final form
TRANSCRIPT
ByLauren Seiler, Sarah Gustafson, Allison Senycz,
and Ryan Nelson
Why do we have dams? Why contemplate removing dams? Costs and benefits of dam removal
◦ Social◦ Ecological◦ Economical
Criteria for dam removal
Generate hydroelectric power Flood control Water storage Recreation Wildlife habitat River navigation
19% of the world’s electricity (REN21, 2006)
103,800 megawatts per year in US (REN21, 2006)
Renewable source of energy Produces no waste Plants last a long time Low operating costs
Controls the amount of flow in waterways, especially after rain or melt events
Protects downstream communities and farms
Dams create reservoirs, can store annual runoff for use during the year
Water used for agriculture, industrial, and municipal purposes
Creates areas for ◦ Swimming◦ Fishing◦ Boating◦ Waterskiing
Many dam areas have become state parks◦ may include opportunities to hike, bicycle, camp,
picnic, and bird watch.
Creates wetlands Creates non-riverine
habitats◦ Animals ◦ Insects
Can create a warm water environment downstream
Dams can provide rail or road crossing Stable system of inland river transportation
◦ Example: logging, ferry, lock & dam
Dams degrade over time and can become dangerous
Block movement of fish and other aquatic species
Natural river flow is altered Reservoirs inundate wildlife habitat Nutrients settle in the reservoir, cannot
reach downstream
Alter the characteristics of the community surrounding the dam
Eliminate or alter any services given by the dam
Community Costs Case Study: Oak Street Dam in Baraboo,
Wisconsin◦ Lost hydroelectric power generated by dam
(Wisconsin DNR, 2006)
Alter the characteristics of the community surrounding the dam
Eliminate dam safety concerns Improve river aesthetics and/or recreation Community saves money on taxes/costs Case Study: Conestoga River in SE
Pennsylvania◦ Improvement of river recreation & community
revenue (American Rivers, 2007)
Removing a dam can be beneficial for river restoration by returning pre-impoundment ecological functions and critical habitat to the river.
Dam removal may not always be necessary to accomplish these ecological improvement goals.
In some situations dam removal may set river restoration back, causing more harm than good.
Therefore it is important to weigh the ecological costs and benefits of dam removal. Image source:
http://www.nmfs.noaa.gov/habitat/restoration/images/NH%20Henniker%20dam%20removal.jpg
Removal of a dam will change or impact:◦ Water flow◦ Fish and wildlife abundance◦ Passage of migratory fish◦ Sediment Movement◦ Water Quality
Image: Removing the Smelt Hill dam on the Presumpscot River in Maine, opened five miles of river and restored habitat for many economically important fish species.
Image Source: http://www.nmfs.noaa.gov/habitat/restoration/projects_programs/crp/
partners_funding/backgroundondamremoval.htm
Removing a dam will restore the natural flow of the stream or river.
Benefits: Improved fish habitats Improved riparian zones
Natural flooding Drained reservoir will
produce new riparian andterrestrial habitat
Case Study◦ 13 Dam removal sites in Wisconsin
Rapid revegetation demonstrates the potential of these sites for riparian restoration.
Temporal vegetation dynamics following dam removal were site-specific (Orr et al, 2006).
Costs:◦ Removing a dam will impact
reservoir habitat and wetland habitat. Possible net loss of wetland
habitat Loss of reservoir fish habitat
It may be possible to “create” natural flow◦ Glen Canyon Dam
In 1996 a large flood was released
Studies following the release indicate that some restoration of beaches and riverine habitat occurred (Collier et al, 1996).
Image Source: http://www.usbr.gov/power/data/sites/glencany/glencany.html
Removal of dam will impact fish in wildlife diversity and abundance.
Benefits Increase in riverine and
riparian species diversity and abundance
Case Studies◦ Florida’s Dead Lake Dam
removal After the removal of the dam,
aquatic species diversity nearly doubled from 34 to 61 (Hill et al, 1993).
Image source: http://news.minnesota.publicradio.org/features/2004/03/22_olsond_dams/
Costs:◦ Loss of reservoir species◦ Temporarily disrupt species
sensitive to changes in water quality and water level
◦ Spread of undesirable non-native species or parasites that could reach vulnerable native species and their habitats.
Costs on fish and wildlife rely, for the most part, on what species are considered relatively “important” in that area.
• Brownlee Reservoir is among the most heavily fished waters in Idaho. Healthy populations of warm water fish such as smallmouth bass, catfish and crappie are especially popular.
Removal of dam will restore natural flow and allow for passage of migratory fish.
Benefits◦ Allows migratory fish to swim upstream to reach native spawning
grounds.◦ Improves downstream passage for juvenile fish.◦ Migrating fish also play an important role in nutrient management of
rivers• Case Studies (American Rivers, 2007)– Neuse River, Quaker Neck Dam in North
Carolina• Removal permanently restored 1000
miles of fish spawning habitat.• The dam removal benefits eight
species of migratory fish, including striped bass, American shad, hickory shad, shortnose sturgeon, and American eel.
American shad (Alosa sapidissirna)
Images Source: http://www.nativefish.org/articles/Migratory_Fish_Restoration.php
Case Studies Cont’d◦ Conestoga River Dams (Lancaster
County) Seven obsolete run-of-river dams
were removed The dams blocked American shad The removal of three of the seven
dams on the Conestoga River opened over 25 miles for migratory fish.
◦ Juniata River Will also open up 20 miles of
spawning ground for migratory fish Contingent upon installation of
downstream fish passages.
Rock Hill Dam before removal
Rock Hill Dam after removal
Images Source: http://www.nativefish.org/articles/Migratory_Fish_Restoration.php
Passage of migratory fish can be accomplished by installing fish passage devices.◦ Fish ladders◦ By-pass pipelines◦ Fish elevators◦ Capturing of juvenile fish and
transported via barges or trucks.
Image Sources: http://www.nwcouncil.org/library/2003/2003-20/hydro.htm
http://www.lakeoroville.water.ca.gov/about/stats/hatchery.cfm
Sediment accumulates in reservoirs and removing the dam will release these sediments downstream.• Benefits– Restore natural sediment
balance– Redistributes essential
nutrients– Re-exposing gravel and
cobble upstream– Restores sediment to coastal
beaches– Sediment left behind will
produce new riparian zones.
Image Source: www.ies.wisc.edu/research/wrm00/educmorph.htm
Vegetation begins to grow in the sediments left behind after removal of the Rockdale Dam in Wisconsin.
Costs◦ Release toxins that have accumulated behind the dam.◦ Short term damage to spawning grounds, water
quality, habitat and food quality.◦ May take a long time to flush all the stored sediments
downstream Case Study (American Rivers, 2006)
◦ Hudson River, Fort Edward Dam in New York PCB contaminants were found in the river
sediments. The removal re-released these contaminated
sediments and dispersed them downstream at an unsafe level, requiring extensive cleanup efforts.
Dam removal can change many aspects of water quality including temperature, nutrient transport, oxygen content, and turbidity.
• Benefits– restore natural water
temperatures– Enhance nutrient transport– Increase the river’s oxygen
content (through restoration of riffle habitat)
– Reduce turbidity
Rock Hill Dam before removal
Rock Hill Dam after removal
Images Source: http://www.nativefish.org/articles/Migratory_Fish_Restoration.php
Costs◦ Short term increase in turbidity◦ If released too fast, water can
become supersaturated with gas and can cause gas bubble disease in fish downstream
Case Studies Snake River, Little Goose
Dam in Washington◦ Supersaturation of dissolved
gas occurred in the water, turbidity levels increased, and many reservoir fish and insects perished.
Image Sources: http://www.nww.usace.army.mil/lsr/reports/save_salmon/salmontoc.htm
http://zebrafish.org/zirc/health/diseaseManual.php
Cost-benefit Analysis of Dam Failure, Dam Repair, and Dam Removal
Dam Failure◦ Caused by “Do Nothing Approach”◦ Liability issues
Repair the dam◦ Can be costly◦ Still have benefits of the dam
Remove the dam◦ Loss of economic benefits of the dam◦ No more yearly repair costs
Reasons for a dam failure ◦ Overtopping◦ Foundation defects◦ Internal erosion caused
by seepage ◦ Structural failure of the
materials used in dam construction and inadequate maintenance (“Do Nothing” approach)
Overtopping of a dam, causing dam failure
Economical Implications of a failing dam◦ Loss of property◦ Environmental damage◦ Habitat restoration costs
More than 400 dams failed in the U.S. between 1985 and 1994 (Stanley et al., 2003) Damage caused by Cannon Creek Dam failure in B.C.,
May 1995
Survey of 10,000 flood control dams in U.S. ◦ Over 2,200 needed
maintenance◦ Estimated cost: $543
million (Stanley et al, 2003). Costs
◦ Engineering contractors◦ Engineering consultants◦ Permits◦ Construction company
and materials for repair◦ Fish passage structures
$200,000-$400,000 depending on type and size
(Dam Repair or Removal: a Decision-Making Process, 2000)
Former Rockdale dam in Wisconsin with cracks in concrete wing walls and erosion of spillway
Salmon swimming up fish ladder in Oroville Dam, CA(Google Video, 2007)
Lake Perez Dam◦ Built in 1960 in Stone
Valley Recreational Area
◦ Lake drawdown in 2002 for dam rehabilitation $2.8 million project(Stone Valley, 2002)
◦ Drained again in 2008 for dam maintenance No stocking, fishing,
boating, etc. Loss of summer
recreational revenue
Three Repair Scenarios◦ $1,091,500
Rehabilitating most structures, abandoning the turbine raceway
◦ $871,000 Rehabilitating some structures, abandoning the
turbine raceway and the headrace structure◦ $694,600
Rehabilitating the principal spillway, abandoning the headrace structure, and constructing new raceway overflow spillways and fish-passage structure
Costs◦ Engineering
contractors◦ Construction company
for demolition◦ Sediment traps
Possibility of toxic sediments
◦ Restoration of newly exposed area Stream bank
restoration River restoration
Lowell Dam removal on Little River, North Carolina(Google Video, Restoration Systems, 2005)
Time-lapse removal of Marmot Dam, Sandy River, Oregon(Google Video, USGS, 2007)
Estimated removal cost: $216,000
Actual final cost: $238,769 ($200,000 paid by Wisconsin Department of Natural Resources grant)
Costs of removal compared to repair
Dam Removal Case Study: Waterworks Dam, Baraboo River, Wisconsin
(Dam Repair or Removal: a Decision-Making Process, 2000)
Waterworks Dam on Baraboo River, WI (1996)
Former impoundment of Waterworks Dam (2000)
Background◦ Lower Granite, Little
Goose, Lower Monumental, Ice Harbor dams on Lower Snake River in Washington state
◦ Built by U.S. Army Corps of Engineers between 1961 and 1975
◦ Facilitate barge travel and generate a small portion of Northwest’s electricity
Lower Granite Dam on Lower Snake River, Washingtonhttp://www.bluefish.org/fourdams.htm
Costs of keeping the dams includes:◦ 2004 Federal Columbia Snake River Salmon Plan,
salmon recovery costs, dam operation and maintenance, sediment control, major dam repairs
Costs of removing the dams includes:◦ New Federal Columbia Snake River Salmon Plan,
additional salmon recovery costs, dam removal and river restoration, power replacement, converting barge to rail transportation, increased shipping rates, irrigation investments, private well modifications, municipal and industrial water use modifications
• Graphically represents costs associated with removing the dams
• Results shown over 10-year and 20-year totals
Costs of keeping the four dams◦ $7.8 to $9.1 billion over a 10-year period◦ $15.7 to $18.2 billion over a 20-year period
Costs of removing the four dams and replacing the current dam benefits◦ $6.2 to $9.1 billion over a 10-year period◦ $11.1 to $16.6 billion over a 20-year period
Savings with dam removal◦ $12 million to $2 billion over 10 years, and $2 billion to
$5 billion over 20 years
• Dam removal will produce five-fold increase in new revenue • Tourism• Recovered fish runs• Outdoor recreation
Does the watershed have a management plan that needs criteria met?
Goals must be established with the dam removal in order to best manage the issue◦ Removal for Safety?◦ Removal for Costs of Maintenance?◦ Removal for migratory fish?◦ Removal for recreation?
• Not all dams meet criteria for removal• Dams usefulness may out way environmental issues
• Power Production vs. Migratory Fish, etc.• Community Views and their goals and objectives • Stake Holders
– Local Residents/Business’s– Watershed Groups– Recreational River Users– Government (DNR, FBC, …)
• Land Use Post-Dam Removal– Park Land– Development– Forest– Unclaimed ownership
Dam Density/ Connectivity Fish Habitat/Wetlands Special Concern Species Water Quality Effects Safety, Maintenance &Costs Sediments
Drawdown Removal Lower Snake River
*Rank these by importance
Determine the number of dams on the stream. Sets priority to streams based on how many dams would have to
be removed in order to accomplish goal of removal. How many miles of stream are opened after removal? Can be 1 mile of main stem, but many miles of tributaries. Fish that must pass through 5 dams with a 90% success rate will
result in a 41% smaller population than initially (Gregory et.al. 2002)
•(Gregory et.al. 2002))
Assessment of the habitat Does the habitat mimic the natural setting? Native fish species exist both above and below dam? Is a CWF changed to a WWF due to the dam?
Wetlands Removal will cause for
wetland loss. Was the dam established
before or after the Clean Water Act?◦ CWA would claim these areas as
wetlands if dam was constructed before CWA
◦ Mitigation would be required if wetlands are lost
Endangered/Threatened Species◦ Salmon◦ Mussels◦ Shad
# of End. Species to benefit from removal
Klamath River, Oregon
Salmon Kill caused by the inability to run upstream
Are there differences between upstream and downstream habitat?◦ New communities present between these hydrologically connected
areas? Will local/watershed water problems be alleviated by the removal
of the dam?◦ More cold water downstream or less summer stress to fish.
Is it a HQ/EV CWF?◦ Due to their productivity, is the dam worth disturbing this quality fishery
Is it impacting a headwater stream? Physical/Chemical Features
◦ D.O. Levels◦ Temp.◦ Nutrients◦ DOC/DIC
Is the dam malfunctioning? Is there a high risk of failure? Who will be affected in the event of a failure? Does the cost of maintenance exceed revenue generated? Does the dam still serve its intended purpose?
Not your typical “dam”Grassflat Run, Pennsylvania
•Yet another issue with Abandoned Mines in Pennsylvania
•RR Bridge left unmaintained clogged, creating a dam and blew out.
Is there a benefits for a sediment flush?◦ Coastal, Bar formation, bed load
Is it undesirable to flush the sediments?◦ Macroinvertebrates, Fish eggs, Downstream Aesthetics
Analysis conducted to see if the sediments are contaminated?◦ Lead, PCB, etc…
Can you sell the sediments?◦ Cobble, sediment, river rock have been sold for landscaping and other purposes
River Form◦ Pool/Riffle Development takes several years, depending on the # of discharges that can move
sediment (Pizzuto, 2002)◦ Account for this in planning
Savage Rapids Dam, Rogue River Oregon
Appx.200,000 yds^3 of sediment stored
Flushing Chosen
An alternatives analysis was conducted in order to determine the most effective way to manage the dam, accounting for the social, ecological and economical benefits and costs.
Table 1. Comparison of Alternatives (WDNR)
Table 2. Comparison of Environmental Consequences of the alternatives. (WDNR)
Classified a State Natural River Zone Priority Removal by the Mich. DNR
◦ Re-established the “rare, high-gradient reaches” in the Huron Watershed
Dam Construction◦ Henry Ford made it for Electricity, but abandoned it after
all the required land wasn’t obtained. Bridge is still used today.
◦ No Longer serves its intended purpose Decision Making
◦ Alternatives analysis conducted to see benefits vs. cost◦ 18 months of research conducted during analysis◦ Residents were asked to input in there ideas for the
future of the dam
- Above is a photo looking upstream at the dam
- Top-right shows the deteriorating dam and bridge
- Right - Accumulated sediments with Purple Loosestrife
Dam removal is a viable option not only for ecological functions but also for social and economical reasons as well.
Beneficial results are site specific and may be able to be accomplished using other techniques.◦ Fish ladders◦ Managed floods
Sites that are being considered for dam removal should conduct in depth research beforehand to see if it meets the criteria for a beneficial removal.
American Rivers, "Success Stories Report." American Rivers. 2007. 20 Apr 2008 <http://www.americanrivers.org/site/DocServer/SuccessStoriesReport.pdf?docID=221>. “
Collier, M.P., R.H. Webb, and E.D. Andrews. 1997. Experimental Flooding in the Grand Canyon. Scientific American 276:82-89.
Dam Repair or Removal: a Decision-Making Guide." WRM 2000 Decision-Making Process. 2000. University of Wisconsin. 12 Apr. 2008 <http://www.ies.wisc.edu/research/wrm00/econintro.htm>.
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"Dam Safety in British Columbia - Who is Responsible?" Ministry of the Environment: Water Stewardship Division. 1995. Province of British Columbia. 14 Apr. 2008 <http://www.env.gov.bc.ca/wsd/public_safety/dam_safety/responsible.html>.
"Dams: Do Costs Exceed Benefits?" 2007. Property and Environment Research Center. 15 Apr. 2008 <http://www.perc.org/perc.php?id=1021>.
Department of the Interior. 1995. Final Environmental Impact Statement: Elwha River Ecosystem Restoration, Olympic National Park, Washington, 674pp.
Gregory, Stan, Hiram Li, and Judy Li. "The Conceptual Basis for Ecological Responses to Dam Removal." Bioscience 52 (2002): 713-721. Proquest. Penn State Paterno Library, University Park, PA. 20 Apr. 2008.
Hill, M.J., E.A. Long and S. Hardin. 1993. Effects of Dam Removal on Dead Lake, Chipola River, Florida. Apalachicola River Watershed Investigations, Florida Game and Fresh Water Fish Commission. A Wallop-Breaux Project F-39-R. 12 pp.
Michigan Department Of Natural Resources, and Michigan Department Of Environmental Quality (MDNR and MDEQ) . "Dam Removal Guidelines for Owners." (April 2004). 20 Apr. 2008 <http://www.michigandnr.com/PUBLICATIONS/PDFS/fishing/dams/DamRemovalGuidelinesForOwners.pdf>.
Orr, C.H., E.H. Stanley. 2006. Vegetation development and restoration potential of drained reservoirs following dam removal in Wisconsin. River Res. Appl. 22(3): 281-295.
Pizzuto, Jim. "Effects of Dam Removal on River Form and Process." Bioscience 52 (2002): 683-692. Proquest. Penn State Paterno Library, University Park, PA. 20 Apr. 2008.
Revenue Stream: An Economic Analysis of the Costs and Benefits of Removing the Four Dams on the Lower Snake River, Save Our Wild Salmon Coalition, 2005.
REN21. 2006. “Renewables Global Status Report 2006 Update” (Paris: REN21 Secretariat and Washington, DC:Worldwatch Institute).
Riggs, Elizabeth H.W. "Case Studies in River Restoration Through Dam Removal - Argo Dam and Mill Pond Dam, Huron River Watershed, Michigan." The Huron River Watershed Council (June 2003). 20 Apr. 2008 <http://www.hrwc.org/pdf/dexterdam.pdf>.
"Spring Trout Stocking Cancelled At Lake Perez." PFBC 2008 Press Release. 25 Mar. 2008. Pennsylvania Fish & Boat Commission. 14 Apr. 2008 <http://www.fish.state.pa.us/newsreleases/2008/perez_cancel.htm>.
Stanley, Emily H., and Martin W. Doyle. "Trading Off: the Ecological Effects of Dam Removal." Frontiers in Ecology and the Environment 1 (2003): 15-22.
Stone Valley's Lake Perez." Stone Valley. 7 Feb. 2002. The Pennsylvania State University. 14 Apr. 2008 <http://www.psu.edu/ur/archives/intercom_2002/Feb7/stonevalley.html>.
Warrick, Jonathon. "Dam Removal on the Elwha River in Washington—Nearshore Impacts of Released Sediment." Sound Waves - USGS Coastal Science Newsletter. Feb. 2005. United States Geological Survey. 20 Apr. 2008 <http://soundwaves.usgs.gov/2005/02/research.html>.
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