Street Snow Removal


A short video of hard working staff plowing in formation during a recent snow storm. Note the additional "plow wing" on the lead truck that lets the operators plow a few more feet of roadway each pass. The wing can be raised and stowed out of the way with the push of a button. Three of the four trucks have a live bottom system, which spreads ice slicer before the rear wheels for better traction while a third truck in line has a vbox spreader at the rear of the truck.

Submit a snow removal service request through My Thornton.

Our Task

There are over 374 miles of Primary Streets (like 120th Avenue and Colorado Boulevard) in Thornton. There are 308 Secondary Streets (like Eppinger Boulevard and Cottonwood Lakes Boulevard), and an additional 619 miles of Residential Streets, which totals more than 1,300 miles of road within city limits. Snowplows continuously plow all Primaries to keep roads open, followed by Secondaries routes as weather permits.

​​​​​​The city divides storms into three classes and responds accordingly. 

  • Class I - A storm that lasts less than 12 hours with snow accumulations of less than 4 inches.
  • Class IIA storm that lasts more than 12 hours with snow accumulations between 4 and 8 inches.
  • Class III A storm that lasts more than 24 hours and snow accumulations greater than 9 inches.

In the event of any snowstorm, the city's first commitment is to clear the Primaries, then the Secondaries — and keep them cleared. In the case of a Class III storm (and only in this case), the city will bring in additional equipment to plow residential streets. Residential streets will receive one pass down the middle of the street, not a curb-to-curb street clearing, and the snow is plowed to the right side of the street.

During large storms, snowfall may be so heavy that only Primaries can be maintained in a passable condition until the storm lets up. When Primaries are clear, then Secondaries are plowed.

For more information on snow removal, please visit:

​​Streets - First Attention  

Priorities - The first priority for city plows are the primary routes: the major arterial streets such as Colorado Boulevard, Washington Street, 104th Avenue, 120th Avenue, and 136th Avenue. Next to be plowed are the secondary routes which include local collector streets, school zones, and fire station zones. ​Residential streets are only plowed for a Class III storm as defined above.

​During a StormIn a Class I or Class II storm, city crews will plow only selected streets identified as Primary and Secondary routes. Primary and Secondary routes make up 496 lane miles of Thornton's street system. In a Class I storm, Primary routes are treated within three hours of the snow beginning to accumulate on roadways. Secondary routes will be cleared of snow and ice after the primary routes are completed.

Tertiary Routes - In the event of a storm, which meets the Class II definition plus a prolonged period of freezing temperatures, a decision is made to plow Tertiary routes which include an additional 55 miles of neighborhood streets.  These routes are cleared by Street Operations personnel once the primary and secondary streets are cleared and treated.  These routes will receive one pass down the middle of the street, not a curb-to-curb street clearing.

During Class II and Class III storms, snowfall may be so heavy that only Primary routes can be maintained in a passable condition until the storm abates. When Primary routes are clear, then Secondary routes are plowed.  Residential streets are only plowed during Class III storms. 

Residential Streets and Plowing Shifts  

Residential Streets - After residential streets are plowed, residents will not necessarily see bare pavement. The emphasis for residential streets is to create a single passable lane down the middle that can be navigated by passenger vehicles equipped for winter travel. 

Blocked Driveways - During heavy snowfalls, problems arise for residents when mounds of snow left on the sides of streets may block driveways, these are also known as windrows. Although a concerted effort is made to avoid this, it is not always possible. Residential streets are plowed down the center of the street in an effort to avoid covering sidewalks, parked cars, and blocking driveways. The city of Thornton does not remove or haul away snow as part of this program, and it is the resident's responsibility to clear these windrows.

Snowplow Deployment and Shifts - When the snow hits, all of our crews and equipment work 12-hour shifts and in the event of a Class III storm, the city also has its contractors working to remove the snow.