The River Mile: A Model for Urban Riverfront Development

Purpose and Approach | Healthy River, Healthy City

The River Mile’s scale (62 acres), its relation to the South Platte River, and its adjacency to the downtown, prompted an ambitious vision: a high-density, mixed-use neighborhood that integrates Denver’s long-neglected river into design, function, and lifestyle.  The future development will bridge historic barriers, address lingering housing shortages, revitalize the river, and create a walkable urban destination.

To accomplish this, the project negotiates between the Urban and the Natural.  This spectrum can be seen in any transect from the River to the Development – one is to be valuable, new habitat; the other is to be the most densely populated area in the city.  The Natural required ecological revitalization, a new river corridor, and comprehensive water quality strategies.  Whereas the Urban demanded pedestrian bridges, multi-modal options, and a wide diversity of open space.

The River Mile plan posits a strong model for resilient riverfront development and envisions a rich urban addition to Denver.

Role | Integrating Urban and Natural

The multi-year, multi-phased project required the Landscape Architect to work closely as part of two large multidisciplinary teams to plan both the river restoration and the horizontal site infrastructure of the development.  Due to the Landscape Architect’s early inclusion, the team was uniquely positioned to integrate the design of the streets and open space with the river restoration down to the river’s edge. For example, landscape collaborated with engineering to incorporate unique stonework as functional river armoring and indicators of river access points.  They intentionally shaped the river to accommodate planned ADA access, amenity zones, and future parks.  Landscape coordinated with ecologists to develop native plant communities tied to different flood elevations – in essence designing a tiered riparian section from scratch.

The project scope also included a public engagement and community stakeholder process which resulted in rezoning the site, a masterplan for the restoration of the river, and a clear understanding of peoples’ desires for the development. The public wanted an energetic river with water access, parks, cafes, and trails. However, the City wanted a more natural, ecologically-focused river.   To functionally and aesthetically knit these two worlds together, the landscape architect played the role of both moderator and challenger.

Specifically, the Landscape Architect worked with the engineers, the City, and the Client to fit the river design to the ecological, environmental, and social needs of the space.  The City waived stormwater detention requirements; the Engineer adapted designs to accommodate emergent wetlands and river access; and the Client adjusted the property line to make these changes possible.

Context | An Isolated Corner of Town

The site posed many challenges to the goal of a natural, interconnected neighborhood. In the mid-1800’s, settlement of the site stalled due to its location in the 100-year floodplain. Instead, it became a railyard and locomotive depot and the site was eventually given Superfund status.  Through the 20^th century, the parcel was further isolated by new highways, rail lines, and arterial streets.

One requirement for the plan was to connect to adjacent amenities and dislocated neighborhoods. Two pedestrian bridges, a regional bike trail, a hierarchy of paths, and many urban bike lanes tie the site into the surrounding parks, the downtown business district, and institutions such as the aquarium and children’s museum.

Ecologically, the site will blend into the surrounding environment with a curated plant palette and will remediate the historic pollution and degradation of the river and its banks.  The most critical factor of the site context is the 100-year floodplain which required a wholesale redesign of the river.

Environmental Sensitivity & Sustainability | Follow the Water

The team’s solutions for the river unlocked both the viability of the site and the character of the urban planning.  Therefore, the hydrologic updates to the river had to also enhance the environmental design.

Aggradation, pollution, and a general out-of-sight-out-of-mind mentality left the river in a sorry state. First, Engineering re-graded the site and removed an eight-foot dam downriver to move the development outside of the 100-year flood plain.  The river restoration aims to produce a healthy river by dredging, deepening, meandering, and revegetating it.  What had been a barren waterway will now have new life as fish habitat, bird ecosystems, and large stretches of native vegetation.

The urban design incorporates green infrastructure elements such as new emergent wetlands, bioretention, and a series of connected water quality measures with permeable pavers, level spreaders, and stormwater planters to treat the water before it flows to the river.

Special Factors | Reviving the River, Prioritizing Pedestrians

• The River – The River Mile reimagines the riverfront as its heart. Not only does the water redeem ecological function, it is a space for humans to explore, play, and gather.  With bridges, docks, hard/soft pathways, seating, plazas, and access points, the river will incite rediscovery as it invites people down and into the water.  This mile of activated riverbank will buzz by performing as transit, retail, recreation, and respite.  Yet, punctuating this stretch will be protected pockets of high-functioning riparian habitat.
• Urban Design – The orientation of the street grid, the location and typology of open spaces, and the connections offsite were significantly influenced by the input of the Landscape Architect to form a comprehensive urban design. Even the site’s fill strategy mutually resolved below-grade service access and the overarching green infrastructure network.  The street design promotes multimodal options by imposing parking maximums, 10-mph local street speeds, and frequent intersections to dissuade excessive vehicle traffic.  For this effort, ADA and cycling advocates were consulted to ensure the streets are as safe as possible.
• Open Space – The open space plan exceeds the total acreage required by the City and all residents will be within a 5-minute walk to quality public space or neighborhood park.  The site will not only provide quantity, but a variety of spaces: festival streets, river plazas, water access, playgrounds, and more.
• Equity – Equitable design extends beyond the street.  The River Mile champions the largest allocation of affordable housing in Denver’s history. The block layout encourages a diversity of uses from small-scale business to large, riverfront developments.  This diversity of housing options, retail types, and commercial opportunities will be critical to the development’s inclusivity over time.

Significance | A Model for Urban Riverfront Development

The River Mile project represents three major contributions to the field of landscape architecture.

1. First, it displays the value of our field on the big stage: the involvement of the Landscape Architect at the beginning of the process resulted in a plan that balances the Urban and the Natural.  Landscape Architects can ensure the big visions are fostered early, protected often, and realized fully so that neither scale, complexity, or competing priorities dilute the magic of the original vision: an active, high-density neighborhood that respects and integrates a healthy riverfront.
2. Second, the project propels critical planning principles such as high-density, mixed-use, pedestrian focus, and ecological resilience. Those principles will provide more equitable, more comfortable, and more functional cities – cities better adapted to support us in a changing climate.  The Plan’s diversity of open spaces, green infrastructure, and emphasis on the river will deliver a better Denver today and for years to come.
3. Finally, building a neighborhood requires more than roads and roofs. It requires a community. Restoring the river presents numerous benefits and among them will be its contribution as a defining source of character.  The elegance of cleaning historic pollution, reviving an environment, and providing a community symbol all in one is a testament to the power of landscape architecture.

The Development Infrastructure Master Plan is approved, the Landscape Architect progressed The River Mile plans to Construction Documentation, and construction is projected to start next year.  The river will again welcome all comers to its water.