Platte Street Plaza

Purpose and Approach: This half-acre plaza is situated at the east end of the prominent Highland bridge spanning I-25, a major arterial thoroughfare that created a barrier for pedestrian and bike commuters from west neighborhoods into downtown Denver. Despite its role as a major bike and pedestrian connection, Platte Street Plaza was a barren and lifeless space, even as Platte Street itself underwent a development renaissance in the mid-2010s. The plaza was little more than expansive concrete, deteriorating infrastructure and safety hazards. An absence of pedestrian amenities, and a lack of lighting made the space intimidating to use after dark. Adjacent businesses had no amenitized outdoor areas. Through a public-private partnership between the City & County of Denver and Unico Properties, the landscape architect was engaged to redesign the plaza, which now functions as the heart of the neighborhood.

Role of the Landscape Architect: The landscape architect led the design effort to create a sense of arrival and placemaking that was contextual with the adjacent historic buildings. With a layered landscape approach, the site design promotes connection and enhances circulation, aesthetics, experience and most importantly, pedestrian safety. The transformation turned a thoroughfare into a place where people can gather, linger and socialize.

Context: The Highland Bridge, built in 2006, connects the Highlands neighborhood and downtown Denver, making it one of the few safe multimodal connections between the two fast-growing neighborhoods. Within the immediate project area are the confluence of two riverfront bikeways, the Millennium Bridge leading to the Denver Union Station transit hub, 16^th Street Mall and Lower Downtown.  These connections all come together within the general area of Platte Street Plaza, forming a node used by thousands of people every day for commuting.

Special Factors: Within the plaza, the landscape architect defined areas for different uses. The plaza edges provide ‘eddies’ to support café seating for the adjacent businesses and pedestrians. These seating areas are separated from the primary circulation route in the central plaza by custom illuminated timber benches arranged along the plaza edges, and planters containing shade trees and a blend of native and xeric plantings. A vibrant hardscape activates the ground plane with banded pavers running perpendicular to the primary circulation route, slowing bicyclists and other wheeled commuters through the space.

The plaza appropriately responds to a variety of goals set by the City, the Downtown Denver Partnership and the adjacent building owners. By concentrating commuters and primary circulation through the middle of the plaza, conflicts are mitigated while route and clarity of usage is elevated. Clear sight lines are re-established, and safety is enhanced through artfully designed lighting.

Two local artists painted custom murals reflecting local culture and history. The art serves the dual purpose of activating a concrete sound wall buffering the adjacent freeway and anchoring the northwest edge of the plaza. This area is further softened by native plantings, Tivoli Festival Lighting and outdoor dining furniture.

Existing retail fronts both sides of the plaza, creating opportunities for outdoor dining, which have been enhanced through the softening effects of added plantings and a new tree canopy. Secondary circulation paths define this transition zone for passive activation, with edges that slow traffic through the use of concrete plinths, stairs and accessible rails. East-west movement is safely facilitated along this linear multimodal link.

Despite over six feet of grade change across the site, the main thoroughfare remains free of stairs and accessible to all. Banded brick pavers help obscure the grade change while defining the primary circulation route through texture and color, slowing wheeled commuters passing through. The pavers ground the adjacent architecture through complementary color and materials, and honor the site’s historical context while retaining a contemporary feel.

Hess ‘Residenza’ lighting fixtures illuminating the plaza offer a modern rendition of traditional lanterns, increasing safety and tying together the historical architecture of the buildings to the south and the newly constructed Circa building to the north. Black finishes on the light fixtures mirror the black banding in the hardscape, planter curbs and site benches while relating back to the dark metal accents on adjacent buildings.

Lush native plantings are introduced within custom black metal planters, softening this previously barren plaza. The palette includes an abundant variety of hardy shrubs, grasses, and perennials in schemes highlighting the banded hardscape, reinforcing simple, linear geometries. Paying close attention to scale, plants and trees were chosen to thrive in this challenging urban hardscape condition. Microclimates are improved with trees, cooling down the urban heat island and supporting Denver’s goal to enhance the urban tree canopy. Each tree receives support from 1,300 cubic feet of soil, providing a welcoming environment for the new urban forest to thrive.

Timber benches headline the plaza as a custom-built site element. These not only define the main thoroughfare perimeter but provide flexible moments of retreat to sit and relax. Through quality design, these benches tie together durable plaza finishes and aesthetics, and contribute to the plaza’s u­­nique sense of place. Two ten-by-ten-inch timbers are pulled together structurally and supported by black steel to form the custom benches.  At night, these benches are illuminated from below, further improving pedestrian safety and igniting a magical nighttime experience.

Environmental Sensitivity and Sustainability: The renovated plaza design reduces the original reflective concrete by 43%, lowering temperatures and solar reflectivity into adjacent buildings. Multiple shade trees mitigate the darkness of the brick paving, and dense shrubs and grasses screen utility infrastructure.

An important function of the newly designed plaza is stormwater filtration, capturing runoff within planters at higher grades before filtering it through landscaped areas.

Significance: Platte Street Plaza’s completion marked the beginning of a new chapter for the neighborhood, providing a space for adjacent businesses, residents and visitors to linger over coffee or ice cream. The improvements equally serve cyclists, pedestrians with strollers and people on scooters and skateboards. The transformation from a blank swath of concrete to a vibrant plaza with numerous amenities fosters social interactions and provides a destination in an area with a high need for open space. This successful revitalization has become the heart of a blooming historic district and has had an even bigger impact than originally imagined. The landscape architect led this successful outcome by addressing challenges with a creative response that has been fully embraced by users.

A successful collaboration between private and public sector, this rejuvenated plaza now meets the demands of the community and the goals of the City and the sponsoring developer. A win-win collaboration, the plaza is creating long-term economic value for adjacent development projects.  The improvements complement the composition and character of the block, supporting the renaissance of this quickly revitalizing district.

Importantly, the plaza addresses environmental and safety challenges through the introduction of stormwater filtration and the delineation of space between commuters and passive users. The plaza additionally plans for and accommodates modern technology demands, with free public wifi and power sources to host community and civic activities. Public meetings, farmers markets, pop-up events and more activate the plaza. This flexibility supports the Downtown Denver Partnership and Denver Parks and Recreation’s master plan goals for public spaces and adds meaningfully to the social fabric of the public realm in Denver.