Important Notice: Please Comply with Statewide Stay at Home Order

Visit our coronavirus page to stay up-to-date on the latest information and resources.



Resilient St. Vrain

Areas of Work & Schedule

Press Enter to show all options, press Tab go to next option

Resilient St. Vrain: Restore & Revitalize


The Resilient St. Vrain project is divided into work areas called reaches. A reach is an engineering term used to describe a particular section of river or creek.

Construction on this very large project is taking place in phases. It began at the downstream end of the St. Vrain Creek (at Sandstone Ranch) in 2016. The work will take many years to fully complete, including time for vegetation to take hold and grow. All construction dates and costs are estimated and subject to change as the project progresses. View funding and estimated construction dates for reaches >

Current Reaches

The City Reach follows the St. Vrain Creek through urban, developed areas of Longmont. Construction work here will:

  • restore the flood-damaged St. Vrain Greenway
  • protect people, property and infrastructure by improving the creek channel
  • reduce future flood risks by shrinking the size of the floodplain
  • be completed in an environmentally responsible manner

City Reach 2A: Main Street to just west of South Pratt Parkway


Construction began in August 2018 and is expected to last approximately 12-15 months.

  • This reach includes a wider creek channel between Main Street and South Pratt Parkway.
  • Modular block walls are being installed in the tighter urban corridor west of South Pratt Parkway.
  • Over 150,000 native plants will be added, along with over 30,000 square feet of wetland sod and nearly 10 acres of seeding. View a list of species planted through the Resilient St. Vrain Project >
  • South Pratt Parkway Bridge has been replaced.

City Reach 2B: West of South Pratt Parkway to BNSF Railroad Bridge


Construction began in July 2019 and is expected to last approximately 12-15 months.

  • BNSF Railroad Bridge will be replaced as part of an agreement between Longmont and BNSF.
  • The St. Vrain Creek channel will be improved to help protect the community from future flood risks.
  • Modular block walls will be installed in this reach.
  • The St. Vrain Greenway will be closed during most of the work in this area. The trail closure begins in July 2019. On-street detour routes are posted, and signs like those shown below are at each end of the detour. Click the image to open a PDF that can be downloaded or printed for reference.

Map showing route of St Vrain Greenway Trail Detour

Future Reaches

Izaak Walton Reach 1: Upstream of BNSF Railroad Bridge to Boston Avenue


This reach is currently in the final design phase, which is anticipated to conclude later in 2019. Construction is anticipated for 2020.

  • A sanitary sewer pipe that crosses the St. Vrain Creek upstream of the Boston Avenue Bridge will be relocated.
  • Modular block walls will be installed in this reach.
  • This is the shortest reach within the Resilient St. Vrain project.

Izaak Walton Reach 2: Boston Avenue to Sunset Street


Longmont has partnered with the U.S. Army Corps of Engineers on a feasibility study regarding work in the area located between the BNSF Railroad Bridge and Lykins Gulch. This reach is under consideration for the USACE's project work and funding. Read more about the feasibility study >

  • Sunset Street Bridge has been replaced.
  • Boston Avenue Bridge will be replaced.
  • Once work has been completed in this reach, the floodplain to the north of the St. Vrain Creek will be mitigated.

Upstream of Sunset Street to Airport Road


  • Completing work through Roger's Grove/Hover Road would achieve the Resilient St. Vrain project's goal of removing the majority of the developed portions of Longmont downstream (west) of Hover from the 100-year floodplain.
  • Final design work on these areas has not yet begun, and funding has not yet been secured.
  • This area includes Roger's Grove Nature Area/Fairgounds Pond, Golden Ponds Nature Area and Lykins Gulch.
  • Creek crossings at Hover Street and Airport Road are in this reach.

Completed Reaches

City Reach 1: Left Hand Creek confluence (east of Martin Street) to Main Street



    Sandstone Reach


      Sandstone Reach follows the St. Vrain Creek through the Sandstone Ranch Nature Area and surrounding open space. Construction began in November 2016 and continued through spring 2018.

      Goals of work in this area were to:

      • restore the flood-damaged St. Vrain Greenway. The trail is now fully open though this area.
      • stabilize creek banks to protect trails, access roads and infrastructure from future flood damage
      • help nature re-establish vegetation and wetlands habitat for fish and wildlife. Nearly 200,000 native plants were added. View a list of species planted through the Resilient St. Vrain Project >


    Free viewers are required for some of the attached documents.
    They can be downloaded by clicking on the icons below.

    Acrobat Reader Download Acrobat Reader Flash Player Download Flash Player Windows Media Player Download Windows Media Player Microsoft Silverlight Download Microsoft Silverlight Word Viewer Download Word Viewer Excel Viewer Download Excel Viewer PowerPoint Viewer Download PowerPoint Viewer
    View Full Site