US 36 Bridges at St. Vrain and Left Hand Creek

Slope protection on an irrigation supply ditch, March 2018

Project Facts

  • Budget: $10 million to $20 million

Project Team

  • Contractor: American Civil Constructors

Project Update

On March 8, 2018, crews poured the bridge deck on the Left Hand Creek Bridge. They will continue to work on the two bridges just west of Lyons by armoring the slopes and channel under the bridge and building new wing walls for the bridge that will be replaced. This work may require short traffic holds as equipment moves in/out of the area.

Traffic Impacts

  • Normal work hours: 8:30 a.m. – 3:30 p.m. Monday through Friday
  • Traffic will be reduced to one lane during paving.
  • A 25 mph speed limit will be strictly enforced within the mile-long workzone during this two-week window.

Damage Overview

This section of US 36 is one of the main corridors providing access between Estes Park and Boulder crossing both the St. Vrain Creek and Left Hand Creek. Floodwaters caused extensive damage to these channels as well as the structures along US 36. Damage included large amounts of debris an sediment deposit, erosion of the roadway embankment, overtopping of the roadway, scour damage of the bridge piers and abutments, and exposing underground utilities. 



One of the goals in the repair process is to introduce certain betterments to roadway facilities that were damaged and make them more resilient to similar storm events in the future. Having analyzed the damage caused during the flood event, certain design elements will be incorporated in an effort to prevent or lessen the severe damage that significant flood events can cause. The permanent repair phase will allow for the betterment of drainage facilities and erosion protection areas throughout the corridor that can handle the high flows from large storm events and protect facilities from potential damage in the future.

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