The Dell at the University of Virginia

The primary goals of the design were to restore Meadow Creek to a more ecologically productive and daylit condition, to create an effective stormwater treatment facility, and to develop a space that that would become a public recreational and educational amenity in the heart of the historic campus – all in a relatively narrow corridor of open space. An additional challenge was presented by the very modest budget with which these ambitious goals were to be achieved.

Solution

In order to maximize useable field space, basketball, and tennis courts, a limited stormwater capacity was determined for the site. Two-year storm events are accommodated in the stream channel, while runoff from larger storm events is diverted by a flow-splitter into an existing underground pipe that carries the excess water to a larger stormwater treatment facility 0.75 miles downstream. In response to the modest budget, the majority of the plants were installed as plugs, small container sizes, or in seed form, but were closely spaced. This proved to be a fine, perhaps even preferable, method for installation and within a short time the plantings filled in very nicely.

• A 1,200 linear foot section of piped stream was daylit and restored to a more naturalized profile with meanders and vegetated stream banks, which capture sediment and solids, reducing sediment load downstream.
• The 0.75-acre, 12-foot deep stormwater pond can detain up to 1.45 million gallons of stormwater.
• The pond includes wetland benches and a sediment catchment forebay, which increase water storage and reduce flow rate. This creates successful opportunities for suspended sediment to settle before water continues downstream.
• Extensive areas of bioretention filters (rain gardens) upstream from the detention pond purify and increase infiltration of runoff from built upland sites.
• The Dell operates in tandem with the John Paul Jones Arena stormwater treatment facility, located 0.75 miles downstream and designed to accommodate larger storm events. Runoff entering the stream channel that exceeds the design capacity of the Dell is diverted through an upstream “flow splitter” and redirected to the arena facility through the original underground pipe that once fully contained the now daylit Meadow Creek.
• 99% of the plants installed at the Dell are native to Virginia. Designed as a native botanic garden, the site is organized into three zones, showcasing plants and plant communities indigenous to each of the three major ecological zones of Virginia: upland Mountain, intermediate Piedmont, and lower Coastal Plain. 
• Significant areas of wetland forest were restored through the implementation of this project.
• Trees harvested on site were used in the bio-engineering of the restored stream channel.
• The majority of the materials used in construction, including stone, wood, pavement materials and crafted metal hardware, are local to the area.

• While the project has been highly successful overall, maintenance has been a challenge. The project requires more active and aggressive management than the maintenance staff was accustomed to, due to the native plant palette. Despite a certain tolerance for natural succession in the plant community, invasive exotic species must be actively controlled through aggressive removal. In order to address this issue, the landscape architect provided the University Grounds maintenance staff with extensive training and education sessions addressing the maintenance and long-term goals of this native plant landscape. The planting plan also reflects an important strategy employed in order to aid maintenance personnel in the identification of desirable and undesirable (exotic) species. Plants were massed in single species groups, thus creating more readily identifiable clusters of desirable species, which assists in the identification and removal of opportunistic exotic invasives.
• The academic community has actively embraced the educational opportunities provided by the facility. The Dell has proven to be an excellent resource and an ongoing case study opportunity for many students who have been involved in water quality testing and monitoring; design research and proposals; and botanic education courses. Partnerships with the student body and with various schools within the University have proven to be very valuable and have resulted in the collection and analysis of excellent data and feedback that has enabled the University to effectively gauge the efficacy and success of the design.

Steel Light Poles and Luminaires: Spring City Electrical Manufacturing Company
Steel Anchors for Wood Construction: Simpson Strong-Tie Company Inc.
Coir Fiber Erosion Control Matting: Rolanka International, Inc.
Stone Coping on Walls, Spillways, and Pond Edge: Luck Stone Corporation
Plants and Planting: Ivy Nursery
Organic Compost: Panorama Pay-Dirt

Project Team

Executive Architect: VMDO Architects
Landscape Architects and Ecological Design Consultants: Biohabitats of Maryland, Inc.
Landscape Architect: Nelson Byrd Woltz Landscape Architects
Construction Management: Barton Malow
Civil Engineer (Stormwater Master Plan): Nitsch Engineering
Local Civil Engineer: Patton Harris Rust & Associates
Client: The University of Virginia
Review Agency: Commonwealth of Virginia Department of Conservation and Recreation

Role of the Landscape Architect

The firms Biohabitats, Inc. and Nelson Byrd Woltz collaborated closely throughout the design process, reviewing and critiquing the other’s work. Biohabitats, Inc. engineered the stream restoration, designed the biofiltration basin, and specified the meadow seed mix. Nelson Byrd Woltz developed the master plan and project concept, site details and the planting design.