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In the Houston suburb of Clear Lake, an almost 200-acre nature park called Exploration Green is underway, complete with wetland preserves and at least six miles of hike-and-bike trails. But what makes it special is the park’s primary function of mitigating flooding for the community through its five detention basins.

The recreation and detention site, once the Clear Lake City Golf Course, has been part of the community for more than 50 years. With increased development in the surrounding area in recent years, the old methods of managing runoff — outdated drainage channels — didn’t hold up.

Residents several years ago took steps along with the local water agency, Clear Lake City Water Authority, as the community realized more drainage was needed. In 2005, when the golf course’s owner decided to sell it to residential and commercial developers, the Water Authority had heard enough concerns from residents and witnessed plenty of flooding in the area. The Water Authority began to consider the potential impact of converting the golf course into condos and townhouses.

Each of the five detention ponds can store as much as 100 million gallons of water. Although the first detention pond was only 80 percent completed at the time Harvey made landfall, it protected 150 to 200 homes from flooding.
Photo: Exploration Green Conservancy

After two hydrologists determined that the development would dramatically increase flooding in the area, the Water Authority purchased the land for $6.2 million in 2011 with the idea to convert the property into detention. The result is Exploration Green, a former golf-course-turned-park now being converted into a system of detention ponds to hold stormwater during major rainfall events.

The need for this kind of project became clear last August during Hurricane Harvey, which brought unprecedented rainfall to the Houston area. The neighborhoods around Exploration Green were inundated with 45 inches of rain. Harvey’s extensive flooding has resulted in city leaders and agencies around Houston searching for solutions. Doug Peterson, the vice president of nonprofit Exploration Green Conservancy, believes that projects like Exploration Green provide the answer. Founded by residents, Exploration Green Conservancy is a nonprofit that helps plan the recreational area and raise funds for conservation, recreation, and amenities for the park.

“Exploration Green can and should be replicated all across Houston,” Peterson said. “It’s a good approach for having flood and stormwater countermeasures that are more than just levees and are focused on green spaces and amenities that people appreciate in addition to flood protection.”

Each of the five detention ponds can store as much as 100 million gallons of water. Although the first detention pond was only 80 percent completed at the time Harvey made landfall, it protected 150 to 200 homes from flooding.

Engineering challenges

The former golf-course-turned-park is being converted into a system of detention ponds to hold stormwater during major rainfall events. Photo: Stan Cook

The 178-acre project will ultimately protect several thousand homes in the Clear Lake area from flooding during a storm event. The detention ponds will be excavated by 2021, according to Abigail Stanhouse, P.E., a project engineer at Lockwood, Andrews and Newnam, Inc. (LAN), the planning, engineering, and program management firm that prepared the plans and construction documents and is overseeing construction of Phase 1.

“Due to the nature of the project, a lot of input and expertise is required from different groups, which in turn, requires iterations and modifications to the design,” Stanhouse said. “Typically, we’ll do our designs and they’re set, the work gets done, and we’re finished.” This project required a lot of coordination from everyone involved, she said.

Technical knowledge was also required from different parties. The project’s different elements, such as incorporating wetlands, has required expertise from outside agencies. For example, Texas Coastal Watershed Program, an extension of Texas A&M AgriLife, is coordinating the wetland effort. There will be 39 acres of wetlands throughout Exploration Green, as well as more than 100 acres of upland and island areas.

Texas Coastal Watershed Program, an extension of Texas A&M AgriLife, is coordinating wetlands development. Photo: Jerry Hamby

Phase 1 of the project was divided into three sub-phases — Phase 1A and 1B are complete, with 171,420 cubic yards excavated, while Phase 1C was 80 percent complete by mid-January, and weather-permitting, was expected to be completed in February. Phase 1C requires 177,230 cubic yards of excavation. In its entirety, Exploration Green Detention Facility will provide 38 acres of permanent water storage and additional storage room for water runoff. The water storage area is equivalent to 750 Olympic-sized swimming pools. The project’s first two phases were designed to contain runoff from a 100-year storm, of which there have been at least seven in the Clear Lake area in the last 40 years.

“It’s worked out well that we split Phase 1 up,” Stanhouse said. “The knowledge we have gained along the way has assisted in the planning of Phase 2, and we’ll apply it to future phases as well.”

She cited the challenge of using native grasses in the project as an example. While Bermuda grass is typically seen at detention basins in the area, incorporating native Texas plants and grasses was important for the client, she said. LAN collaborated with the Harris County Flood Control District to learn what types of native grasses would provide the needed turf establishment in the ponds and be resilient enough to survive underwater after a storm event.

Community centerpiece

There will be 39 acres of wetlands throughout Exploration Green, as well as more than 100 acres of upland and island areas planted with native grasses and wildflowers. Photo: Jerry Hamby

“Exploration Green really is a centerpiece to the community,” Stanhouse said. The project is exceptional in that the entire Clear Lake community has been involved since the beginning.

“The local community got upset (when the condominium development was proposed) and mobilized, putting up signs and having meetings and calling their local officials among other things,” Peterson said. “The community has been very supportive from the get-go.”

Stanhouse also said the community aspect made a difference in how LAN designed the project. “Most of the projects we work on are underground pipelines. They’re not something that people are going out their backdoor every day to see,” she said, so this highly visible project required the engineering team to be more open to community input and collaboration.

Peterson described the collaboration process as “organic,” saying that “people were going to town hall meetings to express their interests and what they wanted here, right in the heart of the Clear Lake area. The project has generated a lot of excitement among residents because we don’t have a lot of parks here, and here’s an opportunity to create a 200-acre nature park,” he said.

Clear Lake City Water Authority is funding the excavation of the project to the tune of $28 million, but “when it comes down to it, the Conservancy will raise funds to create and manage the park,” Peterson said. To this end, the Conservancy is coordinating with local-area nonprofits such as Trees for Houston, the Galveston Bay Foundation, and the Texas Coastal Watershed Program.

So far, the Conservancy has raised $1.3 million through private donations, business sponsors, and grants, but Peterson said they need another $7 million. The money will be used to build six miles of hike-and-bike trails throughout the project, plant thousands of trees, and develop other amenities such as an education center, picnic tables, and park benches.

Peterson called this community collaboration “innovative,” citing the Clear Lake City Water Authority’s foresight to build a project like Exploration Green with the community, nonprofits, and other partnerships.

“The Water Authority had the vision for this. They went out on a limb and fought for it, planned for it, and did everything required to raise money for the excavation,” Peterson said. “When Harvey came along and filled the Phase 1 area right to the top, it held 100 million gallons of stormwater. It worked just the way it was supposed to.”

“The project spans such a wide portion of the district that someone can ride their bike through Exploration Green to the park-and-ride nearby, commute downtown (by bus) and back,” Stanhouse said. “The fact that the community will have a safe place to ride their bikes through town is huge.”

Conclusion

For decades, Peterson drove by the golf course without thought for its potential. He hopes that the site’s transformation will be a boon to the community. Even with just the first phase under construction, residents are proud to live so close to the nature park, he said.

Despite the $7 million the Conservancy has left to raise, Peterson is optimistic. He called the fundraising a challenge but hopes that residents will be inclined to donate as they recognize the natural beauty of Exploration Green.

“The last time I walked around Phase 1, it was great to see the progress. I mean, the whole area that had been excavated was green,” Peterson said.

He said that wildlife is coming back to the area quicker than he expected. Even though the park is surrounded by residential neighborhoods, wildlife has found a home in Exploration Green. From hawks and turtles to native water birds, “it’s amazing to see…I think the wildlife can somehow tell when it’s their land again,” he said.


Kelly Shipley is an associate and project manager at Lockwood, Andrews & Newnam, Inc. (LAN; www.lan-inc.com), a planning, engineering, and program management firm. She can be contacted at kdshipley@lan-inc.com.

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