Marine Construction

Protecting Our Coastlines

by Roger P. Michniewicz, P.E. (Coastal Engineering Co.)

All along the coastal border of the United States, beaches, coastal dunes, and coastal banks are eroding. While coastal processes are complex with many variables contributing to the way coastal systems function, in simple terms, there is not enough sand to maintain them. Globally, the relative rise in sea level – caused by a continuation of the melting of continental glaciers and a general trend of continental subsidence – is causing a slow and deliberate decrease in shoreline quality.

Locally, our New England weather is a major contributing factor to coastal erosion. Each nor’easter or seasonal hurricane pounds our beaches and washes away sand, beach grass, rocks, trees, and sometimes, homes. Powerful storms displace tons of sand along the beach and modify off-shore sand bars, creating breaks in local barrier beach systems, allowing a previously protected area to become highly vulnerable.

Retreat

Since erosion is a natural occurrence, what can be done to work with nature to provide an ecologically sound balance? In the wake of recent super storms that devastated coastlines, some believe the best response is retreat; they believe that some communities should not be allowed to rebuild. This does not bode well with property owners and communities with a vested interest in protecting the properties. At first glance, it may make environmental sense to leave the coast in its natural state. However, coastal retreat is illogical in the minds of many shorefront community members. Instead, communities often join together to rebuild and to protect the shoreline by responding proactively to the effects of erosion. This leads to a demand for environmentally sound solutions that are practical and economically feasible.

Shorefront Protection

Seasonal and year-round people flock to the Cape and Islands because of our beautiful and thriving beaches. Healthy beaches are invaluable to coastal communities in that they are a major draw for vacationers, generate much needed tourism dollars, and create job opportunities. Healthy beaches also protect what lies upland of their sandy shores – roads, water lines, septic systems, hotels, commercial buildings, and private residences. Environmentally, healthy beaches protect wetland resources and habitat for a wide variety of flora and fauna.

Cape Codders have learned to be proactive about thwarting erosion and, for decades, have helped coastlines survive by making them resilient. Since erosion occurs on our bay-side, sound-side, and outer Cape beaches, a widespread approach that addresses the particular characteristics of each system is necessary.

Experts agree that stabilizing the shores of our beaches, bays, rivers, and canals is the best defense against coastal erosion. Stabilization projects involve what coastal engineers term shore protection in conjunction with a beach restoration and maintenance plan. Shore protection is generally categorized as “soft” or “hard” solutions.

Soft Solutions
Generally speaking, “soft” solutions include beach grass plantings, sand/snow drift fencing, and fiber roll technology. A fiber roll is a collection of coconut fibers rolled together, encased in organic netting, and anchored at the base of the coastal slope.

Hard Solutions

“Hard” solutions are placed up against a coastal dune and come in the form of a rock revetment, concrete sea wall, or bulkhead.

Beach Nourishment

Both approaches may be accompanied by beach restoration whereby sand is removed from an offshore or upland area, or dredged from a waterway, and added to beaches or coastal areas where sand has been lost. Placement of sand on a beach restores the eroded beach to a stable configuration and replenishes sand lost off shore (or down shore) during significant storm events. Coastal engineers have found that beach restoration is an effective method that can sustain the shoreline for a long time. 

Environmental Regulations

The road to putting remedies in place to address erosion can be arduous. Before a stabilization project can get underway, the property must be evaluated and subsequently deemed to be threatened by coastal erosion, as determined by the local Conservation Commission. Depending on the scale and complexity of the project, federal and state regulations, and/or local by-laws may apply. One or more environmental permits may be required before any work can be done. Applying for permits requires in-depth knowledge of a multitude of governmental regulations and, often times, requires the experience of an environmental permitting specialist. Furthermore, here in Massachusetts, the Wetlands Protection Act allows for only “soft” solutions to be used to protect a coastal bank for a dwelling built after 1978. If you are thinking of addressing erosion problems on your property, or in your community, it is advantageous to engage a qualified consultant to carefully review local rules, regulations, and permitting guidelines before embarking on an erosion control project.

Shorefront Property Ownership

Before investing in coastal property, it is important to know how the property has fared during past seasonal storms and what measures have been taken to protect the shoreline and coastal bank. A wise first step is to perform a shoreline risk assessment, examining such factors as geographic location; flood zone profile; proximity to shoreline; existing erosion control structures; and the history of storm frequency/rate of erosion. Additionally, researching federal, state, and local wetland regulations is time well spent.

RMichniewicz-2012
Roger P. Michniewicz, P.E., is a Marine Division Manager for Coastal Engineering Company, Inc. He can be contacted at 508.221.6724 or rmichniewicz@coastalengineeringcompany.com

If you already own a beachfront home or live on any type of coastal bank, it is important to inspect your property and evaluate levels of coastal bank deterioration after storms and with each change of season.

If you have concerns about erosion, consider engaging an experienced professional engineer to inspect your property and prepare a shoreline risk assessment. Should your property be prone to erosion and at risk, you may need to more forward with a shorefront protection plan. If so, your licensed marine engineer can also:

– design shoreline protection

– oversee environmental permitting

– provide construction oversight

– inspect the shorefront protection system upon completion and periodically thereafter
With an understanding of a property’s historical response to erosion; knowledge of what is currently in place to protect the shoreline; details about what has been approved to stabilize the shoreline (and associated cost); and a desire to work cooperatively with the shorelines’ natural cycles, the sandy shores can be enjoyed for many years.