Dredging

dredging

2018 US Army Corps (Red)

2017 NJDOT (Green)

2017 Manasquan Borough (Blue)


Dredging Benefits

Manasquan is a community with over 6 miles of tidal coastline.  Maintenance of its waterways is of critical importance to the Borough.  Sediment dredging protects recreational and commercial use of our waterways and supports a healthy maritime ecosystem.  An additional benefit of dredging is realized when environmentally acceptable dredged material is transferred to area beaches to build up the beach berm.  The berm is the front-line defense against beach erosion caused by hurricane, tropical storm and nor'easter wave action. In fact, during a 2017 dredging operation the dredged material was successfully and effectively used to improve the Manasquan beach berm.

Flood Mitigation - A Common Misconception

One common misconception about dredging is that it mediates or even protects against coastal flooding and/or storm surge.  Manasquan's waterways are tidal and connected to the Atlantic Ocean.  This connection is the primary driver for coastal flooding.  Simply put, no matter how deeply dredged a tidal waterway may be, even at low tide, the additional capacity created by dredging is already full prior to any storm.  Because of this, flood attenuation remains unchanged despite the depth of the channel. 

Government Waterway Dredging

There are several government agencies that engage in dredging including the US Army Corps of Engineers (Army Corps) and the NJ Department of Transportation (NJDOT).  The Army Corps is responsible for maintaining federal navigable waterways.  Examples of such waterways include the Manasquan Inlet and the 3,000-mile long Intracoastal Waterway which includes portions of the Manasquan River.  Locally, the Army Corps regularly deploys a dredge/barge nick-named the "Currituck" to survey and dredge the Manasquan Inlet (see the area highlighted in red above).    NJDOT is responsible for maintaining state navigable waterways, such as Crabtown Creek, which connects the Glimmerglass to the Manasquan River.  In 2017, Manasquan partnered with the NJDOT to dredge Crabtown creek and other area waterways (see area highlighted in green above).  Over 40,000 cubic yards of sand from this project were delivered to vulnerable areas along the beachfront berm to provide additional coastal and storm surge protection.  Also in 2017, the Borough removed material from the municipal marina boat slips during renovation in the area of Perrine Boulevard (see area highlighted in blue above).  Some of the material dredged from this area was utilized as cap fill at the Monmouth County Reclamation Center via a shared service agreement.   

Going Forward

Manasquan is actively exploring opportunities to continue its efforts to maintain and improve its waterways.  Dredging is an expensive and complex undertaking.  Issues such as extensive planning, complex permitting, environmental testing and material handling all must be considered.  As an example of the expense involved, it is currently estimated that the cost to dredge and dispose of three feet of material from Stockton Lake could cost up to $10 million.  The governing body is currently studying successful dredging initiatives undertaken in other jurisdictions and researching the availability of grant funding and possible cost-sharing opportunities with state and federal agencies.