Designing Houston Zoo's Galapagos Islands Exhibit Proves Rewarding for Engineers

Jun 02, 2023

Engineers working on the Houston Zoo's Galapagos Islands exhibit paid careful attention to the natural habitat of the animals and made sure conservation practices were followed.Photo courtesy of Walter P Moore

Providing engineering services for the Houston Zoo's Galapagos Islands exhibit was a challenge for two Walter P Moore engineers but a gratifying change of pace.

"We were building [the exhibit] for the animals. We had to consider how they lived and their environment. There were so many things you don't see in other designs, said Ted Vuong, an infrastructure engineer and managing director of Houston civil engineering.

Structural engineer and Project Manager Jessalyn Nelson described working on the project as "really, really cool." She continued, "We were always learning… We had many conversations with the zoo staff who shared their knowledge about the animals and their habitat."

Many of those conversations required the engineers to think out-of-the-box, they said.

From working in a 500-year floodplain to using materials deemed safe for animals, the engineering and design principles used in building retail space only applied partially to constructing a zoo exhibit.

The exhibit, which opened in early spring, highlights the delicate balance of an ecosystem. The Galapagos Islands, located off the coast of Ecuador, are part of an isolated archipelago home to various rare animals. According to the zoo, roughly 97 percent of reptiles and land mammals, 80 percent of the land birds, and more than 30 percent of the plants found there are endemic. Most of the animals in the exhibit are closely related species.

Preserving the zoo's environment and surrounding conditions was paramount to the zoo and the design team, said Vuong, adding that creative and out-of-the-box thinking was necessary to overcome issues related to how to construct around 100-plus-year-old trees and ensure they not only survive but thrive to how to create storage areas to accommodate detention in constrained and developed areas. The engineers used non-traditional stabilization strategies to construct pavement around the trees and incorporated low-impact design strategies throughout the zoo's existing and new landscaped areas. These strategies reduced detention storage requirements and allowed traditional detention structures to be considerably smaller in size and cost, giving the zoo more programmatic options.

The state of the existing utilities also posed a major problem for the infrastructure engineering team. Vuong said many of the utilities were beyond their life, failing, and undersized based on current codes. Much of the non-gravity utilities were installed in a "spaghetti" like manner; over, under, shallow, with minimal clearance. Many areas had utilities that were difficult to locate and identify because they weren't on any record drawings or as built.

It took months to solve the utility issues, he said. In the end, engineers created a graphical information system (GIS) cataloging all the zoo's utility infrastructure. They designed new infrastructure with maintenance and access a key consideration by creating utility corridors and routing them outside of hazardous areas and difficult-to-reach or work areas.

Houston code changes also created a challenge for the engineering team. During the project, city leaders decided to revise its floodplain requirements. That led to a race against the clock. The team raised buildings 2 feet above the 500-year floodplain just in time to beat the clock.

"The Galápagos exhibit demonstrates how effective utility planning and phasing can successfully bring upgrades and modernize infrastructure that has been serving the zoo for decades. Simultaneous integration and implementation were critical to the zoo's operations and their ability to serve the community," he said.

Nelson's goal was to design a zoo that "didn't consist of flat lines and straight plains all the time … We had to come to each piece of the project with fresh eyes. Each piece we had to approach with a different mindset."

Since engineering a zoo isn't an everyday project, her team was in forward-thinking mode; they continuously examined drawings, brainstormed and held in-depth conversations with the zoo's staff.

A critical consideration was the zoo's numerous aquarium tanks, including fresh water, salt water and a mixture. Several different custom concrete mix designs were required for the different tanks. Careful material selection was important throughout the space to protect the animals from toxic exposure and avoid corrosion. This ranged from stainless steel precast connection elements to galvanized rebar and fiberglass-reinforced structural shapes.

"We built it how it needs to be built, not how we wanted to build it," she said.

Nelson and Vuong's part in the Galapagos Islands exhibit will remain a professional and personal career highlight. Nelson explained it was a team build requiring close work with zoo staff and other engineers. The key to the project's success "required a buy-in from all partners involved."

The Galapagos Islands exhibit opened in the spring as part of the Houston Zoo's $150-million Centennial Campaign started in 2018. While the majority of the Galapagos Islands is complete, a few projects are still ongoing, the engineers said.

Dan has reported for national and regional newspapers for three decades. During that time, he's covered topics ranging from three octogenarians who were known as the original Daisy Dukes because in their youth they ran moonshine in Appalachia to Latin American politics. For the last decade or so, he's focused on global energy, mainly natural resources.

He has won numerous awards during his career, all of which are sitting in a bottom desk drawer collecting dust.