Lower Mississippi River (LMR) Dredging Update 121119
The Corps of Engineers Mississippi Valley New Orleans (MVN) continues dredging operations in response to record shoaling deposited by historic long-term high river stages (record flood event created by record precipitation levels). The MVN is working to recover authorized channel dimensions on the Crossings Above New Orleans. The Corps continues to operate two dustpan dredges on the Crossings. There is shoaling along the channel boundaries in Southwest Pass and the Corps is working to secure a cutterhead dredge under Southwest Pass Cutterhead Dredge Rental Contract #3-2019. Weeks Marine was the low bidder, contract details are being finalized, the cutterhead is expected to start dredging in Southwest Pass by mid- January 2020.
DUSTPAN DREDGE(S) ON THE CROSSINGS ABOVE NEW ORLEANS:
WALLCE McGEORGE: The industry dustpan dredge WALLCE McGEORGE continues dredging full channel dimensions (500 feet by 45 feet) at Arlington Lights (Mile 226 Above Head of Passes [AHP]). The industry dustpan dredge commenced dredging on the Crossings on May 9, 2019.
JADWIN: The Corps dustpan dredge continues dredging full channel dimensions at Red Eye Crossing (Mile 224 AHP). The government dustpan dredge commenced dredging on the Crossings on June 27, 2019.
HURLEY: The Corps dustpan dredge HURLEY completed dredging operations on the Crossings. The dustpan worked on the Crossing from May 4, 2019 to December 4, 2019 before being released to the Memphis District.
CUTTERHEAD DREDGE(S) IN THE HOPPER DREDGE DISPOSAL AREA (HDDA):
J.S. CHATRY: The J.S. CHATRY continues dredging on the HDDA contract, all material is being beneficially used in the Pass A Loutre Wildlife Management Area (PALWMA). Supplement funding was utilized to allow the MVN to extend this contract from 12 million cubic yards (mcy) to 15.075 mcy of material to be removed from the HDDA. The cutterhead dredges have now beneficially utilized approximately 12 mcy of material from the HDDA and restored roughly 960 acres. When this project is completed in early 2020, approximately 1,200 acres will have been recreated in the PALWMA.
The Carrollton Gauge (New Orleans) reading at 1000 hours today was 10.65 feet, with a 24-hour change of + 0.70 feet.
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.
Please see the report attached in pdf format and note that updated river forecasts predict the river stage to continue a steady rise. A crest of approximately 12 feet on the Carrollton Gauge on December 15, 2019 is predicted with agreement across multiple forecasts before beginning a slow fall.