Salesforce Park is a lush landscape that stretches four city blocks atop a transit center in San Francisco. With lawns, hillocks, lavender beds, leafy trees and a walking path, it gives commuters a relaxing place to wait for their bus and attracts people who live and work nearby looking for respite in the middle of a busy city.
Despite its presence as a calming oasis, Salesforce Park faced stressful start-up challenges.
The transit center abruptly shut down shortly after opening in August last year when cracks were discovered in two steel beams. Officials hoped for a quick turnaround, but the project became mired in delays. After 10 months of inspection, analysis and repair, it finally reopened in July.
Building a park 70 feet in the air atop a transit center showed how complex it can be to piggyback green space on active infrastructure. Such projects require coordination among many consultants and, often, multiple levels of government, with possible construction delays, cost overruns and pushback from residents.
These projects are “complicated from a design point of view and a maintenance point of view,” said Adrian Benepe, senior vice president and director of national programs for the Trust for Public Land and a former New York parks commissioner.
Still, with land for urban parks scarce and prohibitively expensive, the practice is becoming increasingly common.
“It’s a way of making infrastructure do double or even triple duty,” Mr. Benepe said. Parks add value not only for relaxation, recreation and human health, he said, but also for combating heat, absorbing storm water and providing habitat for wildlife.
And an infrastructure project with a park can cost less than two projects undertaken independently, said John Parkinson, a lecturer in construction administration at the School of Professional Studies at Columbia University.
“There’s an economy of scale and an efficiency,” he said.
The idea of building parks on infrastructure can be traced to the rails-to-trails movement, which for four decades has transformed abandoned rail corridors into walking and biking paths. Nationally, 2,150 rail trails cover 24,143 miles, according to the website of the Rails-to-Trails Conservancy, a nonprofit organization.
The wildly popular High Line in Manhattan, which opened in 2009, gave impetus to the idea of adding greenery to infrastructure that is raised off the ground. Conceived, funded and built by the nonprofit Friends of the High Line, the park has inspired so many infrastructure-reuse projects that its founders formed the High Line Network to help others learn the ropes — and avoid pitfalls.
The High Line is considered a design and tourism triumph, but it has also drawn criticism for accelerating gentrification along its route and not better serving residents of nearby public housing.
The United States has more than 100 infrastructure-reuse projects, which generally require a “tremendous amount of tenacity and time” to complete, said Asima Jansveld, vice president of the High Line Network.
Despite the extra complications, adding green space to functioning infrastructure has gained traction.
In the Bronx, the Croton Water Filtration Plant is topped by a sculptural nine-acre golf course. And the Denny Substation, opened by Seattle’s electric utility this year and designed by the architecture firm NBBJ, boasts a lawn and a dog run. The $210 million cost ran $100 million over projections, in part because of the lag between planning, which occurred during the recession, and construction, which happened during Seattle’s building boom.
The vast majority of projects are built on transportation infrastructure, however, including so-called deck parks over highways — adding green space while stitching back together sections of cities that the roadways ripped apart long ago. One proposed deck park in Atlanta even goes by the name the Stitch.
In Dallas, an idea to build a park over the Woodall Rodgers Freeway gestated for decades. Klyde Warren Park, designed by Jim Burnett of OJB Landscape Architecture, opened in 2012, connecting the Uptown neighborhood with the arts district and downtown.
The Woodall Rodgers Park Foundation, which orchestrated the project, plans to expand it to the west. Construction of the new segment is expected to begin in late 2020 or early 2021. But expenses have risen: The original 5.2-acre park cost $110 million, and the 1.5-acre addition is projected at $100 million.
In Washington, the 11th Street Bridge Park over the Anacostia River, conceived in 2011, has also faced delays. It was supposed to open this year, but construction is now slated to begin in 2021 and be completed in 2023.
Because the park will cross a navigable waterway near a naval yard, the Coast Guard, the Army Corps of Engineers and the Department of Defense have all had to weigh in on the project, in addition to the governmental bodies that typically review plans for public space.
But the time spent coordinating with government agencies and acquiring permits allowed for more than 1,000 meetings with residents of low-income communities to understand what they sought to gain from the project, said Scott Kratz, director of Building Bridges Across the River, the nonprofit organization that is spearheading the park.
As a result, the $139 million capital campaign includes not only $74 million for the construction of the park and $10 million for its maintenance but $55 million for preserving affordable housing and job training. The initial estimate of $40 million would have covered costs for the park alone.
Below Salesforce Park in San Francisco, the transit center is cloaked in a lacy, undulating aluminum veil. Designed by Pelli Clarke Pelli Architects, the hub and park had a $2.2 billion price tag. It was built by the Transbay Joint Powers Authority, a group of Bay Area government and transportation agencies.
Salesforce, a software company whose bullet-shaped Salesforce Tower connects to the new park, acquired naming rights in exchange for covering the $30 million annual cost of maintaining the center and the park.
The center was challenging enough on its own: A box-shaped space had to be dug deep underground to accommodate tunnels for commuter trains and a future high-speed rail line. Because San Francisco is prone to earthquakes, the center had to be built to the highest seismic standards.
Adam Greenspan, the design director at PWP Landscape Architecture and lead designer of the park, said he worried that, as time ticked by, the park would be viewed as a luxury and Transbay would cut its financing. Its irrigation, landscaping and structural elements accounted for nearly $32.3 million of the total project cost, a figure that does not include electrical work and the park’s fountain, which sprays when buses arrive.
Its 5.4 acres, however, have effectively doubled open space in the area, providing a place to get active or to just relax.
Biederman Redevelopment Ventures, which manages the park, has organized programming to draw people up to the roof. Friday night sessions of salsa or swing dancing typically attract 300 to 350 people, according to Biederman. On weekdays, an average of 850 people, many who work in nearby office towers, frequent the park at lunchtime.
And it will get busier when the stores inside the center start opening this fall, said Mark Zabaneh, executive director of Transbay.
“Did the park make the project more complicated?” he said. “Yes. But based on feedback, we wouldn’t have done it any other way.”