The Federal Energy Regulatory Commission

Safety Signage

at Hydropower Projects

October 2001

===================================================

Division of Dam Safety and Inspections

Office of Energy Projects

Federal Energy Regulatory Commission

Washington, DC 20426

DISCLAIMER

The views, analyses, and conclusions in this document are those of the individual authors 

and various staff members and do not necessarily represent the views of the Federal 

Energy Regulatory Commission or any of its members. Neither the Commission, the 

authors, or their organizations, nor any person acting on their behalf: (1) make any 
warranty, express or implied, with respect to the use of any information, apparatus, or 

product disclosed in this document; or (2) assume any liabilities with respect to the use of, 

or damages resulting from the use of, any information, apparatus, or product discussed in 

this report.

ACKNOWLEDGMENTS

Safety signage at Hydropower Projects was developed by compiling existing information on 

signage and safety issues, extracting those elements that related to hydropower projects, 

and applying the knowledge and experience of many Commission staff members and 

project owner representatives who, through their day-to-day activities, have developed 

practical expertise in this area. We gratefully acknowledge the following for their direct 

and indirect assistance in producing this document. *

Hydro Public Safety Issues Group *

Hydro Users Group Public Safety Committee

National Water Safety Congress

U. S. Army Corps of Engineers

U. S. Bureau of Reclamation

U. S. Coast Guard

National Park Service

Occupational Safety and Health Administration

Tennessee Valley Authority

Other contributors of materials and examples

In addition, our thanks to those organizations listed in the "Web Links" section. By 

accessing Safety Signage at Hydropower Projects on the hydropower page of the 

Commission's internet site (https://www.ferc.gov) users will also be able to link to many 

safety related internet resources.

*This document has been developed with the help of HPSIG and HUG. HPSIG is a group 

of FERC hydropower project owners interested in maintaining the highest level of public 

safety at their projects through, (1) promoting open communication on these issues; (2) 

facilitating technical assistance and providing expert resources; (3) reviewing public 

safety issues; and (4) participating in cooperative efforts with FERC (such as the 

development of this document). HUG is a coalition of hydropower project owners, 

operators and affiliated interests in the Midwest that emphasizes consistency in signage, 
increased knowledge and cooperation among its members. Both groups are leaders in 

safety around dams and reservoirs.

TABLE OF CONTENTS

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I. FERC'S ROLE IN PROMOTING EFFECTIVE SAFETY 

SIGNAGE 1

II. INTRODUCTION 3

III. KEY CONCEPTS IN PLANNING, DESIGN, 

CONSTRUCTION,

AND MAINTENANCE OF SAFETY SIGNS

5

A. Assessing the Need for Signage 6

B. Effective Design 8

1. Text Height and Sign Proportions 8

2. Sign Shape 12

3. Panel Planning 13

4. Typography 14

5. Color and Contrast Use 14

C. Standardized Format and Message 16

1. Language 16

2. Symbols and Pictograms 17

3. Sign Message 19

D. Sign Placement and Location 22

1. Lighting 25

2. Construction Materials 26

E. Regular Maintenance 29

IV. EXAMPLES OF POTENTIAL HAZARDs REQUIRING 

SAFETY SIGNAGE 32

A. Upstream of the Facility 33

1. Lake Levels 33

2. Recreation Sites--Boat Launches 33

3. Recreation Sites--Portages 34

4. Ice 34

5. Bridges, Cables, and Transmission Lines 35

6. Uniform State Waterway Marking System 35

B. At the Facility 36

1. Dams 36

2. Spillways 37
3. Intake Structures 37

4. Powerhouses and Ancillary Facilities 38

5. Canals 38

6. Bypassed Reaches 38

C. Downstream of the Project 40

1. Tailraces 40

2. Water Levels 40

3. Slippery Surfaces 41

D. Types of Activities, Special Events, and Temporary 

Conditions 42

V. ANNOTATED SIGN EXAMPLES 44

A. Examples of Bad Signage 46

B. Boating Safety 61

C. Dam Ahead (Danger) 75

D. General/Miscellaneous 88

E. Interpretive or Informational 114

F. Portages 120

G. Project Operations 127

H. Spillways and Intakes 149

I. Symbols 161

J. Tailraces 192

K. Water Levels 200

VI. BIBLIOGRAPHY AND WEB LINKS 218

A. Bibliography 218

B. Web Links 223

APPENDIX A Selected Chapters from USACE Sign Standards 

Manual (Reports EP 310-1-6A and EP 310-1-6B, last updated 

1995) See web link to order a copy from the USACE.

Table of Contents

Introduction (1)

Principles and Guidelines (2)

Program Plan and Documentation (3)

Design Standards (4)

Directional Signs (6)

Recreation Area Signs (7)

Recreation Symbol Signs (8)

Traffic Signs (9)

Industrial Safety Signs (11)

Regulatory Signs (12)

Interpretive Signs (13)

Appendix Table of Contents

Materials and Specifications (B)

6.2 MB

15.1 MB

24.5 MB

12.6 MB

10.2 MB

34.9 MB

53.1 MB

38.6 MB

30.8 MB

23.0 MB

18.7 MB

24.2 MB

0.6 MB

1.3 MB
Sign Maintenance Procedures (C)

Reproduction Materials(F)

0.6 MB

2.2 MB

APPENDIX B FERC Guidelines for Public Safety at 

Hydropower Projects

APPENDIX C Oregon Uniform Sign Guidelines for Recreational 

Boat Launching and Transient Tie-Up Facilities

APPENDIX D HUG Public Safety Committee Recommendations

LIST OF FIGURES

Figure 1. FHWA standard for sign font height 9

Figure 2. An example of USACE sign design 11

Figure 3. Examples of one, two, and three panel signs 13

Figure 4. Symbols of the Uniform State Waterway Marking 

System 17

LIST OF TABLES

Adaptable Safety Priority Hierarchy 4

LIST OF ACRONYMS

ADAAG American with Disabilities Act Guidelines for Buildings 

and Facilities

ANSI American National Standards Institute

ASDSO Association of State Dam Safety Officials

FERC or

Commission Federal Energy Regulatory Commission

FHWA Federal Highway Administration

GIS Geographic information systems

GPS Global positioning systems

GSA General Services Administration

HAGL Height above ground level

HDO High density overlay

HPSIG Hydro Public Safety Issues Group

HUG Hydro Users Group

ISO International Organization for Standardization

MDF Medium density fiberboard

MDO Medium density overlay

NPS National Park Service

OSHA Occupational Safety and Health Administration

PWC Personal water craft

USACE United States Army Corps of Engineers
USBR United States Bureau of Reclamation

USCG United States Coast Guard

USWMS Uniform State Waterway Marking System

I. FERC's ROLE IN PROMOTING EFFECTIVE SAFETY SIGNAGE

One of the Federal Energy Regulatory Commission's (FERC or Commission) roles is to 

provide regulatory oversight to help project owners create and maintain safe hydropower 

projects. The potential for drownings, and other accidental deaths and injuries on project lands 

and waters is of concern to the Commission and project owners. Licensees and exemptees 

identify and address public safety issues at their projects, and the Commission staff reviews 

these activities to help project owners ensure that the operation of these projects does not 

endanger the public.

Commission staff inspects approximately 2,600 hydro facilities each year. These inspectors 

are vigilant in watching for unsafe conditions during their inspections. The objective is to 

identify potential hazards and require that appropriate safety measures be in place, before 

accidents occur. This review and assessment must be conducted on a project-specific basis. As 

each project has its unique configuration of hydropower facilities, reservoir size and use, 

topography, and recreational uses and sites, the potential dangers vary widely as well. 

Accordingly, each project's plan to address these potential dangers, through the use of signs and 

other devices, is unique.

The Commission's role is not to set signage standards for uniform applicability, but rather 

to require that each project owner takes the appropriate actions, including placing the 

appropriate signage, to safeguard the public from harm at and around its hydropower project. 

To this end, FERC requires that a Public Safety Plan be developed by the owner of any project 

where public safety measures are necessary. The plan includes a list of each safety device at the 

project and a schematic drawing showing the location of each device. Such safety devices, 

include fences, signs, boat barriers, buoys, log booms, audible devices, night illuminations, and 

warning lights. The plan is kept current by the project owner and reviewed by Commission staff 

during each operation inspection for accuracy and adequacy.

This "Safety Signage at Hydropower Projects" document was developed by FERC to 

provide hydropower project owners with easy-to-access information and examples of safety 

signage suitable for use at their facilities. Although general information on safety signs is 

available, information specific to hydropower projects can be difficult to locate. Such specific 

information is often interspersed within larger, more general texts. This document presents the 

most relevant generally available information, and directs interested individuals to more 

detailed references and resources. Providing FERC licensees and exemptees with a central 

location for safety sign information is one step toward helping project owners to create the 

safest environment possible at these hydroelectric projects.

This document contains:
1 an overview of safety signage concepts and current standards 

(section III);

2 examples of possible dangers associated with hydroelectric 

projects that require signage (section IV);

3 annotated signage examples (section V);

4 a safety bibliography (section VI.A);

5 an internet resource list with links to safety web sites (section 

VI.B); and

6 supporting safety documents (appendices A through D).

II. INTRODUCTION

Recreational use of Commission-licensed hydropower facilities has increased in past 

decades and is projected to continue to increase in the future. This increase is primarily due to 

two factors: increased popularity of water-based activities and increased overall population of 

the United States. The U.S. population is projected to expand by 30 percent over the next 20 

years. In addition, recreation participation is anticipated to continue growing at high levels. In 

particular, water-based recreation has increased dramatically over recent years, and the trend is 

for continued growth. For example, the number of individuals participating in motor boating 

increased from 33.6 million to 51.4 million from 1983 to 1999, an increase of 53 percent in just 

16 years (NSRE, 2000).

The percent of the population taking part and the types of water-based recreation activities 

also have been changing. One extreme example of this is the use of personal water craft (PWC). 

The jet water propulsion technology for PWCs was originally developed in the late 1960s, but 

they have only been available commercially since the mid-1970s. PWCs and jet boats can be 

used in water not formerly accessible to conventional propeller-driven boats: river rapids, ocean 

surf, shallows, and narrow reaches of rivers and reservoirs (Cordell, 1999). According to the 

USCG, PWC numbers in the United States have increased from about 100,000 in 1987 to 

approximately 1,100,000 in 1998. Along with this increase in the number of PWCs in use, the 

number of associated accidents, injuries, and fatalities also has increased. The manner in which 

PWCs are operated differs from conventional motor boats. They tend to be operated in a more 

erratic or circular motion, as opposed to the standard linear motion of other motor boats. This 

change in activity patterns of recreational users may affect the signage that is necessary at a 

given hydropower dam and associated reservoir.

These changes in population, use, and recreation types have changed the landscape of 

safety issues that project owners face at hydropower projects. Different recreation activities 

often compete for the same space at a site (e.g., use of PWCs and use by swimmers). This 

creates direct safety risks, such as collisions, or indirect risks, such as overcrowding, which may 

encourage recreators to use other project areas that, historically, were unused. Dam owners and 

operators need to be aware of these safety risks and address associated safety concerns. 

Bresnahan et al. (1993) adapted the work of previous researchers Barnett and Brinkman to 

create a "current consensus" on how to develop a safety hierarchy to address such changing 
concerns (table 1). The "safety hierarchy" identifies priorities and options for eliminating or 

reducing risks once they have been identified.

Table 1. Adaptable Safety Priority Hierarchy (Bresnahan et al., 1993, as modified by the staff).

Priority Action Hydropower project examples

First Eliminate the 

hazard and/or 

risk

Raising high voltage electric lines to heights 

above where sailboat masts and anglers' fishing 

lines and tackle may come close enough to create 

an electric current to ground through sailboaters or 

anglers. Designing deep water intake structures 

versus surface intakes. Moving/designing beach or 

marina areas to a safe distance from the dam crest 

or intakes. Modifying ramping rates to increase 

reaction time of downstream users.

Second Apply 

safeguarding 

technology

Installing fences, gates, escape ladders, safety 

rings, boat barriers, warning sirens, strobe lights 

and other physical protective measures.

Third Use warning 

signs

Providing conspicuous signage denoting nonobvious safety hazards.

Fourth Train and 

instruct

Conduct public outreach meetings with user 

groups or other safety officials.

Fifth Prescribe 

personal 

protection

Require personal flotation devices, hard hats, 

boots or operator certifications.

Most projects have had safety design modifications put into place over the life of the 

project. Fencing, gates, and even video cameras have been incorporated to increase safety at 

hydropower projects. However, safety signage continues to be a critical part of maintaining safe 

conditions, in part because of the hidden nature of many of the potential hazards at hydropower 

projects. Signs that effectively warn, inform, and educate the public about potential safety 

hazards are an integral part of a comprehensive safety plan.
III. KEY CONCEPTS IN PLANNING, DESIGN, CONSTRUCTION, AND 

MAINTENANCE OF SAFETY SIGNS

What is a safety sign? For the purposes of this document, we include any form of signage 

that has a potential impact on public safety. These include not only the prohibitive and warning 

signs commonly recognized as having a direct safety message, but also other sign genres 

including directional signs, informational signs, interpretive signs, and those signs that 

specifically denote areas where activities are allowed. Signs with symbols or messages that 

mark swimming areas, inform the public of portage routes or even parking signs serve a public 

safety purpose in that they encourage use of safe areas over areas where there are potential risks 

or hazards. Safety signage should address not only activities or actions that are prohibited but 

should also guide and encourage viewers to make safe activity choices.

The first rule of safety signage is to identify potential safety hazards and determine the 

existence of information and regulations that govern safety. A variety of agencies and 

organizations have researched safety signs and their design and provided guidance in this area. 

National, international and regional agencies and organizations include: the Occupational 

Safety and Health Administration (OSHA), the American National Standards Institute (ANSI), 

the International Organization for Standardization (ISO), the Federal Highway Administration 

(FHWA), the General Services Administration (GSA), the United States Army Corps of 

Engineers (USACE)(see appendix A for USACE Signage Guidelines), the United States Bureau 

of Reclamation (USBR), the United States Coast Guard (USCG), the Association of State Dam 

Safety Officials (ASDSO), the Hydro Public Safety Issues Group (HPSIG), Hydro Users Group 

(HUG) and FERC (see appendix B). Many of these organizations and agencies have published 

information regarding the concepts and principles of proper safety signage and produced 

regulatory or suggested guidelines for sign planning and production. Another national source of 

sign design guidance is the Americans with Disabilities Act Guidelines for Buildings and 

Facilities (ADAAG). The complete guidelines are available on the Access Board website (see 

web links in section VI.B ). The ADAAG include specific requirements for various aspects of 

signage, and these requirements are discussed in the appropriate sections of this document 

(ADAAG, 1998).

A dam owner should know of any state or local regulations regarding safety signage or dam 

safety. It is an important part of properly assessing signage needs and possible design 

requirements. For example, in Pennsylvania, legislation is proposed that may require the 

posting of specialized signage at non-power producing dams (see web links in section VI.B ). 

Other states, such as Oregon, have published guidelines regarding safety signs at specific types 

of site. The Oregon guidelines entitled "Uniform Sign Guidelines for Recreational Boat 

Launching and Transient Tie-Up Facilities" (see appendix C) was prepared by the Oregon State 

Marine Board (OSMB) in 1997. The guidelines include specific information on capitalization, 

text size, arrows, abbreviations, sign shapes, materials and even enforcement information. All 

of this information may have an impact on how a dam owner assesses, designs, places and 

maintains signs at their project. Section VI.B of this document (Safety Signage at Hydropower 

Projects) contains web links to several of the groups and web sites mentioned above, providing 

further safety information.
While the specific approach of each agency or group to safety may vary, the basic elements 

of an effective safety signage program are the same:

• conduct a thorough needs assessment;

• develop an effective design;

• standardize format and message;

• properly place and locate signs;

• and perform regular maintenance.

All of the elements together form a complete and comprehensive safety signage plan. 

Without properly assessing the need for signs, effective signage is never developed; a poorly 

worded sign will not be effective; if poorly placed, even a well designed sign will not be 

effective; and effectiveness decreases in areas where sign maintenance is neglected. In the 

following section, we examine each of these elements, describe associated pitfalls, and identify 

the most important components of each aspect of an effective safety signage plan.

A. Assessing the Need for Signage

When developing or updating the safety signs at a project, the dam owner or operator must 

inventory the potentially hazardous areas at the project and identify the users affected by 

dangerous areas. Because each hydropower project has site-specific characteristics that may 

pose unique hazards to the public, each project owner must examine all of the areas affected by 

the dam. In many cases, however, the issues at a number of different facilities are similar 

enough that some uniformity among projects is possible.

Each hydropower project has some features in common with others, but also many projectspecific features that may require specialized signage not available in an "off the shelf" format. 

A comprehensive site review should be conducted if a current safety plan is not available. The 

USACE Sign Standards Manual Volumes I and II (last updated in 1995) provide detailed 

guidance on how to conduct a thorough sign inventory (publications EP 310-1-6A and EP 310-

1-6B are available at no cost). Contact the USACE via its web site (see web links in section 

VI.B ) to request these documents.

Include the following steps when assessing signage needs:

• document existing signs, including construction materials, text, placement, condition, 

and projected replacement times;

• review local, state, and federal signage regulations, as well as any signs specifically 

required by license articles;
• assess any recreational/project changes that may require new signs such as creation of a 

new access area, increased PWC traffic, use of fishing tubes or other new technology, 

operational changes, or trail construction;

• review any recent accidents or safety issues at the project or nearby facilities to identify 

possible problem areas;

• examine any public safety concerns received in the form of phone calls, letters, or email; 

and

• identify any planned project changes or events that may require permanent or temporary 

signage (e.g., fishing tournaments, canoe portage construction, and sale or subdivision 

of project lands or lands adjacent to project lands that would increase reservoir use).

The review also should identify any new signage needs, modifications, replacements, and 

removals. For example, the change from a peaking mode to run-of- river operation may 

necessitate a change in signage and, in some cases, sign removal.

A note about technology: Technological advances in the past several years have made digital 

cameras and electronic documentation of signage much more affordable for even small dam 

owners. Electronic record keeping of both text and graphics, including site maps and photos, is 

highly recommended. Reordering signs, copying examples of other signs in use, and analyzing 

standards all may be completed much more easily using electronic methods. Computer 

applications using three-dimensional modeling and global positioning/ global information 

systems (GPS/GIS) technologies can be used to identify exact sign positions, schedule 

maintenance, and help determine the site of future signs.

Key Concepts

• Typical safety signage may not address site-specific safety issues.

• Identify any federal, state, and local regulations that may apply.

• Reviews should include existing signage, project history, public concerns and public 

safety hazards.

• Review any project changes for impacts on signage needs.

B. Effective Design
A number of factors influence a sign's effectiveness. The text height, sign size, typography 

(font style), color, symbols used, shape, phrasing, and the message conveyed all have an impact 

on how a sign will be perceived. Generally, signs should be designed for the first time viewer 

assuming no prior knowledge. An OSHA report "Hazard Communication: A Review of the 

Science Underpinning the Art of Communication for Health and Safety" (OSHA, 1997) 

reviewed studies conducted to determine factors affecting labels and signage. This report, while 

primarily about product labeling, provides summary information on general safety signage 

design concepts. A web link to this report is contained in section VI.B of this document.

1. Text Height and Sign Proportions

Text height is generally a function of two factors: the intended viewer's distance from the 

sign and the priority of that line of text within the total sign legend. All the text on a sign 

(known as the legend) should be sized based on the distance from which it is to be viewed, the 

speed of the viewer, and the manner of movement (e.g., foot, car, or boat). (1) In compliance 

with FHWA standards, letter height is calculated for people with at least 20/40 vision. Figure 1 

illustrates the calculated letter height for signs and their intended application. The USACE 

defines the calculated text height as "A," where "A" is the height of the first capital letter in the 

main body or "Bond Copy" of the sign legend.

1. Text height guidelines vary slightly. See FERC, 1992; USBR, 2000, USACE, 1995, and 

FHWA, 2000, for suggested letter heights. Individual site characteristics vary, and individuals 

should use available information to determine the standard that is most appropriate for their 

situation.
For distances greater than 1,512 feet, the first capital letter height of a sign legend (A) is 

calculated by dividing the viewing distance by 28 and rounding up to the nearest inch.

Figure 1. FHWA standard for sign font height (Source: USACE, 1995, as modified by the 

staff)

"A" is used as the base measurement for proportioning other text, borders, and spacing on 

the sign panel. For example, the headline (top line or highest priority phrase such as "Danger") 

size is 1.5A or 1.5 times the height of the first capital letter in the main body of the sign. Use of 

a ratio or proportioning method such as this allows the designer to determine the way a sign 

will ultimately be perceived. Text height, spacing between lines, the distance to the sign edge, 

arrow or symbol sizes, and logos or graphics can all be properly scaled using a method similar 

to this one. Proportioning is an important part of creating effective, readable signs.
Figure 2 shows the relative ratio of the font height, line spacing, and borders for a USACE 

site sign. The distance "X" is equal to the length of the longest legend line plus 1.5A. Also 

included are the measurements for the sign size, posts, and mounting height in Height Above 

Ground Level (HAGL). Mounting method, height, and sign size vary with text height. The 

USACE sign proportion regulations are designed to increase the readability, clarity, and 

effectiveness of the signage for the viewer. The border provides a visual separation between the 

text on the sign and the environment, while line spacing groups associated text together 

allowing the reader to visually prioritize the information being given. In relation to sign size, 

the HUG Public Safety Committee recommends a minimum size of 2 feet by 2 feet for "Dam" 

and "Thin Ice" warning signs, as well as for "Take Out" and "Canoe Portage" signs. They also 

recommend a minimum of 4 feet by 4 feet for other message and warning signage. Appendix D 

contains a copy of HUG recommendations for font size, coloration, sign lighting, sirens, 

strobes, and other safety issues.

Font proportions also are important to capture the viewer's attention, give prioritized 

information, and set up a hierarchy of concepts. In its 1997 report on product labeling, OSHA 

reports that a 2 point increase in font size from 10 to 12 point text (a 20 percent increase) 

between the bond copy and the headline drew the viewer's attention to the heading and 

increased the labeling effectiveness. Although this differs from the USACE proportion of 150 

percent of bond copy height, the concept of differing font height for emphasis is well accepted. 

A combination of suitable text height and properly proportioned sign components ensures that 

signs are readable and effective.

Figure 2. An example of USACE sign design with text heights given in A (the height 

of the first capital letter in the copy body of the legend text) (Source: USACE, 1995, as 

modified by the staff)

The ADAAG require that letters and numbers on signs shall have a width-to-height ratio 

between 3:5 and 1:1 and a stroke-width-to-height ratio between 1:5 and 1:10 (Section 4.30.2). 

Further, characters and numbers on signs shall be sized according to the viewing distance from 

which they are read. The minimum ADAAG height is measured using an uppercase X. Lower 

case characters are permitted. The absolute minimum height for characters is 3 inches (Section 

4.30.3). For mounting location and height, other ADAAG requirements may apply.

Key Concepts

• Design sign and text size for viewing at appropriate distances.

• Account for mode of viewing (foot or vehicle) during design.

• Determine a standard minimum size for any signage.

• Proper proportioning of text and borders increases effectiveness.

• Increased headline font size compared to bond copy prioritizes message.

2. Sign Shape

FHWA has developed shape-based traffic signage in use across the United States: octagons 

for stop, inverted triangles for yield, diamonds for warning, and rectangles for information. 

Warning signs and labels are often rectangular in shape but include symbols within the sign that 

reflect the standard safety shapes to gain prompt user attention. ANSI Z535.3 (1991) standards 

state that the perimeter of the label panels may take on the surrounding shape of safety symbols, 

although justifications for this allowance are not specified. Safety shapes recommended by 

ANSI Z535.3 (1991) and ISO 9186, along with their associated meanings are as follows:

• Equilateral triangle resting on base: Warning and hazard alerting;

• Circle: Mandatory action;
• Circle with 45 degree slash from upper left to bottom right: Prohibited action; and

• Square or oblong as necessary to accommodate text: information.

The HUG Public Safety Committee recommendations advise that warning signs used for 

"Dam" and "Thin Ice" be diamond shaped, and that informational signs should be square. They 

also recommend using a 2- or 4-inch minimum width border of international orange (similar to 

the Uniform State Waterway Marking System [USWMS] [see section III.C.2]).

Key Concepts

• Use pre-existing sign shape standards to increase viewer recognition.

• A shape standard is effective when printed on a sign of a differing shape (e.g., a 

prohibition circle on a square sign).
3. Panel Planning

There are three 

common panel types used 

for safety signage 

applications: one, two, 

and three panel signs 

(figure 3). A one panel 

sign can have a signal 

word, a message, or a

symbol/picture. A two 

panel sign has 

combinations of signal 

word, message, and 

symbol/picture. A three 

panel sign uses all three 

combinations. It is 

important to prioritize any 

signal words (trigger 

words) so that they are 

larger than other message 

text and located at the top 

of the sign (ISO 

Recommendation No. 

3864, Safety Colors and 

Safety Signs contains 

more information on 

panels and is available for 

purchase from the ISO; 

see web link in section 

VI.B)

Figure 3. Examples of one, two, and three panel signs 

(Source: Bresnahan et al., 1993, as modified by the staff).
4. Typography

Typography describes 

the arrangement style or 

general appearance of 

printed text. Agencies 

have differing 

recommendations on the 

choice of letter style and 

capitalization. For 

example, USACE 

standards require that all 

sign legends be in 

Helvetica type face. They 

also recommend that only 

the initial letters of any 

text be capitalized; they 

cite evidence of increased 

comprehension and 

"glance" legibility when 

only the first letter is 

capitalized compared to 

the entire legend. 

Common ANSI 

standardized warning 

signs have all capitals 

used for the headline text. 

All capitals in the 

headline may increase 

hazard recognition in 

viewers. Conversely, use 

of italic, script, or other 

more stylized fonts is 

discouraged because they 

increase comprehension 

time and decrease 

readability. Although the 

USACE requirements 

stipulate a flush left text 

alignment, centering of 

sign legends is also a 

common practice. Full 

justification of text across 

the sign should be 

avoided because it 

decreases legibility.
Key Concepts

• Choose a more simple font for increased comprehension speed.

• Consider the effect of capitalization on comprehension and glance readability.

• Do not full justify sign text.

5. Color and Contrast 

Use

Color and contrast are 

important factors in 

designing appropriate 

signage. The contrast 

between the text and the 

background is important in 

determining the legibility 

of a sign. Often signs 

consist of dark lettering on 

light backgrounds or vice 

versa. Viewers discern 

varying levels of perceived 

hazard associated with 

different colors. Red has 

the highest level of 

perceived hazard, followed 

by orange, yellow, blue, 

green, and white (OSHA, 

1997). Color can make a 

difference in perceived 

hazard even when the other 

aspects of the sign remain 

the same. One study 

showed that signal words 

such as "Deadly" connoted 

less hazard when printed in 

green than when printed in 

red. Another study, 

conducted by Dunlap, 

Granda, and Kustas in 

1986 tested several 

different language groups 

including English, German, 

Scandinavian, and Spanish 
for the effect of colors on 

hazard perception. The 

results showed that the 

perceived hazard hierarchy 

was the same across 

language groups. This is 

particularly important for 

signs in areas where 

English is not the viewer's 

first language. 

Standardized headlines 

using combinations of 

colors such as a black outer 

border, red inner area, and 

white text are common in 

many types of signs are 

more effective in 

conveying the existence of 

a hazard than other 

color/contrast 

combinations (OSHA, 

1997).

Background color and reflectivity also can affect safety signs. Low light conditions at 

night, dusk, dawn, or during inclement weather may reduce visibility and make existing signs 

ineffective. Use of a light or reflective background material can increase visibility. At sites 

where night-time activities are common, licensees or exemptees should conduct night trials to 

assess sign effectiveness. See section III.E for a discussion of maintenance of reflectivity of 

signs.

FHWA has developed color codes establishing general meanings for eight colors that are 

used to convey traffic control information. The meanings that are associated with these colors 

by the general public make them appropriate for use at hydropower projects. The following 

general meanings can be used when designing signage:

Yellow General warning

Red Stop or prohibition

Blue Road user services guidance, tourist information, and 

civil defense route

Green Indicated movements permitted, direction guidance

Brown Recreational and cultural interest guidance

Orange Temporary traffic control

Black Regulation

White Regulation
The USWMS provides specific colors to be used on the buoys associated with it. These 

colors have recently changed and are being merged with the United States Aids to Navigation. 

The system uses red, green, and white colors to mark safe channels for travel. (For full details 

on the USWMS [see section III.C.2]; see section VI.B for web site.) The ADAAG also provide 

guidance for finish and contrast on signs: "The characters and background of signs shall be in 

eggshell, matte, or other non-glare finish. Characters and symbols shall contrast with their 

background, either light characters on a dark background or dark characters on a light 

background."

Key Concepts

• Colors connote varying levels of hazard.

• The four colors most effective in communicating perceived hazard are red, orange, 

yellow, and blue in descending order.

• A black-red-white headline design with capitalized trigger word increases effectiveness.

• Pre-existing color standards for safety signs have preconditioned public response to 

specific colors.

C. Standardized Format and Message

1. Language

A significant percentage of U.S. residents do not use English as their primary language, 

which may present a problem for safety officers trying to design effective signage. Initially, 

assess the surrounding community and visitors to find out what primary languages are used and 

determine the need for specialized signage. If there is a need, two common methods of reaching 

non-English speaking groups are the use of symbols or pictograms and the use of signs with 

text translated into other languages.

If the message is easy to convey using symbols (e.g., No Swimming or No Boats), then it 

may be adequate to include symbols on the posted signs. This method has been shown to 

increase effectiveness in all viewer groups of any language if the symbol meaning is clear. 

Examples of standard pictograms can be found in the USACE Sign Standards Manual 

(reproduced in part in appendix A of this report and in section V.I illustrating common USACE 

symbols); these are primarily based on the National Park Service (NPS) symbol system. Other 

sources include the ANSI sign standards and FHWA. Symbols can increase the effectiveness of 

signs by adding recognition value, clearly defining restricted activities, and increasing retention 

time.

Areas with higher concentrations of non-English speakers or requiring depiction of more 

difficult concepts such as No Trespassing and Fast Rising Water may require additional signs 
posted in a second language. Dam owners also may create specialized graphics designed and 

tested through the ANSI Z535 series of signage protocols. Whenever a translated sign is used, 

an identical sign in English should be placed beside it. The viewer can directly compare the two 

signs and may recognize the same warning and symbol if only the English version is posted in 

other areas. Note that any signs printed in non-English languages should be checked by a 

person fluent in that language to ensure accurate translation.

Key Concepts

• Assess the primary language of the audience and monitor over time.

• Symbols and bilingual signage increase viewer comprehension.

• Standardized symbols are better recognized by the public than unique graphics.

• Non-English signs should always be paired with English signs.

2. Symbols and 

Pictograms

As 

mentioned 

previously, 

adding symbols 

and pictograms 

can make any 

sign more 

effective. They 

may be used to 

easily display 

activities allowed 

or prohibited at a 

site. Appendix 

A and section 

V contain 

examples of 

pictograms used 

by the USACE 

for recreation 

signage. For 

prohibition 

notices, ANSI 

recommends 

placing a red 

circle with a 
slash through it 

over the activity 

symbol. For 

pictograms, the 

ADAAG provide 

"Raised and 

Brailled 

Characters and 

Pictorial Symbol 

Signs 

(Pictograms)." 

Although, in 

general, braille is 

not required for 

safety signs, it 

should be 

considered on a 

case-by-case 

basis. The 

ADAAG state, 

"Pictograms shall 

be accompanied 

by the equivalent 

verbal 

description 

placed directly 

below the 

pictogram. The 

border dimension 

of the pictogram 

shall be 6 inches 

minimum in 

height." Another 

standard for 

safety symbols is 

the United States 

Coast Guard 

(USCG) 

USWMS.
Figure 4. Symbols of the Uniform State Waterway Marking System 

(Source, USCG web 

page http://www.uscg.mil/d11/oan/paton/state_buoys.htm accessed March 

9, 2001).

For full details on the USWMS see web links in section VI.B. It 

uses standardized symbols and colors to guide boat user actions 

(figure 4). These symbols were developed in 1966 to provide an 

easily understood system for operators of small boats. They are the 

accepted standard for lake and inland waters not shown on nautical 

charts. The USWMS is currently being revised. It is being merged 

with the United States Aid to Navigation System. The phase-in 

period is linked to the buoy''s lifecycle to avoid unnecessary 

replacement cost to the agencies responsible and should be complete 

by the year 2003 (see web links in section VI.B ). The USBR (1992a) 

interim working guideline "Public Safety Around Dams and 

Reservoirs," stipulates that, where possible, buoy markers should 

include text identifying specific hazards such as dams, intakes, or 

spillways in addition to any warning symbols.

Project-specific graphics or symbols should be used with care, planning, and testing. Use of 

standardized symbols or a professionally designed graphic is encouraged over "home made" 

versions of typical pictograms. A good example of a commonly used specialized graphic is the 

Minnesota Department of Natural Resources "Drowning Machine" sign which is used across 

the state. Similar signs are used in Wisconsin. This sign is included in section V.C. Symbols 

may be used without accompanying text, but with reduced effectiveness. Also, in some cases, 

such as in Oregon, sign text is required to be able to impose fines or other legal action on 

violators (see appendix C). Dam owners should check with local and state law enforcement 

officials or legal counsel to identify applicable laws. In addition, the dam owner should consult 

with local officials to gain concurrence that they would enforce a posted regulation or 

prohibition.

Key Concepts

• Symbols and pictograms increase comprehension and effectiveness of signs.

• A combination of symbols and text is more effective than a symbol alone.

• The use of standardized USWMS marking symbols can increase sign recognition in 

boaters.
• The USBR public safety guidelines support the use of text in combination with 

USWMS symbols.

• Non-standard symbols may be less effective in clearly identifying hazards or 

prohibitions unless properly designed and tested.

• Use of symbols without text may limit enforceability of prohibitions.

3. Sign Message

After enough information has been gathered, and decisions on basic sign characteristics 

have been made, finalize the legend text. Finalization should begin only after the dam owner 

has:

• sought out and collected safety information and guidance materials;

• searched records of past safety concerns at their projects (and other projects in the area);

• documented the placement and condition of the existing signage and assessed the need 

for new or modified signage;

• determined the viewing distance and computed the correct font and sign size;

• decided on the most effective shape of each sign;

• chosen a standard font and capitalization protocol;

• reviewed color schemes and reflectivity for effective day-time and night-time warnings;

• concluded which languages are required for each sign; and

• adopted a symbol system for land- and water-based signage.

Following these steps will enable the dam owner to set up safety signage guidelines which 

may then be applied to new and replacement signs in the future.
One of the challenges of designing effective signage messages is developing signs that will 

be understood by a wide range of audiences. The following needs should be factored into the 

design of the message. Do the signs:

• grab the attention of the viewer?

• clearly convey nature of and the magnitude or level of risk using signal words?

• promote visitor recognition?

• give adequate time for the proper response?

• account for the education level of the viewer?

• prioritize risks from highest to lowest?

• communicate consistently?

Getting the viewer's attention can be achieved with differing font sizes, color patterns, 

wording positions, and by using capital letters as discussed in the previous section. However, 

the words in the sign legend are a critical part of effective sign design.

Trigger or signal words are often used in the headline of a sign to grab the viewer's 

attention and immediately convey a specific level of risk or hazard. OSHA's standards clearly 

define signal words. For example, "Danger," "Warning," "Caution," and "Notice" have specific 

meanings and should only be used in appropriate situations:

Danger--an imminently hazardous situation which, if not avoided, will result in death or serious 

injury. This signal word is only used for the most extreme situations.

Warning--A potentially dangerous situation which, if not avoided, could result in death or 

injury.

Caution--A potentially dangerous situation which, if not avoided, may result in minor or 

moderate injury. It also may be used to alert against unsafe practices.

Notice--General informational text
The broad use of signal 

words for safety warnings and 

labels has increased viewer 

recognition and perceived 

hazard of products and sites 

where the markings are used. 

They are also easily understood 

by all education levels and 

have high "glance" legibility. 

USBR Public Safety guidelines 

(1992) state that a sign should 

ideally "warn of the hazard 

with the intensity 

commensurate with the 

outcome...explain how to avoid 

injury... and explain the 

consequences of failing to 

conform or obey the 

admonition." Generally, if the 

hazards are known and 

recognized by viewers, then 

the signs may not need to 

include consequences. If 

multiple warnings or 

prohibitions are used on a 

single sign, prioritize them so 

that the most important 

information is on top. 

Remember to use only critical 

text, discarding any technical 

or unnecessary information in 

favor of a succinct message. 

When possible, clearly identify 

the hazard on signs. This 

educates the public and may 

result in more voluntary 

compliance than a simplystated directive.

Keeping signage consistent increases recognition and decreases the time the viewer needs 

to comprehend the message. The same warning legend, size, and format should be used for each 

occurrence of a particular potential hazard project-wide. Dam owners also may increase 

recognition, compliance, and safety by designing project signage that is consistent with preexisting sign standards.Interpretive signage offers a unique opportunity to communicate 

specific messages to visitors that may be appropriate at hydropower projects. Development of 

interpretive signage is a complex process beyond the scope of this report, but it is worth 
mentioning as a valuable option for owners and operators. Interpretive messages often are used 

to change behavior, educate, or evoke an emotion in the viewer. These signs support 

management objectives, tell a story, and reveal meanings of and relationships among built, 

manipulated, natural, cultural, and other natural resource features (USBR, 2000). Interpretation 

of a phenomenon that exists may offer an opportunity to educate the visitor as to the potential 

hazards associated with or in the vicinity of the object of interest.

Key Concepts

Gather knowledge base, assess existing conditions, and decide on basic sign characteristics 

for the complete safety signage program before designing specific signs.

• Use signal words appropriate to the level of risk.

• If appropriate, identify the hazard.

• Emphasize succinct legends, avoiding technical terms or jargon.

• Consider viewing time, education, and risk prioritization when choosing and arranging 

legend text.

• Keep sign design, and hazard-specific text, consistent for the entire project and, if 

possible, with pre-existing sign standards.

D. Sign Placement and Location

Safety signs should be placed based on the location of the potential hazard and the 

minimum distance required to avoid the hazard. Signs should attract the eye of the intended 

viewer. It is important to locate signs so that persons entering an area from any direction can 

see one or more of the signs. The location of the signs should be determined using sight lines 

for the location from which the individual is most likely to be viewing the sign. In some cases, a 

floating sign or buoy may be most appropriate. The USBR Public Safety Guidelines (1992) 

state that:

Posting signs should be consistent from point to point. Where the hazard is present over a 

large area such as a waterfront, large spillway, or conveyance structure, signs should be 

installed along the full length of the hazard. If a number of signs are installed at a set spacing, 

an illusion of safety may exist where a sign is omitted. Under these circumstances one could 

reasonably conclude that the prohibited activities are not only permitted, but are safe.

The height of a sign should be such that the intended audience can read it. The USACE 

recommends mounting at eye level: 5 to 6 feet standing; 4 to 6 feet driving a car, and higher for 

trucks and recreational vehicles. Other potential audiences that should be considered are 

snowmobilers and horse back riders. Mounting height is measured from the viewer's ground 

level up to the bottom edge of the sign panel. Post lengths should be adjusted for grade changes 

off trails and roads. Changing reservoir levels also may affect proper attachment height and 

method. The USACE also recommends that signs mounted next to roadways are a minimum of 
6 feet from the edge of the shoulder and, if there is no shoulder, 12 feet from the edge of the 

traveled way. Where this is not possible, the posts should be made of a breakaway design. 

Ultimately the most effective viewing height may change. Reservoirs that have large water 

level fluctuations should have signage placed to be best viewed at full pond or at the level when 

most people are recreating. Spillway warning signs should be placed far enough upstream of the 

dam so that swimmers and boaters will be able to move against the current to shore without 

being swept over the spillway. These distances should be assessed under high flow conditions 

when the currents are strongest.

Ideally boat barriers should be installed at an angle to the current so that a swimmer holding 

on to the cable will be pushed toward the shore. Tailrace barriers should be placed far enough 

downstream so that common watercraft cannot approach too closely and be swamped when the 

project begins operation. This is particularly true in areas where fishing tubes are popular.

Safety signs commonly are located at public access points. Placement next to informational 

or interpretive displays, restrooms, garbage cans, fish cleaning stations, and boat ramps 

increases sign exposure. Repeated exposure to the same warning may increase effectiveness if it 

is not overdone. Dual exposure methods, such as placing dam warning signs at boat ramps and 

then again on buoys or boat barriers, increase the viewer's exposure and compliance rate. 

However, overexposure with redundant signs in the same viewing area or overstating the level 

of risk of an activity may desensitize viewers and reduce compliance. Occasionally, moving 

signs to different locations, or changing the sign in some noticeable way, may keep frequent 

users from passing a sign that becomes "part of the landscape" after repeated viewing.

The use of buoys, boat barriers, fences, and other barrier devices can be an important 

reinforcement for signage. These types of deterrents make it more difficult for visitors to 

accidentally put themselves into a potentially hazardous situation. Although a full discussion of 

these barriers is beyond the scope of this document, project owners and operators should be 

aware of their advantages and consider them on a case-by-case basis.

Some other things to consider in determining proper sign placement are sun and glare, 

shadows, orientation, and visitor safety. As a general rule, place signs on the right hand side of 

the roadway, as close to the standard location as possible. The following guidelines are excerpts 

from USBR (2000); please see the original document for full guidelines. In some cases, the 

guidelines presented offer additional information or alternatives to USACE guidelines. Where 

guidelines differ, site-specific assessments should determine the requirements that most 

effectively meet the demands of the site.

(1) Signs should be placed where they provide adequate time for viewer response, considering 

things such as approach speed, road conditions, etc.

(2) Select locations that minimize viewing obstructions. Some common placement locations to 

be avoided, if possible, include:
(a)Dips in the roadway or trail.

(b) Just beyond the crest of a hill.

(c)Where the sign may interfere with the normal operation of the facility.

(d) Too close to trees or foliage that could cover the face of the sign.

(3) Place the sign within the viewer's "cone of vision."

(4) Guidelines for installation of Warning, Regulatory, and Guide signs on roads are as follows:

(a)Height - The bottom of the sign should be a minimum of 3 feet above the level of the 

roadway on roads posted for speeds of 30 mph and over. For roads posted for speeds less than 

30 mph, the bottom of the sign should be set a minimum of 30 inches above the ground where 

the sign is being placed.

(b) Lateral Clearance - The distance from the edge of the roadway to the inner edge of sign can 

range from 6 to 12 feet. The normal minimum is 6 feet. In cases where the roadside topography 

precludes the 6-foot minimum, the inner edge of the sign shall be no closer than 2 feet from the 

edge of the road with no shoulder and no closer than 2 feet from the outer shoulder

(c) Canting - Normally, signs should be mounted approximately 93 degrees to the direction of, 

and facing, those that they are intended to serve. This canting aids in the reduction of mirror 

reflectivity. Sign faces are normally vertical; but on up and down grades, it may be desirable to 

tilt the sign from vertical to improve readability.

(5) Sign coordinators and road engineers should be aware of "sign clutter," a situation in which 

new and different signs are added to a location over time, and the overall effect is to force the 

viewer to wade through a mass of uncoordinated information to obtain the information he or 

she needs. "Sign clutter" situations should be reevaluated to combine, redesign, and eliminate 

signs to reduce clutter.

Regardless of a sign's location, it should stand out from its surroundings. Signs that blend in 

with their surroundings are less likely to be noticed and consequently less likely to be complied 

with. Section V of this document contains examples of proper and improper signage placement, 

design, and upkeep.

Key Concepts

• Place signs at the location of the potential hazard and visible from far enough away to 

allow the viewer to respond to the warning.

• Post at a height that is appropriate for viewer.
• Place boat barriers far enough upstream or downstream to ensure swimmer and boat 

safety.

• Double exposure increases effectiveness, but too much signage desensitizes the visitor 

and may reduce compliance.

• Signs should stand out from their background.

1. Lighting

Lights may be used to illuminate signs, the dam itself, and potentially hazardous areas. 

Lighting signs should be considered at dams, tailrace areas, switchyards, and even boat barriers 

for night visibility, particularly if boating at night is a regular activity. Specially designed signs, 

including lighting, often may be necessary so that safety devices are effective under adverse 

weather conditions. Lighting also may reduce vandalism. A regular lighting inspection program 

should ensure that lights are functional.

Key Concepts

• Assess night use and lighting needs.

• Maintain system regularly.

2. Construction Materials

The materials used to construct a sign have an impact on durability and, as the sign ages, 

legibility. The location of a sign determines the type of material used in its construction, and the 

cost of the sign should be weighed against the durability. The more durable the sign, the less it 

will be susceptible to vandalism and damage. Some possible sign materials include: plastic, 

wood, high density overlay plywood, fiberglass, and sheet metal (aluminum or steel). Use of 

paper, cardboard, or laminated paper should be limited to temporary signs or when a 

replacement has been ordered. Particle board also should not be used for permanent signs. 

Temporary signs should be removed immediately after more permanent signs are in place. The 

USACE Sign Standards Manual provides detailed guidance on the construction and mounting 

of signs, including suggested materials, thickness, attachment hardware, finishes, and 

reflectivity (see appendix A).

The following list of commonly used materials is taken from USBR (2000) (note that the 

listing of specific brands of materials is not an endorsement of the product):

1. High Density Overlay (HDO) Plywood - Marine quality, 3/4-inch plywood with one side 

covered with a high density, slick material (the overlay), to which adhesives cling quite 

strongly. Commonly used as a substrate for pressed-on materials such as reflective vinyl. This 

substrate should be used extensively for larger signs. It weathers well.

2. Medium Density Overlay (MDO) Plywood - Marine quality, 3/4-inch plywood with one side 

covered with a smooth but more porous overlay than HDO. This takes paint much better than 
HDO because the porosity of the overlay allows the paint to bond with the substrate better.

3. Medium Density Fiberboard (MDF) - A pressed-particle board product that takes paint (silk 

screening) very well and weathers well.

4. Plastics that may be used include:

Acrylic, which is a hard, rigid material that withstands abrasion well but breaks easily. It is 

often used as a clear protective covering over another sign.

Polycarbonite is similar to the acrylic panel but is softer, with a greater flex. Its softness makes 

it more likely to be marred by dust and blowing sand

Polyethylene and polypropylene are fairly common materials that are suitable for most routine 

sign applications. They are soft materials that have sufficient rigidity to stand up as small signs, 

but not so rigid that they are easily broken. They come in basic colors, and they take paint (silk 

screening) well. Generally, they weather well; however, their softness makes them easy prey to 

vandals wielding sharp or pointed instruments. Initial and replacement costs are low.

5. Carsonite© - Carsonite is a patented material that combines fiberglass and epoxy resins to 

make a strong but flexible substrate. Used most often in a thin, vertical format, it is also used 

for small routine signs. Its hard, impervious surface is best used as a substrate for decals, 

although silk screening is possible. It is very resistant to impact and weather. Initial and 

replacement costs are low.

6. Aluminum - A long used, common substrate for routine, smaller signs. Message usually silk 

screened onto substrate. Easily and significantly damaged by bullets and other forms of 

vandalism. It has good weather resistance. Medium initial and replacement costs.

7. Tyvek - A fibrous, paper-like material that has good short-term resistance to inclement 

weather and animal damage. Very flexible and light. Easily stapled to wood.

8. Cardboard - A paper product that degrades quickly in inclement weather. Takes paint (silk 

screening) well, depending on the slickness of the surface. Easily nailed or stapled. Used 

primarily for seasonal posters.

9. Porcelain enamel on steel - This material is highly resistant to scratches, impacts, and 

weathering. Most often used on interpretive signs, it offers a very appealing appearance, but at a 

high initial and replacement cost. It lends itself well to the use of graphics. While expensive, it 

has a lifetime of 20 years or more.

10. Fiberglass embedment - In this process, a paper image is embedded in a fiberglass/epoxy 

resin panel. Preparation of the first image is initially a high cost. Second, third, and subsequent 

copies can be quickly and cheaply made at the time of the original and set aside for later 

embedment at a relatively low cost to replace a damaged or stolen original. The fiberglass 

resists scratching, impact, and weathering very well.
11. Metal - Engraved or acid etched metals, aluminum, and stainless steel are often used for 

signs. Such signs have a long service life, are generally good or very good in their resistance to 

scratching or impact. Initial cost is generally medium to high, as is the replacement cos

12. Redwood - Routed redwood signs have been a federal land managing agency standard for a 

long time. These types of signs are expensive because of the high material and fabrication costs.

13. High Density Foam Boards - Three-dimensional signs made by cutting a matt and 

sandblasting to the desired depth. Sand blasting and matts may also be used to make threedimensional wood signs from 2-inch thick material.

The method of mounting the sign should be adequate to withstand any elements that the 

sign will be subjected to, including possible inundation from flood conditions. The USACE 

Guidelines contain recommendations for post size and footing depth based on frost depth,

number of posts, sign size, and panel height (USACE, 1995). USBR (2000) suggests mounting 

signs on suspended cables if a sign cannot be placed appropriately to avoid debris or heavy 

flows. Cables however may pose a risk to anglers or sailboats, so consider site-specific 

recreation use before installing a cable suspension system.

Key Concepts

• Use materials of suitable durability for site-specific conditions.

• Replace temporary signs with permanent ones as soon as possible.

• Assess possible recreation impacts before installing a cable system.

E. Regular Maintenance

Public safety reviews should be conducted frequently, and protocols should be put in place 

to gather and assess public comments and reports from personnel about maintenance needs. 

Sign maintenance is one of the most problematic areas of a safety signage program. Inadequate 

maintenance may reduce compliance with prohibition signage, inaccurately or ineffectively 

warn of potential hazards, and indicate limited enforcement. A well maintained system is safer, 

and it demonstrates to visitors that the dam owners are safety- and community-minded.

Vandalism is perhaps the most common reason for required sign maintenance. A program 

of increased site visitation; requests to police to include public sites on patrols; effective 

lighting; and, in severe cases, remote monitoring may all curb vandalism. Signs in vandalismprone areas should be made of durable materials to make vandalism difficult and repairs easy. 

In combination with the above measures, signs that are vandalized should be replaced or 

repaired as quickly as possible. Enforcement action may be critical to stopping vandalism, 

particularly when the community knows of direct enforcement measures such as arrest and 

fines. Additionally, allowing increased access to popular areas that do not contain potential 
hazards may help decrease vandalism directed at gaining entrance to specific reservoir/river 

sites.

Standard maintenance plans should have contingencies for repairing physical damage from 

vehicles, replacing missing letters, applying protection from weather damage, preventing 

overgrowth by foliage, decreasing redundancy between signs, and removing mold and mildew. 

The USBR (2000) sign guidelines offer suggestions for developing a maintenance schedule, as 

does the USACE Sign Manual (USACE, 1995). The schedule should address, but not be limited 

to, the following points: damage, visibility, legibility and appearance, maintenance objective, 

condition survey, and maintenance performance. In addition, the guidelines suggest repair 

techniques for a variety of sign types and damage. Fading also is a problem with many signs 

(e.g., red pigments tend to fade more quickly than others). Using brass or stainless steel 

attachments may reduce rust staining as can placement of signs above possible high water 

marks, as long as it would not remove the sign from the intended viewer's cone of vision. 

Pruning trees and bushes and mowing grass from around signs should take place on a regular 

basis.

In addition, if possible, when standardizing signage, use one of two methods: (1) replace all 

the signs at a particular access area or site, or (2) replace all of one type of sign project-wide 

(e.g., "No Trespassing" signs). This will increase viewer recognition of safety signs and 

minimize the variation in signage at the project.

Certain signs are designed specifically so as to be seen at night. The reflectivity of these 

signs should be tested periodically. To test visibility, create a small panel (about 8 inches by 10 

inches) using sheeting which has an acceptable level of reflectivity. At night tape the test panel 

to the face of the sign. Step back about 30 feet, hold a flashlight about 2 inches from your face 

and shine it at the sign (USBR, 2000).

1. If the inspection panel is brighter than the sign, replace the sign within the year.

2. If the sign is brighter than the inspection panel, the sign still has several years of life 

remaining.

3. If the sign and the panel have equal brightness, the sign has 1 to 2 years of useful life 

remaining.

Key Concepts

• Conduct frequent inspections to ensure that signs are maintained and repaired as needed.

• Take precautions to help reduce vandalism to signs.

• Repair or replace damaged signs quickly.

• Check the reflectivity of signs that are meant to be seen at night.
• Set up reporting protocols for employees or visitors to report signs in need of repair.
IV. EXAMPLES OF POTENTIAL HAZARDS

REQUIRING SAFETY SIGNAGE

A site or condition represents a significant public safety hazard if there is reasonable potential 

for a visitor to suffer injury or death because of an inherent condition at that site. The potential 

for injury or death is related to the nature of a hazard as well as the frequency and type of 

visitors to a site. For example, an area that has a relatively benign hazard that is subject to 

frequent visitor usage may be considered a large or significant public safety hazard because of 

the greater possibility of an injury occurring at the site. A high hazard condition, even with low 

visitor usage, should be considered a significant public safety hazard.

The first step in developing a sign plan is to inventory site-specific characteristics and the 

dangers associated with them. Types and locations of dangers should be identified with the 

purpose of creating a safer environment while still providing reasonable access to the public. In 

the following section, we list some of the most common hazardous areas that may be found at 

hydropower projects, and explain the applicability of signage throughout the project area.

A. Upstream of the Facility

A Hazardous areas 

marked by buoy lines

C. Strong 

unpredictable currents 

above and below dam 

gates

G. Submerged hazards 

above and below dams

H. Open spillways may 

not be visible from 

above dam

J. Ice that forms near a 

dam is often thin and 

unsafe

Source: HUG Safety 

Pamphlet entitled 

"Fatal Attraction"

This is the area above the dam that is influenced by its operation, including the reservoir 

impounded by the project or areas of the river that are affected by a change in the operation of 

the project.

1. Lake Levels
Project operation may cause the level of the reservoir to fluctuate. Sometimes the 

fluctuation is minor, and at other times the level may rise or drop by a number of feet in the 

course of a day or two. As lake depths change, objects protruding from the lake bed that 

normally are not hazardous for users may become problems. Similarly, areas that at high 

reservoir levels are suitable for launching, taking out boats, or for passage may become 

unsuitable as the reservoir level drops. If the level of the reservoir fluctuates noticeably during 

the traditional recreation season for an individual project, signs can help make recreationists 

aware of these potentially hazardous situations. In some cases, it may be possible or even 

necessary to mark submerged objects with signs, buoys or floating barriers. Narrow channels 

can be marked to offer safe passage through shallow areas. As a reservoir level drops, it may be 

necessary to adjust the marked navigational channels so that navigation is still possible.

2. Recreation Sites--Boat Launches

Boat launches provide an opportunity for making users aware of potential hazards in the 

vicinity of the ramp itself and potential hazards that are located throughout the project area.

Boat launches are good places to post area-wide information, such as regulations, 

hazardous conditions and areas, clearances at bridges and power lines, and other safety 

information. It may be appropriate to have a map of the reservoir at the boat launch, identifying 

potentially hazardous areas, swimming areas, and bridges. Signs marking safe swimming areas 

at the boat launch site and the location of other safe swimming areas are also appropriate.

3. Recreation Sites--Portages

Well marked portages may be very important to the safety of boaters attempting to travel 

downstream. Portages should be indicated by appropriate signs that direct boaters to take-out 

points. The portages should be constructed with a safe landing, well upstream of hazardous 

areas such as spillways and intake structures. Canoeists and kayakers may be tempted to go 

over low dams and spillways where the perceived hazard is low. This should be discouraged 

through the use of signs and barriers and through strict enforcement by appropriate officials. 

HUG recommends a crossed paddles symbol on a rectangular sign with or without directional 

arrows to guide recreationists (HUG, 1988). See section V.F for examples of these signs.

4. Ice

During the winter, ice may build up on lakes and reservoirs encouraging public use of icecovered surfaces. Ice fishing, ice skating, cross-country skiing, and snowmobiling are just a few 

of the winter activities that dam owners might expect. There may be a necessity to develop 

signage specific to these types of facilities. Thin ice may be hazardous to a variety of winter 

recreationists. There are specific project features that may cause thin ice conditions. Swift 

currents, devices to prevent gates from icing up, intakes, submerged gates and changing 

reservoir levels may create areas of thin ice. Special measures may be required to warn visitors 

of site conditions and to limit accessibility to areas that may be hazardous. These areas should 

be well marked with signs and, for high use areas, possibly fences. Where ice skating is 

expected, a designated area for ice skating may be the best option for confining the activity to 
safe and well supervised areas where ice conditions can be monitored throughout the winter 

months.

Snowmobile users and cross-country skiers may be exposed to a variety of hazardous 

conditions. Winter hazards have a tendency to change with weather conditions and storms. For 

instance, avalanche danger and ice conditions vary greatly depending upon changing natural 

conditions. Effective route marking is one way of dealing with keeping users away from some 

of the hazards. If possible, limiting access to a few points will allow for information 

dissemination to all of the users of the area. Specific information can then be centrally located 

at access points.

Also, icing conditions at the dam structures may be hazardous. For instance, ice that forms 

on structures can fall causing injury to individuals in the vicinity. Ice formation on lines and 

cables can cause them to sag, which changes the nature of potential hazards in the area.

5. Bridges, Cables, and Transmission Lines

Bridges, cables, and transmission lines that cross the project may be hazardous to users, 

especially if they are low enough to restrict the passage of certain boats or to allow arcing of 

current from lines to sailboat masts. Signage that is suspended over the water via cables should 

be used with care, especially if there is sail traffic. The presence of sailing activity does not 

necessarily preclude overhead signage, but extra care will need to be taken to ensure that the 

safety sign itself does not pose a hazard. Fluctuating reservoir levels may affect the amount of 

vertical clearance, as can hot weather and ice storms that often cause power lines to sag. One 

option is to place staff gages at access points indicating the maximum clearance based on the 

water level. Signs in the vicinity of the lines or bridges should remind recreationists about 

height limitations. The National Electric Safety Code offers guidelines as to the minimum 

height above maximum pond level that is required for various voltages and sizes of reservoirs. 

Any hazards such as these that may extend over a large width of the project should have signs 

at several points along the entire area that is potentially hazardous.

6. Uniform State Waterway Marking System

The USWMS was developed in 1966 and is in use on many of the waterways throughout 

North America. It is a buoy system that is used to mark channels and provide information about 

boat restrictions on water bodies. While designed for use on lakes and other inland waters that 

are not portrayed on nautical charts, the USWMS was authorized for use on other waters as 

well. It provides an easily understood system for small boat operators. The USWMS is 

currently undergoing some changes. It is being merged with the United States Aids to 

Navigation. These changes are being implemented gradually and all users of the systems should 

be in compliance by 2003. Special care should be taken to inform visitors of these changes. 

Information about the USWMS and the modifications can be found on the Boatsafe and USCG 

web sites (see web links in section VI.B )
B. At the Facility

A. Hazardous areas 

marked by buoy lines

B. Sudden water 

discharge from dam 

gates

C.Strong unpredictable 

currents above and 

below dams

F.Slippery surfaces on 

dam structures and 

shorelines

H. Open spillways may 

not be visible from 

above dam

I. Debris passing over 

or through dam

J. Ice that forms near a 

dam is often thin and 

unsafe

Source: HUG Safety 

Pamphlet entitled 

"Fatal Attraction"

These areas include all areas that are directly utilized as a part of project operation. Many 

facilities are now remotely operated, and remote operation or automation of hydropower 

projects may increase the chances of accidents at the projects by eliminating the observations, 

judgments, and warnings of an operator. These unstaffed, remotely controlled facilities may 

start at any time and may require additional safety devices and signage to adequately warn 

and protect the public.

1. Dams

Dams may pose public safety risks, and public access to these structures may be prohibited, 

depending on the dam's location, type, and configuration. Signs and physical barriers should be 

used to keep the public out of unsafe areas on and around dams. Vertical drops, steep slopes, 

machinery are all potentially dangerous elements of dams. When dam access is restricted, it is 

important to cover all land and water access points, with signage and other appropriate safety 

devices.

Some dams have roads, trails, or other public access along the dam crest. When public 

access to a dam is desired (e.g. scenic overlook other recreational activity use) or unavoidable 
(e.g. public roadways), good safety signage, along with other protective measures, must be in 

place to ensure safe use of authorized public access areas on a dam.

2. Spillways

Spillways can cause very hazardous situations. Ungated overflow spillways are particularly 

dangerous because they may be difficult to recognize from the reservoir, and boats can be easily 

drawn over them. The nature of spillways is such that it can be difficult to notice that there is a 

significant change in elevation from one side of the spillway to the other. For this reason, 

overflow spillways are especially dangerous during low light periods. Gated spillways can 

cause hazardous situations depending on their operation. For instance, when Taintor gates are 

raised so that the bottom of the gates are above the water surface, the spillway is essentially an 

overflow spillway and is very dangerous. These types of spillways are also very dangerous 

when the gates are raised to a point where the bottom of the gates are below but near the water 

surface. With the gates in this position, it is not apparent that they are raised, and the water 

surface is often fairly calm. However, the subsurface currents are very swift and dangerous. In 

some gate positions, dangerous whirlpools develop upstream of the gates. However, when gates 

are open only a few inches, they may pass water with little upstream hazard created. Spillway 

releases can create turbulent and dangerous whitewater. When spillway gates are raised or 

flashboards suddenly trip, the unexpected discharges can be hazardous to downstream 

individuals on the shore or in the water.

Deep, submerged spillways and outlet works are generally considered to be relatively safe 

because the hazardous currents are well below the surface. However, since these spillways 

cannot be seen from the surface, they are particularly dangerous to swimmers and scuba divers.

Access to spillways should be restricted. Signs and barriers should be used to keep the 

public out of the spillway area. To increase safety upstream of the spillway, a floating boat 

barrier with appropriate signage may be put in place during the entire recreation season. In 

many situations, floating barriers should be installed at a diagonal so that the barrier will tend to 

push the individual along the barrier in the direction of an escape point. Signs should be of 

significant size and contrast so as to be legible from a distance such that recreationists would 

not have to put themselves into a dangerous situation to read the warning. Access to the dam 

and spillway structures should be restricted through the use of signs and fences.

3. Intake Structures

Inlets to power structures, canals, tunnels, conduits, siphons, or other structures designed to 

pass water through openings in the project can be very dangerous. From the surface, such areas 

may provide little visual evidence of the dangerous undercurrents. Intake areas are usually 

equipped with trashracks that prevent anyone from being drawn into the turbine. However, it 

would be hazardous to be swimming or boating near the intake areas, because a person could be 

pinned against the trashracks making escape improbable. Signs for the intake areas should be 

visible to recreationists approaching the area from any direction. It may be appropriate to install 
boat-restraining devices in addition to safety signage to keep individuals out of the hazardous 

area.

4. Powerhouses and Ancillary Facilities

Power switchyards are located at many facilities. The electrical shock associated with many 

of these facilities usually is obvious, and such facilities are generally well protected with signs 

and fences. High voltage lines associated with these facilities may be in areas where boaters and 

anglers could accidentally make contact with them. Project structures can present many safety 

problems where man-made structures pose a hazard due to vertical walls, drop-offs, uneven 

materials such as rip-rap, or slippery smooth surfaces such as spillway chutes. Signs, barriers, 

and other protective measures should be employed to exclude the public from unsafe project 

areas.

5. Canals

Some facilities have canals associated with their operation, and water may be diverted from 

the river through canals to produce power. These canals can be hazardous if individuals gain 

access to them. In addition to signage, escape ladders and grab lines may also be used as 

additional safety measure in canals. Ultimately, conditions may warrant the use of fencing 

around canals to completely exclude individuals from entering the area. Trash racks, bottom 

siphons or taps, and submerged intakes are all potential hazards that should be considered when 

assessing safety signage needs at canals.

6. Bypassed Reaches

Some riverbed areas below dams have been bypassed for many years. In the old riverbed, 

or bypassed reach, there may or may not be a minimum flow of water. If high volumes of water 

quickly spill into these areas, the potential hazard to individuals below the dam could be great. 

Appropriate signs for these areas are necessary to ensure that individuals are aware of the 

potential danger. In some cases the riverbed may be overgrown depending on the amount of 

time that has passed since water ran in the river on a regular basis. If spillway flows are 

discharged into the river bed, changing water level signs should be placed such that anyone 

entering the area will be aware of the potential dangers. In some cases, dam owners should 

consider the use of a telephone "hotline" with a recording that reports the daily 

release/discharge schedule. In some cases owners are required by license article to provide this 

"hotline." Signage at the hydropower project could be used to make users aware of this feature. 

Warning sirens or other active systems along with explanatory safety signage may be necessary 

to ensure public safety.

C. Downstream of the Project
B. Sudden water 

discharge from dam 

gates

C.Strong unpredictable 

currents above and 

below dams

D.Sudden turbulent 

discharges from 

automatic generators

E.Deceiving reverse 

currents below 

spillways

G. Submerged hazards 

above and below dam

Source: HUG Safety 

Pamphlet entitled 

"Fatal Attraction"

This is the area affected by the discharge associated with power generation or spillway flows. 

The zone of effect will differ from project to project and is largely dependant on project 

operations.

1. Tailraces

Both the powerhouse and tailrace areas can contain significant hazards. Tailrace areas are 

generally more dangerous than intake areas. Sudden increases in tailrace flows when generators 

go on line are often very hazardous to individuals who are near the shorelines, wading, or 

boating in the tailwater areas. The degree of the hazard varies depending on such factors as the 

volume of the flow, the rate of change of the flow, the turbulence created, and the size of the 

tailrace area. Tailrace areas below spillways can become turbulent and dangerous whitewater 

areas. When spillway gates are raised or flashboards suddenly trip, the unexpected discharges 

can be hazardous to individuals in the downstream tailrace area along the shoreline or in the 

water. It is particularly important that signs be placed such that anyone entering the tailrace 

areas will be made aware of the hazards. Warning sirens or other active systems may be 

necessary, in addition to explanatory safety signage, to help ensure public safety.

2. Water Levels

Water levels downstream of the project can change rapidly posing a danger to anyone that 

is in the area at the time of discharges. Adequate signage and warning devices should be placed 

to help alleviate any dangers. This is particularly important if patterns of flow release are erratic 

or changing from their past operations. A public awareness campaign should be implemented to 
inform the public in the event of significant changes in discharge patterns or quantities that 

affect downstream water levels.

The operation of the project can have a major impact on the potential hazard associated 

with it. The full range of operation conditions must be considered in determining the amount 

and type of signage that is required.

Run-of-river operations generally are less hazardous than peaking operations, because the 

flow through the project tends to be more constant. The flow at the project varies with inflow to 

the reservoir. Inflow is affected by precipitation patterns, as well as by any other facilities that 

are located upstream. It is possible to have a project that has no storage capacity and operates as 

run-of-river that actually operates on a peaking schedule because of an upstream peaking 

operation.

Peaking operations tend to be more hazardous than run-of-river, because calm tailwaters 

between generation periods can give recreationists a false sense of safety. As generation begins, 

the tailwaters rise. They can become swift and hazardous in a very short time. Changing water 

level signs as well as audible and visible (light) signals are important in warning recreationists 

of potential and impending danger. The use of a siren and strobe light warning system for 

changing water levels, in addition to safety signage, can help to reduce the risk to individuals in

the area.

3. Slippery Surfaces

Changes in water levels can cause surfaces such as the shoreline or rocks downstream of 

the project to be very slippery. This is especially true during colder times of year when ice 

forms as water levels change or areas that are affected by spray from discharging gates or 

spillways. Signs should be used to remind individuals using these areas, especially if public 

access is allowed, of the care that needs to be taken to avoid injury.

D. Types of Activities, Special Events, and Temporary Conditions
A. Hazardous areas 

marked by buoy lines

B.Sudden water 

discharge from dam 

gates

C. Strong 

unpredictable currents 

above and below dams

D.Sudden turbulent 

discharges from 

automatic generators

E. Deceiving reverse 

currents below 

spillways

F. Slippery surfaces 

on dam structures and 

shorelines .

G. Submerged hazards 

above and below dam

H. Open spillways 

may not be visible 

from above dam

I. Debris passing over 

or through dam

J. Ice that forms near a 

dam is often thin and 

unsafe

Source: HUG Safety 

Pamphlet entitled 

"Fatal Attraction"

The types of activities that take place in the project area can vary greatly from one project to 

another. Some of the factors that influence activities, and therefore signage needs, are the 

size and depth of the reservoir, whitewater or other boating opportunities downstream of the 

project, the presence of sport fish species, the amount and type of public access at the 

project, location of parks and recreation areas, and any state and local ordinances regarding 

speed and type of watercraft allowed. In addition, construction or major maintenance 

activities may represent unique public safety concerns that require special signs, traffic 

control measures, or other curtailed or relocated public access.

Special events at hydropower projects require special considerations. It may be possible to 

partner with a sponsoring organization ensure that safety information is available to all 

participants through posted signs or printed materials. Special events may require new signs. 

There also may be a need for seasonal or temporary signs. For example, nesting periods for 
threatened or endangered species, local development, or other temporary situations may require 

special signs.

Some events, such as fishing tournaments, may last several days and can bring large 

numbers of people to a hydropower project, many of them unfamiliar with the reservoir. This 

combination of a large numbers of people, shared activity space, and unfamiliarity with the 

waterway can increase the level of hazard that is present in the area. Proper planning and the 

use of additional temporary safety signage can reduce the potential risks.
V. ANNOTATED SIGNAGE EXAMPLES

The following section contains examples of various signs in place or planned for FERC 

licensed and exempted projects. Each photograph includes the signage text and brief comments. 

The comments are meant to point out particularly effective (or ineffective) aspects of each sign 

with the goal of training the viewer to identify effective signage design. Some signs also have 

recommendations for changes to make them more effective. Signs were included as examples 

of font choice, spacing, non-technical language, color scheme, trigger words or even general 

placement. Comments and recommendations are presented for conceptual context only, and are 

not legally binding.

Notes

• All company information and site names have either been removed or changed for 

confidentiality.

• The inclusion of company logos and contact information is encouraged on all signs, but 

in small text size along the bottom border of the sign panel. The contact information 

should be designed to avoid visually conflict with or diminish the clarity of the 

displayed safety message.

• These photos and examples were provided by dam inspectors, agencies, dam owners or 

other safety organizations. Examples were also taken from Public Safety Plans, 

operations and inspection reports, site visit photographs and printed and web based 

safety documents. In particular, many examples of safety signage were taken from the 

USACE Sign Standards Manual (USACE, 1995). Portions of this manual are 

reproduced, with permission, in Adobe Acrobat (PDF) file format in appendix A.

• The Symbols section (V.I) is provided as examples of common symbols that be used at 

hydroelectric projects. These examples were taken primarily from the USACE Sigh 

Standards Manual (USACE, 1995). The USACE adapted many of them from the NPS 

and the FHWA.

• Inclusion of signs that represent the style of a particular agency or organization should 

not be construed as a strict endorsement of that style. Signage examples are included as 

noteworthy examples of safety signage concepts that are currently in use.

A. Examples of Bad Signage

B. Boating Safety

C. Dam Ahead (Danger)
D. General/Miscellaneous

E. Interpretive or Informational

F. Portages

G. Project Operations

H. Spillways and Intakes

I. Symbols

J. Tailraces

K. Water Levels
VI. BIBLIOGRAPHY AND WEB LINKS

A. Bibliography

This bibliography is a compilation of documents that were referenced either directly, or 

indirectly (resources listed in documents that were referred to). Documents with an asterisk (*) 

were used directly in developing this document. This is not intended to be an exhaustive list of 

safety signage documents but a starting resource guide. The Commission will be maintaining 

and adding to this safety bibliography as resources become available.

Submissions are being accepted for inclusion into this safety bibliography. Please contact 

FERC at SafetySignageComments@ferc.gov. Please include the reference in the same 

format that follows and a brief description of the document.

*Americans with Disabilities Act Accessibility Guidelines for Buildings and Facilities 

(ADAAG). 1998. (see web links in section VI.B )

ANSI (American National Standards Institute). 1987. Criteria for Safety Symbols. ANSI 

Z535.3, draft. New York: National Electrical Manufacturers Association.

ANSI. 1987. Environmental and Facility Safety Signs, ANSI Z535.2, draft. New York: 

National Electrical Manufacturers Association.

ANSI. 1987. Safety Color Code, ANSI Z535.1, draft. New York: National Electrical 

Manufacturers Association.

Ayres, T.J., M.M. Gross, C.T. Wood, D.P. Horst, R.R. Beyer, and J.N. Robinson (Failure 

Analysis Associates, Inc.). 1994. What is a Warning and When will it Work?, Human Factors 

Perspectives on Warnings. California: The Human Factors and Ergonomics Society.

Blystra, A.R. 1991. Public Safety and Recreation at Dams, ASDSO Annual Conference, 

Association of State Dam Safety Officials, September 29 - October 2, 1991, pp. 146-148.

Braun, C.C., N.C. Silver, and B.R. Stock. 1992. Likelihood of Reading Warnings: The Effect of 

Fonts and Font Sizes. Proceedings of the Human Factors and Ergonomics Society 36th Annual 

Meeting:926-930.

*Bresnahan, T.F., D.C. Lhotka, and H. Winchell. 1993. The Sign Maze: Approaches to the 

Development of Signs, Labels, Markings, and Instruction Manuals. American Society of Safety 

Engineers.

*Cordell, H.K. 1999. Outdoor Recreation in American Life: A National Assessment of Demand 

and Supply Trends. Sagamore Publishing.
Department of Water Resources, State of California. 1987. Safety Survey of Public Use Areas, 

Prepared by Deltavision and DSS Co.

Dionne, E.D. 1979. Effective Safety Signs and Posters. National Safety News (120)4:48-52.

Duffy, T.M. 1985. Chapter 6: Readability formulas: What's the use? In Designing Usable Texts, 

T.M. Duff, and R. Wailer (Eds.) Orlando: Academic Press, Inc., 113-140.

Easterby, R.S. and S.R. Hakiel. 1981. Field Testing of Consumer Safety Signs: The 

Comprehension of Pictorially Presented Messages. Applied Ergonomics 12(3):143-152.

*Federal Energy Regulatory Commission. 1992. Guidelines for Public Safety at Hydropower 

Projects.

*Federal Highway Administration. 2000. Manual on Uniform Traffic Control Devices

*HUG (Hydro Users Group). 1988. Uniform Signing and Warning Device Recommendations, 

HUG Meeting, Wausau, Wisconsin.

*HUG. Undated. Fatal Attraction. Informational Pamphlets.

Kemnitz, C. 1991. How to Write Effective Hazard Alert Messages. Technical Communications, 

First Quarter:68-73.

National Park Service. 1983. Dams and Appurtenant Works, Maintenance, Operations, and 

Safety, Guideline NPS-40.

National Park Service.1988. Sign Manual

National Safety Council. 1992. Today's Supervisor, July.

*NSRE (National Survey on Recreation and the Outdoors). 2000. (see web links in section 

VI.B )

National Water Safety Congress. 1988. Guide for the Safe Operation and Maintenance of 

Marinas, NWSC B-13.

National Water Safety Congress. 1988. Planning, Design, Operation and Maintenance of Inland 

Water Swimming Beaches, NWSC B-12.

National Water Safety Congress, Water Safety and the young Adult, Training Kits #NWSCTM, NWSC-TC, and NWSC-TV Buford, GA.

National Water Safety Congress. Water Safety Journal, Quarterly Publication, Seattle, WA.
National Water Safety Council. 1975. National Directory of Boating Safety Materials - (U.S. 

Coast Guard, Office of Boating Safety).

NBS Building Science Series 141, Collins, Belinda, 1982. The Development and Evaluation of 

Effective Symbol Signs.

*OSHA (Occupational Safety and Health Administration). 1997. Hazard Communication: A 

Review of the Science Underpinning the Art of Communication for Health and Safety.

*Oregon State Marine Board (OSMB). 1997. Uniform Sign Guidelines for Recreational Boat 

Launching and Transient Tie-Up Facilities. Salem, OR

Purswell, J.L.; Krenek, R.F.; and Dorris, A. 1993. Warning Effectiveness: What Do We Need 

to Know. Human Perspectives on Warnings. California: The Human Factors and Ergonomics 

Society:174-178.

Smith, S.L. 1979. Letter Size and Legibility. Human Factors 21(6):661-670.

Tennessee Valley Authority. Sign Standards Manual, Architectural Design Standard DSA10.400.1.

Tennessee Valley Authority, Recreation Resources Program and University of Tennessee at 

Chattanooga. Center for Environmental and Energy Education. 1983. Hazardous Waters : 

Know the Facts about TVA Dams and Tailwaters, In cooperation with the Center for 

Environmental and Energy Education The University of Tennessee at Chattanooga, 1 folded 

sheet.

*USACE (U.S. Army Corps of Engineers). 1995. Sign Standards Manual, Volumes I and II (EP 

610-1-6a and EP 610-1-6b).

*USACE. 1987. Recreation Planning and Design Criteria, EM 1110-l-400.

USACE. 1986. Engineering and Design, Clearances for Power and Communication Lines Over 

Reservoirs, ER 1110-Z-4401, Washington, DC.

USACE. 1988. Public Area Safety Audit, Old Hickory Lake, Nashville District, Prepared by 

Lose and Associates, Inc.

USACE . Water Safety Pamphlet.

*USBR (United States Bureau of Reclamation). 2000. Signs Guidelines for Planning, Design, 

Fabrication, Procurement, Installation, and Maintenance of Signs for Outdoor Public Use Areas 

(Draft).
USBR. 1992. Investigation of Debris and Safety Boom Alternatives for Bureau of Reclamation 

Use, Denver, CO.

*USBR. 1992a. Public Safety around Dams and Reservoirs.

USBR. 1971. Reducing Hazards to People and Animals on Reclamation Canals, Open and 

Closed Conduit Systems Program, REC-ERC-71-36, Denver, CO.

USBR. 1979. Design Standards No. 1, General Design Standards, Chapter 3 Safety Design 

Standards, Engineering and Research Center, Denver, CO.

USBR. 1987. Policy for Public Safety at Reclamation Facilities, Denver, CO.

USBR. Public Safety and Access Program (DRAFT), Denver, CO.

Walbridge, C. "The Trouble With Dams", Canoe Magazine, Volume 7, No. 1

Water Resources Committee and P. A. Fellows. 1939. Low dams. A manual of design for small 

water storage projects, United States. National Resources Committee. U. S. Govt. Print. Off., 

xii, 431 pp.

*Wisconsin Department of Natural Resources, Wisconsin Administrative Code, Chapter 

NR330, Warning Signs and Portages For Dams.

Wright, K.R., J.M. Kelly, and W.S. Allender. 1995, Low-Head Dam Hydraulic Turbulence 

Hazards, ASDSO Western Regional Conference, Association of State Dam Safety Officials, 

May 22-25, 1995, pp. 93-98.

Wright, K.R., J.M. Kelly, R.J. Houghtalen, and M.R. Bonner. 1995. Emergency Rescues at 

Low-Head Dams, ASDSO Annual Conference, Association of State Dam Safety Officials, pp. 

327-335.

Young, S.L. 1991. Increasing the noticeability of warnings. Effects of pictorial, color, signal 

icon and border. Proceedings of the Human Factors Society 35th Annual Meeting 1:580-584.

Young, S.L. 1993. "Increasing the Noticeability of Warning Effects of Pictorial, Color, Signal

Icon and Border. Human Factors Perspectives on Warnings. California: The Human Factors and 

Ergonomics Society:249-253.

B. Web Links

Name Link

The Access 

Board

http://www.access-board.gov/indexes/accessindex.htm
Alaska Boating 

Safety

http://www.dnr.state.ak.us/parks/boating/

American 

Public Power 

Association

http://www.appanet.org/general/links/related.htm

American 

Public Works 

Association

http://www.pubworks.org/

Americans 

with 

Disabilities Act 

Guidelines for 

Buildings and 

Facilities

http://www.access-board.gov/adaag/html/adaag.htm

ANSI Member 

Roster

http://www.ansi.org/public/db_list/member.asp?category=U

Association of 

Energy 

Engineers

http://www.aeecenter.org/

Association of 

State Dam 

Safety 

Officials

http://www.damsafety.org/

Boat Safe http://www.boatsafe.com/

California 

Department of 

Boating and 

Waterways

http://dbw.ca.gov/

Canadian 

Boating Safety 

Office

http://www.ccg-gcc.gc.ca/obs-bsn/main.htm

Clark County 

Marine Patrol

http://www.boatclarkcounty.org/

Colorado State 

Parks Boating 

Safety

http://parks.state.co.us/boating/

Energy Search http://www.energysearch.com/

FERC 

Guidelines for 

Public Safety

https://www.ferc.gov/industries/hydropower/safety/psguideline.pdf
GSA List of 

Signage Terms

http://www.gsa.gov/pbs/firstimpressions/signage/glossary.html

GSA Signage 

Guidelines

http://hydra.gsa.gov/pbs/firstimpressions/signage/signage_guidelines.html

GSA Signage 

Presentation

http://hydra.gsa.gov/pbs/firstimpressions/signage/introduction/introduction.ht

ml

International 

Organization 

for 

Standardization

http://www.iso.ch/

Manual on 

Uniform 

Traffic Control 

Devices

http://mutcd.fhwa.dot.gov/

Michigan Dept. 

of Natural 

Resources

http://www.dnr.state.mi.us/

Minnesota 

Water & 

Boating Safety

http://www.dnr.state.mn.us/information_and_education/water_safety/

National Safe 

Boating 

Council

http://www.safeboatingcouncil.org

National Water 

Safety 

Congress

http://www.watersafetycongress.org/

National 

Survey on 

Recreation and 

the Outdoors 

(NSRE)

http://www.srs.fs.fed.us/trends/nsre.html

Nevada Dam 

Safety

http://ndwr.state.nv.us/engineering/damsafety.htm

Oregon State 

Marine Board

http://www.boatoregon.com/

OSHA Hazard 

Communicatio

n Publication

http://www.osha-slc.gov/SLTC/hazardcommunications/hc2inf2.html

Pennsylvania 

Dam Safety

http://www.dep.state.pa.us/dep/deputate/watermgt/we/DamProgram/Main.ht

m
Pennsylvania 

Dept. of 

Waterways 

Engineering

http://www.dep.state.pa.us/dep/deputate/watermgt/we/we.htm#dam_facts

Pennsylvania 

Fish and 

Boating 

Commission

http://www.fish.state.pa.us/

Pennsylvania 

News Release

http://www.dep.state.pa.us/dep/deputate/polycomm/pressrel/novak/cn0619.ht

m

Pennsylvania 

Fish and 

Boating 

Commission -

Boating info

http://www.state.pa.us/PA_Exec/Fish_Boat/boatinf.htm

Pennsylvania 

Revised Dam 

Marking 

Guidelines

http://www.state.pa.us/PA_Exec/Fish_Boat/damnot2.htm

Pennsylvania 

Low Head 

Dam 

Information

http://www.state.pa.us/PA_Exec/Fish_Boat/lowhd1.htm

USACE 

Nashville 

District Water 

Safety Page

http://www.orn.usace.army.mil/pao/watersafety/

USACE 

Library 

Reference 

Desk

http://www.usace.army.mil/library/libref.html

USACE 

Publications 

Office

http://www.usace.army.mil/inet/usace-docs/

USACE Signs 

Standards 

Program

http://www.mvp.usace.army.mil/mcx/sign_standards_prog/

USACE Water 

Safety Program

http://watersafety.usace.army.mil/

US Coast 

Guard Private 

http://www.uscg.mil/d11/oan/paton/paton_index.htm
Aids to 

Navigation

US Coast 

Guard Boating 

Safety

http://www.uscgboating.org/

US Coast 

Guard Major 

Boating 

Organization 

Links

http://www.uscgboating.org/links/links_majorg.asp

US Coast 

Guard Links to 

State/Territory 

Boating Law 

Administrators

http://www.uscgboating.org/reg/reg_bla.asp

US Coast 

Guard State 

Waterway 

Marking 

System

http://www.uscg.mil/d11/oan/paton/state%5fbuoys.htm

US Code of 

Regulations 

Title 33 -

Navigation and 

Navigable 

Waters

http://www4.law.cornell.edu/uscode/33/

USWMS (New 

information in 

regard to the 

aids to 

navigation 

merger)

http://www.boatsafe.com/nauticalknowhow/uswms.htm

Virginia Water 

Safety 

Coalition

http://www.watersafety.org/

Washington 

Boating Safety 

Officers 

Association

http://www.boatwashington.org

West Virginia 

Dam Safety

http://www.dep.state.wv.us/wr/OWR_Website/index.htm
Wisconsin 

Boating 

Regulations

http://www.dnr.state.wi.us/org/es/enforcement/safety/boatreg.htm

LIST OF PREPARERS

Federal Energy Regulatory Commission

The Louis Berger Group, Inc.

APPENDIX A Selected Chapters from USACE Sign Standards Manual (Reports EP 310-1-

6A and EP 310-1-6B, last updated 1995)

Table of Contents

Introduction (1)

Principles and Guidelines (2)

Program Plan and Documentation (3)

Design Standards (4)

Directional Signs (6)

Recreation Area Signs (7)

Recreation Symbol Signs (8)

Traffic Signs (9)

Industrial Safety Signs (11)

Regulatory Signs (12)

Interpretive Signs (13)

Appendix Table of Contents

Materials and Specifications (B)

Sign Maintenance Procedures (C)

Reproduction Materials(F)

6.2 MB

15.1 MB

24.5 MB

12.6 MB

10.2 MB

34.9 MB

53.1 MB

38.6 MB

30.8 MB

23.0 MB

18.7 MB

24.2 MB

0.6 MB

1.3 MB

0.6 MB

2.2 MB

APPENDIX B FERC Guidelines for Public Safety at Hydropower Projects

APPENDIX C Oregon Uniform Sign Guidelines for Recreational Boat Launching and 

Transient Tie-Up Facilities

APPENDIX D HUG Public Safety Committee Recommendations