Wayne Ferguson Plaza

Challenge

Emerging suburban communities within the Dallas metroplex have a long history of competing for economic development opportunities, sales tax revenue, and community growth. Sprawling economic development patterns have put a strain on the historic downtowns of these formerly agricultural or railroad-based communities. With new investment in commuter rail service coming to the east side of Lewisville, Old Town needed to be strengthened as a destination for both locals and visitors. The city began to reestablish Old Town through the creation of a new City Hall, streetscape improvements on Main Street, and a newly-constructed Center for the Creative Arts. However, a key missing piece in creating a desirable all-season destination was an iconic space to host community functions and draw tourists with programmed events. A parking lot next to City Hall that served as the site of an occasional holiday market but mostly operated as the “back-of-house” for Main Street businesses was identified for redevelopment. While the prospect of a year-round community amenity generated broad excitement, business leaders expressed concerns about reduced parking and negative impacts to their operations, which the design needed to address. 

Solution

The design solution replaced the parking lot with an ambitious urban park that has cultural value in the heart of a small town. It has a programmatic relationship with City Hall and the Center for Creative Arts and connects an area for new uses with the original Main Street retail area. The year-round park accommodates all previously-existing seasonal events but consolidates them in the new community space. Through an in-depth analysis of walking distances and civic area parking capacity, the designers demonstrated to the local business community that greater parking efficiency, improved operations, and increased aesthetic value could be achieved. 

• A 870-sf series of linear rain gardens around the perimeter of the site capture, detain, and treat stormwater runoff from the alley and the park and serve as a visual amenity.
• Wetland rain gardens were built along the alley to capture and cleanse stormwater. They are concrete-edged chambers with layers of crushed gravel, mesh fabric, and rounded gravel underneath and are planted with aquatic plants. 
• 17 out of 35 newly-planted species of trees, shrubs, perennials, groundcovers, water plants, and bulbs are Texas natives. 85% of the tree species are native. Native species are used in the prairie grass garden, wildflower meadows, and rain gardens. 5 of the site’s plant species, Mexican plum (Prunus Mexicana), Texas oak (Quercus buckleyi), columbine (Aquilegia), purple coneflower (Echinacea purpurea), and black-eyed Susan (Rudbekia hirta), are specifically recommended by the Lady Bird Johnson Wildflower Center due to their suitability for North Central Texas and wide commercial availability. 
• Crushed gravel pavement is used extensively, especially along the sidewalks and in tree pits along the historic promenade parallel to Church Street.
• At least 50% of all permanent seating areas are located under tree canopy shade during the summer season to provide thermal comfort for users.
• At least 75% of the materials used come from a maximum of 500 miles from the site.
• Materials used in the construction of the plaza include ipe wood decking, concrete, steel benches, gravel surfaces, and stone. These durable materials have a minimum 30-year life, increasing longevity of the plaza while minimizing long-term costs for maintenance and replacement.
• All of the lights used in the water features are LED fixtures, which create a well-lit, safe space for nighttime activities in and around the water while minimizing electricity use. 36% of all light fixtures on the site are energy-efficient.
• The water-wall and water-walk river (water trough) are combined into one treatment system for water efficiency, recirculation and reuse. The mid-stream weirs are used to maintain a smaller volume of water in the underground balancing tank, allowing for quick start-up. Automated systems for functions like chemical treatment, water level control, activation, control panels with timers and photocells, and wind speed sensing minimize maintenance and save energy.
• Main Street businesses benefit from the plaza as it allows them to open the rear facade of their buildings to increased pedestrian traffic.
• A minimum of 1% of the construction budget was dedicated to public art; the site incorporates work from local and national artists in at least 4 key locations, which relates the space to the nearby Center for Creative Arts.

   

During a week-long charrette in the design development phase of Wayne Ferguson Plaza, the Lewisville community was presented with 3 design alternatives with estimated price tags of $1.9, $2.1, and $2.5 million (2009 dollars). The 3 design alternatives emphasized curvilinear, angular, or organic design elements, forms, and/or features with slightly different programmatic elements based on earlier community input. According to designer records, the community overwhelmingly chose a design with more curvilinear form that featured a historic city timeline promenade on the sidewalk as well as water trough with a children’s adventure playground with a price tag estimated at $2.1 million.

Although the chosen design already included water features and over 50 canopy trees, it was further improved with additional features (such as more water features, interactive pop-jet fountains, 50% more canopy trees, and public arts and sculpture) based on the comments provided by the stakeholders for the other 2 design alternatives. With these design improvements and the added infrastructure, the final plaza’s estimated price tag increased to $3.7 million in 2009. At the project’s completion, the final cost was estimated at $5.2 million (2015 dollars).

• In this region of Texas, there is general concern regarding local high-Pl (plastic limit) clay soils and the challenges they pose to structural stability. Simple infrastructure tends to be oversized and over-engineered in response to these uncertain soils. For example, items as basic as stone curbs incorporate extensive rebar. Designers in areas with highly expansive soils can take steps to avoid certain infrastructure requiring excess structural support in order to reserve more of the budget for above-ground features. For Wayne Ferguson Plaza, one solution was the use of stone walls made up of large boulders. The designers identified these larger pieces of stone that did not require structural footings because of their sheer size and weight - compacted subgrade and a leveling course was all that was required for subgrade preparation. Another example is the “turf steps” located on the south side of the lawn. Stone was used as the stair riser and set on a small structural slab. This structural footing design is far less invasive than typical cast-in-place steps.
• The original design specified large trees in small spaces, leaving inadequate room for future growth. This project helped expand the designer’s knowledge about tree planting and soil requirements, and future projects will aim for 1,000 cu ft of soil or more per tree, depending on site conditions.
• The majority of the plant material was installed early in the construction process and therefore had little to no protection during construction. For example, the rain garden bridge crossings were completed late in the process, which resulted in the previously-installed plants being stepped on and having construction materials piled on them. Although construction sequencing was not the responsibility of the landscape architect, this project illustrated that having greater oversight and influence on the construction process, either in the field or via submittal responses, could address such issues.
• The construction process for Wayne Ferguson Plaza illustrated that it is critical to follow strict documentation practices during construction and to take the time to capture updates and decisions in field reports after every site visit. This communication can be shared when construction issues arise or if there is a change of contractor personnel on the project. Field reports are critical to bringing an inconsistent team up to speed and identifying work that was done poorly or not according to the plan and specifications. For example, there were several instances when the contractor risked damaging work that had been previously completed and already deemed acceptable in terms of form and finish. The landscape architect noted on several occasions that the contractor should protect previously completed work or that work would be subject to rejection. Unfortunately, the contractor caused irreparable damage to some finished paving surfaces and was required to remove and replace them at no cost to the owner.
• There were some mistakes made during construction that had to be accepted to avoid the expense of removing them and beginning again. For example, a vault in the most prominent water feature was installed 11 in too high, causing the top of the vault to conflict with the finished paving elevation above it. To resolve the challenge, a field change was issued to make a larger concrete area than originally planned, which resulted in a larger backstage and green room area behind the stage.
• Rain gardens were built along the alley to capture and cleanse stormwater. The design did not incorporate cleanout ports or monitoring wells from which to take water quality samples. In order to monitor water quality and make sure the system is functioning as intended, it is important to incorporate such features where possible.
• The designer specified as few pole lights as possible, choosing instead to illuminate surfaces and features. This design decision creates an artful atmosphere, reinforcing the sculptural forms of walls, water, and plantings. However, it would be interesting to understand how users of the park feel about the limited overhead lighting. In addition, surface and feature illumination required more fixtures, which means more maintenance, so it would be beneficial to understand if this has been a challenge from an operations perspective. 

Plants and Soils: Anderson Lawn and Landscape
Hardscape: Austin Masonry and JCC
Lighting: Bega Products
Furniture: Custom design by Design Workshop, Victor Stanley
Drainage, Erosion: MDS
Fences, Gates, Walls: Custom work, Austin Masonry
Irrigation: Anderson Lawn and Landscape
Lumber, Decking, Edging: Custom, local carpenter subcontractor
Parks and Recreation Equipment: Victor Stanley, Most Dependable Fountains
Water Management, Amenities: Greenscapes
Water Walls: Greenscapes and Water Design

Project Team

Client: City of Lewisville
Lead Designer and Landscape Architect of Record: Design Workshop, Inc.
Consultant, Fountain Design: Water Design, Inc.
Consultant, Civil and Structural Engineering: Nathan D. Maier Consulting Engineers, Inc.
Consultant, Graphic Design: Moon Design LLC, Temple, TX
Consultant, Irrigation: James Pole, Denton, TX
Consultant, Electrical Engineering: McCreary and Associates, inc., Dallas, TX

Role of the Landscape Architect

The landscape architect was retained by the City of Lewisville to provide planning and landscape architecture services for the plaza, beginning with a transit-oriented development master plan and continuing through design, implementation and construction observation phases. The firm coordinated a multidisciplinary team representing civil and structural engineering, fountain design, graphic design, irrigation, MEP engineering and lighting design. The landscape architect led an extensive inventory and analysis effort focused on sustainability and a multi-stage community-based design process that engaged key stakeholders. The firm worked with city staff to plan for a complex operations and maintenance program to keep the park in optimum condition.