Soft Engineering Solutions for Bank Stabilization; Do They Exist?

Lee Weishar, Ph.D.; PWS Peter Markunas Points of Discussion

• Do we need coastal engineering structures? • Definition of a hard & soft-engineering solution • Some examples of each • Discussion on where the definition may be going, & • Conclusion Are Coastal Engineering Solutions a Necessary Evil? Existing Conditions in Massachusetts • Approximately 192 miles of general coastline (open coast) in MA • Approximately 1,519 miles of tidal shoreline in MA • Many public shoreline protection structures originally constructed in mid to late 1800’s & early 1900’s • Original structures – constructed by Municipalities, State, Federal Government (USACE) Why Do We Need Coastal Engineering Structures? Why Do We Need Coastal Engineering Structures? • Flood control • Protect property (both public & private) • Erosion mitigation • Maritime infra-structure – Navigation – Ports & Harbors • Economics – Fishing – Recreational boating – Commerce What Is A Coastal Engineering Structure? • USACE Coastal Engineering Manual General term applied to impermeable defense structures of concrete, timber, steel, masonry, ect, which reflect a high portion of incident wave energy • Massachusetts Wetland Regulations CMR 310- 10.00 – “Coastal engineering structure means, but is not limited to, any breakwater, bulkhead, groin, jetty, revetment, seawall, weir, riprap or any other structure that is designed to alter wave, tidal or sediment transport processes in order to protect inland or upland structures from the effects of such processes.“ Hard and Soft Coastal Engineering Structures • What is a hard engineering structure? – Bulkheads – Seawalls – Rock revetments – Groins – Jetties – Breakwater – Other Re-Curved Breakwater Vertical Granite Seawall Revetment Fronting Vertical Seawall

Hard and Soft Coastal Engineering Structures • What is a soft engineering solution? • What is the definition of a soft engineering solution – Soft solutions are best identified by their characteristics???? What Is A Soft Engineering Solution • Early Characteristics – Not a permanent structure – Allows natural processes to occur/continue to some degree – Minimizes wave impacts to the shore – Maintains a limited degree of protection – Easily removed Hard and Soft Coastal Engineering Structures • What is a soft engineering solution? • What is the definition of a soft engineering solution – Soft solutions are best identified by their characteristics – However, the definition has metamorphosized over the years – Why???

What Is A Soft Engineering Solution • Early Characteristics – Not a permanent structure – Allows natural processes to occur/continue to some degree – Minimizes wave impacts to the shore – Maintains a limited degree of protection – Easily removed • Recent modifications to the definition of soft engineering solution – Biodegradable – Composed of natural materials

What is Next? How will the definition change next?

Coastal engineering structure means, but is not limited to, any breakwater, bulkhead, groin, jetty, revetment, seawall, weir, riprap or any other structure that is designed to alter wave, tidal or sediment transport processes in order to protect inland or upland structures from the effects of such processes. IS VEGETATION THE NEXT HARD COASTAL ENGINEERING STRUCTURE? Conclusions

• Do soft coastal engineering solutions exist? – The definition of soft engineering solution has been meta-morphisizing over the past 10-15 years – The Dilemma – Require all shorefront projects to replace littoral sediments • Yes they are alive and well – or should be QUESTIONS