A partnership between the City of Longmont and the U.S. Army Corps of Engineers (USACE) is continuing to move the City’s flood mitigation efforts upstream.

The USACE released its final feasibility report and environmental assessment earlier this month. That report is the result of a study begun in 2017 to find a qualifying project with a cost of approximately $15 million as part of the USACE’s Section 205 program.

The feasibility study built on the existing work done through the City of Longmont’s Resilient St. Vrain Project (RSVP) and initially reviewed the section of the St. Vrain Creek extending from the BNSF railroad bridge (near Price Road) upstream to Lykins Gulch, located west of Airport Road.

Ultimately, the USACE determined that its project will encompass the Boston Avenue Bridge upstream to Sunset Street. It will include channel improvements and a levee along the north bank of St. Vrain Creek adjacent to Izaak Walton Pond and replacement of the Boston Avenue Bridge. The Corps will manage final design and construction of the channel improvements and levee, while the City will design and manage the bridge replacement. Construction on the bridge replacement is currently anticipated to begin in mid-2021, with the channel construction to start in 2022.

Under the 205 program guidelines, the local agency (in this case, Longmont) is required to provide a minimum funding match of 35 percent (approximately $5 million). Longmont’s contribution includes:

• approximately $750,000 in funds for final design and construction;
• credit for the City-owned land and right-of-way along the St. Vrain Creek that will be used for the project and acquisition of additional land and easements required for the project; and
• final design and replacement of the Boston Avenue Bridge over St. Vrain Creek.

The City will maintain the area after completion.

The Longmont City Council approved a negotiated Public Partnership Agreement with the USACE for final design and construction at its Aug. 11 meeting. The USACE project is now entering the design phase. The project will be referred to locally as RSVP Izaak Walton Reach 2.

The Resilient St. Vrain Project is Longmont’s extensive, multi-year plan to fully restore the St. Vrain Greenway and improve the St. Vrain Creek channel to protect people, property and infrastructure from future flood risk. It was developed after Longmont experienced catastrophic flooding in September 2013.

Section 205 of the Flood Control Act of 1948 allows the USACE to construct or improve site-specific flood risk management projects. The Section 205 Program differs from other federal funding sources, such as FEMA and HUD, that Longmont has obtained for previous RSVP phases, in that Corps engineers will design, oversee and construct their portion of the project.

The Final Feasibility Report and Environmental Assessment is available for viewing and download on the USACE’s project webpage at bit.ly/usace-longmont.

Follow progress on the Resilient St. Vrain Project at LongmontColorado.gov/ResilientStVrain or by calling 303-651-8416.