4TH ANNUAL CAPE COASTAL CONFERENCE
Putting Regional Sediment Management into Action: Dealing with Natural, Political and Municipal Boundaries
Moderators: Mark Borrelli: Center for Coastal Studies Tonna-Marie Rogers: Dept of Conservation/Recreation
Panel: John Ramsey: Applied Coastal Research and Engineering Brad Washburn: MA Office of Coastal Zone Management Ted Keon: Town of Chatham Heather McElroy: Cape Cod Commission 4TH ANNUAL CAPE COASTAL CONFERENCE
Putting Regional Sediment Management into Action: Dealing with Natural, Political and Municipal Boundaries (75 minutes)
I. Coastal Processes 101 (10-15 minutes)
II. RSM Introduction (~5 minutes each) 1. Modeling Tools for RSM 2. Developing Sediment Budgets 3. CZM’s Perspective 4. Chatham’s Sediment Management Activities
III. Panel/Audience Discussion (~30-40 min) Waves
• 1 cubic meter of seawater = 1 metric tonne
• On average a wave hits the shoreline every 6 seconds – 600/hr – 14,400/day – 5.2 million/year Longshore Sediment Transport Rates of Longshore Sediment Transport
• ~500,000 cubic yards of LST/year • ~1370 cubic yards of LST/day • 137 Dump Trucks sand/day rolling down beach • One every ~10 minutes! Cross-shore Sediment Transport Seasonal Changes to Beach
Fair-weather (Summer) Profile
Storm (Winter) Profile ‘Dynamic Equilibrium’
Erosion Relocation Control Structures
Seawalls and Sediment Transport
People at the coast think….differently
The Real Problem 4TH ANNUAL CAPE COASTAL CONFERENCE
Putting Regional Sediment Management into Action: Dealing with Natural, Political and Municipal Boundaries
John Ramsey: Applied Coastal Research and Engineering 4TH ANNUAL CAPE COASTAL CONFERENCE
Modeling Tools for Regional Sediment Management
John Ramsey, P.E. Applied Coastal Research and Engineering Some General Thoughts on Modeling
• Models Depend on the Quality of Input Data (Garbage In = Garbage Out)
• The “Wow” Graphics Factor Can Often Obscure Model Shortcomings
• Coastal Processes Modeling Is Most Appropriate for the Short-Term A Note on Our Local Conditions
Wave Exposure Average Tide Range open ocean > 8 ft protected 4-8 ft < 4 ft Shoreline Change Analysis
1938-2010
Shoreline Change Analysis
2004-2014
Surface Modeling – Spectacle Island
deposition
scour (erosion) Study Area
Coastal Processes – Wave Modeling
Nantucket Sound Model Grid 32 Wave Cases
Coastal Processes – Wave Modeling
Sediment Transport Modeling
Cockle Cove and Ridge- vale Beaches
Cockle Cove Calibration
Calibration Period
1994-1999
Cockle Cove Beach Nourishment
28,000 Cubic Yards 1,000 ft Length
4TH ANNUAL CAPE COASTAL CONFERENCE
Putting Regional Sediment Management into Action: Dealing with Natural, Political and Municipal Boundaries
Mark Borrelli Center for Coastal Studies
Developing Sediment Budgets
Littoral SINK Cells
SOURCE SOURCE Sources SINK SOURCE And Sinks
NET Direction SINK
19332010
Surface Difference
2010-11
1933
~15ft
1868
From, C. Sherwood and. Foster USGS (pers comm)
4TH ANNUAL CAPE COASTAL CONFERENCE
Putting Regional Sediment Management into Action: Dealing with Natural, Political and Municipal Boundaries
CZM Perspective…
Brad Washburn, Assistant Director [email protected]
Coastal Hazards Commission & Coastal Erosion Commission
• Coastal Hazards Commission (2007) - review of coastal hazards policies/practices - recommendations to implement regional sand management program (inter-agency communication, resource mapping, etc.)
• Coastal Erosion Commission (2015) - document levels/impacts of coastal erosion - strategies and recommendations to reduce or minimize coastal erosion and its impact on property, infrastructure and beaches
CZM Shoreline Change Project
• Uses historical and modern data to depict “shorelines” for selected time frames (mid 1800’s to 2009)
• Appx. 26,000 transects along entire coast
• Planning tool that provides insight into historical migration of shorelines and erosional hotspots
Coastal Structures Inventories Massachusetts Ocean Plan
• Preliminary compatibility assessment and screening analysis identifying potential offshore sand resource areas for further investigation
• Recommended formation of Offshore Sand Task Force
CZM Coastal Resilience Grants Advance local efforts to manage coastal flooding, erosion, and sea level rise impacts through communication and public outreach initiatives, vulnerability assessments, planning activities, engineering projects, and natural storm damage protection approaches. www.mass.gov/czm/stormsmart
• FY14: $2.0 M, 19 awards • FY15: $2.7 M, 18 awards • FY16: $2.2 M, 16 awards • FY17: $1.8 M, 19 awards CZM Coastal Resilience Grants
Century Scale Sediment Budget: Towns of Sandwich and Barnstable – Volume, rate and direction of sand moving along shoreline from Cape Cod Canal to Barnstable Harbor.
CZM Coastal Resilience Grants
Nearshore Sediment Borrow Source for Sandwich Town Beaches – Analyze locations adjacent to Scusset Beach to determine viability to serve as sediment source for beaches downdrift of Cape Cod Canal jetties
Cape Cod Canal Dredging – Sandwich Town Neck Beach Nourishment
CAPE COD CANAL Project Depth: 32’ MLLW Last Dredged: 2010 Dredging Quantity: 170,000 cy Areas Material Type: Sand & Gravel Equipment Type: Hopper Disposal Sites: Cape Cod Canal Disposal Site or Sandwich Beach
NEXT STEPS…
Continued coordination at all levels – Planning, project review & permitting
Continued support to municipalities – Grant funding – Technical assistance
Continued development of planning & technical resources
4TH ANNUAL CAPE COASTAL CONFERENCE
Putting Regional Sediment Management into Action: Dealing with Natural, Political and Municipal Boundaries
Ted Keon Town of Chatham REGIONAL SEDIMENT MANAGEMENT: Implementation at the Local Level Ted Keon, Town of Chatham Atlantic Ocean Nantucket Sound
Chatham NearshoreHydraulic Placement: up to 90,000 cys DirectTruck Pump Haul:-out: 20 cys1,000 to cys5,000 to cys30,000 cys
Hopper Town-wide Dredge/Disposal Strategy
Mechanical
Harwich Chatham
Sediment Deficit
MiIl Creek Inlet
Nantucket Sound Taylor’s Pond
Mill Creek Inlet
Little to no natural sand by-passing
1979 Issues • Poor flushing/water quality • East jetty “flanking” • Navigation impacts Taylor’s Pond • Shellfish habitat impacts • Abandonment of propagation beds
Mill Creek Inlet Jetty “fillet” filled to full entrapment
Oct 2009 Mill Creek Dredging & Sand Management Program Updrift Primary purpose- Ecosystem restoration Nourishment (Back-passing) Secondary purpose- Navigation Shorebird Nesting Habitat Mill Creek Jetty “Fillet” Reduction
Deposition Basin (-5 ft. MLW) Inlet Channel Dredging (-4 ft. MLW)
Downdrift Nourishment (By-passing) Spring 2010
InletDowndrift DredgingBarnstable Nourishment Since County April Dredge 2010 Date QTY Disposal Apr 2010 14,000 cys By-Pass Nov 2010 4,500 cys By-Pass Nov 2011 3,000 cys Back-Pass Apr 2012 2,000 cys By-Pass Oct 2012 4,000 cys Back-Pass Nov 2013 3,500 cys By-Pass Feb 2015 7,500 cys By-Pass Total 38,500 cys
March 2010 Public/Private Partnership
Mill Creek Fillet Reduction
Town Support: • Reduce inlet shoaling • Sand back-passing • Privately funded $$
Beach Disposal
Chatham Red River Harwich Updrift Fillet Reduction • Target volume: 10,000 - 12,000 cys
Booster Pump
Dredge
Mar 25, 2015 Mill Creek Booster Dredge
Approx. 6,000 ft.
Public beach 930 cys Apr 2015
Private beaches 9,800 cys
Red River
Mar 2015 Jun 2015
Thank You 4TH ANNUAL CAPE COASTAL CONFERENCE
Putting Regional Sediment Management into Action: Dealing with Natural, Political and Municipal Boundaries
Moderators: Mark Borrelli: Center for Coastal Studies Tonna-Marie Rogers: Dept of Conservation/Recreation
Panel: John Ramsey: Applied Coastal Research and Engineering Brad Washburn: MA Office of Coastal Zone Management Ted Keon: Town of Chatham Heather McElroy: Cape Cod Commission