Landscape Architecture Magazine

DRIVING CONCERN

BY ALEX ULAM

The new Mosholu golf driving range is part of a controversial water filtration plant project built at the edge of the bucolic Van Cortlandt Park.

From the July 2016 issue of Landscape Architecture Magazine.

Many things are not exactly what they appear to be at the new Mosholu golf driving range, located in the northwest section of the Bronx in New York City. Behind high stone walls and a gate monitored by armed policemen there are carefully crafted illusions worthy of an Olmsted design. A driveway leading into this place looks as if it were carved out of wilderness. On either side are sunken beds of untamed riparian plants that pool with water after rainstorms. Up a slope, past a low-slung building faced in rust-colored steel, you are at the high point of the range. The greens below are composed of hillocks with carpets of turfgrass, plush enough for a nap, which overlook a bowl-shaped depression.

Beneath the driving range is the Croton Water Filtration Plant. At a cost of more than $3.2 billion, it is among the most expensive public works projects ever built in New York City. The driving range sits atop a nine-acre green roof covering the plant, which is said to be the country’s largest contiguous green roof. It replaces an old municipal driving range bulldozed more than a decade ago to make way for the underground filtration plant, which descends about 100 feet into the ground. The subterranean structure is designed to filter up to 30 percent of New York City’s water supply.

The need to purify water, especially water that humans have polluted, has become a hugely expensive and complex challenge—that much is easy to tell from this filtration plant, as well as from the experiences of cities such as Flint, Michigan, that have failed to safeguard their local water supplies. But where to put all of that infrastructure in densifying cities such as New York, where available space is dwindling? One way New York City has dealt with its stormwater issues is by redesigning municipal parkland and public plazas. The most ambitious undertakings involve stacking gray and green infrastructure and mixing industrial and recreational uses. In the past, water infrastructure projects had engineering firms calling most of the shots. The new approach involves multidisciplinary teams in which landscape architects and park planners play key roles.

“There is a strong symbiotic relationship between water departments and parks departments that largely has to do with the water supply,” says Adrian Benepe, Honorary ASLA, a former New York City Department of Parks & Recreation commissioner. “Increasingly, they are joined at the hip in terms of stormwater capture.”

The new driving range has been set back into the preexisting Mosholu Golf Course in Van Cortlandt Park, but it is separated by a moat and walls. Credit: Grimshaw.

However, trying to minimize the impact of an enormous water filtration plant in a New York City park is a formidable design challenge. When you stand at the top of this gently sloping golf course, you can see the world beyond the stone walls. These are referred to in plans as “pedestrian interdiction walls,” which are in turn surrounded by a moat for an added layer of security against terrorists who might want to poison the city’s water supply. Immediately next to the golf driving range is a four-acre facility belonging to the city Department of Environmental Protection (DEP) that was built to service the underground filtration plant and is strictly off-limits to the public. It has a chemical fill station, a police booth, and a secure entrance designed to withstand bullets and blasts. The DEP site also includes a building that serves as an entrance to the underground filtration plant and features golf nets 125 feet high arrayed along its exterior to protect DEP employees from stray golf balls that fly off the adjacent driving range.

Surrounding the driving range and DEP facility outside the secure perimeter is Van Cortlandt Park, which, at 1,146 acres, is one of the largest parks in the city. The new driving range technically is still a part of the park, and beyond its walls you can see scrappy greens of the sundered main section of Mosholu Golf Course under broad canopies of sweet gums and oaks. The golf clubhouse and the moat wetlands have yet to be built. According to Grimshaw, the architects for the aboveground portion of the plant, the second phase of construction won’t even begin until spring 2017. Actual completion is now slated for summer 2019. How well this new landscape will integrate into the Norwood neighborhood and the rest of Van Cortlandt Park remains to be seen. Currently, the site is off-limits to the public and remains mostly hidden from street view by a large decorative stone fence slated to come down when the project is finally complete.

A sketch from March 2007 showing the concept for the driving range and wetland system. Credit: Courtesy Ken Smith Workshop.

In the course of more than a decade of construction, there have been lawsuits to stop the construction as well as countless battles over various issues, such as the several hundred trees that had to be cut down to accommodate the filtration plant. An article in a local newspaper was even devoted to some of the heated exchanges about the removal of a particularly beloved pin oak. “It was a bucolic setting,” Gary Axelbank, the host of the popular radio program BronxTalk, told me. “You would walk by, and there would be people on the driving range, and in the distance, there were big mature trees and streams.”

Even a minor change to a public park can become a combustible issue in New York City. In this case, the Norwood neighborhood has been denied access to a stretch of parkland along a major thoroughfare for more than a decade, and people there have also endured major disruptions from one of the largest construction projects in the city. When the city’s environmental officials decided to build the filtration plant here, controversial state legislation was required to temporarily remove a 43-acre section of parkland for the duration of construction. That legislation also allowed for an unspecified amount of acreage to be permanently taken away to accommodate the filtration plant. To make the project more palatable to Bronx residents and the predominantly Latino neighborhood of Norwood, which is the poorest community bordering the park, the city lavished money on the new driving range and made more than $200 million in additional funds available for park improvements throughout the borough.

With their new highly engineered landscape, the designers have gone to great lengths to re-create aspects of the nature that once existed on the site. “There are two basic requirements for this landscape,” said Ken Smith, FASLA, the principal of the landscape architecture firm Ken Smith Workshop, during a tour of the site on an overcast day in May. “One, that the filtration plant be buried, and the other, that the site be returned to its original use as a park golf course.” Smith, who worked under the architecture firm Grimshaw on the design of the aboveground buildings and the landscape, says that the tree mass removed from the original golf course has been replaced according to a formula established by the parks department. In addition, Smith’s team even measured the distances between the groves’ trees on the outskirts of the filtration plant site and planted new groves of sweet gums and oaks according to the same ratios.

Lightweight blocks of geofoam expanded polystyrene form a base layer for the roof. Courtesy: Ken Smith Workshop.

In many other areas, the landforms have been positioned to conceal evidence of the enormous facility below. Grassy hillocks built of structural polystyrene camouflage the sizable vents and exhaust tubes that extrude from the filtration plant. The extensive use of structural polystyrene also enabled the designers to create a varied topography with up to 12 feet of variation and still keep weight loads manageable on a green roof that, because of its large expanse, could accommodate only an eight- to 10-inch-thick layer of structural soil. The blanket of turfgrass connecting the green roof to adjacent terra firma is so seamless that you can’t tell where the underlying structure begins. In fact, to keep fire trucks responding to potential emergencies from straying onto the roof and falling through, large boulders have been strategically placed on the ground that borders the roof’s otherwise indistinguishable edges.

Smith doesn’t play golf, and dressed all in black, with his trademark thick, black-framed glasses, he doesn’t even look like a golfer. He is willing to learn, though, and he brought onto the project Stephen Kay/Doug Smith Golf Course Design, who provided the templates for how to lay out the targets and also advice about the turfgrass blends. Smith did the topography for the course and disguised the various building elements that dot the site. He made a field trip to Pelican Hill Golf Course in Newport Beach, California, for inspiration. “It was in a natural woodland and had a big gentle bowl to it, so when you were driving into the bowl it was a beautiful experience,” he said. “And here, we had these air intakes and exhausts on both sides, so we had to incorporate them and disguise them as features, so the bowl was really useful.”

The defining aspect of the project is the security walls, which Smith says extend between one and a half and two miles around the site and, in places, are topped off with monitoring systems. The walls are designed to have smooth, long gradients that follow the shape of the land. Smith says that he and the designers considered a number of materials but chose bluestone for most of their wall sections to complement the Cor-Ten steel used on the DEP building. The walls shift from bluestone to gabion baskets as they wind behind the moat. “We did it for cost [reasons],” Smith explains, “and also because of the idea of having a gradient that courses from the public to the less public.”

Ken Smith, FASLA, points out one of the wetlands he designed for the DEP section of the site. Credit: Alex Ulam.

While the filtration plant below is using chemicals such as alum and sodium hypochlorite to filter New York City’s drinking water, the landscape that Smith and Grimshaw designed aboveground re-creates natural processes to control and filter 40 percent of the stormwater from the nine-acre green roof and to capture stormwater runoff from paved surfaces around the site.

Indeed, it appears that everything here, not least the slant of the green roof and the large joints of permeable concrete along the sidewalk approaching the site, has been engineered to capture and filter stormwater runoff, which is among the leading threats to New York City’s environment. The green infrastructure at this site is intended to reduce the amount of stormwater runoff polluted with contaminants such as road salt, auto fluids, and plastic bags from entering the city’s combined storm sewer system, where it mixes with raw sewage. With the sewer system currently operating at twice its design capacity, a snowstorm or heavy rain is enough to overwhelm it and lead to a discharge of pollutants into the city’s waterways, which kills off aquatic life, closes beaches, and emits waterborne vapors linked to diseases.

The state-of-the-art green infrastructure at the Mosholu driving range, if used more widely, could help the city avoid having to build more gray infrastructure such as the water filtration plant that sits beneath it. “This project is intended to be a demonstration project for stormwater management,” Smith says, adding that the landscape addresses the mission of the city DEP, the lead agency on the project, which is in charge of the city’s drinking water infrastructure and its combined storm sewer system.

In fact, the filtration plant actually is the costly consequence of not adequately controlling stormwater runoff in the first place. In 1998, the city was forced to build the filtration plant as the result of a lawsuit by federal authorities who maintained that drinking water conveyed by the Croton Aqueduct System from city reservoirs in suburban Westchester County no longer met new, more stringent standards enacted under amendments to the Safe Drinking Water Act. One of the reasons cited was that New York City had failed to protect the watershed in Westchester adequately from stormwater runoff linked to encroaching suburban development. “It could have been avoided in hindsight if, post-World War II, there had been put in place a comprehensive set of development and land controls in Westchester County,” says Eric Goldstein, an attorney with the Natural Resources Defense Council who has been involved in watershed protection efforts. “At that time the water quality was relatively high,” he says. “It would have been fantastic if city and state officials had recognized the need to control development around Croton Reservoir.”

The Croton Water Filtration Plant does not mark the end of New York City’s mounting challenges to keep its water bodies free of pollution. State environmental officials are requiring the city to take big steps to reduce the more than 27 billion gallons of sewage-contaminated stormwater that is annually discharged into the city’s harbor and waterways from around 460 combined sewer overflows (CSOs). In 2012 the city committed in a landmark agreement with New York State to spend $1.4 billion on gray infrastructure and $2.4 billion on green infrastructure, which can include some of the very systems that landscape architects specialize in designing, such as bioswales, green roofs, and rain gardens.

The landscape is designed to control and filter 40 percent of the water that falls upon the green roof. Credit: Grimshaw.

In the case of the filtration plant, city officials decided that having highly qualified designers on the team in addition to engineers was essential for the success of the project. Initially, the engineers Hazen and Sawyer/Metcalf & Eddy Joint Venture, hired to build the filtration plant, had developed a preliminary golf driving range design in-house, but city officials slapped that plan down. Afterward, the project was put into a design competition under New York City’s Design and Construction Excellence Initiative and awarded to the team consisting of architecture firm Grimshaw and Ken Smith Workshop. “Because it was a highly visible project, we wanted it to be beautiful and high functioning,” says Benepe, the former parks department commissioner. “We also recognized that there was some major inconvenience and dislocation both for the neighborhood having to endure the construction and the golfers having to miss their driving range for so many years.”

One of the most notable ways that this project sets a new standard is by avoiding the inorganic herbicides, insecticides, pesticides, and fertilizers that account for golf courses’ being among the most toxic of recreational land uses. Smith says that the Mosholu driving range is designed to be maintained wholly through organic methods and that it will be one of the first to use fish emulsion as a fertilizer.

Many of the features comprising the elaborate natural filtration system at the driving range won’t be immediately apparent. The vegetation and soils on the sloped roof slow the flow of rainwater, which is guided into drainage baskets filled with stones and directed to underground tanks, where it mixes with groundwater pumped in from other parts of the site. From here the water is pumped up to a gigantic cistern the length of a football field that is hidden away at the edge of the clubhouse, which has yet to be built.

A shaded cell in the complex natural filtration system helps lower the water temperature and dissolve oxygen. Credit: Grimshaw.

The extensive plantings slated to be installed in the security moat that wraps around most of the site will be the most visible green infrastructure. When the moat is fully completed, it will include an outdoor classroom where children can learn about ecology and a series of 10 separate cells that use phytoremediation to remove pollutants from the rainwater that falls on the driving range. The initial set of cells will contain shallow marshes composed of wetland shrubs such as sedges and dogwood. The plantings are intended to slow the water flow and to absorb the pollutants from the driving range, which, because the range is organically fertilized, will be substantially lower in volume than those from a conventional one. The next stop is a series of pitched shaded cells that lower water temperature and help dissolve oxygen. A final cell with floating native lotus and lily pads re-creates a natural ecosystem and serves as a reservoir from which irrigation water can be drawn for the driving range as well as for the adjacent golf course.

Perhaps, once it is finally opened to the public, local residents will come to appreciate this stunning work of landscape architecture, and the memory of having lived and/or worked next to a noisy construction site for more than a decade will fade. However, currently the entire project is still an extremely sore subject in the Norwood neighborhood, says Jeffrey Dinowitz, the New York state assemblyman who represents the area. “It is not like we got anything extra out of it,” he says. “It is an improved facility, but I guarantee you that 100 percent of the people in the community would have preferred the old golf driving range and no construction.”

The new driving range and the hundreds of millions of dollars in park improvements throughout the Bronx that the city has spent as mitigation for the filtration plant also cannot erase the history of a construction project that has been riven with mismanagement, massive cost overruns, extensive delays, and several large-scale fraud schemes perpetrated by contractors. City environmental officials pushed the project on the Norwood community, arguing that the filtration plant in Van Cortlandt Park would be less expensive and provide a more efficient connection to the municipal water supply than other sites that it had considered, such as one on New York City-owned land in suburban Westchester County. The irony of those assertions is that the current price tag of the filtration plant is reportedly around $3.2 billion—more than triple the 2003 estimate of $992 million—and construction of the plant, initially scheduled to last seven years, ended up taking 11 years to complete.

The water filtration and storage system provides 100 percent of the irrigation water needed for the driving range and roofs, plus a 40 percent reduction in potable water use for the entire golf course. Credit: Grimshaw.

Now, although the filtration plant is up and running, there are still clouds of uncertainty over the golf driving range project, which is slated for final completion in the summer of 2019. Despite repeated inquiries, DEP officials did not respond by press time to questions about when exactly the driving range will open to the public or how much the aboveground portion of the project is costing the taxpayers. Assemblyman Dinowitz also says it is not clear to him how public the driving range will be once it finally is open. “Will security issues be raised in the future?” he asked. “Will someone say that this is a terrorist target because it is a filtration plant? And what about the parkland that was supposed to be returned? Time will tell what happens.”

With any luck, New York City will do a better job of protecting its Catskill and Delaware watersheds and thus be able to avoid having to build more water filtration plants in the future. However, owing to the increasing imperatives to control stormwater, many neighborhoods undoubtedly will be seeing green infrastructure similar to what has been built at the Mosholu Golf Course. “I think that under current circumstances you won’t see the city designing parks going forward that don’t provide additional ecosystem services,” Benepe says. “Not so long ago we were trying to figure out how quickly we can get the water off the surface of a park and into the storm drain. Now we have turned around 180 degrees and are saying, ‘How much can we prevent stormwater entering our storm drainage system?’ and that is a sea change in this city and in other cities across the country.”

Alex Ulam is a New York City-based freelance journalist who writes about landscape architecture and urban planning.

Project Credits
Client New York City Department of Environmental Protection (Emily Lloyd, commissioner); New York City Department of Parks & Recreation (Charles McKinney, Honorary ASLA, principal urban designer); New York City Department of Design and Construction (Rebecca Clough, assistant commissioner). Landscape Architect Ken Smith Workshop, New York (Ken Smith, FASLA, principal). Architect Grimshaw Architects, New York (Mark Husser, managing partner; David Burke, project manager). Water Filtration Plant Engineer Hazen and Sawyer, New York (Ed Barboe, senior associate). Civil Engineer Ammann & Whitney, Philadelphia (Joe Riley, vice president; Irene Eells, Highway Department manager). Hydrology Engineer Sherwood Design Engineers, New York (Jason Loiselle, principal). Green Roof Consultant Rana Creek, Carmel, California (Paul Kephart, ASLA, president/principal ecologist). Irrigation Northern Designs, North Haven, Connecticut (Mike Astram, Affiliate ASLA, irrigation consultant). LEED Consultant Atelier Ten, New York (Nico Kienzl, director). Golf Course Design Consultant Stephen Kay/Doug Smith Golf Course Design, Egg Harbor City, New Jersey (Stephen Kay, ASLA, principal). Construction Manager URS/Malcolm Pirnie Joint Venture (now Arcadis), New York (Brian Farrelly, senior resident engineer). Structural Engineer Ammann & Whitney, New York (Joel Stahmer, vice president; John Bosco, project engineer). Lighting Consultant Arup Lighting, New York (Brian Stacy, principal). Security Consulting Ducibella Venter & Santore, New York (Robert Ducibella, senior principal). Ecology Consulting Great Ecology Environment + Design, San Diego (Mark Laska, president).