PROJECT BACKGROUND

The University of Puerto Rico Comprehensive Cancer Center (CCC) is a 12-story, 286,000-square-foot building fully equipped for inpatient and outpatient services dedicated to cancer treatment and prevention strategies. It is located adjacent to the Río Piedras Medical Center in San Juan and is part of the Science City District.

VA was hired to assist RMJM and Hillier architects, who were working with Victor Villegas from Arquiteg, to prepare landscape design for the site, parking lot, service areas, entrances, and a Healing Garden adjacent to the building for terminal cancer patients. The Client also wanted an inviting pedestrian and vehicular entrance that connected the CCC with the design of the Science City Boulevard, both visually and programmatically, so that both projects reinforced each other.

PROJECT CHALLENGES:

•The proposed site infrastructure and buildings were already in the Construction Document phase when we joined the team: we had to face a number of set decisions previously made.

•The Client was concerned for the negative visual impact of a large detention pond proposed by the engineers as the only stormwater management solution, and its unattractive chain link fence all around, which would be seen at ground level upon entering the site and from all the floors of the building.

•The large amount of paved areas in roads and parking lot needed re-design if we wanted to retrofit shade trees and control the quantity and quality of stormwater hold on site and reuse for irrigation or other non-potable uses.

•The building and site as designed did not qualify for LEED certification. The landscape and green stormwater infrastructure design we would propose was the only way to provide all the missing points.

We proposed six design strategies that increased LEED points:

1.Save open space and save on excavation costs by eliminating the proposed detention pond and move any necessary detention needs under the parking lot, which would be already in a cut slope many meters down and would require huge amount of costly fill to be raised at grade as planned.

2.Increase stormwater retention by modifying the quality and drainage capacity of the soil, to decrease the amount of detention needed at the bottom of the site.

3.Specify very porous engineered fill material that qualifies for drainage and bioretention.

4.Design vegetated swales that decrease and filter runoff water generated from the upper Science City Boulevard, from the drive into the site, and from the parking lot pavement at the bottom of the sloping terrain.

5.Integrate these swales with a “grass parterre” made of tall grass biofilters that slow down surface runoff water running across the slope and undulates with the new landform, a gesture amplified across the Science City Boulevard at the scale of the large CCC building

6.Save on underground piping since the water filtered and cleaned by the grass parterre directly enters the Storm-Tanks by gravity, and will be reused for irrigation.

THE GRASS PARTERRE

In this project, linear grass biofilters occupy a large portion of the open space on either side of the entry road. Visually, they are perceived as an appealing pattern to view, becoming part of a low maintenance grass parterre that can be enjoyed from afar upon entrance by driving and from the building upper floors.

The linear shapes (ribbons, drifts) are developed from a pattern already used in the adjacent Science City boulevard, now multiplied into this site to unify the project with its surroundings. The biofilters of tall natural clumping grass alternate to mowed grass lawn and are placed perpendicular to the slope to decrease water erosion.

The flowing, tall grasses intercept runoff water in flocks like a storm of migrating birds and change color during the year from yellowish to green-silvery shades according to the drought or rainy conditions. They are part of an undulating surface that changes perspective from each point of view or approach.

The convoluted path leading to the north entrance of the building. is not arbitrarily curvilinear, as it would seem in plan: rather, it snakes following the concavities that guide surface runoff, a means to admire at each turn some of the trees and landforms Gama grass (Tripsacum floridiana) is ideal for this application as it is resistant to both bog conditions and drought conditions.

A robust, tufted perennial, gamma grass grows to about 50 cm tall and will require two cuts per year. There will be no other plantings in the parterre, except for an occasional tree or scattered palms: the intent is to give the impression of a meadow or savanna landscape, very open, where the contrast between the short, rough textured lawn grass (Bermuda grass) and soft, fined textured silvery Gama grass will be the essence of the design.

Tripsacum dactyloides is a taller, very decorative blue-green grass that we specified at the moister bottom of the slope since its native habitat is along watercourses and wet prairies.

The stormwater infiltrates by gravity and percolates down finding its way downhill underground without the need of drainpipes, according to soil porosity. This reduces the water volumes to be detained in a detention structure downhill in the event of a large storm. During those events, when soil in is already saturated and cannot absorb water fast enough, the excess water flows downhill and is stored into the Rain Tanks under the parking to be further released if needed into its storm outlets.

This provides the possibility to cluster smaller tree species and shrubs among taller specimens that need more root space. Raised curbs are interrupted periodically by curb-cuts in all the islands and curbs are eliminated in the linear portions of the parking lot to encourage the collection of stormwater into the median very close to its source. As for all rain gardens, this is designed to withstand the extremes of moisture and concentrations of nutrients, particularly Nitrogen and Phosphorus, typically found in stormwater runoff.

Additionally, a dense buffer of planting is also proposed at the edge of the site, with an upper level of mixed canopy trees and an understory level of smaller trees closely spaced, selected from native and endemic Puerto Rico plant species. The grass parterre can be interpreted as an artificial “clearing” carved out this edge of archetypical “forest,” which frame it in the background. The occasionally scattered savanna-like tree (like Hymenaea courbaril) or palms in the parterre syncopate the rhythm of the grass clearing when walking or driving nearby. A grove of imperial palms is proposed at the lowest grade and to meet the tall scale of the building in the lawn parterre just below the healing garden. Roystonea oleracea, the imperial royal palm, is used along with Syagrus sancona, or Columbian foxtail, and with Acrocomia aculeata palms and other unusual palms like Livinstona rotundifolia, some of which have been donated or are propagated from the Puerto Rico Botanical Garden.

Contrasting textures and color help the patients discover the complexity of the design, inviting a closer look or tactile experience. The path is disguised as a series of shapes or fragments that interlace with each other (rather than one singular ribbon) to integrate the design in the total pattern of the project of bird-like or wave-like parterre by introducing two colors in the concrete that break up its linearity. Beds and plants and gravel are retained in shape by plastic edging. Recyclable and sustainable materials in the paving aggregates have been specified. The goal is to provide volume without creating too much shade, as the building is already projecting a large shadow for several hours during the day. Also, too many trees would cover the pattern and destroy the two-dimensional view of the garden when seen from above.

We learned that it is prohibited to import palms to Puerto Rico. Therefore, the imperial palms that we wanted to ship from our nursery, had to be replaced by the tall Syagrus sancona, available in Puerto Rico. When looking at the palms upon arrival along the curvilinear drive, the monumental size of the retaining wall would decrease among these palms, interacting with the scuppers inserted in the indentations, as if those bromeliads planted in the scuppers on the wall were scattered in the palm trunks or the upper layers of a rain forest canopy. These palms will resist hurricanes as slender and wide roots in the slope and stormwater sump or infiltration basin used to manage the surface runoff water that we specified. This landscape extending in height and space the constriction given in the Healing Garden walls, and will be a fantastic stage set from the Healing garden foreground experience.