Presented by: Brian Rheinhart, P'E' Project Manager

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Embrey Dam Removal Project EWRI Dam Removal
Workshop 17 August 2004
Presented by Brian Rheinhart, P.E. Project
Manager Norfolk District, U.S. Army Corps of
Engineers Planning, Programs and Project
Management Division, Civil Branch
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Presentation Outline

• Project Introduction
• Dam and Project History
• Reasons for Dam Removal
• Plan Formulation/Alternative Analysis
• Plan Execution
• Dam Breech Video
• Qs and As

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Project Introduction

• Embrey Dam--located 112 miles from the mouth of
  the Rappahannock River, near Fredericksburg, VA
  stands 22 ft high, 1000 ft long the last
  impediment to fish passage

on the mainstem Rappahannock.
Embrey Dam
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Dam and Project History

• 1854 - Wood-and-stone crib dam constructed.
• 1910 - Embrey Dam construction completed.
• 1926 - Virginia Electric and Power Co. acquires
  power plant and dam.

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• Dam and Project History Cont.
• 1968 City of Fredericksburg purchases the dam
  along with 4,800 acres of riparian property
  upstream of the dam for water supply.
• 1997 City of Fredericksburg City Council adopts
  resolution urging demolition of the dam in
  anticipation of new water supply source.
• 1998 Corps completes Recon Study determining
  Federal interest for further study for Ecosystem
  Restoration of the Upper Rappahannock River Basin.

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• Dam and Project History Cont.
• 1999 Corps initiates Feasibility Study for
  Ecosystem Restoration.
• 1999 Removal of the Embrey Dam authorized by
  Section 590 of WRDA 1999.
• 2000 Feasibility Study terminated and Decision
  Document for Removal of the Embrey Dam initiated.
• 2002 Decision Document completed, permits for
  the project issued and construction funds
  appropriated.

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• Reasons for Dam Removal
• To permit fish passage to the upper reaches of
  the Rappahannock River and its tributaries.
• To improve recreational opportunities on the
  river.
• To eliminate the need for expensive repairs and
  maintenance.
• The dam no longer serves any purpose.

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Plan Formulation/Alternatives Analysis

• Impounded Sediments
• Embrey and Crib Dams
• Historic Rappahannock Canal

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Stafford County
Embrey Dam
Interstate 95
Historic Rappahannock Canal
City of Fredericksburg
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Alternatives Analysis Considerations

• Historical
• Social (Community Support and Interest)
• Environmental (NEPA, Permits, Mitigation,
  Riparian Restoration)
• Engineering and Design
• Costs
• Schedule

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Impounded Sediment Alternatives

• No Action/Erosion
• Removal in the Dry by Mechanical Methods
• Removal in the Wet by Hydraulic Dredge

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Removal of Dams Alternatives

• Instantaneously by Explosives
• Staged by Mechanical Methods
• Initial Breach by Mechanical Explosives then
  Staged Mechanical

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Historic Rappahannock Canal Alternatives

• Canal Extension Upstream
• Diversion Pipe Upstream
• Upstream Pump Station in the Vicinity of Embrey
  Dam
• Canal Aeration and Mixing System with
  Supplemental Pumping from Downstream Tidal
  Portion of the Rappahannock River

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Selected Plan/Project Elements

• Sediments--Dredging with Upland Disposal
• Embrey and Crib Dams--Initial Breach by
  Mechanical Explosives, then Phased, Full
  Removal by Mechanical Methods
• Rappahannock Canal--Aeration Downstream Pump
  System
• Riparian Restoration

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Project Execution

• Sediment Removal
• Rappahannock Canal Aeration Downstream Pump
  System
• Embrey and Crib Dam Removal
• Riparian Restoration

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Sediment Removal
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Dredge Material Containment Site
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Graded Containment Site
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Partial Breach of Crib Dam
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Rappahannock Canal Aeration System
Pump Station Location
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Embrey Dam Initial Breach
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Post-Breach Exposed Embrey Dam
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Post-Breach Exposed Banks
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Post-Breach Exposed Crib Dam
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Riparian Restoration Area
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Questions and Answers
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Web site http//www.nao.usace.army.mil/
Brian.K.Rheinhart_at_usace.army.mil 757-441-7768