Living with Erosion

Living With Erosion

Greg Berman (Woods Hole Sea Grant & Cape Cod Cooperative Extension)

June 6, 2018 MVCC - 2018 What is Erosion ? The Erosion Problem: Education Perspectives

It’s all sediment transport! What is Erosion???..... just more leaving than coming in Accretion Dynamic Equilibrium Erosion General Coastal Processes Longshore Sediment Transport

+3’/yr +4’/yr +5’/yr +8’/yr

-2’/yr -2’/yr -1’/yr 0’/yr Direction of Direction of Longshore Current Longshore Current

Deposition Erosion Downdrift Coastal Structure

Source: MORIS: CZM’s Online Mapping Tool Longshore Sediment Transport

Google Earth Engine: Timelapse is a global, zoomable video that lets you see how the Earth has changed over the past 32 years. It is made from 33 cloud-free annual mosaics, one for each year from 1984 to 2016, which are made interactively explorable by Carnegie Mellon University CREATE Lab's Time Machine library. General Coastal Processes Perpendicular Transport…….Blocked input

1.3mi Living with Erosion

1. Erosion of glacial landforms is the MOST important source of sediment for dunes and beaches in Massachusetts.

2. Wind and waves then transport sediment.

3. Without erosion and then longshore re-deposition there would be no beaches. Living with Erosion

1. Erosion of glacial landforms is the MOST important source of sediment for dunes and beaches in Massachusetts.

2. Wind and waves then transport sediment.

3. Without erosion and then longshore re-deposition there would be no beaches.

Thanks for contributing sand to our coastal resource areas The Spectrum of Coastal Erosion Control Methods • Do nothing

1. Will system recover by itself?

2. How far is the structure from the water?

3. Grandfathering protects structures (not lawn) before August 10, 1978

Photo Credit: Ann McNichol The Spectrum of Coastal Erosion Control Methods • Do nothing • Vegetation

Plant Natives: Root systems stabilize. Take up water. Break the impact of raindrops or wave-splash. Slow down runoff

Remove Invasive The Spectrum of Coastal Erosion Control Methods • Do nothing • Vegetation • Re-grade The Spectrum of Coastal Erosion Control Methods • Do nothing Horizontal • Vegetation • Re-grade • Managed retreat

V E R T I C A L Adaptation - Brewster

09/29/2015 - 01/15/2016 - 10/12/2017 The Spectrum of Coastal Erosion Control Methods • Do nothing Photo Credit: Ted Keon • Vegetation • Re-grade • Managed retreat • Beach nourishment = Fill of a CRA

Sacrificial Cobble (Mixed)

Photo Credit: CZM The Spectrum of Coastal Erosion Control Methods • Do nothing • Vegetation • Re-grade • Managed retreat • Beach nourishment • Sand fencing The Spectrum of Coastal Erosion Control Methods • Do nothing • Vegetation • Re-grade • Managed retreat • Beach nourishment • Sand fencing The Spectrum of Coastal Erosion Control Methods • Do nothing • Vegetation • Re-grade • Managed retreat • Beach nourishment • Sand fencing • Fiber rolls Diameter 12”-20” The Spectrum of Coastal Erosion Control Methods • Do nothing • Vegetation • Re-grade • Managed retreat • Beach nourishment • Sand fencing • Fiber rolls The Spectrum of Coastal Erosion Control Methods • Do nothing • Vegetation • Re-grade • Managed retreat • Beach nourishment • Sand fencing • Fiber rolls • Coir Envelopes The Spectrum of Coastal Erosion Control Methods • Do nothing • Vegetation • Re-grade • Managed retreat • Beach nourishment • Sand fencing • Fiber rolls • Coir Envelopes

Photo Credit: 2Fathom The Spectrum of Coastal Erosion Control Methods • Do nothing • Vegetation • Re-grade • Managed retreat • Beach nourishment • Sand fencing • Fiber rolls • Coir Envelopes The Spectrum of Coastal Erosion Control Methods • Do nothing • Vegetation • Re-grade • Managed retreat • Beach nourishment • Sand fencing • Fiber rolls • Coir Envelopes C E S

WPA: 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. The Spectrum of Coastal Erosion Control Methods • Do nothing notch • Vegetation • Re-grade • Managed retreat • Beach nourishment • Sand fencing • Fiber rolls • Coir Envelopes C E S • Groin

Direction of Direction of Longshore Current Longshore Current

Deposition Erosion Downdrift Coastal Structure The Spectrum of Coastal Erosion Control Methods

• Do nothing +3’/yr +4’/yr +5’/yr • Vegetation +8’/yr • Re-grade -2’/yr • Managed retreat -2’/yr -1’/yr • Beach nourishment 0’/yr • Sand fencing • Fiber rolls

• Coir Envelopes Source: MORIS: CZM’s Online Mapping Tool C E S • Groin

• Jetty The Spectrum of Coastal Erosion Control Methods • Do nothing • Vegetation • Re-grade • Managed retreat • Beach nourishment • Sand fencing • Fiber rolls • Coir Envelopes C E S • Groin • Sand Bags

• Jetty The Spectrum of Coastal Erosion Control Methods • Do nothing • Vegetation • Re-grade • Managed retreat • Beach nourishment • Sand fencing • Fiber rolls Gabion (10-20 yrs) • Coir Envelopes C E S • Groin • Sand Bags • Gabion

• Jetty The Spectrum of Coastal Erosion Control Methods • Do nothing • Vegetation • Re-grade • Managed retreat • Beach nourishment • Sand fencing • Fiber rolls • Coir Envelopes 1.3mi C E S • Groin • Sand Bags • Gabion • Breakwater / Sill • Revetment

• Jetty • Seawall The Spectrum of Coastal Erosion Control Methods • Do nothing • Vegetation • Re-grade • Managed retreat • Beach nourishment • Sand fencing • Fiber rolls • Coir Envelopes C E S • Groin • Sand Bags • Gabion • Breakwater / Sill • Revetment

• Jetty • Seawall • Bulkhead The Spectrum of Coastal Erosion Control Methods • Do nothing How the “Spectrum” could be used: • Vegetation • Re-grade Notice of Intent (NOI) →→→→ Alternative Analysis • Managed retreat …start at top and move down, • Beach nourishment explaining why each one isn’t suitable. • Sand fencing • Fiber rolls • Coir Envelopes C E S • Groin • Sand Bags • Gabion • Breakwater / Sill • Revetment

• Jetty • Seawall • Bulkhead The Spectrum of Coastal Erosion Control Methods ↑ Resilience ≠ ↓ Natural Systems Questions ?