ESA 324 - Dams Project

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Effects of Dams & Dam Removals

Transcript of ESA 324 - Dams Project

DAMS Patrick Devon

Amber Geller

Frankie Pappalardo

A what?Merriam-webster  : a barrier preventing the flow of water or of loose solid materials (as soil or snow); especially : a barrier built across a watercourse for impounding water

Textbook: basic, fundamental management tool used to control, regulate, and deliver water for a variety of purposes.

Classifications: Gravity concrete Concrete arch Earthen embankment

Not a levee

StructuresConcrete arch dam

StructuresGravity Concrete

Structures

Earthen Embankment

Who cares?“Since 1950, the number of large dams has climbed from 5,000 to more

than 45,000—an average construction rate of two large dams per day for half a century.”

Globally, 364 large water-transfer schemes move 14 trillion cubic feet (400 billion cubic meters) of water annually from one river basin to another—the equivalent of transferring 22 Colorado Rivers.

Purposes: Flood Control IrrigationRecreationNavigationHydroelectric generation

Primary Purposes

StakeholdersRecreational users of

waterwaysFishing, Kayaking,

Canoeing, NaturalistsCommercial FishersLandowners

Benefits of DamsRecreationFlood ControlWater StorageIrrigationMine TailingsElectrical GenerationDebris ControlNavigationRiver Regulation

Negative ImpactsAltered natural and human

environmentsReduced stream flowsDegraded water qualityImpacts on migrating fishTransformation from river

system to reservoirReduced transport of

sediment

Dam Removal?

In some cases it is beneficial to remove dams for the following reasons

Reestablishment of a natural flow regime (flow)

Transformation from reservoir to river system

Change in river temperatures and oxygen levels (water quality)

Sediment release and transport

Migration of fish and other organisms (connectivity)

MichiganPurposes:

transport goods (ie: logs)

milling operations

electricity

flood control

navigation

recreation

Michigan2500 dams across the

states114 hydropower

production

Stronach DamManistee County, Michigan

Built in 1912, ~ 3 miles upstream of the Manistee River & Pine River confluence

No longer serving it’s intended purpose: hydroelectric power

Removal began in 1996, gradually restored until 2003.Since 1998 Dr. Hayes has been involved in studying the

environmental effects

Stronach Dam

1996 2003

Big Rapids DamMuskegon River, Mecosta CountyBuilt in 1914, 17 foot tall hydropower dam.In 1966 a portion of the dam was removed negligently.

There remained a 5 foot section of the dam which lead to several drowning deaths.

Many groups rallied to remove the Big Rapids Dam in 2000/2001.

Big Rapids Dam

Original Dam2000

2001

Dam Controversy

Should dams be built?Should dams be left

alone?Should dams be

removed?

What’s at Stake?• Environmental Factors:

• Loss of aquatic populations• Damage of habitat

Social Factors:• Mortality• Water source• Recreation• Electricity

Resources:• Time• Money• Workers

RecommendationsCost/Benefit Analysis every step of the wayDam removal should have priority over dam construction Stress and be very detailed with loss of NR evaluation Quicken the permit approval process for dam repairs and

dam removalIncrease inspection frequency of high hazard dams to

every yearEducate dam owners, consultants, emergency

management personnel, and the public about dam safety