RiverSouth wins 2023 Texas ASLA Honor Award
Located just south of downtown Austin’s treasured Lady Bird Lake, RiverSouth thoughtfully responds to its constraints to transform an underutilized, triangular site into a sustainable vision for future development within the South Central Waterfront District. Approached as a pilot project for a district transitioning toward more urban and dense development, the design team embraced experimentation, established superior design standards beyond code requirements, and demonstrated a commitment to environmental responsibility that sets a high bar for future projects in the area.
Formerly the site of a lone Hooters restaurant set within a solid block of surface parking, the triangular lot was a tangle of overhead utilities and was an inhospitable space. Little shade or environmental benefits were provided by the few non-native, ornamental trees relegated to the parking lot’s edges, while the curb to curb impervious surfaces caused all stormwater to sheet-flow off of the site to dump directly into storm sewers. The site’s redevelopment into RiverSouth, a 15-story office building on track for LEED Gold, represents a major contribution to the social, environmental, and economic health of not only the parcel itself but to the district as a whole.
The site’s location within the Barton Creek floodplain and its adjacency to the Colorado River engendered a commitment to the sustainable management of water. The collaboration between landscape, architecture, and engineering demonstrates a superior approach to addressing stormwater, informing a wide range of design decisions throughout the project. The ground floor of the tower is lifted 8 feet above street level in response to predicted flood elevations, and all roof rain water and A/C condensate is captured and stored for reuse in irrigation. The water storage tanks, with a capacity totalling 58,000 gallons, allow for all planting to be fed entirely by reclaimed water from the site. In addition to treating 100% of the stormwater from within the site, the landscape design takes the additional step of integrating more than 800 square feet of rain gardens within the right of way that filter water from the adjacent road.
Recognizing the vast ecosystem services that healthy, mature trees provide—from reducing heat island, absorbing pollutants, capturing carbon, to creating habitat and more—all trees throughout the project are provided with soil volumes that exceed city and industry standards. This additional soil volume, created through the design of large, connected beds in both the streetscape and roof terrace, ensures the trees’ long-term health and ability to provide maximum environmental benefits into the future. Despite the site’s redevelopment from a single, small restaurant to a 15-story tower, the quantity of trees drastically increased from 6 ornamental trees to 53 shade trees, showcasing the possibilities of thoughtful, high-density design.
The streetscape, defined by three high-traffic roadways, is designed to promote human comfort and engage the public realm. In response to the elevated ground floor of the tower, the design of vegetated slopes instead of retaining walls address the grade change from sidewalk. This not only increases planting area, but the lack of hard, vertical barriers promotes a sense of openness between private and public spaces. Comfortable sidewalks—wider than the code minimum in preparation for a denser future urban fabric—are shaded by 30 new street trees. Grade-separated bike lanes are integrated into the streetscape on all three sides of the property, reclaiming area from the roadways to provide a safe space for cyclists away from vehicles.
The true gem is the 7th floor roof garden, a lush oasis that creates a refuge from the urban environment. Tucked behind the tower and sheltered from the intense western afternoon sun, a woodland-inspired garden utilizes raw, unfinished, and natural materials such as recycled bamboo, steel bar grating, and textured concrete pavers that embrace the patina of time. The square footage devoted to planting exceeds that of occupiable space, allowing for the use of large shade trees instead of small ornamental trees. Twenty three native cedar elms were installed at various sizes to further evoke a naturalistic, forest-like feel. The subtle topographic design creates shallow berms and slides below the walkways, giving the impression that the steel and bamboo boardwalks hover above a pre-existing landscape.
On a site where space is limited and environmental goals are high, every portion of the landscape is somehow performative. Whether supporting accessible and multimodal circulation, combating heat island, or increasing urban biodiversity, each element of the design works toward achieving one or more goals to improve the urban environment. As the first built project to set the tone and direction for the South Central Waterfront District, RiverSouth aims to not only create meaningful social and environmental impacts within its own site boundary, but also influence Austin’s future development toward greater positive change.