Category Archives: Marsh Restoration / Creation

Why Dredging Sea Dog Creek Was Necessary - Ellicott Dredges

Why Dredging Sea Dog Creek Is Necessary

Anglers navigating Sea Dog Creek near the Town of Hempstead, New York, are now able to safely travel the creek with relative ease in shallow areas this summer; however, this hasn’t always been the case. In 2012, clogged floodwaters created by Superstorm Sandy made it almost virtually impossible for large commercial vessels to navigate charted waters between the eastern end of Sea Dog Creek and nearby Long Creek.

Recently local workers from the Department of Conservation and Waterways used an Ellicott 460SL “Swinging Dragon®” dredge, known as the “Hempstead Bays” to remove 8,000 cubic yds³ (6,116 m³) of sand from nearby Sea Dog Creek. The swinging ladder dredge was purchased by the Town of Hempstead from dredge manufacturer Ellicott Dredges in 2008. Crews used the dredge to remove sand and water to dig down to approximately 12 ft (3.6 m).

One of the many challenges the crew faced during the dredging process included working within very short dredging windows. In addition, they were not allowed to use clean sand within the boundaries of regulated title zones. Despite some limitations, crews were able to overcome these obstacles to complete the project over the course of two weeks

Impact of Hurricane Sandy

There is little doubt that Hurricane Sandy had a tremendous impact on the local region. In fact, when flooded waters swept through the local area, it created a shoal near the eastern end of Sea Dog Creek causing it to clog making virtually impossible for casual boaters to navigate the creek.

Conservation Biologist Dr. James Browne noted that Hurricane Sandy had a tremendous influence on the formation of a sandbar causing the waterway to clog.

“Simply put, was sand stirred up along the beaches, and ebb shoal bar. The materials were then pulled into the bay during the storm surge. The sand was then deposited at some locations which slowed the flow of water. When conditions returned to normal, there was very little to no water in some of the channels.  Traditionally some of these areas range from 4 to 6 ft. in depth. The minimized water levels were then exposed causing a sandbar to form at extreme low tides. This made it hard to navigate a vessel without water underneath of its keel,” noted Dr. James Browne.

The Environmental Impact On Sea Dog Creek

Sea Dog Creek is the only inland waterway route for vessels to navigate north of the fixed bridge close to nearby Point Lookout. The recent improvements now make it easier for commercial boats to travel freely. However, a more pressing problem includes making better use of clean materials that include the enhancement of salt marsh projects.

Hempstead council members were unable to obtain marsh restoration on the emergency permit granted to them by the NYSDEC. Additional funding is being sought for future marsh restoration work sourcing material from Sea Dog State marshes and shoals. The hope is that the additional work will reduce flooding during future storms.

Almost every channel in the surrounding region remains clogged. Therefore additional dredging is required to keep waterways clear. Thankfully, the Town of Hempstead has the necessary dredging equipment in-house to address environmental disasters. This keeps recovery costs reasonably low should an unfortunate incident occur in the future that impacts nearby waterways.

The NYSDEC Funds Sea Dog Restoration Project

A group of officials representing the Town of Hampstead led by Councilman Timothy D’ Esposito asked the NYSDEC to accelerate the necessary dredging permit process after several vessels ran aground due to shallow water conditions.

Town officials needed a state waiver from the NYSDEC to begin dredging in state intercoastal waterways. That’s because this is typically the time of year when spawning season starts for flounder fish.

Thanks to the help of the NYSDEC the Town of Hempstead Department of Conservation and Waterways was granted a 10-year dredge permit to maintain Sea Dog Creek.

The entire operation was completed under an approved emergency permit issued by the New York State Department of Environmental Conservation (NYSDEC.) Councilman D’Esposito noted, “Our biggest challenge was obtaining the necessary permits that were needed to begin the Sea Dog Creek restoration project.”

Hempstead town officials are now planning to start additional dredging projects slated to begin in the fall of 2018.

 

Two Ellicott Dredges Work to Restore National Wildlife Refuge

DELAWARE, USA – Two Ellicott 460SL dredges are currently being used in a large tidal marsh restoration project at Prime Hook National Wildlife Refuge in Delaware. This is one of the largest marsh restoration projects ever in the eastern U.S. The project will restore a highly damaged tidal marsh/barrier beach ecosystem covering about 4,000 acres (1618.7 ha) within the former freshwater impoundment system on the refuge. This coastal wetland restoration improves the ability of the refuge marshes to withstand future storms and sea level rise and improves habitat for migratory birds and other wildlife.


One of the two Ellicott 460SL dredges in operation

AMEC and their marine subcontractor, Dredge America, have had great success since the restoration work began in June. Each dredge operates 10 hours per day, six days a week. “We are happy with the dredges and appreciate Ellicott’s support not only with this project but with all of Dredge America’s projects across the U.S.”, says Sam Robinson, Project Engineer for Dredge America.

They have already dredged more than 1.5 miles (2.4 km) of tidal channels and plan to dredge 30 total miles (48.3 km) of channel by next summer.

dredge-americaDredge America’s Jason Collene beside an Ellicott 460SL dredge

The first phase of the project will focus primarily on draining the marsh and improving tidal circulation. They will begin pumping sand onto the shoreline to close the breaches and create a back-barrier marsh platform. Overgrowth of phragmites, an invasive species of perennial grass, has resulted in the reduction of the wetland area. Establishing a constant salt water flow will help eliminate the phragmites. This restoration of habitat and natural tidal water circulation will enable salt marsh vegetation to return and flourish, improving the resilience of refuge wetlands against future storms and sea level rise, and providing valuable habitat for birds and other wildlife.

 prime-hook-wildlife-refugePrime Hook National Wildlife Refuge

You can view the dredges in operation on Ellicott’s YouTube channel. Prime Hook National Wildlife Refuge also posts updates on their Facebook page, so check that out as well!

Specifications – 460SL Swinging Dragon Dredge

Discharge Diameter: 10″ (245 mm)

Max. Digging Depth: 20′ (6.1 m)

Total Power: 440 HP (330 kW)

Pump Power: 320 HP (240 kW)

Cutter Power: 40 HP (30 kW)

For more information, please contact Ms. Robin Manning, Sales Administrator.

Email: [email protected]

Ph: (410) 545-0232

 

Ellicott 460SL Swinging Ladder dredge to be used for marsh restoration at Prime Hook National Wildlife Refuge

Prime Hook Refuge work to start in June

Work to restore the marshes at Prime Hook National Wildlife Refuge is expected to start June 15, the first phase in a $38 million plan to build storm and sea level rise resiliency on the 10,144-acre federal holding along Delaware Bay.

Step one will be to carve out relic drainage channels that historically allowed the marsh to drain. Once drainage is restored, 1.1 million cubic yards of sand will be pumped onto the beach just south of Fowler Beach road to fill openings that formed or were worsened during Superstorm Sandy.

A created dune will be planted with grasses to help stabilize it and allow the adjacent wetland to recover from decades of human manipulation, including 25 years where water levels were lowered and raised to accommodate wildfowl.

The marsh, despite its proximity to Delaware Bay, was maintained as a freshwater wetland. When storms broke through the dunes, it rapidly converted to a salt marsh and freshwater plants died. The marsh will be planted with salt-tolerant species.

The project is expected to last 30 years even if sea level rises 1.6 feet by mid-century as some projections suggest,” said Al Rizzo, project leader for the Coastal Delaware National Wildlife Refuge Complex Bombay Hook National Wildlife Refuge and Prime Hook National.

Read Full Article at: http://www.delawareonline.com/story/news/local/2015/06/03/prime-hook-refuge-work-start-june/28438141/

Ellicott Dredge Leads Gulf of Mexico Marsh Restoration for BP Spill Recovery in Louisiana

dredge-marsh-restorationThe Lake Hermitage Marsh Creation – NRDA Early Restoration Project involves the creation of marsh within a project footprint known as the “Lake Hermitage Marsh Creation Project” developed for and funded through the Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA) Program. This project substitutes approximately 104 acres of created brackish marsh for approximately 5-6 acres of earthen terraces that would otherwise have been constructed within the CWPPRA project boundary.

The Lake Hermitage Marsh Creation – NRDA Early Restoration Project will create approximately 104 acres of brackish marsh in lieu of the 7,300 linear feet of earthen terraces that was included in the final design of the base CWPPRA project. This additional marsh area will be constructed entirely within the base CWPPRA project’s terrace boundary. Sediment will be hydraulically dredged from a borrow area in the Mississippi River, and pumped via pipeline to create new marsh in the project area. Over time, natural dewatering and compaction of dredged sediments should result in elevations within the intertidal range which would be conducive to the establishment of emergent marsh. The 104-acre fill area will be planted with native marsh vegetation to accelerate benefits to be realized from this project.

The Lake Hermitage Marsh Creation – NRDA Early Restoration Project is located within the Barataria Hydrologic Basin in Plaquemines Parish, Louisiana, to the west of the community of Pointe a la Hache, and northwest of the community of Magnolia. This basin was identified as a priority area for coastal restoration, and has been the focus of extensive study and project design and implementation.

Source:  noaa.gov