The Urban Drainage and Flood Control District (UDFCD), Jefferson County, and City and County of Denver have partnered with Jacobs Engineering Group (Jacobs) and ECI Site Construction Management, Inc. (ECI) to design and construct improvements to Marston Lake North Drainageway between South Garrison Street and Stanford Avenue and Balsam Park.

The proposed improvements are located within Jefferson County and the City and County of Denver. Nearby streets that bound the project are South Garrison Street to the west and Balsam Parkway to the east. Drainage within the project limits flows from west to east.

Project Goals

• Develop a sustainable urban design that removes structures from the regulatory 100-year floodplain that reduces the 100-year peak flow in the Marston Lake North Drainageway and increases the capacity of the drainageway.
• Design a healthy system that provides natural appeal that is easy to maintain.
• Improve water quality.
• Improve trail infrastructure.
• Reduce the amount of open/standing water.
• Stanford and Balsam Park improvements (at the Lake’s Lake) include removing and replacing the existing baffle drop with a sculpted concrete drop as well as a new low water crossing.

Quincy Lake East Detention Pond Improvements

The project will remove the existing concrete forebays and trickle channels, existing outlet structure and pipes, and the current permanent pool. During construction, the grade in the detention pond will be modified to provide additional stormwater capacity and reduce the risk of stormwater flows spilling from the detention pond and drainageway.

Improvements will also enhance the recreational value of the detention pond:

• The pond will be constructed with landform variability to promote greater variety in the landscape and vegetation and improve aesthetics of the pond.
• New forebays, trickle channels, and outlet structure will be constructed with current design standards; the amount of open/standing water will be significantly reduced and the detention pond will be eligible for maintenance by UDFCD. .
• Construct a trail system within the detention pond to provide recreational access and opportunities while also providing access to maintain the detention pond infrastructure.
• Construction of a new diversion structure on Marston Lake North Drainageway to divert flood flows from Marston Lake North Drainageway to Quincy Lake East Detention Pond