Light at end of tunnels
Building of land bridge makes headway at Memorial Park
The Memorial Park land bridge that will add 25 acres of native prairie over six lanes of traffic has reached a construction milestone: Two pairs of concrete tunnel tubes are in place with 500,000 cubic yards of dirt piled on top.
Passersby essentially see four giant mounds of dirt where Houstonians used to run, walk and play, but it’s now possible to envision how people and wildlife can traverse the north and south sides of the park safely and in an environment true to the city’s origin as Gulf Coast prairie.
Thomas Woltz, owner and principal at the Nelson Byrd Woltz landscape architecture firm that developed the park’s master plan and designed the $70 million land bridge over Memorial Drive, said that the project and others like it are a timely answer to urban density and encroaching freeways.
“We’re in a fascinating moment where we have built our cities without generous planning of public spaces, unfortunately, and this is across America, not just Houston,” Woltz said. “We build buildings and look for where we can make public green space. It’s where we find ourselves as a nation.
“It occurs to us, what if the landscape could become triumphant over the gray infrastructure of an urban city?
What if we could lift people, plants, prairie and wildlife up and over this tear through the public park?” Woltz said. “We basically are generating new acreage of parkland above the highway. It’s the park triumphing over the highway.”
The work
Work on the concrete arches began in late 2020, with 18-wheelers trucking in 6-foot sections of formed concrete to create long tunnels through which three lanes of traffic will run, eastbound and westbound. Within months, new roadways that will replace the existing sections of Memorial Drive were poured, and by early summer, the dirt was dumped on top of the structure. Some is still exposed, waiting for waterproofing before it, too, is covered in dirt.
The Kinder Foundation, which donated $70 million toward work in the park’s master plan, the Houston Parks Department and Uptown Development Authority are partners with the Memorial Park Conservancy on this project, and Kinder’s director of parks and green space, Sarah Newbery, has worked closely with Memorial Park Conservancy staff.
By the first quarter of 2022, drivers — some 55,000 vehicles travel through the park on Memorial Drive daily — will be routed onto the new lanes and through the tunnels, first the eastbound lanes and later the westbound lanes. The old roads will return to usable parkland, contributing even more acres of prairie grasses.
A new basin that will be a “wet prairie” was created when the construction crew dug up dirt to cover the concrete tubes; it will provide a place for water to go during heavy rains. Top soil stored there already has an initial cover crop planting to improve the soil and prepare it for the native prairie plantings that will come later.
Though the tunnels will open to traffic early next year, the whole project — part of a 100-acre section of the park’s master plan — won’t be ready for Houstonians to venture onto it until late 2022.
The land bridge will benefit wildlife and humans alike, with lawnlike space and benches, in addition to the native plantings.
Houstonians may often refer to their city as being built on a swamp, but the reality is that much of the area was Gulf Coast prairie, a vanishing ecosystem.
Conservation efforts
What’s important to Newbery and Memorial Park Conservancy president Shellye Arnold is that both the work at the recently completed Eastern Glades project and this land bridge help make the park more resilient to drought and flooding, something that ultimately will help the city, too.
After Hurricane Harvey, soil samples taken in various places around the city found that soil from Memorial Park ended up as far away as the Houston Ship Channel. Randy Odinet, vice president of capital projects and facilities at the park conservancy, said a major storm like Harvey can erode the banks of the section of Buffalo Bayou that runs through the park by 15 feet, sending soil and silt wherever the water goes.
Prairie grasses help because their roots can run 8 to 12 feet deep, so the soil absorbs more water and allows less erosion. If soil stays in the park, it won’t contribute to flooding in neighborhoods or waterways elsewhere. The grasses also naturally combat carbon emissions, helping clean the air.
Though it can take five to seven years for a prairie ecosystem to truly establish, Newbery said the new plantings will draw wildlife, birds and even insects that once thrived here but are long gone from the park.
Hines Lake in the park’s Eastern Glades is one example. When
that section of the park reopened with the small lake and wetlands, it quickly became the home of a pair of least grebe waterbirds, which nested and hatched chicks. The pair returned this year and can be seen there now, swimming with their chicks.
Woltz is excited that some of the land is returning to its origins, grasslands where Karankawa Indians once lived and even conducted controlled burns to generate new growth that drew bison to their hunting grounds.
Parks and green spaces where people can gather for exercise or community are more important than ever, he said.
“COVID has really taught us that public access to nature should no longer be considered a ‘nice to have,’ it’s an ‘essential to have’ for our psychological and physical well-being,” Woltz said. “I feel like access to public landscape and nature should be part of our democratic rights, along with life, liberty and the pursuit of happiness.”