Posted on: March 24th, 2016 by Stas




The Port of Stockton (POS), located in California’s San Joaquin Valley, is positioned near many distribution centers serving Northern California. It is also the nearest port for many San Joaquin Valley farm exporters who currently ship out of the Ports of Oakland, Los Angeles and Long Beach. The POS could be an import and export embarkation point for containers going to and from the major California ports, but navigational problems complicate establishing scheduled services for container shipping. A tug/barge M-580 service between the Ports of Stockton and Oakland reduced truck traffic along the I-580 freeway corridor, but was discontinued after operational and marketing problems. There are efforts being made to revive the M-580 service.

Waterborne access to and from the POS is challenging more vessels with deeper drafts. The reasons are: daylight limitations, shallow stretches that can only be negotiated at high tide, fog, the need for maintenance dredging to keep the ship channel at 33 feet and now, a seasonal water hyacinth infestation that prevents ships from docking at night undermining turnaround times and productivity.

The navigational and safety issues that impede maritime traffic flow on the San Joaquin River are:

  • The Benicia-Martinez Rail Drawbridge (aka Union Pacific Railroad Bridge) built in 1930 is old and in need of replacement.
  • Funding is needed to replace antiquated levees along the San Joaquin River that could fail in an earthquake or heavy rain causing flooding to the surrounding communities and a breakdown in waterborne traffic.
  • Fog and shallow areas of the river slow and stop waterborne traffic leading to delays and schedule uncertainties.
  • The seasonal water hyacinth threat to navigation.


In 2015, the POS had 247 ship arrivals compared to 230 ship arrivals in 2014. Port Director Richard Aschieris noted that cargo volume was down slightly to 3.87 million metric tons in 2015, from 4.11 million metric tons in 2014, reflecting a change in the mix of cargo being moved through Stockton. “As things change, as demands change for cargo, what we’re handling is always changing,” he said. Coal exports, which have been the leading tonnage cargo, slipped to a projected 1.07 million metric tons in 2015 from 1.74 million metric tons in 2014. The decline was due in part to the high U.S. dollar making the price to foreign buyers too expensive.[1]

The Sacramento–San Joaquin River Delta, or California Delta (Delta), is an expansive inland river delta and estuary in Northern California in the United States. The Delta is formed at the western edge of the Central Valley by the confluence of the Sacramento and San Joaquin Rivers and lies just east of where the rivers enter Suisun Bay. The Delta is recognized for protection by the California Bays and Estuaries Policy. The city of Stockton is located on the San Joaquin River on the eastern edge of the Delta. The total area of the Delta, including both land and water, is about 1,100 square miles (2,800 km2).

The Delta was formed by the raising of sea levels following glaciation leading to the accumulation of Sacramento and San Joaquin River sediments behind the Carquinez Strait, the sole outlet from the Central Valley to San Pablo and San Francisco Bays and the Pacific Ocean. The narrowness of the Carquinez Strait coupled with tidal action has caused the sediment to pile up forming expansive islands. Geologically, the Delta has existed for about 10,000 years since the end of the last Ice Age. In its natural state, the Delta was a large freshwater marsh consisting of many shallow channels and sloughs surrounding low islands of peat and tule.

Since the mid-19th century, most of the region has been gradually claimed for agriculture. Wind erosion and oxidation have led to widespread subsidence on the Central Delta islands; much of the California Delta region today sits below sea level behind levees earning it the nickname “California’s Holland“. Much of the water supply for central and southern California is also derived from here via pumps located at the southern end of the Delta which deliver water for irrigation in the San Joaquin Valley and municipal water supply for southern California.[2]



A key transit point is The Benicia-Martinez Rail Drawbridge (aka the Union Pacific Railroad Bridge) built in 1930. It has been described as “an old, rusty metal railroad bridge between Martinez, California and Benicia, California which is located between the North-bound bridge and South-bound bridges carrying I-680 freeway traffic.” The metal Benicia-Martinez Rail Drawbridge is a crucial bridge for mariners because it represents both the governing height restriction for ships and poses the narrowest passage point for waterborne transportation. The Burlington Northern and Santa Fe Railway and Amtrak have trackage rights, as well as the Union Pacific Railroad. The drawbridge’s lift span horizontal clearance is 291 feet and vertical clearances are 70 feet (closed) and 135 feet (open).[4]

There has been growing concern by California and Federal agencies about the aging bridge.[5] Shipping executives worry that the bridge may one day malfunction and either not be able to go down or lift up.  Such malfunction could:

*Stop rail traffic

*Stop daily vessel transits

*Stop both

The result could be a goods movement stoppage that could last for years if the bridge needs to be replaced. The Benicia-Martinez Rail Drawbridge is owned and repaired by the Union Pacific Railroad.

According to the Bar Pilots’ Guidelines:

“a. During average tidal conditions, vessels can normally pass without time restrictions if the air draft is no higher than 132 feet.

b. Vessels 800’ or longer, or beam greater than or equal to 130’, must transit the bridge at or near slack water and daylight only.

c. Any vessel of PANAMAX Class or larger or with air draft of more than 132′ must coordinate with the Operations Pilot.

d. Maximum beam permitted will be 140’ or less.”[6]

The Guidelines also lay out the following:


1. Transit Drafts

Contact the Operations Pilot for maximum allowable transit drafts.

Deep drafts for specific transits may be decreased depending on navigation factors such as date, time, tidal conditions, soundings, weather conditions, vessel size and type, etc.

During the period from December to April, rapid shoaling may occur on the river. The pilots may be notified by the Army Corps of Engineers or receive other information of depth changes/shoaling requiring maximum drafts to change on very short notice.

All transit drafts refer to fresh water drafts.

All vessels should have 1’ (30 cm.) drag by-the-stern.[7]

2. Size Limitations

In general, the narrow channel limits the size of vessels above New York Point to the PANAMAX class (750’ LOA x 106’ beam).

Contact the Operations Pilot before scheduling any vessels over 700’ LOA.

Vessels over 520’ LOA and/or 73’ beam should adjust drafts to have a minimum one (1) foot trim by the stern.

3. Air Draft

The air draft limit for an unrestricted transit during an average tidal cycle is 132 feet.

Vessels with an air draft of greater than 132 feet should contact the Operations Pilot for allowable transit time.

4. Daylight Transits

The following vessels will be allowed daylight transits only:

i. 650’ and above LOA;

ii. 100’ and above beam;

iii. vessels with severely limited visibility due to design or other factors;

iv. vessels with a deep draft exceeding 31.0’ (9.45 m.)

5. Rapid Shoaling

During the period from December to April, rapid shoaling may occur on the river. The pilot may be notified by the Army Corps of Engineers or receive other information of depth changes requiring drafts to be changed with very short notice.

6. Underkeel Clearance

See page 7, 2. Minimum Underkeel Clearance (UKC) for recommendations[8]

7. Fog Season

From November to March, frequent periods of severely restricted visibility occur. Considerable Delays may be experienced. Contact the Operations Pilot to schedule the most expeditious transit time to avoid the fog.[9]

Other points of reference are:

1)  The San Francisco Bar Pilot Station is located approximately 12 miles west of the Golden Gate Bridge. Transit time between the San Francisco Bar Pilot Station to the POS roughly ranges between 8 to 10 hours depending upon the individual characteristics of the vessel.

2) There are shallow points in the San Joaquin River which cannot be transited until high tide. Vessel transit times are subject to delays at certain areas on the river that are very shallow at low tide. Find the best online pokies and win jackpot! The vessel must wait until a high tide allows sufficient draft for passage.  This is particularly true in the summertime when a lack of rain reduces the water level in the river. Currently, the maximum allowable deep draft is 33 feet of fresh water with a minimum 1-foot drag by the stern. Allowable drafts can change on very short notice. There are 1.5 tide stages involved with a 9-hour transit. Currently the main controlling depth is just off Antioch, California, but the pilots still must also take into consideration other controlling depths along the way – each at varying tide stages.[10]

3) In the wintertime, heavy rain creates pressure on aging levees along the river. As a result, pilots and the U.S. Coast Guard will slow or delay transit of the vessel if its displacement of water was to cause the levees to move. There have been proposals to replace these levees because of the threat of massive flooding to San Joaquin Valley residents and farmland if the levees collapse. A 2011 New York Times Magazine report noted: “Starting in the 1870s, farmers began building 1,100 miles of levees around the delta to control floodwaters and create farmland out of Tule marshes. Today, many of those levees are old, decrepit and leaking. Jeffrey Mount, a geologist at the University of California, Davis, predicts that there is a 64 percent chance of a catastrophic levee failure in the delta in the next 50 years.” The state of the Sacramento-San Joaquin Delta region is drawing growing criticism because of the need for a strategy to replace aging levees or dikes. A 2012 American Planning Association report charges, “California’s Delta is failing, and no entity seems able to change this. The sweeping economic, governance, resource management and land-use planning changes that are needed to reverse the trend are simply not politically feasible — at least not until a calamity makes a continued stalemate less desirable than decisive action.”[12]

4) As referenced in the Bar Pilots’ Guidelines, there are fog problems in the winter and summer that delay ships. In the summertime, coastal fog at the Golden Gate Bridge (GGB) can cause delays for vessels transiting between the GGB and New York Point. In the wintertime, Tule fog causes visibility problems that will force vessels to heave to.  Tule fog is a thick ground fog that settles in the San Joaquin Valley and Sacramento Valley. Tule fog forms from late fall through early spring (California’s rainy season) after the first significant rainfall. The official time frame for Tule fog to form is from November 1 to March 31. This phenomenon is named after the Tule wetlands (tulares) of the Central Valley. Tule fog is the leading cause of weather-related accidents in California.[13]

5) Shipowners and captains have raised concerns about the shallow draft at POS piers.  However, recent dredging, if maintained, should ensure that the advertised draft at the piers and the ship channel is 33 feet.

6) The water hyacinth problem that has developed in recent years has delayed ships from moving in and out of POS. Following summer growth, the infestation becomes so dense that the piers at POS cannot be distinguished on the radar at night, according to POS officials. Increased funding from the State of California is being invested to slow the infestation usually by spraying.[14]  This practice has raised concerns about toxins in the river. The greener solution may lie in the investment of one or more water harvesters to reduce the water hyacinth growth at POS berths and at the City of Stockton waterfront.[15]

7) The M-580 tug/barge service provided for barges, cranes and improvements for on-dock rail. The service transported containers between the Ports of Stockton and Oakland relieving truck traffic congestion on the I-580 freeway. The failure of this service was due to slow acceptance by shippers. The concerns were compounded by start-up operational issues. Many shippers now wish the M-580 tug/barge service was restarted because of truck congestion at Port of Oakland terminal gates and along the I-580 corridor. A Port of Stockton report found that each container transported by tug/barge reduced carbon emissions by 80% compared to transport by truck on the I-580 freeway.[16] There are now efforts being made to revive the M-580 service.


[1] http://www.portofstockton.com/port-sees-record-in-ship-traffic

[2] https://en.wikipedia.org/wiki/Sacramento%E2%80%93San_Joaquin_River_Delta

[3] http://sfbarpilots.com/wp-content/uploads/2016/01/GuidelinesHighlighted.pdf

[4] https://en.wikipedia.org/wiki/Benicia%E2%80%93Martinez_Bridge#Railroad_bridge

[5] http://www.contracostatimes.com/breaking-news/ci_26525724/crude-by-rail-one-federal-inspector-oversees-all

[6] http://sfbarpilots.com/wp-content/uploads/2016/01/GuidelinesHighlighted.pdf

[7] The S.F. Bar Pilots advise that this “requirement is expected to be amended to change “drag” to “trim” and state that if a vessel is not trimmed at least 1’ by the stern, it will be moved by daylight only.”

[8] The keel runs in the middle of the ship, from the bow to the stern, and serves as a basic foundation or spine of the structure, providing the major source of structural strength of the hull.

[9] Ibid.

[10] http://sfbarpilots.com/wp-content/uploads/2016/01/GuidelinesHighlighted.pdf

[11] http://www.nytimes.com/2011/07/03/magazine/sacramento-levees-pose-risk-to-california-and-the-country.html?_r=0

[12] See American Planning Association report: https://www.planning.org/planning/2012/jan/waterwarriorsside1.htm

[13] https://en.wikipedia.org/wiki/Tule_fog

[14] http://www.recordnet.com/article/20150601/NEWS/150609956

[15] Port of Stockton officials

[16] Port of Stockton, “Air Quality/Greenhouse Gas Technical Report for the Short-Sea Shipping Project” (2010)




















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