This project added a pair of land bridges over a road dividing Houston’s largest park in order to reunite its north and south sides and improve connectivity for both visitors and wildlife. It’s a key early part of an effort to restore the park’s ecological systems and boost its resiliency under a 10-year master plan.

With a goal of minimizing the work’s environmental impact, the team designed the 96-acre project to balance the amounts of excavation and backfill. They repurposed excavated soil for backfill over the concrete structures for the land bridges so there was no dirt movement outside the project site. They also were able to mine silt sand found on site to place around the concrete structures for needed drainage and to alleviate hydraulic pressure on segment walls. Concrete from the existing road was also repurposed for steps on one of the land bridge mounds.

Photo by Nick Hubbard

“In essence, there were no trucks hauling dirt in and out of the jobsite,” says Raj Tanwani, practice director at engineering firm Ardurra Group Inc.

Unlike soil, precast concrete segments for the four 30-ft-radius arches were delivered to the site. After initially planning to cast in place, Tanwani says they designed the bridges without a particular manufacturer in mind, leaving the precast option open for contractors. They selected a precast arch headwall system from a local supplier that uses freestanding cantilever pieces connected by a structural beam. The result saved time and money compared to the cast-in-place method.

The project reintroduced Gulf Coast prairie and wetlands in addition to adding land bridges over a road dividing the park.
Photo by Nick Hubbard

The scope of work in the project also included reintroducing endangered native Gulf Coast prairie and wetlands areas on both sides of Memorial Drive. The team also built a channel to help manage storm runoff and improve resilience against flooding in the area.

“It’s an iconic project which has changed the picture of Houston,” Tanwani says. “Houston was never thought about as a park city. This one project has changed the perspective.”