High Line Canal Stormwater Quality Pilot Project

Please Note: As the High Line Canal Stormwater Quality Structure construction project gets underway, please keep in mind that the work is taking place in an active waterway. Plans, schedules and completion dates are subject to change due to weather, water levels and other factors.  The latest construction information will be posted on this project webpage. 

Wellshire Golf Course

Anticipated completion: late June 2021

• Construction of Water Quality Structure in the High Line Canal just west of S. Colorado Boulevard, adjacent to the 9th hole.

S. Ash Street at High Line Canal dead-end

Anticipated completion: late June 2021

• Street and sidewalk reconstruction (“drive-through forebay”) to filter out debris and clean stormwater prior to release into the Canal.

High Line Canal immediately west of S. Dahlia Street

Anticipated construction start: late June 2021

• Construction of  Water Quality Structure in the Canal just west of S. Dahlia Street.
• High Line Canal trail will be closed from S. Dahlia Street to just east of the S. Bellaire Street bridge.
• A detour is in place directing bicyclists to proceed south on S. Dahlia Street, then west on E. Eastman Avenue in the designated bike lane on the north side of E. Eastman between S. Dahlia Street and S. Colorado Boulevard.
• Denver Parks and Recreation will perform trail repairs while the trail is closed for installation of the Dahlia Water Quality Structure.

S. Bellaire Street at High Line Canal dead-end

Anticipated completion: late June/early July 2021 

• Street and sidewalk reconstruction (“drive-through forebay”) to filter out debris and clean stormwater prior to release into the Canal.
• The pedestrian bridge over the High Line Canal connecting S. Bellaire Street to the Canal trail has been reopened. Please use caution when using the sidewalk to access the bridge, as crews are completing restoration work in the S. Bellaire cul-de-sac. 

S. Dexter Street at High Line Canal dead-end

Anticipated completion: late June/early July 2021

• Street and sidewalk reconstruction (“drive-through forebay”) to filter out debris and clean stormwater prior to release into the Canal. 

High Line Canal at I-25 between S. Grape Way and S. Holly Street

Anticipated construction start: early July 2021

• Construction of Water Quality Structure in the Canal.
• Bicycle access will be maintained; however cyclists may be directed to dismount in the construction area.

E. Eastman Avenue and S. Glencoe Street Intersection

Anticipated construction start: early July 2021

• Installation of underground water quality vault in storm sewer system that removes debris and sediment prior to canal release.
• Intersection will be closed to through traffic for approximately 4 to 5 weeks.
• Work will require intermittent water disruptions. Impacted property owners will be notified in advance. 

S. Forest Street and High Line Canal Dead-end/Bridge Repair

Anticipated completion: mid-July 2021

• Street and sidewalk reconstruction (“drive-through forebay”) to filter out debris and clean stormwater prior to release into the Canal.
• Pedestrian bridge over High Line Canal connecting S. Forest Street to High Line Canal trail will remain accessible during this phase of construction.
• Bridge will be closed to undergo deck/plank repair after the Holly Street bridge is replaced and opened to pedestrians (see below).

S. Holly Street Bridge Replacement over High Line Canal

Anticipated demolition/bridge removal start: mid-July 2021
Anticipated new bridge installation start: early August 2021
Anticipated completion: late August/early September 

• Removal of existing damaged bridge.
• Installation of new bridge to replace damaged bridge. 

S. Holly Street between E. Eastman Avenue and the High Line Canal

Anticipated construction start: mid-July 2021

• Installation of underground water quality vault in storm sewer system that removes debris and sediment prior to canal release.
• Traffic on South Holly Street adjacent to construction will be reduced and narrowed for access heading north.

The High Line Canal Stormwater Quality Pilot Project is a groundbreaking “green infrastructure” project undertaken by the City of Denver’s Department of Transportation and Infrastructure (DOTI) in collaboration with the High Line Canal Conservancy, the Mile High Flood Control District and Denver Water. The approximately one-mile long stormwater management project includes installation of three stormwater quality structures in the Canal to clean and hold stormwater for slow release over an extended period of time.

The project also includes installation of two underground stormwater vaults to remove trash and sediment as well as four locations where slotted curbs (“forebays”) and grass swales will be installed at existing storm outfalls on the south side of the Canal to help clean stormwater flowing into the Canal.

Construction has begun at Wellshire Golf Course and will proceed east in Mamie D. Eisenhower Park culminating at the Interstate 25 underpass. The construction timeline is posted on the project webpage (denvergov.org/DOTIprojects). Please keep in mind that the High Line Canal Stormwater Quality pilot project construction is taking place in an active waterway. Plans, schedules and completion dates are subject to change due to weather, water levels and other factors. The project is currently scheduled to take approximately 7-9 months to complete.

The stormwater quality structures in the Canal consist of a partially buried concrete wall with surrounding boulders, a 24”x 40” weir plate, and an 18”x 24” aluminum slide gate, giving the structure both function and aesthetics.  The Canal structures at Wellshire Golf Course and S. Holly Street will have an additional 7’ wall made of pressure treated wood logs. These structures were designed to resemble historical water management devices that once occupied the Canal. Illustrations of the various stormwater quality structures are included on the project website.

A forebay is a slotted curb that slows and cleans stormwater as it flows from the street and into the Canal.  Holes in the street curb allow stormwater to pass though, and the stormwater ponding at the curb forces solids to settle in the gutter rather than entering the Canal.  Street-sweeping trucks can drive through the gutter and sweep up the dirt and solids.  Behind the curb, stormwater passes through a swale (a grassy, permeable zone) that further cleans stormwater before spilling into the Canal.

Access to and along the High Line Canal trail will be restricted along short distances while the water quality features are built in the Canal west of S. Dahlia Street and east of S. Holly Street. During construction of the S. Dahlia structure, a trail detour will be in place from S. Dahlia Street and Eisenhower Park to S. Colorado Boulevard via E. Eastman Avenue. Signage will be in place in advance of the closure to alert trail users, and details about the closure will be posted on the project web page and included in email updates.

Additionally, bridge closures will be required for approximately six weeks at S. Bellaire Street and at S. Forest Street on the south side of the Canal while crews install each forebay. The bridges will not be closed at the same time. As construction involves the use of heavy equipment, please follow and adhere to all directional signage and safety protocols during construction.

Construction crews will clear limited sections of shrubs, vegetation, volunteer shoots, and small invasive trees in Denver Water property in order to access the Canal during construction. At this time, no privately owned trees have been identified for removal, and only one City-owned tree may need to be removed for construction at S. Forest Street.

Construction will occur generally from 7 a.m. to 5 p.m. on weekdays. Saturday work may occasionally be required, between the hours of 8 a.m. and 5 p.m.

DOTI has created a webpage devoted specifically to this project, and construction updates will be posted regularly. Visit www.denvergov.org/DOTIprojects, scroll down to "Storm/Sanitary Sewer Infrastructure" and click on "High Line Canal Stormwater Quality".

To sign up and receive emailed project updates, please send a request to ccd.constructionupdates@gmail.com.

• For general questions not requiring an immediate response, email ccd.constructionupdates@gmail.com or call the project hotline 720 460-9055. Emails and messages are checked daily during normal work hours.
• For questions about active construction issues requiring an immediate response during normal work hours:
  • Austin Konkel, contractor, akonkel@hamoninfrastructure.com, 303 472-6296
  • Gary Padilla, Project Manager, gary.padilla@denvergov.org, 720 291-5731
  • Mark Barry, on-site inspector, mark.barry@denvergov.org, 303 877-6083