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Marion Street Storm System




The purpose of this project is to further address significant historical flooding areas in the Whittier, Five Points and City Park West neighborhoods. This phase of the project will connect into the recently completed 33rd Street Outfall project, at the intersection of MLK Jr Boulevard and Marion Street. Future phases will extend this storm sewer infrastructure south to the intersection of 21st Avenue and Downing Street, where it will tie into, and relieve, an overburdened existing 84” storm sewer system. 

General Information

This project will install new 8’ x 8’ Reinforced Concrete Box Culvert in Marion Street to the intersection with 27th Avenue. 

In addition to installing the new 8’ x 8’ storm sewer infrastructure, the Marion Street System project will:

  • Install new storm inlets and manholes
  • Install new water quality features to reduce trash/debris from entering into the storm sewer system
  • Install new ADA compliant pedestrian ramps at all intersections
  • Upgrade existing curb cuts to be compliant with City of Denver transportation standards
  • Relocate and install new Denver Water main lines
  • Replace Denver Water lead service lines with new copper lines from the new water main to the property owners’ meter
  • Provide new bike lane at East Whittier Island Park
  • Reshape Marion Street to provide greater surface water storm runoff capacity
  • Provide new full depth paving on Marion Street

map of work along Marion Street from MLK Jr. Blvd to 27th Avenue 

Project Status

Project Start: Construction is expected to begin in July 2020, with completion anticipated in March / April 2021. These dates may be pushed out a few weeks if there are unforeseen COVID-19 impacts.

Estimated Completion Date: March 2021

Future Phases: Dates TBD

Council District: 9

Neighborhoods: Whittier, Cole, Curtis Park, Five Points

Virtual Information Session

We invite you to learn more about the upcoming Marion Street System Project:

In lieu of a physical community meeting, we will be holding a virtual information session via Microsoft Teams.

We encourage you to submit questions prior to the meeting via the project email address ( — these questions will be answered live, after the presentation.


Construction Methods, Impacts and Detours


Construction Methods: Storm drainage systems are far beneath the surface of city streets, and thus require shoring of the excavation sites to ensure the safety of the workers below. There are many types and methods of shoring that have been used on previous stormwater projects — some of these methods are more invasive than others. Sheet piling and beam and lagging shoring systems are examples of shoring methods that are more invasive. Slide rail and trench boxes are examples of the less invasive shoring systems. 

For this phase of the Marion Street System project the contractor will be using a slide rail system, a minimally invasive shoring method. As a result, we don’t anticipate having any vibration issues—but we will have vibration monitors in place throughout the project.

Impacts: To minimize disturbance to the neighborhood on this large-scale construction project, closures on Marion Street will be limited to three blocks and two intersections at a time. Any one block is anticipated to be closed for a two to three-month period of time. During this time, residents should anticipate not being able to access on street parking and curb cuts in front of their property. 

Homeowners will always have front entry access to their homes via the sidewalks. As ramps at the intersections are replaced, there will be some sidewalk closures near the intersections, but access for pedestrians to cross will be maintained on one side or the other as work progresses.

Alleys will remain open throughout construction. Trash pick-up in this area is through the alleyways so we anticipate no interruption to trash / recycle service.

Parking in front of residences will be affected for the three-month period during the work on each section of Marion. We are working on plans to assist with parking, but residents should prepare to find other parking during this period. 

Detours: 31st Avenue is anticipated to be the only arterial street that will be detoured during this construction project.  While closed, vehicular traffic will be detoured to 29th Avenue and Bruce Randolph Avenue.  The detour for the 31st Ave protected bike lane is still being finalized. All collector and local street traffic will be detoured to adjacent streets and avenues.  

RTD will experience bus stop closures and detours to routes 28 and 43. Please visit for more information.


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Hotline: 720-677-0330
Call or text the project hotline; get weekly updates, leave a voicemail or text with questions or concerns.

Text MARION to 31996 to receive text updates during construction.

City and County of Denver

Matt Fariss, Project Manager
Department of Transportation & Infrastructure
720-667-7052 (Mobile)



Concrete Works of Colorado
Mark Almond, Project Manager