LMR Dredging Update 71519.pdf

The Corps of Engineers Mississippi Valley New Orleans (MVN) has resumed dredging operations in Southwest Pass (SWP) and on the Crossings Above New Orleans to respond to active shoaling deposited by long-term high river stages (historic flood event and precipitation levels). There are three hopper dredges presently working in the area of SWP (2 industry hoppers and 1 government hopper) and two dustpan dredges working to restore half channel width on the Crossings.  Federally authorized channel dimensions on the Crossings are 500 feet wide by 45 feet deep, the Corps continues to focus on the central 250 feet of channel or half of the authorized channel width.  The MVN will advertise Southwest Pass Hopper Dredge Rental Contract #12-2019 later this week, in an effort to secure an additional industry hopper dredge.

 

UPDATED: TRANSIT RESTRICTIONS AT SOUTHWEST PASS (SWP):

 The Bar and Federal Pilots increased their maximum draft recommendation to 42 feet (freshwater) this morning based on updated channel surveys provided by MVN.  This is the controlling maximum draft for all vessels transiting Southwest Pass as implemented this morning (Monday, July 15, 2019).  This matches the controlling draft established before Hurricane Barry moved through the area.  The draft had been reduced to 40 feet immediately after the Ship Channel was reopened, for approximately 24-hours. 

 

INDUSTRY HOPPER DREDGE(S) IN SOUTHWEST PASS (SWP):

 STUYVESANT:  The industry hopper dredge STUYVESANT (Dutra Group) is presently dredging on assignment at the Head of Passes (Mile 1.5  Above Head of Passes [AHP] to Mile 0.5 Below Head of Passes (BHP) . The STUYVESANT began dredging under Southwest Pass Hopper Dredge Rental Contract #10-2019 on June 14, 2019.

 NEWPORT:  The hopper dredge NEWPORT (Manson Construction) is dredging from Mile 0.5 BHP to Mile 1.5 BHP.  The NEWPORT is now dredging under Southwest Pass Hopper Dredge Rental Contract #8-2019.  The NEWPORT began dredging in SWP on November 28, 2018.

 

GOVERNMENT HOPPER DREDGE(S) IN SOUTHWEST PASS (SWP):

 WHEELER: MVN’s hopper dredge WHEELER is dredging in the area of Cubits Gap approximately Mile 4.0 AHP to Mile 2.0 AHP under Red Flag Emergency Callout #5-2019 tonight.  The Red Flag Call Out was extended to approximately August 31, 2019 after Southwest Pass Hopper Dredge Rental Contract #11-2019 could not be awarded.

 

CUTTERHEAD DREDGE(S) IN SOUTHWEST PASS (SWP):

 C.R. McCASKILL: Weeks Marine’s cutterhead dredge C.R. McCASKILL is expected to start dredging at Mile 1.0 AHP on the western channel toe by July 20, 2019 under Southwest Pass Cutterhead Dredge Rental Contract #2-2019.

 CAPTAIN FRANK: Weeks Marine’s cutterhead dredge CAPTAIN FRANK is expected to start dredging at Mile 5.0 BHP on the western channel toe by July 24, 2019 under Southwest Pass Cutterhead Dredge Rental Contract #2-2019.

 

CUTTERHEAD DREDGE(S) IN THE HOPPER DREDGE DISPOSAL AREA (HDDA):

R.S. WEEKS: The industry cutterhead dredge R.S. WEEKS (Weeks Marine) resumed dredging operations in the HDDA yesterday afternoon, all material is being beneficially used in the Pass A’Loutre Wildlife Management Area (PALWMA).  Approximately 5.0 million cubic yards of material have now been beneficially placed in the PALWMA from the HDDA.

 

DUSTPAN DREDGE(S) ON THE CROSSINGS ABOVE NEW ORLEANS:

WALLCE McGEORGE: The industry dustpan dredge WALLCE McGEORGE resumed dredging the central 250 feet of channel at Baton Rouge Front (Mile 231.5 AHP).  The industry dustpan dredge commenced dredging on the Crossings on May 9, 2019.

JADWIN: The Corps dustpan dredge JADWIN has resumed dredging operations on the central 250 feet at Belmont Crossing (Mile 154 AHP).  The government dustpan dredge commenced dredging on the Crossings on June 27, 2019.

 HURLEY: The Corps dustpan dredge HURLEY is being repaired at Red Eye Crossing (Mile 224 AHP) and expected to return to dredging on Wednesday, July 17, 2019.  The government dustpan dredge commenced dredging on the Crossings on May 4, 2019

 

The Carrollton Gauge (New Orleans) reading at 0900 hours was 16.18feet, with a 24-hour change of – 0.09 feet. 

 According to the National Weather Service the storm driven crest on the Carrollton Gauge reached 16.93 feet at 1400 hours on Saturday, July 12, 2019.  The forecasts now predict the stage to remain steady over the next week and to then begin a slow steady fall reaching 14.1 feet by August 11, 2019.

The graph below is reproduced from NOAA’s National Weather Service website and represents an experimental product to account for the complexity of accurately predicting long-range precipitation.  This forecast projects stage levels based on expected precipitation for 2 days (top) and 16 days (bottom) and was developed within the North American Ensemble Forecast System (NAEFS) computer model and highlights Quantitative Precipitation Forecasts (QPF).  Along with the forecasts, a shaded area is also provided to indicate uncertainty for the forecast each day in the future.   These plots are experimental and not an official forecast product.

There are 168 bays still opened at the Bonnet Carré Spillway, no additional bays are expected to be opened. 

Please see the attached report for complete details related to dredge locations (assignments), channel conditions and the latest information on now Tropical Storm Barry.