georgeann keersm
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Great Marsh Coalition 2013TRANSCRIPT
How Natural Coastal Systems Function for Flood/Pollution Control and Storm Damage Prevention and the
Effects of Human Alterations
Georgeann Keer, Project Manager, Mass Division of Ecological Restora8on
Department of Fish and Game
Mary Griffin, Commissioner
n Physical Restora8on n Freshwater and Salt Water
n Flow Restora8on n RIFLS, Dam Management, Comprehensive Water Planning
n Technical Assistance (Riverways Program) n Adopt-‐A-‐Stream, Wild & Scenic Rivers, Water Quality, etc.
The mission of the Division of Ecological Restora5on is to restore and protect the Commonwealth’s rivers, wetlands and watersheds for the benefit of people and the environment.
Division of Ecological Restora8on (DER)
North Shore: Amesbury, Beverly, Danvers, Essex, Gloucester, Ipswich, Lynn, Manchester, Marblehead, Nahant, Newbury, Newburyport, Peabody, Revere, Rockport, Rowley, Salem, Salisbury, Saugus, and Swampscott
The Massachuse>s Coastal Zone
Both figures from A Guide to the Coastal Wetlands Regulations, MA Dept. of Environmental Protection, 1979
Original: Clearwater Estates, MA Dept. of Environmental Protection, 1987
Salt marshes
Tidal Flats
Salt Ponds
Shellfish Beds
Coastal Freshwater Streams, Ponds and
Wetlands (BVW)
Submerged Aquatic Vegetation
Eelgrass Beds
Beaches Barrier Beaches Rocky Shores
Dunes Banks
Bays Sounds
Uplands (Buffer Zones)
Natural Systems in the Coastal Zone
Marine Estuarine Riverine / Lacustrine / Palustrine
Bays & Sounds
• Large physically protected bodies of water.
• Support many coastal habitats (eelgrass beds, shellfish beds, salt marshes etc.).
Submerged Aquatic Vegetation / Eelgrass Beds
Mass Bays Program: Eelgrass Beds, Manchester Harbor, MA
Photo: Ruppia maritima, Marilee Lovit, NEWFS
Pollution Control: • Leaves facilitate deposition of particles and
absorb pollutants, improving water quality (Short and Short, 1984).
• Absorb nutrients such as Nitrogen and Phosphorous.
Flood Control & Storm Damage Prevention: • Attenuation of wave energy(Fonseca & Cahalan,
1992). • Erosion control functions, stabilizing sediment with
extensive roots and rhizomes (Ward et al. 1984).
Provincetown Center for Coastal Studies
• Dredging.
• Excessive nutrients from urban runoff cause harmful algal blooms that block the sunlight / impede growth.
• Structures, such as docks, can prevent eelgrass from getting enough sunlight.
• Scarring and uprooting of plants from boat propellers, chain anchors, and moorings
• Some shellfish harvesting practices, such as hydraulic clamming, damage eelgrass beds.
Human Alterations Loss of Habitat Loss of Ecosystem Services
www.buzzardsbay.org
www.buzzardsbay.org
Beaches Barrier Beaches Rocky Shores
Dunes Banks
Pollution Control: • Beaches and dunes provide water
quality services through water filtration, nutrient cycling, nutrient uptake and water storage.
• Dune vegetation takes up nutrients such as Nitrogen and Phosphorous / Pollutants.
Flood Control & Storm Damage Prevention: • Coastal Dunes, Banks and
Beaches supply sand to / maintain each other.
• Attenuation of wind and wave (Fonseca & Cahalan,1992) energy.
• Absorb storm surge. • Delay or prevent inland
flooding.
VLAAMS INSTITUUT VOOR DE ZEE
http://www.landforms.eu/Lothian/beach.htm
http://indiancountrytodaymedianetwork.com/2012/10/30/hurricane-sandy-passes-tribes-begin-assessing-damage-143084
The Trustees of Reservations: Crane Beach
Human Alterations Loss of Habitat Loss of Ecosystem Services
Coastal structures such as riprap and seawalls decrease the amount reduce sediment supplied directly to the shoreline, caused by the reduction of dune and bank erosion.
Coastal structures (harbors, jetties, groins, breakwaters etc.) alter movement of sediment along the shoreline.
Offshore dredging impacts both sediment transport and wave energy, increasing beach erosion.
Upland stabilized by development interrupts natural erosion and sediment transport toward beaches.
http://www.learnnc.org/lp/multimedia/14416
http://www.dispatch.com
http://www.huntingtonbeachca.gov/residents/parking/
www.clearwater.org
MA DER / Applied Coastal Engineering, Inc.
Salt marshes
Salt Ponds
Tidal Flats
Shellfish Beds
Pollution Control: • Salt marshes are highly productive
systems; vegetation takes up nutrients, pollutants, sinks for carbon.
• Filter-feeding shellfish remove microscopic particles (phytoplankton, contaminants, etc.) from the water, improving turbidity, light penetration, and overall water quality as well as serving as a source of nutrients.
Flood Control & Storm Damage Prevention:
• Salt marshes, tidal flats, salt ponds have a high carrying capacity / act as basins for storm surge and rainfall run-off.
• Wave attenuation by salt marsh vegetation (Yang et al. 2012) and shellfish (Oysters: Scyphers et al. 2011)
• Salt marsh vegetation, shellfish beds stablize sediment and reduce shoreline erosion.
Betty Flowers www.essexheritage.org
Wade et al. 1999.
…I wish I had some oysters. I’m not talking about oysters to eat — although a dozen would be nice to go with that leftover bottle of Champagne that I really should drink if the fridge goes off. I’m talking about the oysters that once protected New Yorkers from storm surges, a bivalve population that numbered in the trillions and that played a critical role in stabilizing the shoreline from Washington to Boston. …
An Oyster in the Storm By PAUL GREENBERG NY Times Published: October 29, 2012
Salt marshes
Salt Ponds
Tidal Flats
Shellfish Beds
Human Alterations Loss of Habitat Loss of Ecosystem Services
Direct filling of habitat leads to habitat loss and function, lack of migration potential.
Transportation crossings (bridges, culverts, roads & paths) impound or restrict tidal flow. Altered hydrology reduces flood storage capacity, alters sediment transport.
Tide-gates control flow to tidal marshes / salt ponds. Lack of proper operation reduces flood storage capacity upstream.
Salt marshes
Salt Ponds
Tidal Flats
Shellfish Beds
Human Alterations Loss of Habitat Loss of Ecosystem Services
• Non-point source pollution including fertilizers, run-off from impervious surfaces lead to habitat degradation and loss of function. Marsh collapse.
• Coastal development at the mouth of estuarine systems prevents migration of primary tidal channels, increased risk of mouth closure.
• Ditching
Deegan et al. 2012 Trnerr.org
Coastal Freshwater Streams, Ponds and
Wetlands (BVW)
Pollution Control: • Freshwater wetlands are highly productive
systems; vegetation takes up nutrients, pollutants, sinks for carbon.
• Stabilized sediment is prevented from carrying pollutants / affecting water quality downstream.
Flood Control & Storm Damage Prevention:
• Reduce danger of damaging floods by preventing rapid runoff of water / slow floodwaters to reduce damage.
• Storage / holding basins for floodwaters.
• Vegetation stabilizes sediment and creates friction / absorbs energy from floods and wave action, reducing erosion.
Restored Freshwater Marsh, Fairhaven, MA / NOAA
Human Alterations Loss of Habitat Loss of Ecosystem Services
• Filling of wetlands decreases / removes flood storage capacity.
• Non-point source pollution including fertilizers, run-off from impervious surfaces / point-source pollution lead to habitat degradation and loss of function.
• Channelized and impervious surfaces reduce infiltration, increase runoff and accelerate movement of floodwaters
L.A., Hieu Nguyen
Alewife Brook, MA, Magicpiano
www.buzzardsbay.org
• Transportation crossings (bridges, culverts, roads & paths) impound or restrict stream flow. Altered hydrology reduces flood storage capacity, alters sediment transport.
• More than 3000 dams in MA • 43 are flood control dams • 44 licensed hydropower dams • 164 water supply dams • Federal, state, NGO, municipal owners
…and what about Dams?
DAM!
DAM! HOT!
HOT DIGGETY
DAM!
• Block fish passage
• Warm temperatures
• Trap sediment and nutrients
• Degrade water quality
Uplands (Buffer Zones)
Pollution Control: • Vegetation uptake of
nutrients and pollutants. • Stabilized sediment is
prevented from carrying pollutants / affecting water quality downstream.
Flood Control & Storm Damage Prevention: • Healthy upland natural
communities soak up precipitation and allow it to slowly drain into streams and rivers while moderating stream flows and limiting erosion.
• Natural rates of erosion
supply sediment to maintain habitats (wetlands, beaches etc.) downstream.
• Undeveloped upland
provides space for wetland migration (Long-term).
Smith, J.A.M. 2013
Bartlett Dam Removal, Alex Hackman
Uplands (Buffer Zones)
Human Alterations Loss of Habitat Loss of Ecosystem Services
Primary alteration to upland habitat is development. Uplands are least-protected habitat (lacking in regulations as compared to wetlands etc.).
• Increased impervious
surface exacerbates flooding from runoff and contributes toward non-point source pollution.
• Hardened structures (buildings, paving, etc.) interrupt flow, increase flooding, and alter natural patterns of sediment transport that sustain habitats downstream.
Fall River, MA, Herald News
Left, Photograph by Mark Holtzman; right, By George Riethof.
DER Projects n Over 1,000 acres of coastal
wetlands restored
n Over 200 miles of stream continuity restored
n 73 active projects
n Over 75 restoration projects completed
n Over 30 dam removal projects in design and permitting
n 5 active urban river revitalization projects
n Assisting on largest salt marsh restoration project on eastern seaboard (1,110 acres- Herring River, Wellfleet)
Briggsville Dam, Clarksburg, September 2008
Photo by B. Lambert
15 feet
June 2011
Newman Road, Newbury
Worlds End, Hingham
2009 2010
Ballou Dam, Yokum Brook, Becket 2006
September, 2011
Jones River, Kingston, MA
Summary • Human alterations to the coastal
landscape have significantly affected the pollution control, flood control, and storm damage prevention functions of these natural systems.
• Look at restoration opportunities to
address loss of these functions.
• Look ahead at how Global Climate Change / SLR will change these systems and incorporate in future plans / designs.
Wetlands to provide a storm surge buffer for New York City. Image from Architecture Research Office