American Society of Landscape Architects
ASLA Home  | ASLA Honors and Awards  |  Awards Jury  | Awards Press Release  |  News Room & Publications

<< back to main page



X Zone
Meredith schildwachter, Student ASLA & kyle Hebel, Student ASLA

University of Colorado at Denver
Advisors: Leila Tolderlund, Associate ASLA and Tony Mazzeo.

Narrative Summary
Our project site is located in Denver, Colorado north of downtown in a historic but fading industrial area known as River North. River North is bounded by I-70 to the north and I-25 to the west with Brighton Boulevard serving as a major thoroughfare and the South Platte River a potential resource and amenity. Currently Denver has plans to expand its commuter and lightrail network through the Fastracks program. One component of this plan is the east corridor rail line which runs from downtown Denver to Denver International Airport. Five new commuter rail stations are planned along this corridor, including one in River North. The corridor includes some of the most polluted landscapes in the nation and is littered with greyfields and brownfields of various size and levels of toxicity. This presented us with a unique opportunity for landscape architectural response due to the number and nature of forgotten, poisoned and ignored spaces and the changes set to come.

Two major goals were established to direct our thought process. First, we wanted to prepare the land for a change to come due to the development of the new commuter rail line. Secondly, we intended to find a new solution for dealing with the polluted landscape that is deeply rooted in the ideas of radical gardening.

We began by collecting map data including land use, zoning, roads, railroad, hydrology, parcel information, and demographics. We collected environmental data such as EPA brownfield studies and soil samples. Given the nature of the environmental data, we focused further efforts on gathering information on remediation technologies. We also consulted with experts in the fields of remediation, development, and planning. Another layer of our data collection involved an examination of historic photographs and maps of the area. Finally, we visited the site frequently and collected data in the form of photographs, sketches, and notations.

From this research we concluded that remediation had to play an integral part in this project. Thus, we began analyzing the traditional approaches to the mitigation of polluted sites and were continuously searching for new ways of working within that framework that are more ecologically sensitive. We found four major categories of remediation techniques currently in use to mitigate contaminated sites, including:

  1. treatment
  2. containment
  3. excavation and disposal
  4. natural attenuation

More specifically, treatment includes processes such as bioremediation, phytoremediation, and the many detailed treatments like vapor extraction and air sparging. Containment refers to capping or lining the site and also solidifying and stabilizing the soil. Excavation and disposal is the removal of contaminated soils on or off site. And finally, natural attenuation is the process in which the landscape is left alone and natural processes clean it up over time. Our analysis included an examination of how these techniques work scientifically, function, and impact the landscape.

As we studied the remediation technologies, we supplemented our analysis with a series of mappings. These mappings took two major forms. The first series of mappings were recordings. Recordings are mappings of contextual data which we organized using GIS. The recordings were compiled at two scales: 1”=4000’ and 1”=500’. The recording at 1”=4000’ overlaid data for the analysis of the entire county of Denver and provided an overview of the east corridor rail line. The recording at 1”=500’ focused on the River North area providing a more detailed examination of the site.

The second series of mappings were speculations. Speculations are more intuitive, a cognitive type of mapping. Speculations overlaid image, text, and diagram providing a fuller understanding of the nature of each remediation technology and its impact in the landscape. Speculations were also used to explore how specific sites might evolve over time.

After analyzing remediation technologies and site conditions, we felt it was imperative to choreograph an implementation strategy for remediation that was directly woven into the future plans for development. The most important component of this project was the creation of a new zoning type as an enabling device for change. The zoning code is written as follows.


Sec. 59-521. Description of district.

The X zone is intended to be an alternative to conventional master planning that is flexible, emergent, and reactionary allowing for a mix of uses that create an eclectic community. The X zone has been developed as a tool for working with “otherlandscapes, the forgotten, poisoned landscapes of the post-industrial age. This zone is meant to serve as a catalyst for remediation and development in an alternative way. It allows for an eclectic mix of development, rooted in the ideas of radical gardening, and based on the idea of live, work, remediate .

Sec. 59-522. Purpose.

The X zone allows a response to the landscape and its conditions that promotes the emergence of a network of open space as an integral component of development. The nature of the land provides an opportunity for this to occur because of the need for remediation. By incorporating “greenremediation technologies, landscapes may be easily incorporated into the open space network and made accessible to the community . The pollution of the landscape determines the outcome of development.

Additionally, the X zone is designed to promote an eclectic mix of development that accepts the relics of the past while building towards the future.

Sec. 59-523. Permitted uses.

The X zone district permits open space, residential, mixed use, commercial, and industrial uses, however, location is determined by adjacencies and will be reviewed by a committee consisting of business owners and residents.

Sec. 59-524. Remediation/Open Space

Remediation serves as the first step towards change. The sites of remediation are the foundation of the open space network. The sites that are most contaminated are remediated to an acceptable level and remain as open space. These open space sites create a network that is vibrant, active, and critical to the community. The sites of least contamination serve as residential development areas where a higher density of development is tolerated. Remediation technologies are implemented according to levels and types of contamination; however, incentives encourage remediation techniques that are “greener” and of lighter impact on the land. As remediation is being implemented, people are encouraged to interact with the land.

Tax increment financing (TIF) is used in urban renewal areas. This allows tax revenues generated by redevelopment to be rolled back into the area to help finance the project. The new tax revenue that is created finances additional remediation efforts and open space development.

Sec. 59-525. Development.

Development negotiates open space and is based upon levels of contamination. Residential units are located in areas of least contamination. Historic buildings, thriving businesses, and the rail station also serve as focal points for initial development. All development must be located adjacent to existing development and compatible uses to create high density areas. Adjacencies shall determine development type. For example, incompatible uses such as industrial and residential are not located adjacent to one another.

Transfer of development rights shall be used as a incentive where the most contaminated sites are left as open space while allowing development at a higher density in less contaminated areas.

1Radical gardening is a kind of middle operation inhabiting a space between the seemingly oppositional pairs of culture and nature. The difference between the traditional version of gardening and the radical version is that the latter sets out to intentionally complicate the hierarchical structures beyond recognition, aimed at deforming, reforming, and eventually transforming the practice of landscape into a higher form of itself. (Anthony Mazzeo 2005)

2The idea of a new form of community in which remediation is incorporated into everyday life as a result of re-inhabiting a post-industrial landscape.

3“Green” remediation technologies refer to methods that are of lighter impact on the land and more environmentally sensitive. These technologies include but may not be limited to phytoremediation and bioremediation.



ASLA Home  | ASLA Honors and Awards  |  Awards Jury  | Awards Press Release  |  News Room & Publications