Weir Gulch Channel Improvements and Decatur St Bridge

Project Overview

Weir Gulch Segment 1 is a key project in a high-priority basin to reduce flood risk to the Sun Valley neighborhood, increase pedestrian and bike mobility, promote natural habitat and increase recreation along this section of the gulch.This project is a partnership between Denver Parks and Recreation, the Mile High Flood District (MHFD) and the City and County of Denver.

The scope includes replacement of the existing concrete culvert at Decatur Street with a bridge and channel modifications along Weir Gulch from the South Platte River to 8th Avenue. The channel improvements will provide additional conveyance capacity while providing diverse plantings.  Redesign of the adjacent trails and sidewalks to increase mobility along the corridor is also included in the project.

Project Location

Weir Gulch near W 9th Ave & Decatur

Project Timeline

Decatur Street and the Weir Gulch Trail are expected to reopen by mid-September 2026.

This extension is due to spring weather delays that impacted critical bridge work, and unforeseen utility conflicts that required coordination and safe relocation. Keeping the road and trail closed through mid-September allows crews to maintain safe access to the site, move materials and equipment efficiently, and improve public safety as the project team finalizes this phase of work.

Construction activities on Weir Gulch Segment One are expected to be complete by the end of September 2026

Current Project Activities

Construction activities began on Monday, Oct. 20, 2025. As of August 2026, crews have:

• Completed the concrete pour for the drop structure, which will control the flow of water as it passes downstream and provide critical flood mitigation for the Sun Valley neighborhood.
• Placed boulders and other hardscaping elements around the concrete drop structure and secured them with grout.
• Demolished the final remaining portion of the concrete box culvert.
• Installed pedestrian railings on the Decatur Street bridge.
• Placed topsoil, continued planting trees and shrubs, and established native grasses along the trail corridor.
  
  

As construction continues, crews will:

• Install stormwater infrastructure along the 9th Avenue roadway.  
• Install solar lighting along the trail to provide visibility and promote public safety.
• Build the approach to connect the new Decatur Street bridge to the existing roadway.
• Pour new concrete for the sidewalks on Decatur Street. 

Closures and Detours

Decatur Street and 9th Avenue Closure

As of Thursday, Nov. 13, the 9th Avenue and Decatur Street intersection is closed. The road closure is necessary as crews will demolish the existing concrete culvert to facilitate construction of the new Decatur Street bridge and promote the natural habitat of Weir Gulch. Vehicles, pedestrians and cyclists will be detoured around the construction area. 

RTD Bus Route 9 Detour

RTD Route 9 will be detoured to 8th Avenue and Federal Boulevard between the South Platte River and Federal Boulevard.

Trail Closure

As of Thursday, Nov. 13, the Weir Gulch Trail between 8th and 9th avenues from Federal Boulevard to the South Platte River Trail is closed as since it’s an active construction zone. 

Cyclists will be detoured to Hazel Court, the Lakewood Gulch Trail, Bryant Street and Alcott Street to access the South Platte River and Weir Gulch trails. The Weir Gulch Trail is open west of Federal Boulevard.

Work Hours

Construction workdays and hours are anticipated to be Monday through Friday from 7 a.m. to 7 p.m. These hours could be adjusted for specialty work.

Heavy equipment may operate between the hours of 7 a.m. to 5 p.m. any day of the week. Material deliveries and staging may occur overnight. All project activities and schedules are weather dependent and subject to change.