas have a different rate than passive areas. Once the infiltration rate is determined for that park area, the water is divided into 2 or 3 watering cycles. The watering cycle will water for a given time-frame then the water is allowed to soak into the soil before the second or third cycle begins. This practice allows for the soil to take in more water over a given period of time and helps to promote deeper roots for the turf or plant.

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.

football game

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.

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Q. Will Eastlake 3 and Hunter's Glen Lakes be refilled in the spring?
A. The lakes will be refilled as the water supply allows.


Water Waste:

Q. What is considered water waste?
A. 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.


Q. How will notification of violations for water waste be handled?
A. 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.


Q. Is there an appeal process for violations?
A. 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.

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Commercial/Industrial Questions:

Q. Are there any restrictions for restaurants?
A. Restaurants are encouraged to serve water only upon customer request.


Reporting Water Waste:

Q. What do I do if I see water waste?
A. 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 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.

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