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Glenbrook Detention Basin


The City and County of Denver is constructing a permanent flood protection stormwater detention facility for the Marston neighborhood in South Denver. This new facility, located in the city-owned natural area south of Garrison and Union Park, will enhance storm water detention and water quality throughout the area and mitigate flood risks to adjacent residential properties.

The existing basin was identified as inadequate after flooding in 2005, and plans have been under review since 2010 to improve current conditions. The proposed design will preserve the most of the wetlands in the existing detention basin to promote native vegetation and habitat, in accordance with Denver's Urban Drainage Master Plan.

Project Features

  • A stormwater detention and water quality basin, to temporarily hold water for a few hours during heavy storms to help prevent residential flooding
  • Underground storm sewer facilities with water quality vaults
  • Disconnection of stormwater from Bowles Irrigation Ditch
  • New landscape and irrigation facilities
  • New concrete trail system to connect the existing trails to the neighborhood and Garrison and Union Park, with add-on to the loop trail to the west

Updates — Week of June 18, 2018

  • Project complete!
Project Status: Complete

The final design for the Glenbrook Detention Basin and associated storm water pipes on Garrison Street was completed in March of 2017. Construction began in October 2017 and will conclude in June 2018.


City and County of Denver

Paul Bountry, Construction Engineer, P.E.
Wastewater Capital Projects Management, Denver Public Works
303 446 3719 |

Aaron McMichael
Project Inspector


MA Mortenson, Inc
Rafe Messer
Project Superintendent


Design: 2016–2017

Construction: 2017–18

  • Mid-October to March: install new stormwater pipes under S. Garrison Street between W. Stanford Ave. and Garrison and Union Park, and under Wagon Trail Drive.
  • March to June 2018: improve stormwater detention basin in the natural area south of Garrison and Union Park. 

Construction is expected to begin in October and last between six and eight months. During construction, traffic control signs will be used to close portions of Garrison and Union Park, as well as some roads, sidewalks, and paths in the area. One sidewalk will remain open at all times streets temporarily closed to traffic. Traffic will be detoured onto adjacent street, but residents will have access to their individual home. 

This will be an active construction site with open excavations and equipment in the neighborhood. Caution should be exercised near all construction operations.

During installation of the new stormwater pipe, homes on S. Garrison Street (between W. Stanford Ave. and Garrison and Union Park) will have temporary water and sewer disruptions lasting 6 to 8 hours. A notice will be delivered to the front door of residences the day before the disruption of water and sewer services. The contractor will knock on residential front doors the morning of service disruption as a reminder.

First Community Meeting — March 30, 2016

Denver Public Works and Denver Parks & Recreation held a community meeting to invite feedback on the proposed facility.

Second Community Meeting — May 26, 2016

Denver Public Works and Denver Parks & Recreation held a follow-up community meeting to discuss changes made to the proposed facility design as a result of the feedback from the previous community meeting.