The Chattahoochee River provides a drinking water source for more than 3.5 million people, including 60 percent of metro Atlantans. The Chattahoochee Nature Center (CNC) is located on the Chattahoochee River in Roswell, Georgia and sits on a beautiful site comprised of 127 acres of native plants and gardens that showcase the area’s beauty. The CNC is celebrating their 40th Anniversary throughout 2016, and their mission is to provide unique learning experiences focused on the Chattahoochee River that connect all people to the natural world and empower them to positively impact their local environments. The property includes a River Boardwalk, The Discovery Center, wetland demonstration gardens and woodland trails that are home to over 50 species of injured, non-releasable wildlife.

After leading the master planning efforts for the Chattahoochee Nature Center, Lord Aeck Sargent designed two built environments at the site, the two-story 10,000 square foot Discovery Center, which is the new entrance for the CNC, and the 4,000 square foot Ben Brady Lakeside Pavilion, an outdoor space for educational programs and special events.

Built into a hillside, The Discovery Center blends with the landscape and visitors enter through the upper level. “The Discovery Center Museum includes a two-level exhibit hall featuring both permanent and changing exhibits focusing on stewardship, conservation and education; a theater/classroom that seats 65 people; a lobby; and support spaces, such as offices and catering facilities. The building also has a rooftop terrace that provides views of the river and surrounding landscape.

“Given the Center’s mission of protecting the Chattahoochee River, measures to protect the river were a key sustainable design focus for the project. Natural stormwater management features were used throughout to reduce and treat stormwater. Constructed wetlands capture and filter runoff from the site. Roof runoff is harvested in cisterns for use in toilet flushing and minimal site irrigation. A majority of the site is landscaped with a native plant palette requiring no irrigation. Energy efficiency measures include a vegetated occupiable roof, daylighting, improved thermal envelope and high-efficiency HVAC equipment,” (Lord Aeck Sargent).

In October 2010, The Discovery Center was certified Gold LEED with over 200 environmentally efficient and friendly practices and materials going into the construction of this unique building. The Discovery Center features engaging interactive exhibits; live, native animals; the Chattahoochee River Resource Gallery; exquisite Native Plant Gardens; The Nature Exchange; unique gifts and learning tools; and the Native Green Roof Terrace.

Located just off the upper exhibit gallery, the Green Roof Terrace offers stunning views of the surrounding forest and wetlands and winter views of the Chattahoochee River. Designed by EDAW (now AECOM) using the Extensive Garden Roof® system from American Hydrotech, the Chattahoochee Nature Center greenroof covers about half the lower roof of The Discovery Center. Metal railings separate the terrace from the greenroof, making it inaccessible although completely visible. The other half of the Native Green Roof Terrace provides a spacious Trek patio deck with comfortable seating and tables for outdoor gatherings.

Planted with mostly native plants of the rock outcroppings found naturally in the Georgia Piedmont, “This will be the first roof in the region to incorporate this many native plants representing a wonderful natural community you can see at Stone Mountain and Mount Arabia preserve,” (Henning von Schmeling, CNC Operations Senior Director personal communications, 2009). Henning was growing rare and endangered natives (including several rock outcrop species) in his CNC nursery facilities for the project and landscape architect Micah Lipscomb from EDAW (now AECOM) collaborated with Henning von Schmeling to design the unique plant palette.

“The Chattahoochee Nature Center’s roof top garden is a unique display of plants native to granite rock outcrops in the Piedmont region of Georgia. With over 90% of granite outcrops in the southeast located in the state of Georgia, this landscape is a signature part of the local landscape. Most people are familiar with Stone Mountain, but they are not aware of the unique assemblages of plants that have adapted to the extreme environments of granite outcrops.

“Many of the species found on these granite outcrops are found nowhere else in the world. Several endangered plants grow on these outcrops. The thin soils, limited water, and extreme temperatures of granite outcrops are remarkably similar to the conditions on green roofs. The plants found on granite outcrops are well suited to thrive on a green roof like the Chattahoochee Nature Center’s Discovery Center,” (Chattahoochee Nature Center website). The CNC says the greenroof has a valuable environmental educational role in two key areas: 1) exposing the public and visitors to a plant palette not currently used in the greenroof industry; and 2) educating visitors about the underappreciated landscape of granite rock outcrops.

Over 80% of the greenroof features the granite outcrop plant palette, and the rest consists of sedums and other more traditional non-native plants included for both seasonal interest and as a counterpoint to the natives. Massed together to form a colorful tapestry year-round, with several planted in rock crevices, the native greenroof plants include: Sandwort (Minuartia uniflora); Large Flowered Tickseed (Coreopsis grandiflora); Pine Weed (Hypericum gentinioides); Little Blue Stem (Schizachyrium scoparium), Confederate Daisy or Stone Mountain Daisy (Helianthus porterii), Cottony Groundsel (Senecio tomentosa), Prickly Pear Cactus (Opuntia compressa), Appalachian Fameflower (Talinum teretifolium), Small’s Stonecrop (Diamorpha smallii), Spiderwort (Tradescantia ohiensis), Hairy Lip Fern (Cheilanthes lanosa), and Georgia Rush (Juncus georgianus). Interpretive signage on the Native Green Roof Terrace allows CNC education staff to use the space to teach the benefits of living roofs.

A reservoir was built into the wall just outside of the doors upon exiting the building from the River Resource Gallery on the bottom floor where rainwater is funneled from the slightly inclined upper butterfly roof of The Discovery Center. The four underground cisterns can hold up to 4,600 gallons of water, which are used to supply the low flow toilets and occasionally irrigate the gardens.

The $9.7 million project, which includes the Discovery Center and Ben Brady Lakeside Pavilion, exhibits, landscaping and site work, was privately funded. Major gifts included grants from the Robert W. Woodruff Foundation; the Chattahoochee Greenway Fund; The Kendeda Foundation; and a challenge grant from The Kresge Foundation.

The Discovery Center’s greenroof was made possible by a generous grant from The Home Depot Foundation. If you would like to know more about the LEED Gold features of the Chattahoochee Nature Center’s The Discovery Center, ask a Visitor Service Associate for more information or take the self guided Green Building Tour during your next visit.

The Chattahoochee Nature Center, The Discovery Center received the 2010 AIA Atlanta, Committee on the Environment award and the 2010 Greenprints Conference Showcase Winner. The Chattahoochee Nature Center is a unique place where people connect to each other and the land through a shared respect for nature: a safe place where interaction with nature excites the senses and encourages learning.