Historic Fourth Ward Park, Phase 1

Challenge

Project Goals:

• Provide stormwater storage capacity to eliminate combined sewer overflows in the area during storm events, while preventing localized flooding and reducing pollutant loads in the runoff discharged from the site.
• Catalyze the economic revitalization of the areas along the BeltLine and reduce risk for developers in a flood-prone area. 
• Establish a precedent for future additional green spaces along the BeltLine.
• Create a community destination and provide additional public green space to serve a growing population while providing recreation opportunities in a park-poor area.
• Remediate an abandoned industrial brownfield site along the BeltLine.

• The detention basin, which has a storage capacity of 7 million gallons, can detain a 500-year storm event to alleviate flooding and CSO discharge. 350 acres are directly connected to the park by surface, and another 500 acres are connected via the sewer system. Water enters the park at 4 entry points. 
• 100-year and 500-year storm levels are indicated with horizontal bands on the granite veneer basin walls to allow visitors to better understand the site’s stormwater function. These modeled storms were chosen because hydrograph scenarios predicted flood levels that would fill the entire lower basin and therefore could be represented as continuous bands on the walls around the park.
• The floating fountain in the detention basin is an aesthetically pleasing aerator that circulates water, adding oxygen and improving water quality. The release of air keeps it floating, and a tether attached to the bottom of the pond keeps it in place.
• The south plaza stream channel is an ephemeral stormwater channel that sends an artfully-designed stream through one of the site’s largest gathering spaces. Benches line the sides so people can watch water flowing during or following a rain shower. When water is not flowing in the channel, it still serves as an attractive sculptural element.
• The site has 4 distinct planting zones: aquatic, wetland, drought-tolerant, and southern heritage. The southern heritage-designated zone is part of the BeltLine Arboretum plan, which separates the 22-mile BeltLine corridor into planting zones based on physical or historical features within that particular zone.
• In the wetland zone, a littoral planting shelf surrounding the basin is planted with a mix of tuckahoe (Peltandra virginica), pickerelweed (Pontederia cordata), broadleaf arrowhead (Sagittaria latifolia), and chairmaker’s bulrush (Schoenoplectus americanus). Aquatic species in the basin include scarlet hibiscus (Hibiscus coccineus), spiderlily (Lycoris radiata), and water canna (Canna glauca).
• A .25-mile running trail loops around the detention basin area and is used extensively by walkers and joggers.
• The amphitheater seats up to 500 people and is used for exercise classes, weddings, and performances. It is made up of terraced turfgrass, retaining walls with a granite veneer, and a stage of exposed aggregate concrete with concrete pavers.
• A series of large, sculptural, granite stones make up a sculpture plaza, north plaza fountain, and 17-ft-tall water wall by artist Maria Artemis. Much of the granite was salvaged from a local quarry.
• Phase II’s lawns and playing fields are partially irrigated with water from the basin, which is stored in a 20,000-gallon cistern.
• At the time of completion, the park had one of the largest displays of LED lighting in the state of Georgia.

The district’s combined sewer overflow problem could have been solved with a traditional gray solution like new sewer tunnels with an estimated cost of $70 million, but local advocates campaigned for the less expensive $23-million Historic Fourth Ward Park. The park manages nearly the same amount of water as the proposed sewer tunnels, released the city from the consent decree from the U.S. Environmental Protection agency, and saved the City approximately $50 million while providing multiple additional benefits.

• No maintenance budget was originally proposed for the park because construction was partially funded with Tax Allocation District (TAD) dollars that could not be allocated to maintenance. Currently the park is maintained by the City of Atlanta Department of Parks and Recreation, but their capabilities are limited to that of a typical park, primarily mowing and trash collection, and workers are not trained to maintain a stormwater park. Additional funding should have been identified to provide ongoing specialized maintenance for the park.
• After construction began, 76,000 cu ft of lead, diesel, and asbestos-contaminated soil was discovered on site from its use as a construction and demolition waste site in the 1970s. Clean-up ultimately added $1.8 million to the construction cost, drawing funds away from other portions of the project.
• The initial rate to rent space for an event was $350, and the City of Atlanta was surprised by the level of demand for wedding rentals since it was one of the least expensive wedding venues in Atlanta at the time. As demand could not be met, it quickly became apparent that the rate needed to be substantially increased. BeltLine Inc. uses profits from event rentals to fund other BeltLine projects.
• Catfish are present in the pond, and smaller fish can be seen swimming in the shallow areas. Fishing takes place on site even though there is a “no fishing” sign. The design team did not anticipate the presence of fish or program the pond for fishing, so facilities provided are not ideal for that type of use.
• The central steps in the amphitheater received more pedestrian use than anticipated. Initially, the turfgrass on each seating level was continuous between each flight of stairs. After the turf began to wear, granite pavers matching the treads and seat wall veneer were added to create a continuous hardscape connection between flights of stairs.
• Many of the original littoral shelf plantings, particularly broadleaf arrowhead, were immediately eaten by Canada geese before they could become established. The contractor was still on the site at the time and replanted the area with a modified plant palette that was less appetizing to geese, including hardy water canna and pickerelweed. The most significant ongoing plant-related challenge is preventing more aggressive plant species from dominating the site.
• The contractor recommended smooth, rounded disc-shaped river stones to line the south plaza stream channel. The bond with the mortar bed failed in places where flow volume and channel slope was more moderate than flat, causing some stones to become loose. The impressions left in the mortar from the missing stones provide a visual texture to the channel but don’t have the same aesthetic appeal as the stones themselves. In addition, the loose stones are being stolen, which cannot be controlled. In the future, a different bonding agent or alternative stone will be recommended to keep them in place.
• The contractor recommended an anti-graffiti product that was not specified in the original design, and it was applied to the granite wall veneer. It has been successful and the landscape architect plans to use this product, a water- and oil-proof anti-stain for granite, for future projects.
• Originally, conventional spread footings were specified for the retaining walls; however, it became apparent during construction that larger spread footings were required for the walls than for other areas within the park due to the sloped grades. These larger footings would have caused harm to root zones when placed near large trees. The spread footing walls were exchanged for a soil-nail wall during construction to lessen impact on existing root zones and save 3 existing mature trees from having to be removed.
• The floating fountain was added to the project during the value engineering phase as an alternative to a higher-cost, much larger underwater aeration system. The floating fountain does an adequate job aerating the pond, but it is not as aesthetically impactful and has created a maintenance issue that would not have existed with the original design. On windy days, mist from the fountain is blown around the lower basin, and a large accumulation of silt on the railing and the amphitheater stage has resulted. The railings are not galvanized, which would have allowed them to withstand the spray and prevent staining.

Exposed aggregate concrete: Kafka Granite – Violetta Quartz, Starlight Black Granite
Concrete paver: Hanover Architectural Products – Prest Paver
Glass paver: American Specialty Glass, Inc. – Custom Blend Glass Aggregate
Rock curb: Hanover Architectural Products  – Battered Rockcurb
Railing: Forms + Surfaces – Silhouette Railing
Recycled decking: Trex
Backed/backless bench: Landscape Forms – Austin Bench 
Trash receptacle: Landscape Forms - Plainwell Litter Receptacle
Security gate: Master Halco – Attleboro Double Swing Gate 
Lighting: Phillips – Color Kinetics C-Splash 2
Anti-graffiti stone sealer: Tenax – Glydex Water Based Sealer

Project Team

Client/Owner: Atlanta BeltLine Inc., City of Atlanta Department of Watershed Management
Landscape Architect: HDR
Lighting Subcontractor: Womack and Associates
Geotechnical Engineering: Willmer Engineering
Public Relations: PEQ
Artistic Renderings: CTC Designs
Artist: Maria Artemis
Contractor: Astra Group
 

Role of the Landscape Architect

Development of Historic Fourth Ward Park was a collaborative design effort led by landscape architects with the support of planners, hydrologists, civil engineers, structural engineers, electrical engineers, and a local artist. Serving as project manager, the landscape architect fostered proactive and consistent communication between disciplines, allowing the engineering goals to be seamlessly integrated into the aesthetic elements. The landscape architects led a series of public meetings to ensure the grassroots vision of local advocates for the park was incorporated into the final design.