Appendix B 

Meeting Handouts and Information Displays 
FOLSOM DAM SAFETY AND FLOOD DAMAGE REDUCTION ACTION

Draft Environmental Impact Statement/Environmental Impact Report (Draft EIS/EIR)

WEL COME

Folsom Dam and Reservoir are one of the largest facilities of its type upstream of a major U.S. metropolitan area. 

In addition to providing water supply, power, and recreational opportunities, the Folsom Facility is also operated to provide 

flood protection benefits to Sacramento. To ensure that the Facility is capable of meeting its multiple purposes well into 

the future, improvements to its structures and operational flexibility are necessary. 
ROLES & RESPONSIBILITIES

Folsom Dam Safety and Flood Damage Reduction Action

Draft Environmental Impact Statement/Environmental Impact Report (Draft EIS/EIR)

Although the Bureau of Reclamation (Reclamation) and the U.S. Army Corps of 

Engineers (Corps) share common interests regarding the structural integrity, 

security, and operations of Folsom Dam and Reservoir, Congress has assigned the 

agencies differing roles and responsibilities. Reclamation is the agency assigned 

with maintaining the facility, and ensuring public safety related to structural 

integrity of the dams and dikes that comprise the Folsom Facility. The Corps’ 

primary responsibility is the use of the Folsom Facility to reduce the risk of flood 

damage in the areas that are within the historic floodplain of the American River. 

Through a cooperative effort, Reclamation and the Corps have been evaluating 

the structural integrity and flood damage reduction capabilities of the Folsom 

Facility. These evaluations have identified seismic, static, hydrologic, and 

security concerns that need to be addressed to ensure public safety. Congress 

has authorized Reclamation and the Corps to collaborate in identifying common 

solutions to the issues identified for Folsom Dam. 

IMPROVING THE STRUCTURAL INTEGRITY OF FOLSOM FACILITIES

Reclamation is responsible for the safety, security, and structural integrity of Folsom Dam. Reclamation is actively assessing structural improvements for three Dam Safety issues, including: 

hydrologic (overtopping or failure during a large flood event), static (leakage through earthen dams and dikes), and seismic (movement of the dam during an earthquake). In addition, 

Reclamation is proposing to upgrade security features for the Folsom Facility.

FLOOD DAMAGE REDUCTION

The Corps is the primary Federal flood management agency in the region. The Corps coordinates flood control operations with Reclamation, The Department of Water Resources, The Reclamation 

Board of the State of California, and the Sacramento Area Flood Control Agency (SAFCA). The Corps has prepared a Draft Post Authorization Change (PAC) report that is available for public 

review concurrent with the Draft EIS/EIR. The PAC report describes recommended changes to the Folsom Dam Modifications and Folsom Dam Raise Projects.

JOINT FEDERAL EFFORT

This Draft EIS/EIR addresses project alternatives that include elements of the individual missions of Reclamation and the Corps. The alternatives in the document incorporate actions that both 

agencies could take jointly to address common hydrologic concerns (the “Joint Federal Project”) and actions that could be implemented separately to address specific dam safety, security, 

and flood damage reduction under specific authorizations and appropriations. For this Draft EIS/EIR, the Corps is a cooperating agency, and intends to adopt the Final EIS/EIR to satisfy NEPA 

requirements for the flood damage reduction elements of the selected alternative. The Reclamation Board is the CEQA lead agency, and SAFCA is a responsible agency under CEQA. 

JFP Gated Auxiliary Spillway -- Line Drawing
PURPOSE

Folsom Dam Safety/Flood Damage Reduction Area

Draft Environmental Impact Statement/Draft Environmental Impact Report

There are concerns related to how the Folsom Facilities would perform during a 

large earthquake. Of greatest concern is movement of the main concrete dam and 

failure of the Mormon Island Auxiliary Dam (MIAD). The Draft EIS/EIR assesses the 

following options: 

• Reinforcement of the main dam to increase stability, including reinforcement 

of pier and gate structures, increasing shear resistance of foundation and 

concrete blocks, and foundation strengthening improvements.

• Stabilization of MIAD, which is founded upon potentially liquefiable materials. 

Alternatives to reinforce MIAD include excavation and replacement of the 

foundation materials, and stabilization of the structure through jet grouting. 

 

S E I S M I C

H Y D R O L O G I C

The hydrologic issues are both dam safety and flood damage reduction concerns. 

Overall, the hydrologic aspects of the alternatives address the ability of the Folsom 

Facilities to safely manage large flood events without overtopping or failure of any 

of the dam facilities, and within the design capabilities of the levees along the lower 

American River when water is released from the facilities during a large storm event. 

The Draft EIS/EIR addresses several hydrologic control options, including: 

• Construction of the Joint Federal Project (JFP) Gated Auxiliary Spillway along the left 

abutment of the Main Dam that would allow for earlier releases. The JFP Gated Auxiliary Spillway would meet Reclamation’s Dam Safety objectives and the Corps’ Flood 

Damage Reduction objectives. The proposed JFP Auxiliary Spillway at Folsom Dam 

and Reservoir would consist of a control structure with six 23-ft by 33-ft submerged 

tainter gates and have a total channel length of approximately 3,200 feet. 

• Dam Raise that would raise all retention facilities including earthen and 

concrete structures to a height necessary to increase flood storage capacity. 

• Improvements to facility structures (dikes and dams) to strengthen the 

structures and protect crests from wave wash

S T A T I C

The static concern relates to seepage of water through earthen dikes and dams. The 

primary option under consideration involves improvements to the filters and drains 

that would receive and control any seepage water. 

S E C U R I T Y

Folsom Dam has been designated as a National Critical Infrastructure Facility. Any 

compromise of the facility could result in grave property damage and loss of life. 

The objective of the Security Project is to upgrade the existing level of security by 

upgrading key security features. 

The proposed improvements address five areas 

including Hydrologic, Seismic, Static, Dam Security, DAM SAFETY & FLOOD DAMAGE REDUCTION

and Flood Damage Reduction considerations. The 

Folsom Dam Safety/Flood Damage Reduction (DS/

FDR) EIS/EIR provides assessments of alternatives 

that would address these issues. The Draft EIS/EIR 

has evaluated five alternatives, identifying potential 

impacts and mitigations for each.

Folsom Dam Safety and Flood Damage Reduction Action

Draft Environmental Impact Statement/Environmental Impact Report (Draft EIS/EIR)

Flood Damage Reduction

Seismic Reinforcement of Concrete Dam
EIS/EIR PROCESS

• The Record of Decision (ROD) is the final step of the 

NEPA process.

• Multiple RODs may be developed to correspond with 

each agency’s authorities and authorizations.

• The ROD(s) will document the alternative or alternative 

features selected by Reclamation and the Corps, in concert 

with the Reclamation Board and SAFCA.

• The ROD(s) will identify all of the alternatives

considered and summarize and address comments 

received on the Final EIS/EIR. 

• The ROD(s) will include measures

to avoid or minimize effects 

from the selected alternative.

• A Notice of Determination (NOD) 

will complete the CEQA process 

for California.

Decision Making and EIS/EIR Process

The National Environmental Policy Act (NEPA) and the 

California Environmental Quality Act (CEQA) are both 

processes that provide an opportunity for the public and 

agencies to help clearly identify and define environmental 

issues and alternatives to be examined for a proposed 

action. The NEPA/CEQA process is intended to help public 

officials make decisions and take corrective actions based 

on an understanding of the environmental consequences. 

How is the Public Involved?

The public is involved at three stages of the EIS/EIR 

process. First, the public is invited to make comments 

and suggest alternatives to the project during project 

scoping (see Scoping below). Second, the public is asked 

to comment on the results of the environmental analyses 

described in the Draft EIS/EIR (one of the purposes of this 

meeting). Third, the public is allowed to comment on the 

Final EIS/EIR and Environmentally-Preferred Alternative, 

particularly in the manner that comments on the Draft 

EIS/EIR were addressed.

 

Scoping

Scoping meetings were held by Reclamation, the Corps, 

the Reclamation Board and SAFCA in December 2005 

to receive initial public comments on the Folsom Dam 

Safety/Flood Damage Reduction Action. 

Public Review and Comment on the Draft EIS/EIR

The purpose of these hearings is to present the five 

alternatives analyzed in the Draft EIS/EIR and to present 

the tentatively preferred alternative. The general public 

and Federal and State agencies are invited to provide 

comments in person, by mail, or by email or fax. All 

comments are due by close of business January 22, 2007. 

Comments received during the 50-day review period will 

be addressed in the Final EIS/EIR. 

Public Review of Final EIS/EIR

Once the Final EIS/EIR is complete, it will be released for 

a 30-day period before Reclamation prepares and adopts 

a decision. It is during this period that the Corps will 

circulate its Notice of Intent to adopt the Final EIS/EIR and 

the Reclamation Board will certify the Final document. 

W H AT A RE T HE ROD A ND NOD?

Folsom Dam Safety and Flood Damage Reduction Action

Draft Environmental Impact Statement/Environmental Impact Report (Draft EIS/EIR)

NEPA/CEQA Process

80s 90s 04 05

operational

problem

Reclamation & Corps

seeking solutions

October 2005: Notice of

Intent/Notice of Preparation

(NOI/NOP) of Draft EIS/EIR

March 2007:

Final EIS/EIR

May 2007: Record of Decision/

Certification and Notice of

Determination (ROD/NOD)

Late Fall 2007:

Construction Begins

storms of 86 | | | | | | | | | | | | Corps’ dam 

raise/Folsom 

modification

Gate fails Reclamation Safety 

of Dams Evaluation

06 07

December 2005:

Scoping Meetings

Dec. 2005 to Dec. 2006:

Draft Enviromental Impact Statement/

Environmental Impact Report

January 2007:

Public Review and Comment on the

Draft EIS/EIR

(You are Here)

Engineering Process

Draft EIS/EIR

The Draft EIS/EIR identifies 

Alternative #3 (the JFP Gated 

Auxiliary Spillway with Potential 

3.5-foot Parapet Wall Raise) as 

the environmentally preferred 

alternative that meets the Purpose 

and Need of the Folsom DS/FDR 

action. 

An Environmentally-Preferred 

Alternative — CEQA Requirement
PROPOSED ALTERNATIVES

Folsom Dam Safety and Flood Damage Reduction Action

Draft Environmental Impact Statement/Environmental Impact Report (Draft EIS/EIR)

No Action/No Project Alternative: The No Action/No Project Alternative is essentially the existing 

conditions for the Folsom Facilities. No action would be taken to upgrade the structural integrity, 

improve hydrologic control, or provide additional flood damage reduction benefits to the Sacramento 

area. The risk of dam failure and downstream flooding would remain the same.

Alternative 1: Fuseplug Auxiliary Spillway, No Concrete Dam Raise/Embankment 

and Crest Protection.

Fuseplug auxiliary spillway

No raise 

Jet grouting at MIAD

Toe drains and full-height filters at MIAD and Dikes 4,5 and 6

Alternative 2: Fuseplug Auxiliary Spillway with Tunnel, 4-ft Dam/Embankment Raise

Fuseplug auxiliary spillway

Potential 4 ft. raise

Excavate and replace foundation at MIAD

Improved drains and filters at MIAD, Dikes 4, 5 and 6 and Left and Right Wing dams

Alternative 3: Joint Federal Project (JFP) Gated Auxiliary Spillway with Potential 3.5-ft Parapet 

Wall Raise

Gated auxiliary spillway

Potential 3.5 ft. concrete parapet wall

Jet grouting at MIAD 

Toe drains and full-height filters at MIAD, Dikes 4, 5 and 6 and Left and Right Wing dams

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Alternative 4: JFP Gated Auxiliary Spillway with 7-ft Dam/Embankment Raise

Gated auxiliary spillway

Potential 7 ft. earthen raise

Jet grouting at MIAD

Toe drains and full-height filters on all embankments

Alternative 5: No Auxiliary Spillway, 17 ft Dam/Embankment Raise

No auxiliary spillway

17 ft. earthen raise

Excavate and replace MIAD

Toe drains and full-height filters on all embankments

Features Common to All Action Alternatives

All of the action alternatives include features to increase seismic stability and improve facility 

security; they include:

Seismic improvements to main concrete dam blocks and foundation

Improve or replace existing spillway piers and gates

Security upgrades

Downstream overlay at MIAD

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PROPOSED ALTERNATIVES The Folsom DS/FDR Draft EIS/EIR evaluates 

the no action and five action alternatives. The 

action alternatives selected for evaluation 

best address the screening criteria relative to 

each Folsom Facility structure. Each action 

alternative meets the purpose and need/

project objectives and considers technical, 

institutional, and economic criteria. 
IMPACTS AND MITIGATION

Folsom Dam Safety and Flood Damage Reduction Action

Draft Environmental Impact Statement/Environmental Impact Report (Draft EIS/EIR)

B I O L O G I C A L R E S O U R C E S :

POTENTIAL IMPACTS AND MITIGATION

W A T E R Q U A L I T Y

IMPACT:

• Construction within and adjacent to reservoir

MITIGATION: Adherence to Stormwater Pollution Control Plan, 

Water Quality Sampling Plan requirements

T R A N S P O R T A T I O N

R E C R E A T I O N

IMPACT:

• Temporary loss of Folsom Point Recreation Area

• Temporary closure of walking and bike paths near 

 construction zones

MITIGATION: Timing of closure due to construction work to occur 

during non-peak recreation season, when feasible

C O N S T R U C T I O N N O I S E

IMPACT:

• Increase in ambient noise levels

• Heavy equipment operations

• Rock excavation blasting

MITIGATION: Noise production adheres to county and local ordinances; blasting to occur only during daylight hours, noise barriers 

installed where practical

V I S U A L A E S T H E T I C S

IMPACT:

• Landscape form and color changes due to excavation and storage of 

earthen materials

• A potential concrete parapet wall changing appearance of top of dams 

and dikes

MITIGATION: Revegetation of disturbed areas to minimize aesthetic 

impact

The Draft EIS/EIR analyzes local, downstream, and 

cumulative impacts of the alternatives. The features 

associated with the action alternatives in the Draft EIS/

EIR involve activities with the potential for impacts both 

at the reservoir, and within the communities around 

the reservoir. Most of the impacts from construction 

are considered short-term (beginning and ending 

with construction) and can be mitigated to “less than 

significant.” Detailed descriptions of the impacts and 

mitigation for each action alternative are described in 

the Draft EIS/EIR, but are summarized here.

IMPACT:

• Loss of Oak and Other Habitat Types

• Loss of Valley Elderberry Longhorn Beetle Habitat

MITIGATION: Adherence with USFWS Biological Opinion requirements 

and the development of a Mitigation, Monitoring, and Reporting Plan

A I R Q U A L I T Y

IMPACT:

• Fugitive dust emissions

• Diesel vehicle emissions

MITIGATION: Application of Best Available Control Technologies as 

outlined in an Air Quality Management Plan (AQMP)

IMPACT:

• Construction worker traffic

• Materials transport traffic

MITIGATION: Transportation Management Plan (TMP) to identify truck 

routes and worker shift times that avoid congestion and rush hour traffic