Urban wetlands: another approach

By CHARLES ANDERSON
Anderson & Ray

How do you like your man-made wetlands? Stirred into a homogeneous, "natural" texture? Or maybe on-the-rocks, with large chunks of "art" swimming about? After some earnest sampling and experimentation with such conventions and preferences, we've come to appreciate another approach to urban wetland design.

The Reserve at Pritchard Beach is a three-phase project of the Seattle Department of Parks and Recreation. It will cost a total of $650,000 and involves recreation of a wetland environment on the shores of Lake Washington, in the Rainier Beach area. The design has been done with the goal of honestly conveying its ecological functions as well as its designed, urban context - a "shaken, not stirred" wetland.

The resulting landscape, now under construction, offers the public a created wetland with ecological integrity that also suits its urban use and location. It is neither "stirred" to bland predictability nor "on the rocks" with dropped in "art" pieces.

Ecological enhancement of this seven-acre, former lake-bottom was the foremost priority in design development, as was honestly responding to the site's urban context. The hydrology and buried physiology of the site were used to create five ecological and experiential environments. The environments, while creating habitat and sustaining plant reclamation, create a compelling and pleasant human experience. Four of the environments model natural wetland conditions and plant communities. Another environment serves as a contrasting model of a traditional man-made park. Each environment is anchored with "surprises," such as a "classroom" made of big leaf maples, floating metal platforms or seasonal "fairy rings" of flowers.

The Pritchard Beach Reserve is designed to convey its ecological functions as well as its urban context.

The Park

The first environment is The Park. The Park is familiar and welcoming to the person stepping out of his car or locking his bike at the main entrance to Pritchard Island bathing beach. As a continuation of its historic character, The Park is grand, open and festive.

The sound of swimming children and the sight of brightly-colored towels dotting the lawn are reassuring symbols of public recreation and free access. What distinguishes the entering view of this nostalgic environment is the undulating edge between the lawn and a shimmering field.

This informal wet meadow, of native wetland perennials and associates, leads the eye from Lake Washington's shoreline toward the interior of the reserve, which can only be glimpsed through the next environment.

The Alder Gallery

The second environment, the Alder Gallery, symbolizes the first step in nature's reclamation of environments. Human clearing or development of the region's predominant forest landscape often encourages Nature to quickly react with a monolithic healing environment like the Alder Gallery. Other events that would create this include landslides, fires and avalanches.

The Alder Gallery, like the succesional stands of alder one would find in the wild, is an almost monocultural environment of repeated geometry and unified texture. Almost 1,500 red alders, planted last year between four and 10 feet apart, will create a dense colonnade of smooth, vertical, gray lines within a unified structure of airy foliage. A boardwalk will take visitors into the heart of the Alders and their succesional understory. This immersed environment, punctuated with a small viewing platform of metal mesh, will show students the dramatic manner in which colonizing plants heal the land.

Also within the Alder Gallery environment, overlooking the central pond, is a primary gathering space called the Maple Cathedral. This is a semi-circular, double-rowed planting of 14 big-leaf maples around low, curved, gabion-and-granite benches. The space is designed for a class of up to 30 students to hear a lesson. Eventually, the arched canopy of maples will lend a gothic spirituality to the space.

The Gateway

The third environment is the Gateway through the scrub-shrub thickets that border the wet meadow. These dense thickets of wetland shrubs create suspense and a feeling of immersion in the intimate corridors they create around the paths.

The corridors will be places to listen to the rustling movements and songs of birds. A feature in one of the thickets is called the Rose Donut. One path leaving the Alder Gallery passes through this dense, fragrant planting of two native rose species before bringing walkers into the more grand space of the central wet meadow. The Willow Circle, a thicket of mixed willow species and twinberry, serves as the scrub-shrub threshold to theother entrance.

Wet Meadow

The fourth environment is the Wet Meadow. This light, open environment is accessed by a boardwalk that brings visitors from the dense Gateway environment on either side. Seasonally wet meadows like this one are among the most endangered and precious habitats in our region, as many of them occupied flat, lowland areas that have been drained for development. Many native plants and animals of our region have become disturbingly rare with the vanishing wet meadows.

In Pritchard Reserve's model of an urban Wet Meadow environment, native moist-meadow and emergent-wetland perennials will create a soft, pasture-like texture. A large, dark, year-round pond, thickly ringed with reeds and other emergent and aquatic plants, gives a reflective "heart" to the edge of the meadow.

As seasonal surprises and playful short-term features to bring interest to the infancy of the constructed wetland, "fairy rings" will appear in the Wet Meadow. Spring-flowering bulbs and summer-flowering perennials will bring a succession of giant, bright circles of color to the meadow before disappearing magically into the surrounding texture. Over time, as the Wet Meadow is established, these circles will dissipate into the surrounding composition.

Upland Overlook

The fifth environment is the Upland Overlook. This is the final destination of the reserve visitor. Symbolic of the mountain-top vista that marks the achievement of a traditional visit to the "wild," the path gently climbs from the wetland to the edge of the Cloverdale Street causeway.

A large metal pier, aligned with and similar in character to the gathering platform in the Alder Gallery, provides visitors with an overall view of the site and the journey just completed. Big-leaf maples will form a tunnel with their branches over the pier. The Upland Overlook area is planted with an upland wooded community of Douglas firs and big-leaf maples. This will someday be a dark, forested edge and backdrop to the relatively open reserve.

The experience of this "shaken, not stirred" urban wetland would then be offered in reverse-order to the visitor. Since a loop trail will eventually be constructed, a different route may be taken on the way back, to find a surprise that was missed on the way to the Upland Overlook. Phase two of construction is now underway at Pritchard Reserve.

The major grading, some of the paths, and most trees were installed with last year's grants and other funds raised by Friends of Pritchard Beach. A preliminary, experimental seeding was done on the Wet Meadow to read germination zones for different species of plants. This will guide seeding practices in the future.

Presently, the first of the two boardwalks is under construction. This will complete the primary path that connects the entrance of The Park environment to the destination of the Upland Overlook area. The curved benches of the Maple Cathedral will be constructed soon, which will open the site for teachers to hold outdoor, environmental education classes at the reserve.

Urban, environmental enhancement projects should not just be about habitat but should also serve our human need for expression in our shared, open spaces.

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