One-Star Certified Pilot Project
Location: Seattle, Washington
Project Size: 1.6 acres
Project Type: Open space - Park
Site Context: Urban
Former Land Use: Greyfield
Terrestrial Biome: Temperate Broadleaf & Mixed Forests
photo by: Gustafson Guthrie Nichol
Theater Commons and Donnelly Gardens is a highly visible sustainable demonstration project at a major entry to Seattle Center, a 74-acre urban park and cultural/arts center in downtown Seattle. The design transformed an existing 1.6 acre parking lot, service road, and isolated lawn area between the Intiman and Repertory Theatres into a welcoming, green, and pedestrian-focused entry for the Seattle Center campus. The site is used on a regular basis by visitors, staff and theater patrons, and during the many outdoor festivals that Seattle Center hosts throughout the year.
Sustainability is integrated into the public experience of the space, especially through the treatment of stormwater on the site. The amount of non-permeable site surface is reduced through both the landscape design and the use of permeable unit pavers for the North Entry Court and South Terraces.
A large Cascadia Region native plant garden, designed and installed by Seattle Center Landscaping staff, occupies the center of the site. The garden's topography creates a series of connected bio-retention garden basins to collect and filter on-site stormwater run-off. Additionally, the bio-retention gardens were sized to collect and filter the run-off from the Repertory Theatre roof adjacent to the site. This provided a successful precedent for retrofitting an existing building drainage system to connect to a natural drainage system.
The site is located on a cultural/arts and civic campus in an urban neighborhood in the City of Seattle, at the base of Queen Anne Hill, one of the many hills that make up the city. Historically, the site was at the edge of a wet meadow and a relative low point in the surrounding topography.
Surrounded by mountains and water, Seattle is located within a temperate marine climate, with mild, wet winters and warm, dry summers. Puget Sound, a saltwater inlet, borders the city to the west and the freshwater Lake Washington borders the city to the east. The Olympic Mountains are located across Puget Sound to the west on the Olympic Peninsula. To the east, beyond Lake Washington, is the Cascade Mountain Range.
SITES Features + Practices
The notable sustainable features in the project include:
- Bio-retention gardens and evaporation gardens that collect run-off from both the non-permeable site surfaces and the adjacent theater roof.
- Permeable paving within the north parking court and on the south seating terraces.
- A regional native plant garden that was designed, selected, and installed by Seattle Center landscaping/gardening staff. In a unique collaborative process, GGN led the conceptual design and sustainable concepts in the planting design and then Seattle Center staff selected the plant palette, layout, and did the planting.
- Locally sourced materials for paving and planting.
The most notable strategies used to earn SITES credits include:
- Involvement of multiple user groups in the final design outcome of the site.
- Involvement of a multi-disciplinary team in the development of a sustainable design solution.
- Treatment of stormwater run-off from beyond the site boundary by re-directing an existing building's drainage leaders through the site's bio-retention gardens.
- Seizing on the site's high visibility and public access to showcase sustainable design with educational outreach activities and interpretive signage.
- Development of a simple, replicable, and affordable precedent for sustainable pedestrian streets at Seattle Center.
The integrated design team had a significant influence on the development of the strategy for the on-site stormwater management. The investigation and inventiveness of MKA, the civil engineers, really enabled the project to expand its water collection and filtration beyond the site's non-permeable surfaces to include the roof of the existing adjacent Repertory Theatre.
The final design of the bio-retention gardens, a collaboration between GGN and MKA, resulted in an innovative system design. Several distinct basins collect the rainwater to maintain visual interest at the surface of the garden. Below the surface, all of the basins are connected by a continuous gravel infiltration bed. This design handled the required stormwater runoff capacity of the system while maximizing aesthetic variety at the surface.
Maintenance + Stewardship
The Theater Commons site is open to the public year round on a 24/7 basis and provides a unique opportunity to view stormwater detention ponds, Cascadia native plants, and sustainable materials up close. Theater Commons is a symbol of Seattle Center's ongoing commitment to sustainable design leadership and is a highly visible model for showcasing emerging green technology and ecology, meshing good design with ecological function through a series of integrated site features.
To enrich the general visitor experience and theater patron experience at Theater Commons, several site tours highlighting sustainable design features have been conducted each year. This helps realize a key goal of the Seattle Center Century 21 Master Plan (2008) to highlight ecological systems in new and reclaimed landscape projects and to emphasize public education opportunities. The tours have included members of the public, visiting colleagues from other cities, and Seattle City staff.
The owner was an integral member of the project team throughout the project. For example, Seattle Center Landscaping/Gardening Staff designed, selected, and planted the regional native plants that were installed in the garden. Because the staff was involved in the design process, they are even more invested in maintaining the landscape so that the sustainability goals of the project continue to be met over time.
Although there is not a formal monitoring system in place at the moment, the site is maintained by Seattle Center staff, who monitor the plant and bio-retention garden performance as an essential part of regular maintenance activities.
One of the main challenges in the design was satisfying the multiple programmatic requirements of several different client and stakeholder groups on a relatively small site. A formal stakeholder group was involved in the design process through regular design updates. Primary stakeholders included representatives of all the major festivals that are held at Seattle Center, Seattle Center Events, Redevelopment and Maintenance Staff, and the Staff and Board members from the Intiman and the Repertory Theatres. A secondary stakeholders group was formed midway through the design to address accessible design issues.
Each group had particular requirements that needed to be met in the site design. For example, the site had to provide regular maintenance vehicle access to the campus while maintaining an overall identity as a main pedestrian entry. The landscape design also had to accommodate set-up spaces for multiple festival tents while minimizing the overall areas of pavement on the site to meet the sustainability goals. The site also needed to provide accessible design features to meet the needs of campus visitors and theater patrons alike, such as accessible parking, loading, seating, and pathways.
Another challenge was to create a simple, replicable, and affordable precedent for pedestrian streets at Seattle Center. With a limited budget, the team designed a simple, cost-effective street standard that can be easily replicated throughout Seattle Center. The locally-sourced materials palette was chosen so that pervious pavers could be used on the campus streets where conditions allowed. Otherwise, impervious pavers in the same material and color palette were used. For example, at Theater Commons, shallow-laid historic trolley tracks beneath Second Avenue North prevented the use of pervious pavers on the street. Therefore, in this project a model was developed to use impervious pavers on the street, with adjacent infiltration areas that collect and filter stormwater.
Project Goals + Successes
The goals developed by the client and stakeholders for Theater Commons are listed below. They included:
- An inviting entry, welcoming people to Seattle Center's campus and strengthening the arrival experience to the Intiman and Repertory Theatres from both Mercer Street on the north side and August Wilson Way on the south.
- Increasing the visibility for both the Intiman and the Repertory Theatres by reinforcing the identities of the theatres and articulating clear, visible entries for each theater.
- An attractive pedestrian route, using quality materials, planting, street trees and amenities to link Mercer Street to August Wilson Way and the inner campus while maintaining the access corridor needed for service vehicles, campus-wide festivals and other public events.
- A series of spaces that connect and support the Intiman and Repertory theatres, developing a distinct sense of place that draws on the cultures of the two theaters and Seattle Center, encourages public interaction and easily accommodates spillover from theater events.
- A stronger neighborhood identity for Seattle Center, incorporating landscape and urban design concepts developed as part of the Theater District Plan and Century 21 Master Plan, establishing campus design precedents, and advancing the design vocabulary and clarity of design features for the Seattle Center campus and neighborhood edges.
- An improved interface between the theatres and the "Center of the Center," coordinated with the artistic vision and streetscape design for August Wilson Way and better integrated with the Theater District with the International Fountain areas.
- A flexible design that will work over time to reinforce the Century 21 Master Plan, accommodate future capital improvement plans of the theaters, and function well for the diversity of users, while recognizing that functions and priorities change over time, and that multiple users, like the festivals at Seattle Center, will each have programmatic and infrastructure requirements for the use of the Theater Commons.
- Incorporation of accessible design features throughout the site and accessible parking into the north entry court.
It was challenging to redirect an existing building's drainage leaders to the bio-retention gardens due to conflicts between historical as-built records and unknown conditions discovered during construction. However, through the coordination of the design team and the client, the project successfully re-directed the roof run-off and reduced the run-off from the site and the Repertory Theatre roof by 85%. The value of following through on the roof retrofit was an important lesson learned for the design team and the client as Seattle Center considers meeting sustainable goals in the future on a campus with many existing buildings.
Shannon Nichol, Gustafson Guthrie Nichol, Design Lead, Landscape
Amy Cragg, Gustafson Guthrie Nichol, Project Management/Design
Lesley Bain, Weinstein AU, Design Lead, Architecture
Chester Weir, Weinstein AU, Project Architect
Civil Engineering and Structural Engineering:
Drew Gagnes, Magnusson Klemencic Associates, Lead Civil Engineer, Sustainability
Joe Taflin, Magnusson Klemencic Associates, Project Civil Engineer, Sustainability
L. Lief Johnson, Magnusson Klemencic Associates, Structural Engineer
Lighting and Electrical Engineering:
Bev Shimmin, Pivotal Lighting/ AEIEngineers, Designer
Berne Thorpe, Electrical Engineer
McClure & Sons
Jill Crary, Seattle Center Redevelopment Director, Project Review/Oversight
Layne Cubell, Seattle Center Redevelopment, Project Planning
Bonnie Pendergrass, Seattle Center Redevelopment, Construction Management
Beth Duncan, Seattle Center Landscape Manager, Plant Selection and Maintenance