1. DaM Failure: a growing risk as structures age
Marty Pope
Senior Service Hydrologist
NWS Jackson

2. Average risk of any dam breaking in a given year: 1 in 10,000
Average age in years of dams in US: 40
Third of our nation’s dams age: 50 years old
In 10 years, more than 65% of dams in the U.S. will
have reached the half-century mark.
The Cost of Rehabilitating Our Nation’s Dams:
$16 billion to repair the most critical dams next 12
years.
Number of dam break deaths in U.S. since 1887: 4,800
Dam Statistics
Source:
-Damsafety.org Website
-International Rivers Website
As of 2007
Local Govt Owned - 20%
Federally Owned - 4%
Privately Owned - 65%
State Owned - 5
Unknown Owned - 4
Public Utility Owned - 2

3. Significant Dam Failures
In the past 20 years, there have been over 300 fatalities in the U. S. resulting from dam failures.
South Fork Dam – Johnstown, Pennsylvania – failed in 1889, approximately 2200 killed.
St. Francis Dam – California – failed in 1928, 450 killed.
Baldwin Hills Dam – California – failed in 1963, 5 killed.
Buffalo Creek Dam – West Virginia – failed in 1972, 125 killed.
Teton Dam – Idaho – failed in 1976, 11 killed and ½ billion dollars in property damage.
Kelly Barnes Dam – Georgia – failed in 1977, 39 killed.
Lawn Lake Dam – Colorado – failed in 1982, 3 killed.
Kaloko Dam – Hawaii – failed this year, 7 killed.
This is why we have a dam safety program in Mississippi. Every state, except for Alabama, has a dam safety program.
These are some of the more notable dam failures in US history. Some of these dams were very large dams, some were small. Lawn Lake dam was only 24 feet high and impounded 700 acre-feet of water. Some of these dams had a short life span (like Teton Dam which failed on first filling), some of them had been in operation for decades (Like Kaloko and Lawn Lake). The reasons for failure for these dams are varied, but fall into 4 main categories that I will talk about later.

4. The Potential for Catastrophic Dam Failures Is Increasing Nationwide
State-Regulated High-Hazard-Potential Dams,
4,095 state-regulated dams are in need of remediation.
1,819 of these deficient dams are classified as high-hazard-potential dams, and 1,126 are classified as significant-hazard-potential dams.
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
9057
9314
9368
8316
9833
9566
8544
9525
9806
9849

5. Good NEWS: The number of state dam inspections is increasing

6. GOOD NEWS: States are increasing the number of current emergency action plans (EAPs) on high-hazard potential dams

7. Events of Isaac

8. Percy Quinn Dam - Timeline of events – August 30th
At 8:10 am, MEMA reported that the Percy Quinn Dam was expected to fail via
8:26 am, LIX WFO issued Flash Flood Warning for Southwestern Pike County
Warning included Osyka area and all low lying areas of the Tangipahoa River in Mississippi.
LIX WFO coordinated with LMRFC to proceed with dam break analysis
RVFs were coordinated and updated to add dam crest to occurring flood rise for Osyka and Kentwood
At 11:07 am, CEM was composed and activated for Percy Quinn Dam
At 11:11 am, LIX WFO issued Flash Flood Warning to Pike County and Northern Tangipahoa Parish to include Kentwood.
At 2:00 pm, the LIX WFO issued a Flash Flood Statement indicating that the Warning would expire for Pike County and Tangipahoa Parish, but would be monitored and a warning reissued if conditions deteriorated.

9. What are we doing in Mississippi to prepare for this threat?
As a result of the Percy Quin Dam incident during Isaac… the MS Silver Jackets Team (consisting of National Weather Service, US Army Corp of Engineers Vicksburg, United State Geological Survey, MS DEQ Dam Safety Division and MEMA ) along with several local Emergency Management officials have met together to discuss Dam Break incidents and the role of each agency.
Action Items of team:
Team is working for better communications between agencies during a Dam Safety Incident.
Team is working is working to relay a message about a dam safety incident in language all are familiar with including the public.
Team agreed the National Weather Service should be listed as an upper level contact on EAP contact list.
Note: These action items can also be used by Arkansas and Louisiana.
What are we doing in Mississippi to prepare for this threat?

10. Mississippi DEQ Dam Safety Division Actions
All Emergency Action Plan (EAPs) will include language that is consistent with the National Weather Service’s Advisory, Watch, Warning, and Emergency Criterion.
DEQ will rewrite EAP guidelines….this should take a couple of months after a review period.
All Emergency Action Plans will be place a repository that can be accessed by the National Weather Service and Emergency Management Officials.
DEQ will hire a contractor to scan all Emergency Action Plans that will be placed a Website. All should be scanned and on a website in 2 to 3 months.
The MS DEQ Dam Safety will provide NWS and EMA officials needed access to Emergency Action Plans (EAPs) via a website.
DEQ will provide Emergency Managers trainings on Dam Safety and evaluating Dams .
This will be in cooperation with the National Weather Service.
This training will not be available until all EAP guidelines are completed.
DEQ will provide a phone number that will first ring to all of the Dam Inspector’s office telephones and if no one answers….then ring to their cell phones

11. Weather Service Forecast office Operations during an Event
Confirm Report
Is informing Source reliable?
Get information
Issue Appropriate Product
(Watch/Warning)
Qualitative (No specific numbers)
Inform Public
Contact in order listed
Dam Owner
State Dam Safety Office
Supporting RFC
Adjacent and Backup WFO
MIC and HPM
MIC designated as SLO
Region Headquarters
Issue Follow-up Products
Coordinate with RFC
As more information is obtained better quantitative amounts can be given by RFC
Issue Flood Warnings for Lower Reaches if Necessary
Coordinate with RFC if forecast point

12. WFO Operations During Event
Confirm Report
Is informing Source reliable?
Get information
Issue Appropriate Product
(Watch/Warning)
Qualitative (No specific numbers)
Inform Public
Make Contacts in order listed
Dam Owner
State Dam Safety Office
Supporting RFC
Adjacent and Backup WFO
MIC and HPM
MIC designated as SLO
Region Headquarters
Issue Follow-up Products
Coordinate with RFC
As more information is obtained better quantitative amounts can be given by RFC
Issue Flood Warnings for Lower Reaches if Necessary
Coordinate with RFC if forecast point
Determine if dam incident report is from a reliable source. (dam owner, state dam safety official, emergency management personnel, or local law enforcement officials)
“If report cannot be verified, the WFO should use best judgment in selecting the appropriate course of action.”
If reliable, “Obtain as much information as possible about the actual or potential failure.” Enter on log forms.
Data needed:
Names of Dam
Lat/Lon of Dam
Dam Height
Water height in dam
Volume of water in dam
Length of dam
Condition of the dam
Trees in dam
Bank slide

13. Issue Appropriate Product
WFO Operations During Event
Confirm Report
Is informing Source reliable?
Get information
Issue Appropriate Product
(Watch/Warning)
Qualitative (No specific numbers)
Inform Public
Make Contacts in order listed
Dam Owner
State Dam Safety Office
Supporting RFC
Adjacent and Backup WFO
MIC and HPM
MIC designated as SLO
Region Headquarters
Issue Follow-up Products
Coordinate with RFC
As more information is obtained better quantitative amounts can be given by RFC
Issue Flood Warnings for Lower Reaches if Necessary
Coordinate with RFC if forecast point
Flash Flood Watch (FFA)– “A dam or levee may fail and threaten lives or property, but the threat is not deemed to be imminent, or”. Issuance is from 6 to 48 hours before event. Updated: additional Flash Flood Watches (FFA).
Flash Flood Warning (FFW)– “A dam or levee failure is imminent or occurring” Updated: Flash Flood Statements
Civil Emergency Messages (CEM)- “For cases when a potential dam failure is a sufficient threat to warrant the evacuation of downstream areas… to convey the urgency of the situation and ensure widest dissemination of information.
Louisiana – Parishes have the authority to issue CEMs. Can Authorize NWS.
Mississippi – Only Mississippi Emergency Management Agency (MEMA) can authorize CEMs. Can authorize NWS.

14. Make Contacts in order listed
WFO Operations During Event
Confirm Report
Is informing Source reliable?
Get information
Issue Appropriate Product
(Watch/Warning)
Qualitative (No specific numbers)
Inform Public
Make Contacts in order listed
Dam Owner
State dam Safety office
Supporting RFC
Adjacent and backup WFO
MIC and HPM
MIC designated as SLO
Region Headquarters
Issue Follow-up Products
Coordinate with RFC
As more information is obtained better quantitative amounts can be given by RFC
Issue Flood Warnings for Lower Reaches if Necessary
Coordinate with RFC if forecast point
Make Contacts…
Dam Owner
State Dam Safety Officials
Supporting RFC
Adjacent and Backup WFO
Meteorologist In Charge (MIC) & Hydro Program Manager
MIC at the WFO designated as the state liaison office
Personnel at regional headquarters

15. Issue Follow-up Products
WFO Operations During Event
Confirm Report
Reliable Source?
Get information
Issue Appropriate Product
(Watch/Warning)
Qualitative (No specific numbers)
Inform Public
Make Contacts in order listed
Dam Owner
Supporting RFC
Adjacent WFO
MIC and HPM
MIC designated as SLO
Region Headquarters
Issue Follow-up Products
Coordinate
RFC provides quantitative analysis as more information is obtained
Issue Flood Warnings for Lower Reaches if Necessary
Coordinate with RFC if forecast point
Issue Flash Flood Statements with Quantitative Forecast Information
(Regional Supplement) -“To ensure that information and data provided by NWS is consistent”. WFOs should utilize the dam failure scenario information in Emergency Action Plans (EAP), if available.
Simplified Dam Break Model
“Dam Failure Rules of Thumb”
NWS “Dam Catalog”
“The WFO should coordinate follow-up watches/warnings/statements with the RFC, dam/levee owner, and/or local emergency management officials and Dam Safety Officials, if possible.”

16. Issue Flood Warnings for Lower Reaches if Necessary
WFO Operations During Event
Confirm Report
Reliable Source?
Get information
Issue Appropriate Product
(Watch/Warning)
Qualitative
(No specific numbers)
Inform Public
Make Contacts in order listed
Dam Owner
State Dam Safety Office
Supporting RFC
Adjacent and Backup WFO
MIC and HPM
MIC designated as SLO
Region Headquarters
Issue Follow-up Products
Coordinate with RFC
As more information is obtained better quantitative amounts can be given by RFC
Issue Flood Warnings for Lower Reaches if Necessary
Coordinate with RFC if forecast point
If the river reach below the dam is very long, the NWS will need to issue warnings for areas of the lower river or creek basin.

17. River Forecast Center areA of Main responsibility
Weather office’s are not expected to execute dam break models to obtain quantitative information on dam failures. This responsibility falls to the River forecast Center.
WFOs, in collaboration with their servicing RFC, are expected to use the dam failure scenario information from dam EAPs, if available, as the primary source of quantitative information on a flood wave resulting from a dam failure.
If no EAP exists or is available for the dam, dam break models should be used to obtain quantitative information on a flood wave resulting from a dam failure
WFOs should take the lead in collecting information needed by the RFCs to conduct dam break modeling.
Give Support by Providing Quantitative analysis

18. QUESTIONS?