The U.S. Army Corps of Engineers (USACE) dredges more than 200 million cubic yards of materials each year – in addition to maintaining approximately 25,000 miles of existing navigation channels and dredging new construction projects. USACE dredging operations encompass state-of-the-art survey activities and other efforts that, taken together, contribute to America’s economic well-being.
“Because of environmental considerations, some of the dredging projects have different time windows, whether it’s a dredging window or disposal window. In some cases, we might have material placement onto a beach and in those cases, we will restrict it during sea turtle nesting periods. Or with some types of dredges, we’ll have restriction windows for swimming sea turtles…
Christopher Frabotta, chief of the Navigation Branch for USACE’s Galveston District, oversees the operations and maintenance dredging across an impressive swath of coastal Texas.
“We monitor and maintain six deep-draft jettied inlets – or navigation complexes – along the Texas coast,” he explained. “And we also monitor and maintain the 379-mile Texas portion of the Gulf Intracoastal Waterway.”
The area of responsibility includes the Houston-Galveston Navigation Complex, where ships navigate through one inlet and then call on three different port facilities: the Houston Ship Channel or the Port of Houston; the Port of Texas City; and the Port of Galveston.
Frabotta said that the total area encompasses “over a thousand miles of channels” in which USACE performs “about 20 million cubic yards” of maintenance dredging every year.
“We do that through about 15 large-scale maintenance dredging contracts every year,” he added, pointing to another five to 10 “large-scale material placement” and other improvement contracts each year.
“All of the projects are unique,” he emphasized. “Because of environmental considerations, some of the dredging projects have different time windows, whether it’s a dredging window or disposal window. In some cases, we might have material placement onto a beach and in those cases, we will restrict it during sea turtle nesting periods. Or with some types of dredges, we’ll have restriction windows for swimming sea turtles. For some other projects, we might have placement in other endangered species habitats. As an example, down in the channel to Victoria, we have a whooping crane window where we can only work between Oct. 15 and March 1 in certain areas.”
In addition to the environmental considerations, Frabotta expressed pride in the contributions that the Galveston District’s dredging operations make to U.S. commerce.
Referencing calendar year 2014 statistics, he noted that the top 150 ports in the country had a total tonnage – including import, export, and domestic shipment – of 2.6 billion tons of cargo.
Jennifer Kist, survey technician, lowers the conductivity temperature depth (CTD) sensor into the water. The CTD measures conductivity and temperature, which is integral in the creation of sea floor maps. Photo by Sara Corbett
“The ports that are within the Galveston District moved 550 million tons of cargo,” he said. “That’s 21 percent of the [nation’s total]tonnage going through Texas ports.”
He went on to note that the three ports in the Houston-Galveston Navigation Complex had a combined total of 292 million tons of cargo.
“That’s about 11 percent of the nation’s total tonnage coming through one single inlet,” he said, quickly acknowledging that “the majority of that tonnage is imported crude oil.”
“But it’s important to realize that the refineries aren’t going to be relocated,” he concluded. “They are where they are. They’re permitted. They’re here. And there are not many states out there that really are looking to build new refineries.”
In parallel with maintenance dredging operations, other USACE representatives are focusing on new projects – either through early feasibility studies or design management and construction.
One critical element of USACE dredging activities – both maintenance and new construction – involves the timeliness and accuracy of the underlying survey data.
Sharon Tirpak is involved with many of those activities in Galveston District. Summarizing her 22 years in USACE, she outlines nine years working regulatory issues, five years in planning, and eight years in project management.
“About a year ago, I was promoted to the deputy chief of project management as program manager,” she said. “Now I oversee projects that could involve deep-draft navigation, flood risk management, personal storm risk management, or ecosystem restoration projects.”