by Brian Hyde

Interstate Highway 270 in the Denver metro area may appear an unlikely landmark for a stream-related greenway. I-270 parallels Sand Creek until Sand Creek joins the South Platte River northeast of downtown Denver. Farther east, near the point where I-270 intersects I-70, Westerly Creek joins Sand Creek from the south. Sand Creek is home to many greenway miles, and Westerly Creek is trying hard to emulate its bigger sibling. Already a great deal of stream restoration and greenway work has been accomplished on Westerly Creek. In October 2009 master planning began for a particularly challenging segment of the creek, where Aurora and Denver meet each other in the vicinity of Colfax Avenue.
But let’s back up for a moment.
During the 1920’s, Denver developed its first airport, eventually named Stapleton International Airport. During World War II, Lowry Air Field was developed. Both of these facilities straddled Westerly Creek and, as might be expected, obliterated it as a natural stream system. Starting primarily after World War II, the 13-block stream reach between Stapleton and Lowry in Denver and Aurora experienced single-family and multi-family residential development on side streets, with auto-oriented commercial development on Colfax. Predictably, once the upstream watershed started to become urbanized, runoff increased and flooding happened – more than once.
From 1953 to the present, a variety of flood hazard reduction facilities have been built in the Westerly Creek watershed. These include four flood control reservoirs, two of them at Lowry (one constructed in 1953) and two of them integrated into major city parks in Aurora, upstream of Lowry. Between Lowry and Stapleton, a series of culverts with sufficient capacity for a 10% chance flood (10-year flood) carries the creek under streets and buildings (unless a flood exceeds their capacity). As Westerly Creek flows from 11th Avenue through Colfax to Montview Boulevard, roughly half of the corridor length is in 6 separate open channel flow segments. Confined flow occurs in 5 culvert segments, located between the open channel flow segments. The direct impacts of urbanization and flood control engineering on the current flow path are apparent as the alignment contains several 90 degree bends and 2 of the culvert segments each extend for more than 2 blocks before the next open channel segment.
In 2007 the Urban Drainage & Flood Control District (UDFCD) and the Cities of Denver and Aurora began the Lower Westerly Creek Master Drainage Plan Update, examining flood control alternatives for the Westerly Creek corridor in the Lowry/Stapleton area. When complete, the UDFCD study will lead to some changes to the current flood protection system of open channel segments and underground pipes. Particularly from 14th Avenue north to Montview Boulevard, a significant number of streets and buildings face flood risks, and the UDFCD study is pursuing alternatives to reduce the hazard. Approximately 100 buildings in Denver and Aurora are located within the official 1% chance (100-year) floodplain in the area. 1% flood depths on Montview Boulevard, a critical emergency route, would pose problems for emergency traffic to and from the University of Colorado Health Sciences Center in Aurora and for other emergency vehicles in that portion of the metro area.
Fast forward to October 2009.
On October 1, the Greenway Foundation, in partnership with Westerly Creek Connection (WCC), began their effort to prepare a Greenway Master Plan for the Lowry/ Stapleton reach of Westerly Creek. Upon completion, the plan will create a blueprint for a multi-use trail and enhanced green space system that will be integrated with the creek and its floodplain. The Greenway Master Plan will identify options for developing a greenway through the highly urban area and develop design details for the preferred alternative. The study area for the Westerly Creek Greenway Master Plan encompasses 13 blocks, from 11th Avenue to 23rd Avenue.
The greenway will provide:

    Modified channel design configurations for existing open channel sections, with accompanying riparian restoration, allowing safe passage of the 100-year flood;

  1. New open channel sections design, wherever it is feasible to replace existing culverts while still allowing safe passage of the 100-year flood;
  2. An amenity that enhances the community experience;
  3. An environment that is visually and aesthetically inviting;
  4. Elements conducive to outdoor recreation, including handicapped mobility;
  5. Opportunities to improve and enhance health;
  6. A direct connection between the future greenway and existing greenways within Lowry and Stapleton, and beyond;
  7. Educational elements.

The Greenway Master Plan will also address related contextual issues, such as:

  1. Transportation improvements (i.e. widening of the roadway, realignment, drainage) for Yosemite Street from Montview Boulevard to 11th Avenue, within the broader context of the Central Park Blvd./Yosemite Street corridor – from the new I-70 interchange to points south of Lowry;
  2. Potential economic redevelopment opportunities related to the creek within the Colfax and Yosemite corridors;
  3. Acknowledgement of the interface between Aurora and Denver at Yosemite;
  4. Showcasing the history of US Highway 40 (Colfax Avenue).

The Greenway Master Plan will be developed to ensure consistency with the flood protection mission of the UDFCD Drainage Master Plan, taking full advantage of the solid engineering foundation for hazard reduction. WCC believes the UDFCD effort presents them with a unique opportunity to build the Greenway Master Plan upon the flood protection study.
At the outset of the development of this planning process, a Greenway Master Plan Steering Committee was established, including stakeholders who are directly responsible for funding the project and for ensuring appropriate design – Greenway Foundation, Cities of Denver and Aurora, Colorado Water Conservation Board, and UDFCD – as well as property owners, neighborhood associations, business organizations, local and state government agencies, school and education interests, non-profit entities, cycling support organizations, and other interest groups. The Steering Committee will establish and implement policy to guide the planning process. They will represent the concerns of the community and all important stakeholders, both public and private, as the Greenway Master Plan is developed. The Steering Committee held its first meeting on December 8, 2009.
Community outreach is a vital element in developing a Greenway Master Plan, as the plan and the ultimate completed project belong to the community. Public input must enable a sense of ownership within the community; therefore a series of public meetings will be scheduled at appropriate points during the planning process. The first public meeting is scheduled for the evening of January 26, 2010.
In the future, pedestrians and cyclists on the existing Sand Creek Greenway between Quebec Street and Havana Street will be able to turn to the south, cross Sand Creek, and travel along an inviting greenway to the Highline Canal and maybe to Cherry Creek Reservoir. At the intersection of Colfax and Yosemite, they may find new attractions to further enhance their Westerly Creek experience. Other greenway surprises in other locations may await them as well.
Questions about the Westerly Creek Greenway Master Plan may be sent to Brian Hyde of WCC via email (

Colorado Riparian Association