by Walker Wells
 

Longfellow Creek is a 3-mile, year-round urban creek in West Seattle’s Delridge neighborhood that once teemed with salmon. A comprehensive community effort is now underway to restore the creek as a vital fish habitat. Almost ten percent of the stormwater that ends up in Longfellow Creek falls on the ground of High Point, originally a 716-unit affordable housing project built during World War II. Run down and decaying, the project was ripe for redevelopment. With over $37 million in federal HOPE VI funds, the Seattle Housing Authority (SHA), an independent public corporation that functions as both a property manager and a nonprofit developer, began plans to redevelop the entire site into a mixed-income community. Concurrently, the City of Seattle expressed interest in integrating a natural stormwater drainage system into the redevelopment project to treat the stormwater runoff in an ecologically sensitive way and improve salmon habitat.

The Seattle Housing Authority spent time in initial planning determining how it could integrate a natural stormwater management system and identifying the specific permits needed. After deliberation, it agreed to integrate a natural drainage system into the project if the city granted several concessions. These included permitting narrower streets (25 feet wide, with parking on both sides) that would reduce impervious surfaces, assisting in the city permitting process, and supporting an approach that integrates the drainage system into a traditional-looking neighborhood. The city agreed and is also providing $2.7 million to cover the difference between a typical new-construction stormwater system and the natural system proposed by SHA.

The desire to improve the water quality of Longfellow Creek became a linchpin in the overall plan to connect the mixed-income community with the surrounding environment and the larger West Seattle region. Rather than continuing to use an internally focused street circulation plan, the neighborhood street pattern was reinstated. Numerous environmentally responsive strategies protect the watershed and provide an attractive and diverse neighborhood through the natural drainage system, which is the largest in the country.

First, SHA re-built the infrastructure for the entire 120-acre site. This included demolishing most structures (some were deconstructed for reuse) and all streets and utilities, and realigning the street grid so it connected to the larger West Seattle network. With the basic groundwork in place, the team was able to proceed with the design and construction of a completely reinvented High Point, including a new street grid, over 21 acres of open space and parks and playgrounds, the natural drainage system, and a number of community facilities that strengthen High Point’s connection to the larger community.

Upon buildout, High Point will house approximately 4,000 residents in 1,600 units of various types of housing. About half of the units are designated as affordable at various income levels, including senior housing, housing for large families, and eight homes built with sweat equity by Habitat for Humanity. The rest are a variety of single-family homes, carriage homes, and townhomes, offered for sale at market prices. As of fall 2006, 344 affordable units built by SHA and 75 affordable senior units built by the Sisters of Providence were completed, as well as key community facilities, such as a new library and a neighborhood clinic. Some market-rate homes had been completed and sold, and builders were focusing on completing the rest. Phase II of the project is expected to wrap up by 2009.

Green Achievements

Numerous aspects of High Point’s site design address resource conservation and environmental responsiveness. By combining the natural drainage system with traditional neighborhood design, the design team was able to capture synergies stemming from traditional, narrow streets and wide landscaped medians and parkways. Other green aspects are featured in the design and construction of each unit.

Site Design

In developing the master plan the project’s architect, Seattle-based Mithun, used many principles espoused by New Urbanism. Narrower streets (now often termed “traditional streets”) with short blocks promote a pedestrian-friendly atmosphere that encourages social interaction and decreases the impact and importance of cars. Approximately 2,500 trees were added to the site, and over 100 large trees worth $1.5 million were preserved during the construction process. Twenty-one acres of open space include parks and green spaces of all types, from a large central park that acts as the heart of the community to small pocket parks and trails. The natural drainage system adds to the quality of the green spaces throughout High Point. One of the drainage system’s most important elements is four miles of swales, which replace conventional street curbs and gutters with vegetated drainage channels designed to collect, channel, and filter stormwater. The swales line one side of each street and resemble the landscaped parkways that sit between the street and sidewalk in many traditional neighborhoods.

Planted with grass, trees, and shrubs, the swales filter rainwater and offer additional play areas. The swales are made possible by reducing the paved area. Less pavement also reduces the amount of pollutants, such as oil, that enter the system via runoff. The central feature of this system is a pond that, in addition to providing a scenic view and a local gathering place, plays a crucial role in absorbing and filtering stormwater before finally channeling it into Longfellow Creek.

Healthy and Efficient Housing

All housing at High Point is required to meet or exceed a three-star rating by Seattle’s Built Green program, a residential green building program and rating system developed by the Master Builders Association of King and Snohomish Counties in partnership with the City of Seattle. The three-star rating is the highest achievable in the “Community” and “Multifamily” categories. All townhome-style rental units were also built to meet ENERGY STAR standards (ENERGY STAR does not certify apartment buildings.)

Other green aspects include the use of low-emission paint and construction materials in all rental units. The homes also include appliances and fixtures that go beyond code requirements to save energy and water. Each home features a high-efficiency hydronic heating system. All rentals units have ENERGY STAR dishwashers and front-loading, highly energy-efficient washing machines. High Point also includes 35 innovative Breathe Easy homes available to low-income families with children suffering from asthma. These homes were designed to create a preventive atmosphere by minimizing exposure to some of the numerous environmental factors that can trigger asthma, including formaldehyde, dust, pollen, and insect remnants. Breathe Easy homes include high-efficiency particulate air (HEPA) filters that remove irritants from the air, no-volatile-organic compound (no-VOC) building materials, and linoleum floors instead of carpet.

Construction measures also addressed asthma prevention—for example, smoking was prohibited during and after construction. Residents must also promise to avoid asthma triggers such as smoking or having furry pets.

Landscaping outside these homes is comprised of drought-tolerant plants that don’t produce pollen, including many plants native to the Pacific Northwest. Researchers have been tracking the health of the residents of these homes since a year before they moved in, to investigate whether the environment provided by these homes makes a difference to the health of the occupants.

Deconstruction and Reuse

Before the site could be prepared for new construction, the old buildings had to be removed. Twenty-two of the old buildings were deconstructed by hand so that their materials, which included high-quality old-growth fir, could be sold and reused.

Going forward, SHA has mandated that parks and open spaces be maintained using environmentally sensitive approaches. Resident teams of adults and children have conducted environmental outreach, including public education about the value (monetary and environmental) of preserving large trees.