Crissy Field

Challenge

• Reestablish functioning tidal marsh, dune, and beach habitat in the San Francisco Bay.
• Achieve a sustainable balance between cultural and natural resources and provide educational and interpretive opportunities related to these narratives.
• Configure multiuse spaces for seasonal events and daily use.
• Accommodate sailboarding activities.
• Provide access for both vehicles and pedestrians and dedicated pedestrian-bike circulation.

• The restoration of dune and marsh habitats reintroduced nearly 100,000 plants to the site. These plants represent 110 native species, including seven special status species such as San Francisco spineflower (Chorizanthe cuspidata var. cuspidata, dune gilia (Gilia capitata ssp. chamissonis), and San Francisco wallflower (Erysimum franciscanium). 
• The 18-acre restored Crissy Marsh supports migratory birds along the Pacific Flyway including migratory ducks, pelagic birds, and shorebirds. The federally threatened western snowy plover (Charadrius alexandrinus) has been observed roosting on the beach in the marsh’s Wildlife Protection Area. A boardwalk across the marsh allows for wildlife viewing without disturbing native vegetation. Double fences, offset from each other by about 30 ft, provide necessary protection for marsh flora and fauna, particularly fish and birds. The outer two-cable barrier deters most human encroachment, while the recessed rigid wire fence prevents dogs from moving through the vegetated marsh upland. 
• Excavated fill from the creation of Crissy Marsh was reused to create the historic airfield lawn, a flexible event space that supports a variety of large-scale activities including a temporary sculpture exhibit.
• The 1.5-mile-long fully accessible promenade adjacent to the beach connects Crissy Field to the Marina District, the Presidio, and historic Fort Point. It functions as a section of the San Francisco Bay Trail, which runs along the coast of the San Francisco Bay. The promenade is made up of compacted decomposed granite path, several boardwalks, and a pedestrian bridge crossing the salt marsh. 
• 45 acres of asphalt airstrip, roadway, and rubble were removed and recycled for use beneath new pathways and parking areas for Crissy Field. 
• Former military buildings were adapted for use in the park including the Warming Hut Cafe, which was transformed from a 1909 U.S. Engineer Storehouse into a cafe and gift shop. Historic hangars surrounding the airfield now house various recreational facilities including swimming pools, climbing walls, and trampolines.
• The park hosts organized events and festivals ranging from fundraising walks and runs, canoe and paddleboard races, the Crissy Field Day Festival, and the Halloween Festival. The East Beach of Crissy Field is known as one of the best places for sailboarding in the world, with thermal winds and storm fronts that roll through the area. 
• The Crissy Field Center supports a variety of robust education and outreach programs including youth camping, community group programs, high school leadership programs, youth environmental science programs, summer camps, and curricula-based field trips.

During the design process, the landscape architects’ combing of the Presidio archives uncovered not only the early extent of the San Francisco Bay and its marsh, but also the various military (and civilian) patterns and configurations that formed the site after the marsh was filled in for Army use. These patterns helped provide the underlying framework for early alternatives and later proved invaluable in advocating for pedestrian and vehicular parking circulation and a “palimpsest” approach to conveying the site’s history, with no one period dominating but rather many periods overlaid one on top of another.

Early conceptual designs focused on five distinctly different approaches, each varying with regard to inclusion and expansion of restored airfield, tidal marsh, dune field, parking, and perimeter roadway. This approach teased out the support and conflict among competing constituencies for various approaches and configurations, quickly resulting in a balanced hybrid approach for further refinement. It is this hybrid approach which allows the park to be both biodiverse ecological hotspot and urban park.

The most visible expression of this “palimpsest” approach is the grass field. The shape of the grass field reflects not only the early grass airfield configurations (itself a residual byproduct of a late 19th-century wooden vehicule racetrack) but also the later paved airstrip as a promontory point in the marsh. Each are legible as traces on the site.

Tidal marsh establishment is an evolving process and scale matters.
Marsh landscapes are constantly changing systems, with very large ones developing over hundreds or thousands of years, and thus change over a long period of time was anticipated for the Crissy Field salt marsh. However, the mouth closed numerous times within the first four years of construction due to significant sand deposition following major storm events, and debate ensued about whether to re-open it or let the marsh become a closed system, fed only by the collected upland stormwater flow that is diverted to the marsh, essentially allowing it to become a freshwater marsh over time. The decision was made to reopen the mouth and to add some small stabilization infrastructure (rocks and logs). It has since largely maintained the daily tidal exchange, requiring only minor interventions to keep this natural system functioning. The marsh’s ecosystem has continued to flourish.

Slopes influence marsh vegetation establishment.
From initial monitoring reports, it is evident that the success of vegetation establishment and growth varied according to the steepness of the edge conditions. In areas where the intertidal habitat slopes were widest and flattest, some of the “best” vegetated habitat occurred. This area supports a diverse and dense range of marsh plants, and efforts to re-establish a rare salt marsh annual, salt marsh bird’s beak (Cordylanthus maritimus ssp. palustris), were the most successful. In contrast, areas with steeper slopes were associated with lower successful establishment of intertidal plant species.

Winter months are ecologically critical along flyways. 
Although it was not surprising that the wetlands had the highest avian species richness and density compared to the dunes and beach, the significant increase in species richness during winter months (December-February) compared to summer months (June-July) reinforces the importance of planning for migratory bird populations and designing to provide protected habitat rich in food sources. These findings were also consistent in the foredune, dune swale, and rear dune habitat areas.

Native but locally uncommon or rare species should be prioritized in restoration planting design.
The coastal salt marsh planting palette prioritized uncommon, rare, or endangered plant species. It purposely excluded dominantly aggressive species like pickleweed (Salicornia virginica) and prolific native species such as spearscale (Atriplex triangularis), assuming these would naturally colonize in the marsh. By limiting the presence of proliferative species in the first phase of restoration, the planting specialists hoped to provide greater opportunity to establish less common species. Three months after outplanting was complete, the marsh planting achieved what was considered a high (68%) survivorship.

Non-native vegetation can have a place in restoration projects.
Prehistory and natural resource assessments of the project area ruled out the use of non-native vegetation, and yet mature naturalized trees (Monterey cypress, Monterey pine, and Canary Island palm) existed in three locations. These trees were retained to provide much-needed vertical scale and shade to the massive 100-acre parcel, which contained few natural features after years of military use. Additionally, cypress trees were added as an entry grove at the primary entrance, echoing similar historic groves at other entrances to the Presidio, visually tying the project into a larger historic landscape. These tree-filled areas have become popular destinations for respite and gathering.

Public access to sensitive habitats can happen and is important.
Early environmental advocates argued against human access to the marsh to maximize its habitat value. And while marsh restoration without any human presence would be of highest ecological value, it was acknowledged that a marsh within such an urban context would inherently be of lower value. Furthermore, access by people would maximize this urban marsh’s ability to educate and cultivate environmental stewardship. People need to move through these types of spaces to understand and appreciate them. A pedestrian-only path and bridge cutting through one end of the tidal marsh provides some level of public access to a sensitive habitat. The bridge brings pedestrians out over a tidal mudflat and emergent tidal grasses, exposing the city’s visitors to a Bay Area landscape typology that is increasingly difficult to access.

Anticipating demand for multimodal paths is critical.
While high-speed commuter biking was relegated to the edge of Crissy Field along Mason Street, it was anticipated that the promenade would accommodate low-speed bikers, runners, and walkers. This combined pedestrian and bike path was designed as a 20-ft wide, crushed stone bay edge path. However, the designers underestimated the ease of use this extension of the regional Bay Trail would make possible, as well as Crissy Field’s popularity as a destination, and consequently the promenade soon had to be widened to 25 ft within the first two years of opening to accommodate its heavy use.

Protecting culturally historic artifacts sometimes means hiding them. 
The site was previously occupied, first by Native Americans, later by the Spanish Military, and eventually by the U.S. Army. Each of these periods left behind materials, and as contemporary designers the landscape architects viewed them as artifacts to be celebrated. Army occupation left behind buried debris such as bridles, bottles, belts and more—all discarded as no longer useful, but of interest in understanding the historical use of the site and life on an army base during Crissy Field’s prime era of army use, when it was a critical part of U.S. air defense and the site of the first airmail delivery in the country. Rather than unearth these items to be included as a reading of cultural history within the design, the National Park Service preferred to leave them in situ to minimize the potential for vandalism. In a different location on the site, a Native American Ohlone midden ground was discovered during marsh excavation, as evidenced by the dark color, density, and texture of the soil. While likely made up largely of decomposed discarded oyster shells—the trash of daily life—there was the possibility that the site was also a burial ground and that human remains might be present. Designers anticipated that there might be a desire to mark this site to honor its Native American history, but after discussion amongst Ohlone tribal leaders, their directive was to cover the area with soil and back dune scrub vegetation, keeping its presence hidden, left to time and natural process without threat of disturbance. This created a landscape not originally anticipated, which has become a beautiful and serene part of the park, though it also decreased the size of the marsh from what had been originally planned.

Wood benches: Douglas fir, “Timberform Greenway” by Columbia Cascade Company
Picnic tables: Douglas Fir “Rectangular Pedestal Table” by RJ. Thomas Manufacturing Company
Park grills: K-20/S B2 by RJ. Thomas Manufacturing Company
Trash and recycling receptacles: Columbia Cascade Company
Bike rack: “Original Cyclops” by Columbia Cascade Company
Wood bollards: Douglas Fir, 3’ high by Columbia Cascade Company
Metal bollards: Steel, 3’ high by Columbia Cascade Company
Hardscape pavers: “Hexagonal Prest”, 8”x8”x2”, Hanover Architectural Products

Project Team

Client: Golden Gate Parks National Conservancy
Landscape Architect: Hargreaves Associates (now Hargreaves Jones)
Civil and Marine Engineering: Moffatt & Nichol Engineers
Hydrology: Philip Williams and Associates
Structural Engineering: E.G. Hirsch & Associates
Irrigation: Russell D. Mitchell & Associates
Restoration Ecology: Rana Creek Habitat Restoration
Architecture: Tanner Leddy and Maytum Stacy

Role of the Landscape Architect

The landscape architect led a team of engineers, habitat restoration consultants, and architects to develop the restoration plan and site design. The landscape architect and the subconsultant team coordinated extensively with local, state, and national reviewing agencies, including the Army Corps of Engineers, to ensure compliance with all waterfront regulations. They also led the design and implementation of the park through a robust public process.