Let’s talk dirt. Dredging is a not-so-glamorous, but critically important aspect of our Galveston Wharves business.
Every year we dredge along our waterfront to maintain depths of 40-45 feet needed to accommodate the approximately 1,000 ships that call on the port each year. This year we’ll spend about $1.5 million to dredge an estimated 135,000 cubic yards, enough to fill 41 Olympic swimming pools.
We’re responsible for dredging our slips and berths along the Galveston waterfront, up to 150 feet into the ship channel, between piers 10 and 41. We also dredge a small portion of our waterfront property on Pelican Island. The U.S. Army Corps of Engineers dredges its jurisdiction, the middle of the channel, every two years to maintain a depth of 45 feet.
An interesting fact: Congress funded Galveston channel deepening as far back as 1889.
While we benefit from having a natural harbor, removing the silt that builds up is a never-ending task. Silting occurs naturally as currents move sand from Galveston Bay into the ship channel.
DREDGING TO STAY COMPETITIVE
Annual dredging is part of the ongoing maintenance we do to keep the port competitive. We maintain depths of 40-45 feet – the same as the ports of Houston and Texas City. This enables us to compete with regional ports for business and has allowed us to earn millions of dollars in revenue from lay berthing.
Ships on their way to or from Houston and Texas City ports find it convenient to stop briefly at the Port of Galveston for fueling, crew changes, inspections and other services before going on their way.
Another interesting fact: Different ships require different depths. A large grain ship may need 40 feet while the cruise ships that homeport here draw about 30 feet. The Port of Corpus Christi, which serves large liquid bulk ships, maintains a depth of 70 feet.
HOW IT’S DONE
Our local dredging contractor will work from mid-September through October to pump and pipe silt to the port’s 240-acre dredge spoil area on Pelican Island.
The contractor uses a mechanical dredge – basically a 145-foot-long boat with a motor and 12-inch-diameter pipe that sucks up the silt like a vacuum cleaner. Then the dredge pumps the silt through hundreds of feet of flexible pipe to the spoil area. The mechanical dredge can remove up to 10,000 cubic yards of material a day.
SIX WEEKS OF DREDGING, MONTHS OF PLANNING
Months of research, planning and coordination go into preparing for the dredging work.
Our hydrographic contractor surveys the channel twice a year to measure our depths. Then port Operations, Engineering and Construction and Maintenance departments plan out where and how much silt must be removed. We also maintain levees in the dredge spoil area to make sure the dredged silt drains properly.
To minimize impacts to ongoing port activities and revenues, Operations coordinates with its customers, ship pilots and steam ship agents. With 80-90 ships calling on the port each month, it’s a big task to coordinate an around-the-clock dredging operation.