At a public meeting Tuesday the U.S. Army Corps of Engineers will outline a plan that aims to improve commerce and safety on the Gulf Intracoastal Waterway by remaking the floodgates that alter the flows of the Brazos and Colorado rivers.
The plan, described in a 183-page Brazos River Floodgates and Colorado River Locks Systems Feasibility Study that the Corps and the Texas Department of Transportation published in late February, calls for the demolition of the floodgate on the west side of the Brazos River and the construction of a new 125-foot gate on the east side of the river.
At the mouth of the Colorado River in Matagorda County, the plan calls for building new 125-foot floodgates on both sides of the river.
The study estimated the total cost of the improvements on the Brazos River would come to $147.8 million and the cost of the work on the Colorado River would add up to $36.9 million.
Once completed, the new floodgate systems would reduce shipping delays by 78 percent and bring a net benefit of about $11 million each year to the Gulf Intracoastal Waterway, according to the study.
After tearing down the west Brazos River floodgate, the Corps of Engineers proposes to leave the west intersection of the river mouth and the Gulf Intracoastal Waterway open.
Since 1943, when floodgates were constructed on the east and west sides of the Brazos River, the Corps has attempted to control silt and flows from the river into the Intracoastal Waterway from the river. The opening of the west side would bring that era to an end, and allow the Brazos and San Bernard rivers to flow with less impediment in that location, according to the study.
Shipping barges would benefit from that opening because transit times would be reduced and the risk of collisions with west Brazos River floodgate structures would be eliminated if the west gate was removed, the study states.
The opening of the west side would also bring “some flood relief on the San Bernard River,” according to the Corps analysis.
The downside of the open west side, however, would be increased sedimentation of the Gulf Intracoastal Waterway. The study estimates an 8 percent increase in dredging volumes and costs.
The release of the study in February comes 18 years after the Army Corps of Engineers began assessing the feasibility of major modifications to Texas’ portion of the Gulf Intracoastal Waterway, which stretches from the Florida Panhandle to Brownsville.
The agency looked at changes to the Brazos River and Colorado River and in 2004 modeled potential changes, but, according to the study, the results of that effort “languished for a number of years” until the Texas transportation department provided the impetus to continue analysis in 2014.
In the meantime, the condition of the Brazos River Floodgates has continued to deteriorate, a problem the study details. Vessels collide with the floodgates on average 65 times each year, and that has led to “8 feet deep scour holes along the steel sheet pile guide walls” and the “guide wall timber bumpers and steel tangent plates are missing or damaged from constant barge impact.”
The study also outlines the degraded condition of the Brazos River Floodgates: no dependable backup power, leaking buildings and “panel boards that have deteriorated to the point of exposed wiring.”
Although the existing infrastructure on the two rivers is “not conducive to safe barge navigation,” approximately 21 million tons of freight pass through the floodgates each year.
The study can be downloaded online at www.swg.usace.army.mil/Business-With-Us/Planning-Environmental-Branch/Documents-for-Public-Review/.
Hard copies of the study are also available at public libraries in Brazoria, Lake Jackson, Clute, Freeport and West Columbia.
A 45-day public comment period on the study began Feb. 26 and runs through April 11. Comments can be sent to BRFG_CRL_FeasibilityStudy@usace.army.mil or mailed to the U.S. Army Corps of Engineers office in Galveston, P.O. Box 1229, Galveston, Texas 77553.