Navigational Tips

The California Department of Water Resources offers real time reports on the status of water conditions in the Delta. Click for more information.


Additional Information

Cross Delta Channel Gates

The Bureau of Reclamation manages the Cross Channel Gates.  If you have questions you may contact the Operations Office at (916) 979-2194 or (916) 979-2448

There is a dug channel, less than a mile long, connecting the Sacramento River (near Locke and Walnut Grove) with Snodgrass Slough and the Mokelumne River System. There is a pair of hyraulically controlled gates on the Sacramento River end of the channel, with usual low-tide overhead clearance of about 8-1/2 feet, when the gates are in the open position. (Although these gates often are referred to as “locks” they are not locks, they are gates.)

The Channel is deep and allows transit of low-overhead clearance boats when the gates are open. This provides a shortcut between the two waterway systems. Without this shortcut, a boater must travel the entire distance of Georgiana Slough and back upstream the entire distance of the North Fork of the Mokelumne River (or vice versa) to go this same one-mile distance, a cruise of many miles.
Two views of gates in open position, USBR photos. Above. Cross Delta Channel, gates at Sacramento River at left, Walnut Grove in the foreground, DWR photo.

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Montezuma Slough Salinity Control Gates

This structure, located on Montezuma Slough 2.2 miles from the east end (Collinsville end) of the slough. It consists of both a boat lock 20 feet wide and 70 feet long and a “maintenance channel” 66 feet wide on the east side of the slough. Typically lock use is not required from about early spring and summer, usually through August or September, and boaters may pass through the maintenance channel at any hour (there is 16 feet of water depth over the “sill”).

The channel is marked by fixed red lights on piers on the west side, and fixed green lights on the east side. 6 a.m. to 6 p.m. November through April, until further notice.

Presently there is no regularly maintained telephone communications with the lock attendant, but he may be reached by marine band radio on channel 13. Also, there may be an emergency telephone number posted at the installation.

Marker buoys identify a shoal area along the east bank on both sides of the structure, extending approximately 50 feet out from the existing levee. (The control structures can at times create currents great than normal slough currents.)

California Delta Chambers

There absolutely is no way to predict when the facility will go into its “lock mode” — it depends on rainfall and the times of the year that the rainfall is received. Lock mode can start as early as September.

When the gates are in Boat Lock Operations, instructions for locking through are posted at the installation. The boat lock signal is a standard traffic light. Whistle (horn) signals to request opening are two prolonged blasts followed by two short blasts. Hours of operation for the Lock are 6:00 a.m. to 6:00 p.m.

Boat-In Park. There is a nice public park just downstream of the Salinity Gates on the Collinsville side of the slough. There is a very small dock, providing the park with limited boat access.

South Delta Barriers

There are four barriers temporarily across South Delta waterways at certain times of the year, either limiting or totally preventing through navigation of the waterways. The prime purpose of three of the barriers is to improve water quality and depth in the South Delta area. The fourth barrier, a rock barrier in place only part of the year on Old River near its juncture with the San Joaquin River at Lathrop, is for the protection of migrating fish. (Installing or removing a barrier is not an instantaneous process, so dates indicating such activities may bracket a time periods — such as “April 12 – 19″.) South Delta Barriers Link

Ultimately DWR plans to install locks at each of the barriers, but this may be some time off. In the interim, there are retrieve/launch facilities at two of the barriers. Personnel will retrieve your boat at a launching ramp on the near side of the barrier then re-launch it at a ramp on the far side of the barrier. They can handle boats up to about 25 feet in length.

Old River Near San Joaquin River.

This is the fisheries barrier. Most years it goes in place in the spring by April 15 and stays in until May 15 . Most years it also goes in place a second time, this time in the fall of the year by early Oct. and remains in place until late Nov. No retrieve/launch services are available here.

Old River Near Tracy.

This barrier is located upstream of Rivers End Marina (formerly Del’s Boat Harbor) a distance of about one mile. It typically goes in place in early April and comes out  by Nov. 30. There is a free retrieve/launch service here when the barrier is in place. Barrier personnel will put your boat (up to 25 feet in length) on a trailer, remove it from the water, and re-launch it on the other side of the barrier. This service operates  Mon. thru Fri. 8 a.m. – 6 p.m. and 7 a.m. to 7 p.m. weekends and holidays when the barrier is in place.


Grantline Canal.

This barrier is located east of Tracy Blvd. and typically goes in starting in mid-May and is removed by  Nov. 30. It has a retrieve/launch service, which operates  Mon. thru Fri. 6 a.m. – 8 p.m. and 6 a.m. to 8 p.m. weekends and holidays when the barrier is in place.

Middle River.

This is located on Middle River about 500 feet upstream of Hwy 4 and typically goes in place starting in early April. Removal begins in late Nov. and is completed by Nov. 30. It does not have a retrieve/launch service. (It should be noted that this waterways in only marginally navigable, especially for larger, deep-draft craft. So use caution.)

Emergency Telephone Numbers

A cell phone/PCS is considered by us as a marginal second choice for emergency communications because coverage throughout the Delta area can be spotty and unreliable. More importantly, other nearby boaters, who may be able to render assistance, will not be able to hear you. Dialing 9-1-1 will get you in contact the California Highway Patrol; perhaps not a heap of help when you’ve got a problem on the water. If you feel you must use a cell phone for an emergency, then have these emergency numbers handy. And please don’t ever use any emergency number for a non-emergency purpose. (You also may wish to have the cell phone number of your favorite Delta-area salvor handy.)

Important Telephone Numbers

If you have other numbers that need to be on this list, please let us know. Sacramento Sheriff handles handles Isleton police & fire. Do not report bridge discrepancies to the above numbers, see “Drawbridges” below.Thank you to Lauritzen Yacht Harbor and Herb Hickman (Blackfin) for this emergency telephone information.

Delta Flood & Emergency Information

In the event of flood, disaster or other emergency conditions in the Delta, the California Department of Boating & Waterways (CalBoating) may issue special emergency restrictions on Delta waterway use. Such restrictions of Delta waterway use generally will be broadcast periodically on the Marine Band Radio channel 16.  By special arrangements with CalBoating, this Website also will contain complete copies of any such restrictions. CalBoating has a special Website page set aside on which to post any Delta boating emergency restrictions, should any exist. CalBoating Delta Boating Emergency Restrictions

Drawbridge Openings & Clearance

(see Bridges)

Because of the many rivers and sloughs, the Delta has a number of bridges. Some open, some don’t. The ones that open are referred to as drawbridges. The vertical clearance and the hours of operation of these drawbridges are extremely important to boaters exploring the Delta. It is almost routine for a boater to make a long cruise to some intended destination, only to find that a drawbridge of modest vertical clearance blocks their route, and that the bridge’s hours of operation are past and that the bridgetender has gone home.

Report Bridge Discrepancies and problems (light outages, bridge malfunctions, blocked channel, etc.) to the Eleventh Coast Guard District Bridge Section, 510/437-3514, Monday through Friday, 7 am to 3:30 pm, or to the Coast Guard Marine Safety Office other days and times at 510/437-3073.

Delta Bridge History

* HighWater Bridge Clearances  © California Delta Chambers

* We devised this chart of what we think are the “usual high-tide clearances” of the more popular Delta bridges. Use this chart with judgment — it is not the bible, it is not scientific. Clearances are approximate and will be inaccurate for times of plus tides or during high water from heavy rains, spring runoffs are large releases from upriver dams. Use this chart at your own risk.

** Note: special regulations for the Hwy 12 Mokelumne River Bridge — May 1 to October 31, the bridge opens on demand 6 am to 10 pm, except on Saturday 10 am – 2 pm, Sunday 11 am to 6 pm, Memorial Day, 4th of July, Labor Day 11 am to 6 pm it need open only on the hour and 20 minutes before and after the hour.

Note: This Bridge material is © copyrighted by the California Delta Chambers for use in his various Delta Publications. All rights are reserved and it may not be reprinted for use in any publications, or on the Internet without specific written permission of The California Delta Chambers.

For additional Delta Bridge information and other excellent Navigational, Safety, Weather and general Delta information, go to the Lauritzen Yacht Harbor Website.

Coast Guard Local Notice to Mariners
The 11th Coast Guard District’s Local Notice to Mariners carries navigational and on-water event information of value and interest to Northern California boaters. It covers a little of this and a little of that, information that varies from dredging activities to malfunctioning drawbridges.


Safe Boating Classes

Every Delta boater can benefit from a safe boating course, as well as most members of a boater’s family. Courses are an ongoing activity at some locations. For the locations and schedules of courses near you, telephone:

  • Coast Guard Auxiliary:

    • Sailboats — 800/869-SAIL

    • Powerboats — 800/336-BOAT

  • Power Squadron: 800/SEA-SKIL

Delta Water Conditions

Some government web sites can provide a lot of useful information about the Delta.

Or go to the Lauritzen Yacht Harbor site which has sifted through this site and other sources and displays only the pertinent Delta information in real time.

The Sacramento Lock

The William B. Stone (“Sacramento”) lock was taken out of operation quite a few years ago. No longer can you navigate a through route using the Sacramento Ship Channel and the lock.


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