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Travis. C. Tutka, P.E.Senior Dam Safety Program ManagerRisk Management CenterUS Army Corps of Engineers

April 2019

PANEL DISCUSSION WITH NATIONAL WATER SUPPLY ALLIANCE AND THE INTERSTATE COUNCIL ON WATER POLICY

DAM SAFETY OVERVIEW

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- United States - National Perspective - Dam Safety

- Corps of Engineers – Dam Safety Program

- Risk Framework- Assessment- Management- Communication

TOPICS:

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National Inventory of Dams (NID)

Hazard Potential Classifications:

A primary purpose of any classification system is to select appropriate design criteria. Design criteria becomes more conservative as the potential for loss of life and/or property damage increases

• High Hazard Potential * Failure will probably cause loss of human life.

• Significant Hazard Potential * Failure results in no probable loss of human life but can cause economic loss, environmental damage or disruption of lifeline facilities.

• Low Hazard Potential * Failure results in no probable loss of human life, low economic and/or environmental losses.

National Dam Safety PortfolioInventory

High Hazard

Potential

Significant Hazard

Potential

Low Hazard

PotentialUndetermined Total

United States - All Dams (NID) 15,629 11,354 59,679 4,806 91,468

Category % 17.09% 12.41% 65.25% 5.25% 100%

UNITED STATES - DAM SAFETY - NATIONAL PERSPECTIVE

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13%

14%14%

17%

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

National Inventory of Dams - High Hazard Potential Dams

472,207

3,669

10,084

31,977

18,923

9,135

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

Before1800

1800-1899 1900-1919 1920-1949 1950-1969 1970-1989 1990-2018

United Sates - Dams by Completion Year

High Hazard Potential Creep:

- Construction of New Dams- Changes in Downstream Development/Urbanization

Trend

National Inventory of Dams (NID)

UNITED STATES - DAM SAFETY - NATIONAL PERSPECTIVE

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Historic Dam Failures - Within United StatesJohnstown, PA – 1889

2,209 Fatalities

St. Francis, CA - 1928450+ Fatalities

Canyon Lake, SD – 1972237 Fatalities & $60M

Buffalo Creek, WV – 1972125 Fatalities & $50M damages

Teton, Idaho - 1976 11 Fatalities & $400 M damages

Laurel Run Dam, PA - 197747 Fatalities & $10M

1977 Executive Order

UNITED STATES - DAM SAFETY - NATIONAL PERSPECTIVE

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FEDERAL Guidelines For Dam Safety

Ø Initiated in April 1977 by an Ad Hoc Interagency Committee

Ø Published in June 1979 (Re-issued in April 2004)

Ø Provide the Standard for Federal Agency Programs:

– Maintain an Updated Inventory Of Dams – Establish a Dam Safety Officer – Document Design Criteria & Construction Activities – Establish Program for Inspections & Evaluation of Dams – Prepare Operation & Maintenance Plans– Prepare & Maintain Emergency Action Plans (EAP's)

UNITED STATES - DAM SAFETY - NATIONAL PERSPECTIVE

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Agency Statistics:– 33,000 + team members in 110 + countries– 3,000 + Infrastructure Systems – #1 Hydropower Producer in USA– #1 in Outdoor Recreation– $30 B + in Annual Flood Damages Prevented– Navigation Benefits– Many dams relatively untested– Over 330 M Ac-ft of Storage

+2,300 Levees715 Dams

CORPS OF ENGINEERS – INFRASTRUCTURE SAFETY PROGRAMS

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16 9

91

209

324

58

90

50

100

150

200

250

300

350

Before 1900 1900-1919 1920-1939 1940-1959 1960-1979 1980-1999 2000-2018

Corps of Engineers Dams by Completion DateCorps of Engineers Dams

Portfolio Comparisons

CORPS OF ENGINEERS – INFRASTRUCTURE SAFETY PROGRAMS

InventoryHigh

Hazard Potential

Significant Hazard

Potential

Low Hazard

PotentialUndetermined Total

United States - All Dams (NID) 15629 11354 59679 4806 91468

Category % 17% 13% 65% 5% 100%

United States - Federal Dams 1218 316 1173 5 2712

Category % 45% 12% 43% 0% 100%

Corps of Engineer Dams 509 159 53 0 716Category % 71% 22% 7% 0% 100%

Hazard Potential Classifications:• High Hazard Potential * Failure will probably cause loss of human life. • Significant Hazard Potential * Failure results in no probable loss of human life. Can cause economic loss, environmental damage or disruption of lifeline facilities.• Low Hazard Potential * Failure results in no probable loss of human life. Low economic and/or environmental losses.

§ USACE has 716 dams at 559 projects;

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q Understand project risksq Communicate those risksq Perform routine monitoring and emergency

preparednessq Perform actions to reduce risks

9

RISK INFORMED DAM SAFETY PROGRAM

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1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

1.E-03

1.E-02

1.E-01

1 10 100 1,000 10,000

f, Pr

obab

ility

of F

ailu

re

N, Number of Fatalities

Dallas Floodway - West Levee

PFM 2 West - Overtopping

PFM 8 West - Heave

PFM 7 West - Internal Erosion

PFM 13b - Progressive Instability

Risks are unacceptable,except in exceptionalcircumstances

Risks are tolerableonly if they satisfyALARP requirements

Societal Tolerable Risk Limit

Risks may be unacceptable or

tolerable,but will be examined

thoroughly and must at a

minimum satisfy ALARP

requirements

1. Risks that are Commensurate with Benefits

2. Risks that Society does not believe are negligible

3. Risks that owners keep under review

4. Risks that are reduced further if warranted

What is Tolerable?

CORPS OF ENGINEERS – INFRASTRUCTURE SAFETY PROGRAMS Risk Management Guidelines

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Risk Assessment - Inventory of Dams

Ø Established a Dam Safety Action Classification (DSAC) SystemØ DSAC 1 are Highest RiskØ DSAC 5 are Lowest RiskØ Over a third of the inventory (DSAC 1, 2, and 3) has some concern that

warrants further evaluation.

As of 9 Jan 2019

LEGEND:DSAC 1 - Extremely High Incremental RiskDSAC 2 - Very High Incremental RiskDSAC 3 - Moderate to High Incremental RiskDSAC 4 - Low Incremental RiskDSAC 5 - Very Low Incremental Risk

CORPS OF ENGINEERS – INFRASTRUCTURE SAFETY PROGRAMS

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DAM SAFETY INVESTMENT PLAN

• Includes all DSAC I, II, and III Dams• $19.6 Billion Investment to Remediate 285 Dams• Estimated Time to Complete Investment:

37 years @ ~$500M / year

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Risk Communication – With Local Authorities and Public

CORPS OF ENGINEERS – INFRASTRUCTURE SAFETY PROGRAMS

- Responsibility for Managing Risk is Shared

- Important for Local Authorities to Understand their Risk

- Most Infrastructure Projects in the United States are Cost Shared

Communications is Critical:

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q Understand project risksq Communicate those risksq Perform routine monitoring and

emergency preparednessq Perform actions to reduce risks

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RISK INFORMED DAM SAFETY PROGRAM

CONCLUSION