What are the Colorado River Locks?

Published May 1, 2012

Q. What are the Colorado River Locks?

A. USACE Galveston District locks provide navigation access through the Gulf Intracoastal Waterway, assisting vessels crossing the intersection of the Colorado River.

The lock chamber is essentially a stationary box constructed in the GIWW with two matching gates at each end that close. The Colorado River Lock chambers are 1,200 feet long and 75 feet wide, with a lock situated on both the east and west sides of the Colorado River on the GIWW. The gates open or close to allow the water levels to correspond with either the GIWW or the Colorado River levels. One set opens to let the watercraft enter and then closes to allow the water level in the chamber to be raised or lowered depending on the direction of travel. The other set of gates then opens to let the boat leave. The lock chamber never empties completely, but drops only as far as the pool level of the Colorado River or GIWW on either side of the lock.

The filling and emptying of the lock chamber is done by gravity flow that controls the flow of water into and exiting the lock, alleviating the need for pumping. 


Q. When were the Colorado River Locks built?

A. The Colorado River crossing of the GIWW was originally constructed without navigation structures. Due to rapid shoaling of the waterway at the crossing, it became evident that a protective structure would be required to reduce excessive dredging costs.

Plans and specifications were prepared and a contract was issued to the Brown & Root Company for the construction of two floodgates, which were completed in September 1944 at a total cost for new work of $2,251,400. Concurrent and subsequent contracts were issued for construction of buildings, guidewalls, fencing, paving, and landscaping at a total cost for new work of $ 1,038,000.

The floodgates proved effective in the reduction of silt deposition in the waterway, but delays to navigation were experienced due to a frequent and excessive head differential caused by floodwaters in the Colorado River. In May 1951, a contract was awarded to the Texas Construction Company for conversion of the floodgates to navigational locks, construction of mooring walls, turfing, and slope protection. The contract was completed in April 1954 at a total cost for the new work of $3,473,000.

Q. How does a vessel gain entrance into a lock?

A. Vessels are required to call the locks on VHF Channel 13 for passage through the Colorado River Locks. Tows and larger vessels call when they are approximately one mile from the locks to relay information to the operators who direct traffic through the locks. Smaller vessels without radios come to the locks and get visual or verbal instructions from the lock operator and may also contact the locks by telephone at (979) 863-7842 for directions and instructions.

No vessel should enter the locks without being instructed to enter. If a larger craft is exiting the locks, stay clear until the larger craft has completely exited before entering the locks. A red light means DO NOT ENTER while a green light means to proceed with caution.

Q. How many boats travel through the locks each year?

A. Navigation systems across the country significantly contribute to the growth and economic prosperity of our nation. The Colorado River Locks alone enables the transit of more than 12,000 tows, over 30,000 recreational or commercial vessels and 20 million tons of product annually, providing an essential service that significantly impacts local communities, the state and our nation’s economies.

Q. Which safety precautions are put in place to ensure safe passage through the locks?

A. All vessels are required to follow instructions of the operator to allow for safe passage. The locks are located in a “No Wake Zone” area from entrance to exit (both the east and west locks.) Vessels not abiding by this stringent regulation could be cited by a park ranger to appear in federal court for not adhering to safety regulations. Additionally, vessels entering the locks are prohibited from smoking or having flammable devices during entrance into the locks. All vessels must have proper U.S. Coast Guard approved lighting, personal floatation devices on board, and are required to be in seaworthy condition to transit the locks.

All vessels should carry approximately 50 feet of mooring line onboard to safely moor in the locks if instructed to do so. Mariners are advised to be prepared to cast off the mooring line quickly in case of emergency and are encouraged to wear life jackets while transiting the locks.


Q. What are the operating hours of the locks? 

A. The locks are operated 24 hours a day, seven days a week, 365 days a year. The locks are periodically closed to marine traffic for rehab or construction maintenance of the facility. Notices to Navigation along with current conditions of the locks are posted on the district’s website at http://www.swg.usace.army.mil/BusinessWithUs/OperationsDivision/ColoradoRiverLocksSummary.aspx. The website is updated twice daily for current information for customers.


Q. Which locks are Corps operated?

A. There are approximately 250 locks in the United States that are currently operated by the U.S. Army Corps of Engineers. The USACE Galveston District operates two lock facilities, one at the Colorado River Locks and the other at the Wallisville Lake Project.

For more information about navigation within the USACE Galveston District visit http://www.swg.usace.army.mil/Missions/Navigation.aspx.