CK-EHMP 2018, S3-S6, Risk Assessment, Hazard Identification, 4, Dam, Original Submittal

2018 Kentucky Hazard Mitigation
Plan Update – Dam Risk

Assessment
This Risk Assessment will be used to understand Kentucky’s dam-related

risks and to help identify potential mitigation actions that may be
implemented to reduce this risk.
Kentucky’s overall flood risk and to help identify potential mitigation
actions that can be implemented to reduce this overall flood risk.
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Contents
Figures ..................................................................................................................................................... iii
Tables....................................................................................................................................................... iii
Executive Summary ...................................................................................................................................... 1
Introduction .................................................................................................................................................. 1
KDOW Dam Safety Program........................................................................................................................ 2
Dam Hazard Classifications ..................................................................................................................... 2
State Owned Dam Repair (SODR) Program ............................................................................................... 4
National Dam Safety Program..................................................................................................................... 6
National Inventory of Dams .................................................................................................................... 6
Dam Conditions Assessments ................................................................................................................. 6
Types of Dams .......................................................................................................................................... 7
Dam Failures ................................................................................................................................................. 8
Types of Dam Failures .............................................................................................................................. 8
Signs of Potential Dam Failure ................................................................................................................ 9
Impacts of Dam Failures ........................................................................................................................ 10
Emergency Planning .................................................................................................................................. 10
EAP Development .................................................................................................................................. 10
Long-Term Recovery Plans ..................................................................................................................... 11
Risk Assessment.......................................................................................................................................... 13
Inundation Mapping .............................................................................................................................. 14
HAZUS..................................................................................................................................................... 14
NRCS Risk Assessment Spreadsheet Tool ............................................................................................. 15
Seismic Risk Assessment ....................................................................................................................... 16
Seismic Failure Index Methods .......................................................................................................... 17
Seismic Failure Index Results ............................................................................................................ 19
Results of Dam Risk Assessment .......................................................................................................... 23
Mitigation Action Identification ................................................................................................................ 23
References and Resources ........................................................................................................................ 27
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Figures
Figure 1. Regulated dams in Kentucky. ....................................................................................................... 4
Figure 2. Locations of state owned dams. .................................................................................................. 5
Figure 3. Regulated dams in Kentucky with seismic zones defined by county by the PGA from the
MCE. ............................................................................................................................................................. 17
Tables
Table 1. Dam incidents in Kentucky. ........................................................................................................... 12
Table 2. Seismic Failure Indices for dams in high seismic areas. ............................................................. 20
Table 3. Sources of characterization. ........................................................................................................ 24
Table 4. Level of potential for mitigation options. .................................................................................. 24
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Executive Summary
As the Commonwealth of Kentucky’s infrastructure ages, a quantifiable strategy is necessary to
communicate the risks due to dam failure and identify mitigation opportunities and alternatives.
Dam failure is one of the natural hazards encountered in the Commonwealth of Kentucky. The 2018
State Hazard Mitigation Plan (SHMP) update will serve the municipalities and unincorporated areas
of the Commonwealth, dam owners, citizens, and the emergency community by conducting a
comprehensive risk assessment for dams and outline mitigation strategies to identify and address
Kentucky’s dam-related needs. By conducting a holistic assessment of dam-related risks, within the
context of the larger, flood risk assessment being conducted for the 2018 SHMP update, this risk
assessment provides an opportunity to enhance and build upon the implementation of previous
state and regional hazard mitigation plans.
Dams serve many functions throughout the Commonwealth including flood control, water supply,
and recreation. The intended uses for dams may evolve over time dams which may pose significant
hazards when risks are introduced via downstream development or as their components age. The
assessment provides an opportunity to better understand the risks that dams pose and to identify
mitigation options to better manage and reduce dam-related risks.
This risk assessment integrates methodologies from the scientific and emergency response and
management community to gain a better understanding of the social and economic factors
regarding dam failures. It is the hope that the efforts contained herein will encourage
Commonwealth stakeholders, and subsequently, dam owners and communities to understand dam-
related risks and identify mitigation actions that will be part of the solution to managing and
reducing those risks.
Introduction
The purpose of a dam is to impound water, wastewater or other liquids for any of several reasons,
e.g. flood control, human water supply, irrigation, livestock water supply, energy generation, or
recreation or pollution control. Many dams fulfill a combination of the above functions.
Dams are classified according to the type of construction material used, the methods used in
construction, the slope or cross-section of the dam, the way the dam resists the forces of the water
pressure behind it, the means used for controlling seepage and, occasionally, according to the
purpose of the dam. Materials used for construction of dams include earth, rock, tailings from
mining or milling, concrete, masonry, steel, timber, or a combination of these materials.
Dams have many beneficial uses throughout the Commonwealth including flood control, water
supply, hydroelectric power generation, and recreation. Often, dams are designed for an intended
purpose that changes over time (e.g. when a dam designed for recreation becomes a community
water supply). They are dynamic systems that require proper design, maintenance, and operation.
Dams may pose risks both upstream and downstream of the water impounding structure. Often,
large dam owners, such as the US Army Corps of Engineers identify areas upstream and downstream
that must remain protected due to the potential of being inundated by floodwaters. However, most
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areas upstream and downstream of dams are often unrestricted to development, introducing
considerable risks to dam owners, communities, and private citizens. Unchecked or unregulated
development may occur downstream of dams, introducing risks either through deliberate or
inadvertent actions. Additionally, dams may pose a significant risk when their components age or
are not properly maintained. Consequently, catastrophic damage is possible should a dam failure
occur. For these reasons, the Kentucky Division of Water (KDOW) has a dedicated Dam Safety
program established by state statute (KRS 151).
KDOW Dam Safety Program

The Kentucky Dam Safety program, within the Energy and Environment (EEC) Cabinet, Department
for Environmental Protection (DEP), Division of Water (DOW) is responsible for the following
activities within the Commonwealth:
• Inspecting existing dams
• Assessing and ranking dams based on conditions and risks
• Issuing permits for dam construction/rehabilitation
• Managing dam-related risks to minimize hazard creep
• Preparing and reviewing Emergency Action Plans (EAPs)
• Communicating dam-related risks
• Managing the State Owned Dam Repair (SODR) program
A dam is defined by KRS 151 as any structure that is 25 feet in height, measured from the downstream
toe to the crest of the dam, or has a maximum impounding capacity of 50 acre-feet or more at the
top of the structure. Structures that fail to meet these criteria but have the potential to cause
significant property damage or pose a threat to life in the downstream area are regulated in the
same manner as dams. All water impounding structures meeting those requirements, except federal
dams and those permitted by the Division of Mine Reclamation and Enforcement, fall under the
purview of DOW. KRS 151 requires the Kentucky Energy and Environment Cabinet (EEC), Department
for Environmental Protection (DEP), Division of Water (DOW) to identify, assess, and manage the
Commonwealth’s Dam Safety Program. The program was established in 1966, predating the
establishment of the National Flood Insurance Program in 1968 and many other state dam-related
programs. KRS 151.293 authorizes DOW to inspect existing structures that meet the definition of a
dam. The Dam Safety program maintains a comprehensive inventory of all active and inactive dams
throughout the Commonwealth. In determining the frequency of inspection of a particular dam, the
division takes into consideration the size and type, topography, geology, soil condition, hydrology,
climate, use of the reservoir, the expected inundation area downstream of the dam, the condition of
the dam, and the hazard classification of the dam.
Dam Hazard Classifications

Hazard classifications are assigned to dams based on the anticipated impacts should a dam failure
occur. Kentucky’s dam hazard classifications align with the classifications outlined in federal dam
safety guidance and consist of:
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High Hazard (Class C) – Dam structures located such that failure may cause loss of life or serious
damage to houses, industrial or commercial buildings, important public utilities, main highways or
major railroads.
Moderate Hazard (Class B) – Dam structures located such that failure may cause significant damage
to property and project operation, but loss of human life is not envisioned.
Low Hazard (Class A) – Dam structures located such that failure would cause loss of the structure
itself but little or no additional damage to other property.
High- and moderate-hazard dams are inspected by DOW every two years. Low-hazard dams are
inspected every five years. If the structure meets all the necessary requirements as outlined
in Engineering Memorandum No. 5, a Certificate of Inspection is issued to the owner. Otherwise, the
owner is notified of any deficiencies.
There are 954 active dams (177 high hazard – Class C; 132 moderate hazard – Class B; 645 low hazard
– Class A) regulated by the Commonwealth as of May 2018. Additionally, approximately 70 dams
remain in the DOW dam inventory but are no longer active due to being breached, drained or
removed from the DOW dam inspection rotation. The Kentucky Dam Safety Program inspects
approximately 300 dams per year. In determining the frequency of inspection of a particular dam,
DOW takes into consideration the size and type, topography, geology, soil condition, hydrology,
climate, use of the reservoir, the lands lying in the floodplain downstream and the hazard
classification of the dam. High- and moderate-hazard dams are inspected every two years. Low-
hazard dams are inspected every five years.
Recent efforts have highlighted the importance and need for developing Emergency Action Plans
(EAPs) and conditions assessments for dams, particularly those classified as high hazard. Kentucky
has a total of 133 high hazard dams with either full EAPs or simplified EAPs. The percentage of high
hazard dams with EAPs or sEAPs in Kentucky is 75%. Kentucky is above the national average for EAPs
for high hazard dams of 69%, based on the ASDSO Performance Report for Kentucky. Condition
assessment ratings have been conducted on all high hazard dams. DOW has made a concerted
effort to identify hydraulic, structural, geotechnical, and operational deficiencies in the inspection of
dams. Inspection reports assess deficiencies and address a plan of action for dam owners. DOW
conducts condition assessments on all dams as they are inspected.
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Figure 1. Regulated dams in Kentucky.
Locations of DOW regulated dams by county and Area Development District (ADD) is included in
Appendix D.1.
State Owned Dam Repair (SODR) Program

DOW manages the State Owned Dam Repair (SODR) program through statutory authority outlined
in KRS 151.291. Ensures that dams owned by the Commonwealth are compliant with applicable
regulatory standards in order to protect against loss of human life, and critical infrastructure due to
dam failure. Through the SODR program, KDOW invests legislative appropriations for remediation of
state-owned dams. Historically, the appropriations range from $1-2 million per state biennium.
Through SODR, DOW has conducted capital construction projects, proactively acquired at-risk
properties, collaborated with local communities to restrict development downstream of dams, saved
millions of dollars that otherwise would have been spent on upgrading dam structures because of
the change in risk class resulting from hazard creep.
The Commonwealth, through its various agencies, owns 73 dams; 23 high hazard (Class C), 17
moderate hazard (Class B), and 33 low hazard (Class A) structures. A breakdown of state owned
dams by agency is as follows:
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• KY Department of Fish and Wildlife – 26 dams

• KY Department of Parks – 13 dams
• KY Transportation Cabinet – 11 dams
• Kentucky River Authority – 10 dams
• Kentucky Universities – 8 dams
• KY Energy and Environment Cabinet – 3 dams
• KY Department of Corrections – 2 dams
Figure 2, below, indicates locations of state owned dams.
Figure 2. Locations of state owned dams.
Half of high (Class C) and moderate (Class B) state owned dams currently have a “Poor” conditions
rating in the National Inventory of Dams (NID). This fact highlights the need of significant critical
infrastructure in need of repair.
DOW’s employs a risk-based approach to address deficiencies in state owned dams. Structural,
hydraulic (capacity), and maintenance deficiencies are prioritized and multiple remediation options
are considered including capital construction, property and easement acquisition downstream of
dams, regulations in coordination with local municipalities, outreach, and a combination of options.
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Often, a combination of mitigation options is identified as the most effective means to manage and
mitigate dam-related risks.
National Dam Safety Program

The National Dam Safety Program (NDSP) is a partnership of the States, Federal agencies, and other
stakeholders that encourages and promotes the establishment and maintenance of effective Federal
and state dam safety programs to reduce the risks to human life, property, and the environment
from dam related hazards. Additionally, the National Dam Safety Review Board (NDSRB) has been
established to advise the FEMA Administrator in setting national dam safety priorities and considers
the effects of national policy issues affecting dam safety. Review Board members include FEMA, the
Chair of the Board and representatives from four federal agencies (U.S. Departments of Agriculture,
Commerce, Homeland Security, and Interior), five state dam safety officials, and one member from
the private sector. DOW is an active member of the NDSRB - https://www.fema.gov/national-dam-
safety-review-board-members.
National Inventory of Dams

Congress first authorized the U.S. Army Corps of Engineers (USACE) to inventory dams in the United
States with the National Dam Inspection Act of 1972. The NID was first published in 1975, with a few
updates as resources permitted over the next ten years. The Water Resources Development Act of
1986 (P.L. 99-662) authorized the Corps to maintain and periodically publish an updated NID, with re-
authorization and a dedicated funding source provided under the Water Resources Development Act
of 1996. USACE also began close collaboration with the Federal Emergency Management Agency
(FEMA) and state regulatory offices to obtain more accurate and complete information. The National
Dam Safety and Security Act of 2002 and the Dam Safety Act of 2006 reauthorized the National Dam
Safety Program and included the maintenance and update of the NID by USACE. Most recently, the
NID was reauthorized as part of the Water Resources Reform and Development Act of 2014. The NID
is published every two years. (http://nid.usace.army.mil/)
The NID consists of dams meeting at least one of the following criteria:
1) High hazard potential classification - loss of human life is likely if the dam fails,
2) Significant hazard potential classification - no probable loss of human life but can cause
economic loss, environmental damage, disruption of lifeline facilities, or impact other
concerns,
3) Equal or exceed 25 feet in height and exceed 15 acre-feet in storage,
4) Equal or exceed 50 acre-feet storage and exceed 6 feet in height.
Dam Conditions Assessments

During each dam inspection a Condition Assessment is performed that assesses the physical
characteristics of the dam. Dams are assigned as one of the following four conditions: Satisfactory,
Fair, Poor, and Unsatisfactory. See Appendix D.2 for Conditions Assessments of Kentucky regulated
dams.
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The following guidelines have been established for Kentucky to meet the requirement of assigning
appropriate condition assessments to existing dam structures. These criteria reflect how the
Commonwealth regulates dams in accordance with applicable statutes and regulations.
Satisfactory
- Dam has no deficiencies beyond minor maintenance items such as minor brush growth or
saplings, small eroded/bare areas, small areas of non-structural deterioration to concrete,
metal or timber components, debris in the outlets, or similar.
- Dam has no known structural issues.
- Dam may have seepage/leakage issues, provided that they are longstanding, previously
evaluated and deemed to be static or not presenting a stability issue.
- Dam meets design storm event standard for its classification.
Fair
- Dam has maintenance deficiencies beyond the minor ones allowable for “Satisfactory” dams,
but these deficiencies are non-structural and do not affect the safe operation of the dam.
- Dam has no known structural issues.
- Dam may have seepage/leakage issues that, though not deemed an immediate threat to the
stability of the dam, have not been adequately investigated, evaluated or addressed.
- Dam meets at least 90% of its design storm event standard for its classification.
Poor
- Dam has multiple maintenance deficiencies that can affect the safe operation of the dam, some
of which may be structural or need further evaluation by a qualified engineer.
- Dam may have structural issues.
- Dam may have significant seepage/leakage issues that need to be addressed.
- Conditions are not bad enough to warrant a lowering of the reservoir.
Unsatisfactory
- Dam is unsafe. A dam safety deficiency exists that requires prompt remedial action for problem
resolution. Reservoir restrictions may be necessary.
Not Rated
- No condition assessment of the dam has been completed.
- Inadequate information exists to make a condition assessment determination.
- Additional information concerning the condition of the dam is forthcoming from the dam owner.
Types of Dams
Embankment Dams: Embankment dams are the most common type of dam in use today. Materials
used for embankment dams include natural soil or rock, or waste materials obtained from mining or
milling operations. An embankment dam is termed an “earthfill” or “rockfill” dam depending on
whether it is comprised of compacted earth or mostly compacted or dumped rock. The ability of an
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embankment dam to resist the reservoir water pressure is primarily a result of the mass weight, type
and strength of the materials from which the dam is made.
Concrete Dams: Concrete dams are categorized according to the design used to resist the stress due
to reservoir water pressure. Three common types of concrete dams are: gravity, buttress and arch.
Gravity: Concrete gravity dams are the most common form of concrete dam. The mass
weight of concrete and friction resist the reservoir water pressure. Gravity dams are
constructed of vertical blocks of concrete with flexible seals in the joints between the blocks.
Buttress: A buttress dam is a specific type of gravity dam in which the large mass of concrete
is reduced, and the forces are diverted to the dam foundation through vertical or sloping
buttresses.
Arch: Concrete arch dams are typically rather thin in cross-section. The reservoir water forces
acting on an arch dam are carried laterally into the dam abutments. The shape of the arch
may resemble a segment of a circle or an ellipse, and the arch may be curved in the vertical
plane as well. Such dams are usually constructed of a series of thin vertical blocks that are
keyed together; barriers to stop water from flowing are provided between blocks.
https://damsafety.org/different-types-dams
Dam Failures
Hundreds of dam failures have occurred throughout U.S. history. These failures have caused
immense property and environmental damages and have taken thousands of lives. As the nation’s
dams age and population increases, the potential for deadly dam failures grows. No one knows
precisely how many dam failures have occurred in the U.S., but they have been documented in every
state. From Jan. 1, 2005 through June 2013, state dam safety programs reported 173 dam failures and
587 "incidents" - episodes that, without intervention, would likely have resulted in dam failure
(https://damsafety.org/dam-failures). Unfortunately, many dam-related incidents go unreported due
to several factors, including the rural nature of many dams.
Several factors influence loss of life from dam failures including the population at risk (PAR), the
velocity and depth of the flood wave, the time of day or year the dam failure occurs, ease of
evacuation from the inundated areas, and the timeliness of warning about the dam failure. Tools
have been developed, such as Emergency Action Plans (EAPs) to communicate to dam owners,
emergency management personnel, communities, and citizens the risks of dam failure and what
actions must be undertaken to protect life and property.
Types of Dam Failures

Dam failures are most likely to happen for several reasons:
1) Overtopping caused by water spilling over the top of a dam. Overtopping of a dam is often
a precursor of dam failure.
2) Foundation defects and slope instability (e.g. sinkholes or steep slopes)
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3) Cracking caused by natural settling of the dam

4) Inadequate maintenance and operation of the dam
5) Piping. Piping occurs by internal erosion caused by seepage. Seepage often occurs
around hydraulic structures, such as pipes and spillways; through animal burrows; around
roots of woody vegetation; and through cracks in dams, dam appurtenances, and dam
foundations.
https://damsafety.org/what-are-causes-dam-failures
Most dam failures occur due to flooding events that cause overtopping of the dam. Other factors
that may cause a dam to fail include foundation defects, internal erosion caused by seepage (piping),
and inadequate maintenance. Regardless of the manner in which a dam failure may occur,
communities and dam owners must be prepared to deal with the consequences.
Signs of Potential Dam Failure
• Seepage. The appearance of seepage on the downstream slope, abutments, or downstream

area may indicate or be the precursor to a dam failure. If the water is muddy and is coming
from a well-defined hole, material is probably being eroded from inside the embankment and
a potentially dangerous situation can develop.
• Erosion. Erosion on the dam and spillway is one of the most evident signs of danger.
• Cracks. Cracks are of two types: traverse and longitudinal. Traverse cracks appear
perpendicular to the axis of the dam and indicate settlement of the dam. Longitudinal cracks
run parallel to the axis of the dam and may be the signal for a slide, or slump, on either face of
the dam.
• Slides and Slumps. A slide on the face of a dam may cause catastrophic failure of the dam.
Slides may occur for many reasons.
• Subsidence. Subsidence is the vertical movement of the foundation materials. The rate of
subsidence may be so slow that it can go unnoticed without proper inspection. Foundation
settlement is the result of placing the dam and reservoir on an area lacking suitable strength,
or over unsuitable foundation materials such as sinkholes or mines.
• Vegetation. A prominent danger signal is the appearance of "wet environment" types of
vegetation such as cattails, reeds, mosses and other wet area vegetation. These types of
vegetation can be a sign of seepage.
• Boils. Boils indicate seepage water exiting under some pressure and typically occur in areas at
the toe or downstream of the dam.
• Animal Burrows. Animal burrows present a potential risk since such activity can undermine
the structural integrity of dams.
• Debris. Debris on dams and spillways can reduce the function of spillways, damage structures
and valves, and destroy appropriate vegetative cover.
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Impacts of Dam Failures

Dam failures may cause flooding that is much more impactful than riverine or coastal flooding.
Floodwaters from a dam failure may arrive before warning or evacuation can occur and the resulting
environmental impacts can be devastating. Additionally, dams serve as critical infrastructure to many
communities via water supply or power generation. The loss of these means have the potential to be
even more pervasive than the inundation of floodwaters. Often dams serve as a direct or indirect
economic driver for many communities. The loss of recreation, in addition to the other benefits dams
serve, impact the overall social, economic, and environmental resilience of communities across the
Commonwealth and the nation.
Emergency Planning
EAP Development
Emergency Action Planning involves a team of individuals with specific responsibilities related to
developing, reviewing, updating, and implementing the plan. A stakeholder group should be formed
as soon as possible to complete the EAP. The EAP will describe roles and responsibilities in detail.
In the event that the plan is implemented and damage or loss of the dam and/or downstream facilities
occur, the community will need to address recovery.
DOW has developed EAPs for many state owned dams and have provided EAP template forms with
basic dam and community information pre-populated for many municipally owned dams. Although
statewide data sources are excellence starting points, community information unique to the dam is
critical. Upon receipt of this EAP, dam owners should verify the information populated in the EAP. This
process can either be done individually or with the support of an EAP community stakeholder group.
Dam owners should determine the individuals responsible for implementing the EAP and complete the
contact information for each responsible individual in the three emergency level call-down lists and
the Emergency Services Contacts table. A back-up contact should be identified for each primary
contact in order to be prepared in the event that a primary contact is unable to perform their duties.
Please note that the roles listed in the notification call-down lists in the EAP template are generic and
should be revised as appropriate to accurately reflect the local community. Dam owners should also
identify local resources that can be utilized in the event of an emergency. These resources include
equipment and materials that may be needed for emergency remedial actions during an emergency
event.
In addition to the EAP text, an Evacuation Map, as well as inundation maps, are provided showing the
results of the dam study. These data identify potential inundation areas should the dam overtop.
Based on the inundation area, an Evacuation Map indicates areas to be considered for evacuation in
addition to routes that may be overtopped and some critical facilities such as hospitals, schools, and
treatment plants within the community. The evacuation area has been divided into areas and currently
unpopulated zones have been identified based on a review of aerial imagery. By designated
unpopulated areas, responders can focus on areas with greater potential for loss of life. These areas
should be reevaluated at least once a year for any changes in development.
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The data should be reviewed by stakeholder groups and modified to include additional areas within
the inundation area where people may be present that had not been identified, such as parks,
campgrounds, or other recreational facilities. Dam owners should also identify locations that will
require additional time and complexity for evacuation, such as hospitals, nursing homes, hotels,
schools, and community utilities. The Dam Operator should coordinate with property owners or
managers to determine if evacuation plans already exist for these facilities.
Dam owners should develop evacuation plans that include the following, at a minimum: how residents
and businesses within the inundation and/or evacuation areas will be notified; locations of emergency
shelters; which roads should be closed and how this will be accomplished; how residents without
access to vehicles will be transported to emergency shelters; and how food, water, and other supplies
will be provided to evacuees at the emergency shelters. 4-6
Upon finalizing EAPs, dam owners should deliver copies of the EAP to individuals responsible for
implementing the EAP. Dam owners should invite responsible individuals to an onsite review of the
dam to ensure each individual is familiar with the dam and its features. Dam owners are responsible
for maintaining and exercising the EAP. Dam owners should review EAPs at least once each year and
update the document as needed. This annual review should include contacting and verifying the phone
numbers for each of the contacts listed in the EAP.
Long-Term Recovery Plans

Dam owners, community leaders, and state and federal representatives involved in the long-term
recovery of a dam after a partial or total dam failure should carefully coordinate and prepare long-term
recovery plans to facilitate the recovery of critical community functions (drinking water supply, flood
control, recreation, etc.) lost as a result of a dam failure. Long-term recovery plans may be a valuable
resource used in conjunction with EAPs and associated dam failure inundation analyses. The long-term
recovery plans support dam owners in gaining an understanding of risks, mitigation alternatives, and
coordination efforts of post-disaster activities related to the repair or reconstruction of a failed dam.
These activities are intended to help transition the community from emergency response to disaster
recovery after implementation of Emergency Support Function (ESF) #14 – Community Recovery and
other applicable emergency response procedures.
Considerations and approach methods for populating and enhancing long-term recovery plans should
help set the stage for successful, comprehensive plan development.
Since dams are generally considered critical for the needs of the community, a plan should be in place
to restore essential functions provided by the facility in the event of a dam failure. If it is determined
that a dam does not serve a critical need for the region, consideration must be given to the feasibility
of dam reconstruction, including short- and long-term alternative needs, as well as potential future
risks associated with reconstruction.
The long-term recovery plans are not intended to address emergency response activities in the event
of a dam failure, or in the event of a perceived or imminent threat of dam failure. These emergency
response measures are implemented through the Emergency Action Plan (EAP), which is coordinated
by the dam owner, local emergency management officer, Kentucky Dam Safety, and/or Kentucky
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Emergency Management. Long-term recovery plans are designed to synergize with EAPs to help
transition from emergency response to recovery. EAPs contain a multitude of information that should
be reviewed and fully understood in order to successfully transition into short-term and eventually
long-term recovery. EAP information relevant to the long-term recovery may include critical
community contacts, immediate response procedures, the number and type of properties potentially
affected, critical infrastructure impacted, inundation maps, anticipated degree of impacts affecting
downstream properties, and other necessary information.
Long-term recovery plans do not address recovery of all community infrastructure that could be
affected by a dam failure, such as roads, bridges, buildings, power substations, telecommunication
systems, medical facilities, water and wastewater services, and other structures necessary for normal
community function. The plans should also not be considered as a stand-alone document, and must
be implemented in coordination with other, in-effect, local, regional, state and federal master plans
and disaster management response procedures. Plan implementation must consider all appropriate
federal, state, and local standards and regulations.
In support of developing long-term recovery plans, information and data may be retrieved from a
variety of sources including Kentucky’s Dam Safety Database, the dam’s EAP, inundation zone maps,
and other related local, state, and federal mitigation planning and emergency data sources. When
desired information is not available, dam owners may choose to complete new analyses as part of a
commitment to preparedness and to optimize the recovery from a dam failure.
For the most part, the risks due to dam failure are difficult to quantify and understand due to the
relative low probability and high consequences related to dam failures. However, when dams fail the
consequences are often catastrophic. Many outreach and education materials are available from a
variety of sources such as FEMA, DOW, and the Association of State Dam Safety Officials (ASDSO).
Long-term recovery plans are intended to be used as a planning tool that may proactively assist dam
owners to meet challenges should a catastrophic event occur.
Table 1. Dam incidents in Kentucky.

Incident Dam
Dam Name Incident Type URR*
Date Type
Slaughters Lake Dam 2/25/2018 Hydrologic Event Earth Yes
Hematite Lake Dam 6/11/1998 Not Known; Seepage-Piping Earth Yes
Guist Creek Lake Dam 3/1/1997 Inflow Flood - Hydrologic Event Earth No
Kincaid Creek Dam 3/1/1997 Inflow Flood - Hydrologic Event Earth No
Mud River MPS 6A 3/1/1997 Inflow Flood - Hydrologic Event Earth No
Indian Lake Dam 1/1/1983 Piping Earth Yes
Camp Ernst Dam 9/15/1978 Embankment Slide Earth Yes
Caulk Lake Dam 12/16/1973 Seepage Earth Yes
*URR = Uncontrolled Release of the Reservoir
http://npdp.stanford.edu/dam_incidents
Kentucky Dam Safety Program
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The dam risk assessment addresses the Commonwealth’s inventory of regulated dams and has
developed a model for 1) expanding the Commonwealth’s capability to address flood and seismic
risks associated with dams 2) effectively assess, communicate, and mitigate the risks associated with
dams, and 3) develop strategies to mitigate identified risks that can be incorporated in the both the
state and local hazard mitigation planning process.
Additionally, the risk assessment characterizes dam safety and the synergies with FEMA and the
Commonwealth’s Risk MAP program, which serves as the nation’s flood hazard mapping program.
Risk MAP (Mapping, Assessment, and Planning) carries a dam safety component with it; many of the
products created as part of this plan are complementary to the flood risk datasets and products
present in Risk MAP. The results of this risk assessment will be used to prioritize future dam
improvements and mitigation measures.
The outcomes of this risk assessment will serve to:
1) Provide a means to quantify, communicate, mitigate current and avoid future risk associated
with dams.
2) Provide a framework in which the public’s awareness of the risks associated with living
within the risk area of a dam failure will result in effective mitigation of current and future
risk.
3) Develop processes for effectively conducting routine dam risk assessments and measuring
reductions in risk.
4) Create partnerships that successfully leverages Kentucky Emergency Management and Dam
Safety programs with FEMA’s Mitigation and Dam Safety programs.
5) Integrate project outcomes into Kentucky’s hazard mitigation plan and to use project results
to effectively implement mitigation action and eliminate future risks.
6) Assist the Commonwealth of Kentucky in preparing standardized best practices for dam-
related risk assessments, emergency action planning, catastrophic long-term recovery
planning, and risk communication.
7) Educate local and state entities on the risks associated with living downstream of a dam.
Risk Assessment
In order to effectively characterize dam failure risks in the 2018 State Hazard Mitigation Plan update
for Kentucky, several methodologies were applied to create a holistic dam-related risk assessment.
Dam inundation maps and HAZUS risk assessments were conducted on a subset of state and
municipally owned dams. The HAZUS analyses were used to provide information on the expected
damage to the built environment. Additional tools developed by the Natural Resource Conservation
Service (NRCS) and US Bureau of Reclamation (USBR) were utilized to assess the risk of dams based
on their physical characteristics. Information on the risk assessment methodologies may be found
below.
Dam - 13
Assessment
Inundation Mapping
Inundation mapping uses predictive models to identify downstream flooding from a dam failure.
Two failure modes, piping and overtopping, are calculated and the resultant inundation areas are
identified. These data provide a characterization of the risk posed by dam failure to downstream
structures and infrastructure. The models use dam-related information to calculate the breach
parameters. These data may be edited to reflect more accurate and precise information or account
for future conditions, such as increased rainfall or other hydrologic and hydraulic parameters. The
models allow users to specify heights at each modeled cross section to determine how long the
floodwaters will be above the specified height. This is especially important in determining
inundation time and duration for bridges or other structures that are located downstream of the
dam. The outputs provide results on maximum elevation, depth, depth time, and flow for each cross
section in the analysis. These results are then used to create inundation maps within Geographic
Information Systems (GIS). The results of the inundation mapping may be found in Appendix D.3.
HAZUS
HAZUS is a nationally applicable standardized methodology developed by FEMA that contains
models for estimating potential losses from earthquakes, floods, and hurricanes. HAZUS uses GIS
technology to estimate physical, economic, and social impacts of disasters. It graphically illustrates
the limits of identified high-risk locations so users can then visualize the spatial relationships
between populations and other more permanently fixed geographic assets or resources for the
specific hazard being modeled, a crucial function in the pre-disaster planning process. HAZUS
analyses were also conducted for each county leveraging depth grids generated from the National
Flood Hazard Layer (NFHL) as part of the flood risk assessment.
Dam failure depth grids were utilized in HAZUS to create a user defined flood risk for each dam
assessed that provides a more granular analysis than is present in the automated flood depth
generation routines currently present in HAZUS. The analyses provided an estimate of damage and
losses using data provided with the HAZUS software for overtopping scenarios.
HAZUS results may be characterized in many different ways based on the user’s needs. For this risk
assessment, the flood loss estimation analysis for each dam is reported in tabular and spatial formats
in Appendix D.4. The tabular loss reports characterize the direct economic losses for agricultural
products, direct economic losses for buildings, a shelter summary, direct economic losses for utilities,
and direct economic losses for vehicles. The spatial loss format is reported for each dam based on
the total economic loss for buildings at a census block level. Losses were classified using the Natural
Breaks (Jenks) method and depict the census blocks with low, moderate, significant, and high
damage potential.
HAZUS outputs are very useful in assessing the potential damages from a potential dam failure. There
are a multitude of ways to characterize the analysis based on the needs of a particular agency or
individual. The results were based on an overtopping event and illustrate the census blocks affected
by each dam inundation zone. Losses were classified using the Natural Breaks (Jenks) method and
depict the census blocks with low, moderate, significant, and high damage potential. These products
are enormously useful for use in community development plans, local mitigation plans, and for
Dam - 14
Assessment
infrastructure development. Additionally, local data may be utilized to replace the native results
compiled as part of this plan to supplement the risk assessment further. At any rate, the HAZUS
outputs provide a building block for more refined risk assessments in the future.
NRCS Risk Assessment Spreadsheet Tool

The Natural Resources Conservation Service (NRCS) has created a spreadsheet tool that is based
on the U.S. Bureau of Reclamation’s (USBR) Risk Based Profile System (RBPS) developed for
dam safety prioritization. This spreadsheet provides an overall “Total Failure Index” and “Total Risk
Index” that are based on the potential for failure and the consequences of a failure. These values
can be used to rank and compare the dam with other dams to prioritize funding and future studies.
The risk assessment allows for overall dam-related risk prioritization.
The NRCS risk assessment spreadsheet consists of a series of questions that are answered by the
user based on available information for each dam assessed. The spreadsheet tool then calculates a
“Total Failure Index” based on the condition of the dam and its likelihood of failure and a “Total
Risk Index” based on the consequences of a failure and the likelihood of failure. The process
is relatively objective, which is important in order to be able to compare the dams to one another.
The spreadsheet contains five tabs: static, hydrologic, seismic, risk and consequences. The “static”
tab considers the risk of a “sunny-day” failure due to the condition of the dam including the
condition of the principal spillway, past reservoir filling history, seepage and deformation,
foundation geology, and the design, construction and monitoring of the embankment. Dam-specific
information such as the last inspection report and as-built drawings, as well as publicly available data
such as geologic quadrangle maps and soil surveys are assessed. The results are summed to
determine the “Static Failure Index.”
The “hydrologic” tab considers the risk of a failure during a storm event based on the hydrologic
capacity of the dam, and the geometric configuration of the spillways. Users enter values for each
field based on available data, including previous hydrologic & hydraulic analyses, and an overall
“Hydrologic Failure Index” is computed.
The “seismic” tab considers the proximity of the dam to seismic zones and the potential for
liquefaction of the dam foundation. Users enter values based on as-built drawings or publicly
available datasets such as seismic zones and geologic quadrangle maps. For this tab a “Seismic
Failure Index” is computed.
The “risk” tab calculates the “Total Failure Index” and the “Total Risk Index.” The “Total Failure
Index” is the sum of the three failure indices (static, hydrologic, and seismic). The maximum
amount of points for both the static and hydrologic failure indices is 300. The maximum for the
“Seismic Failure Index” is 100. Therefore, the maximum “Total Failure Index” that can be calculated
is 700. A higher risk index number corresponds with a higher risk of failure. For the “Total Risk
Index” the user enters the estimated population at risk and a “fatality rate” based on warning
time, the community’s understanding of evacuation procedures, and the depth and velocity of a
potential dam breach. The failure index for each scenario (static, hydrologic, and seismic) is
multiplied by the fatality rate and the population at risk to come up with a risk index. These risk
Dam - 15
2-7
Assessment
indices are summed to compute the “Total Risk Index.” Because the failure index is multiplied by
the population at risk to compute the risk index, there is no maximum value for the “Total Risk
Index.”
The final tab is a “consequences” tab which summarizes the risk indices and gives an overview of the
dam being considered. Most of the data on this tab is not considered in the computation of the risk
indices, but can be used to compare the different failure impacts of two dams with similar risk
indices. This information can help the end user determine which dam is more of a priority in terms of
funding or further analysis.
The output of the spreadsheet consists of two indices, a “Total Failure Index” (based on the
condition of the dam and its likelihood of failure) and a “Total Risk Index” (based on the
consequences of a failure combined with the likelihood of failure). These numbers can be computed
for all of the dams and used to rank the dams. This ranking can be used for risk prioritization to
determine which of the priority dams are in most need of further analysis or potential
mitigation measures. Tables 2.2 and 2.2 depict the “Total Failure Index” and “Total Risk Index” for
each of the assessed dam. The results of the Risk Assessment Spreadsheet Tool are located in
Appendix D.5.
Seismic Risk Assessment
One component of risk related to dams is the probability of failure and the consequences
(economic and non-economic) resulting from an earthquake. There are four active seismic
zones in Kentucky, each containing dams of all hazard categories (high – Class C, moderate,
Class B, and low – Class A). Thirty-three dams are in western Kentucky, closer to the New
Madrid and Wabash Valley seismic zones, and seven dams are in southeastern Kentucky, closer to
the East Tennessee seismic zone. An area of northeastern Kentucky is also of interest for
seismic loading. Table 2 presents a selection of dams in areas of higher seismic risk in Kentucky.
Seismic information was based on Kentucky Geological Survey (KGS) publications instead of USGS
publications, which are typically used in the NRCS risk assessment methodology discussed above.
KGS specializes in Kentucky-specific geologic hazards; this provides a thorough understanding of
state-specific seismic information that was leveraged for the risk assessment. The NRCS spreadsheet
instructs the user to use USGS mapping to obtain the peak ground acceleration (PGA) on rock for an
earthquake having a 2 percent probability of exceedance in 50 years (2,475-year return period). The
risk assessment utilizes the PGA on hard rock for the Maximum Credible Earthquake (MCE), as
derived by KGS for each county in Kentucky (Wang 2010). Figure 3 presents a map of Kentucky with
the MCE PGA values and the locations of all state regulated dams.
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Assessment
Figure 3. Regulated dams in Kentucky with seismic zones defined by county by the PGA from the MCE.
The probability of dam failure due to an earthquake is controlled primarily by the anticipated PGA,
represented by the seismic load factor. The limited geotechnical information regarding
foundation and embankment materials makes it difficult to identify dams that may have seismic
vulnerabilities, represented by the seismic response factor. Thus, the dams with higher seismic
failure indices are found in close proximity to the New Madrid seismic zone (extreme west
Kentucky) and the Wabash Valley seismic zone (western Kentucky counties along the Ohio River
adjacent to southwestern Indiana). Moderate seismic failure indices are found in areas slightly
farther from the New Madrid and Wabash zones (i.e., the remainder of western Kentucky) and in
areas near small source zones (northeastern and extreme southeastern Kentucky). The remainder
of the state has low seismicity and as a result, dams in these regions have the lowest seismic failure
indices (for PGA less than 0.1 g, the seismic load factor is zero, meaning the seismic failure index is
also zero).
Seismic Failure Index Methods

The Seismic Failure Index is comprised of two components: the seismic load factor and the seismic
response factor. The load factor is based solely on peak ground acceleration on rock, typically taken
Dam - 17
Assessment
from published seismic hazard mapping. The method is not designed to account for local site
effects, such as amplification or deamplification that results from soils at a particular site. The
response factor is based on geometric and material properties, with respect to foundation
liquefaction, embankment freeboard, and embankment cracking.
NRCS SFI
The maximum (worst) possible seismic failure index (100 points) is scaled relative to the static (300
points maximum) and hydrologic (300 points maximum) failure indices. Due to the relatively low
probability of occurrence of large earthquakes, the seismic failure index is the smallest contributor to
the total failure index, which is the sum of the three modes. The total NRCS risk index is the product
of the total failure index, PAR, and fatality rate.
Available data for the KDOW portfolio of regulated dams is often quite limited, particularly with
respect to site-specific embankment and foundation materials. In almost all cases, foundation
materials were assumed based on USDA soil survey maps. Embankment materials were assumed
based on the date of construction and a general assumption about changes over time in the state of
practice for filter design. It should be noted that concrete dams have unique failure modes that
cannot fully be represented by a screening tool designed for earth dams. A separate attempt to rate
concrete dams using a more appropriate tool is discussed below.
Modified USBR Method
In addition to applying the NRCS screening tool, KDOW also attempted to apply a modified version
of the seismic component of the USBR RBPS tool. The goal was to reevaluate the high seismic dams
using a method that accounts for additional seismic load and response criteria, and then to compare
the results against those from the NRCS tool. While the USBR seismic component is very similar to
the NRCS version, it includes an additional factor for potential embankment liquefaction. The seismic
load factor was assessed for two earthquakes; the MCE (using KGS published PGA values, identical to
the NRCS method discussed above) and a smaller earthquake that KGS has designated the “Probable
Earthquake” (PE) (Wang et al 2012). KGS defines the PE as “the earthquake that could be expected
to occur in the next 250 years.” The 250-year return period corresponds to a 26 percent probability of
exceedance in 75 years. Although the specific return period of the PE is not critical for this
application, the event is used to represent a more frequent earthquake that could cause a
seismically-induced dam failure.
Seismic load factors for the MCE and PE were scored using identical methods, and then the two
factors were added to produce a combined seismic load factor. The result is that dams will have
higher load factors if they are located in proximity to source zones that produce significant
earthquakes for both the MCE and PE. Based on the risk assessment, dams located in western and
northeastern Kentucky scored higher than those in southeastern Kentucky, all other things equal.
This is due to the PE for southeastern Kentucky having a seismic load factor of zero (PGA less than
0.1 g), while the PE for western and northeastern Kentucky has a seismic load factor greater than
zero.
Dam - 18
Assessment
Seismic Failure Index Results

Computing the seismic failure index required relatively little site-specific information. The input for
seismic loading was readily available from published KGS seismic hazard mapping. Freeboard
parameters could be calculated based on site-specific information in KDOW files (height of dam,
crest elevation, pool elevation). However, in 75 percent of the cases, site-specific information
was not available to understand the potential for foundation liquefaction, based solely on soil type
or the potential for embankment cracking, based on presence or absence of self-healing filter zones.
Soil types were based on county soil survey maps, which cannot account for potentially localized
variations in soil type and/or removal/replacement of soils during dam construction. The presence
or absence of filter zones was assumed based on when the dam was constructed, in relation to the
general state of practice regarding inclusion of self-healing filter zones in embankment dams.
NRCS SFI
The NRCS method was applied to the high seismic dams and results are included in the Table
below. The maximum possible seismic failure index is 100, compared to a maximum of 300 for both
the static and hydrologic failure indices.
The results ranged from 0 to 30, and were strongly correlated with the PGA, which is the basis
for the seismic load factor. Only one dam (KY0288, Lake Washburn, located in Ohio County)
scored zero, because the PGA for the MCE was below 0.1g. Five dams scored 30, and were
located in counties (Union, Daviess, McCracken, and Henderson) closest to the New Madrid or
Wabash Valley seismic zones. Four concrete gravity dams within the high seismic portfolio each
scored 2, indicating a low probability of failure. This was due in part to the assumption that they
are each founded on rock, thus no foundation liquefaction. This is a reasonable assumption based
on available project records and the general geologic setting. With regard to embankment
cracking, the concrete dams were scored favorably, assuming that even if the concrete were to
crack, it would not erode and widen to allow a catastrophic loss of pool, as could occur for a
cracked earth dam without a self-healing filter zone.
Modified USBR Method
The modified USBR method for earth dams (considering both MCE and PE) indicates a maximum
possible seismic failure index of 600. The USBR results ranged from 0 to 60, with trends generally
mirroring those of the NRCS method. It should be noted that the USBR numerical score cannot
be directly compared against scores from the NRCS method. Again, Lake Washburn scored zero
because the PGA for the MCE and PE was below 0.1g. One dam scored 60 (KY0402, Priester Dam,
located in McCracken County), as it has the highest PGA of any dam in the portfolio. Eleven dams
scored 22.5 or greater, and were located in counties (Union, Daviess, McCracken, Henderson,
and Crittenden) closest to the New Madrid or Wabash Valley seismic zones, except for two in
northeastern Kentucky (Rowan and Greenup Counties. The four concrete gravity dams within the
high seismic portfolio each scored 1.5, indicating a low probability of failure. This was due in part to
the assumptions that they are each founded on rock (thus no foundation liquefaction) and each
could crack without catastrophic loss of the lake upstream of the dam.
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Assessment
Table 2. Seismic Failure Indices for dams in high seismic areas.
Modified Modified
USBR SFI USBR SFI
KDOW NRCS
Dam Dam Type County (Earth (Concrete
No. SFI
Dam Dam
Method) Method)
0001 Des Islet Dam Earth Union 30 45 -
0004 N Fork Little River MPS No 4A Earth Christian 8 7.5 -
0012 Scenic Lake Dam Earth Henderson 30 45 -
0015 Kingfisher Lake Dam Earth Daviess 30 30 -
0016 Carpenter Lake Dam Earth Daviess 15 15 -
0029 Clements Lake Dam Earth Rowan 15 30 -
0037 Smokey Valley Dam Earth Carter 8 15 -
0039 Greenbo Lake Dam Earth Greenup 15 30 -
0042 Fishpond Lake Dam Rockfill Letcher 15 15 -
0044 Beshear Lake Earth Caldwell 8 7.5 -
0075 Whitesburg Impoundment Dam Gravity Letcher 2 1.5 18
0083 Chenoa Lake Dam Earth Bell 8 7.5 -
0113 Elkhorn Lake Dam Gravity Letcher 2 1.5 21
0114 Olive Hill Reservoir Dam Earth Carter 8 15 -
0118 Pine Mountain State Park Lake Dam Gravity Bell 2 1.5 18
0132 Marion City Lake (Old) Dam Earth Crittenden 8 15 -
0133 Marion City Dam Earth Crittenden 15 30 -
0142 Madisonville Reservoir Dam No 1 (North) Earth Hopkins 15 15 -
0143 Madisonville Reservoir Dam No 2 Earth Hopkins 2 1.5 -
0144 Madisonville Reservoir Dam No 3 (South) Earth Hopkins 8 7.5 -
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Assessment
Modified Modified
USBR SFI USBR SFI
KDOW NRCS
No. SFI
Dam Dam
Method) Method)
0145 Lake Peewee Dam Earth Hopkins 8 7.5 -
0148 Loch Mary Reservoir Dam Earth Hopkins 15 15 -
0156 Mortons Gap Reservoir Dam Earth Hopkins 8 7.5 -
0157 Nortonville Lake Dam Earth Hopkins 8 7.5 -
0171 Skinframe Creek Impoundment Earth Lyon 2 1.5 -
0173 Pennyrile Lake Gravity Christian 2 1.5 18
0176 NF Little River MPS 4B Earth Christian 8 7.5 -
0185 University Of Kentucky Youth Camp Dam Earth Hopkins 8 7.5 -
0189 Crofton Lake Dam Earth Christian 8 7.5 -
0192 Providence City Dam (Old) Earth Webster 15 15 -
0193 Providence City Dam (New) Earth Webster 15 15 -
0196 N Fork Little River MPS No 3 Earth Christian 8 7.5 -
0212 N Fork Little River MPS No 5 Earth Christian 8 7.5 -
0275 Cannon Creek Dam Earth & Rockfill Bell 15 15 -
0287 Dixon City Lake Dam Earth Webster 8 7.5 -
0288 Lake Washburn Earth Ohio 0 0 -
0324 Morganfield City Lake Dam Earth Union 30 45 -
0402 Priester Lake Dam Earth McCracken 30 60 -
0578 Kingdom Come State Park Dam Earth Harlan 15 15 -
0657 Boots Randolph Golf Course Dam Earth Trigg 8 7.5 -
0836 Audubon State Park Wildlife Lake Dam Earth Henderson 15 22.5 -
Dam - 21
Assessment
Modified Modified
USBR SFI USBR SFI
KDOW NRCS
No. SFI
Dam Dam
Method) Method)
1132 Daviess County Landfill Sed Pond Earth Daviess 3 3 -
1147 Sloughs Wildlife Area (Cavanaugh Tract) Earth Henderson 15 22.5 -
1164 Moist Soil Unit Earth Henderson 15 22.5 -
Dam - 22
Assessment
While the seismic failure index is driven by proximity to seismic source zones, the risk is also a
function of the potential loss of life and economic consequences. Further, risk should not be
focused on a single failure mode (e.g., seismic) but should consider all viable failure modes and
their relative probabilities.
Results of Dam Risk Assessment

The dam risk assessment was conducted using nationally accepted methodology and using data that
is much more granular than other state or regionally based mitigation plans. This comprehensive
assessment will allow the Commonwealth to make informed decisions based on sound information.
Additionally, the risk assessment serves as an initial baseline for future state and local dam-related risk
assessments. The combination of economic and social factors used in this risk assessment is
extremely valuable when considering potential mitigation options with limited funding.
Mitigation Action Identification

One of the primary goals outlined in the State Hazard Mitigation Plan is to identify actions to
mitigate current risks and avoid future risks associated with dams. The risk assessment
allowed for the rankings based on failure risks, population at risk, and future risks due to
potential “hazard creep” to identify mitigation options that include the following:
• Dam Improvements (capital improvements)
• Easements to disallow the introduction of future risk (“hazard creep”)
• Structure Buy Outs and Relocations
• Flood Protection (berm/floodwall and/or floodproofing)
• Conveyance and Storage
• Warning Systems and Emergency Action Plans (EAPs)
The mitigation screening incorporated the population at risk calculations, HAZUS inventory, and
observations from DOW’s dam inventory database. The data were used to identify densely
populated residential areas, high density structures (such as hospitals, schools, hotels, etc.), mobile
homes, campgrounds, sole access roads, commercial/industrial districts, and critical facilities.
Each category was populated with either a “yes” or “no” to provide a characterization of the
inundation area, and based on the assumptions shown in Table 3.
Dam - 23
Assessment
Table 3. Sources of characterization.
Characteristic of Inundation Area Source

Residential Area (> 15 homes)1 PAR Calculation – Number of homes
High Density Structure HAZUS and Field Observations – identification of school, hospital, or hotel
Mobile Homes/ Campgrounds PAR Calculation and Field Observations – Number of campgrounds
2
Sole Access Roads Map review – location of sole access related to a critical facility
Commercial/ Industrial Districts PAR Calculation – number of businesses
HAZUS and Field Observations – identification of emergency facility,
Critical Facility
treatment plant, school
*PAR – Population at Risk
1
It was assumed that if an area had more than 15 homes, there would likely be a high Benefit/Cost if
improvements were made upstream as opposed to through buy outs.
2
Sole access roads were identified as it related to critical facilities. It was assumed that residences
with an inundated sole access road would be included in an evacuation in the case of an emergency.
The screening provides an assessment of which mitigation options may provide benefit for the
downstream risks. Table 4 below describes the assumptions for each classification based on the
mitigation option, as well as examples of what each level represents for the option. Level 1
indicates that there is high potential benefit or reducing risks for a mitigation option. Level 2 indicates
that the mitigation option will likely provide a risk reduction; however, it may not be the priority
mitigation measure. Level 3 indicates that the preliminary screening shows that the mitigation option
will likely not provide desired benefits to the area inundated by the dam failure.
Table 4. Level of potential for mitigation options.

Mitigation Option Level 1 Level 2 Level 3
Dam Improvements – Does not meet the H&H Does not meet the Dam meets the H&H
Improvements to the dam to design criteria. H&H design design criteria.
meet H&H requirements. criteria.
Inundation area is Inundation area is
densely populated. not densely
populated.
Dam - 24
Assessment
Mitigation Option Level 1 Level 2 Level 3

Easements – Protection of The inundation area is The inundation The inundation area is
undeveloped areas to reduce not considered densely area is considered considered densely
future risks. populated. densely populated, populated.
however, pockets
of open space were
observed during a
map review.
Buy Outs/ Relocations – The inundation area is The inundation No residential structures
Removing the risks from the less densely populated. area is considered were located within the
inundation area in less densely populated. inundation area.
densely populated areas.
Flood Protection Berm/ Treatment plant Nonresidential
Floodproofing – Providing located in or adjacent structure is located
physical protection along to inundation area that in inundation area
critical infrastructure, may benefit from a that may benefit
commercial, or industrial berm. from
property to reduce damage. floodproofing.
Conveyance/ Storage – Road crossings are Treatment plants or

Modification of hydraulic located along Commercial/ Industrial
structures could attenuate downstream reach districts were not
or convey flow to modify and map review identified within the
inundation area. shows varying inundation area.
stages of
development.
Warning System/ Advanced Inundation area Inundation area does not
EAP – Provide more includes densely represent a densely
advanced warning or populated residential populated residential
evacuation system for area, high density development or
densely populated areas. structures. structures.
It should be noted that some items in Table 4 do not have three levels of benefits. For example, buy
outs/ relocations will remove risks from the inundation area and will always provide a benefit.
However, in heavily populated areas, it may be more economical to upgrade a dam as
opposed to buying out numerous structures.
The reviewed mitigation options are not necessarily independent of one another. It was assumed
that mitigation options may work in conjunction with one another. For example, Clements Lake
Dam was identified as benefiting from dam improvements, however, due to the population
downstream, a warning system could benefit the community and a berm around the water
treatment plant in Morehead, KY may provide the desired protection to the critical facility.
Risk MAP-related watershed based maps may provide additional insight to the risks associated with
dams. These products provide a generalized depth for the inundation zone of the dam, arrival times
of the flood wave after a dam failure, and specific call-outs where potential mitigation actions have
Dam - 25
Assessment
been identified. These data are extremely useful in communicating the areas of particular risk to
government officials and the general public.
The intent of the mitigation analysis was to provide direction on options best suited for the
characteristics of dams with a goal to serve as a communication tool for communities to
understand dam-related risks and options for reducing those risks. These rankings were based
on the adjusted total failure index of the dam and probability of loss of life; the dams were
assessed based on a combination of the two rankings. Excerpts of the mitigation screening are
located in Appendix D.6.
Floodplain management is an important and effective tool that may be used as a mitigation
alternative to preclude dam-related hazard creep (e.g. reclassification of lower risk dams to higher
risk dams). A floodplain management plan that includes the following components should be
considered for at-risk areas associated with dams:
1) Potential measures, practices, and policies to reduce the loss of life, damage to property,
public expenditures, and other impacts (such as water supply, economic ramifications, etc.)
in areas proximal to dams;
2) Plans for evacuation and flood fighting should a dam failure occur; and
3) Public education and awareness of dam-related risks.
These components are discussed in greater detail in the Emergency Planning section of this
document. Additionally, should communities choose to develop floodplain management plans in
areas impacted by dams, flood insurance premium reductions via the Community Rating System
(CRS) and the overall resilience of communities may be enhanced.
Given the magnitude of the analyses performed and their applicability to better characterize and
understand the risks of dam failures, this risk assessment provides a suite of products and results
that may be shared with all levels of government, dam owners and the general public. Additionally,
these products may be used to collaborate with dam owners and local governments to achieve cost
effective mitigation options, promote the purchase of flood insurance, and increase the awareness
of the risks inherent to dam-related risks.
Dam - 26
Assessment
References and Resources

Federal Emergency Management Agency. Emergency Action Planning for State Regulated High-
Hazard Potential Dams: Findings, Recommendations, and Strategies, FEMA 608, March 2,
2012, 40 pp.
Federal Emergency Management Agency. Federal Guidelines for Dam Safety: Emergency Action
Planning for Dam Owners, FEMA 64, 1998, 36 pp.
Federal Emergency Management Agency. Federal Guidelines for Dam Safety: Hazard Potential
Classification Systems for Dams, FEMA 333, 1998, 90 pp.
Fread, Danny L. DAMBRK – Revision 4, National Weather Service, 1998 (manual only), or Fread, Danny
L. and Lewis, J.M. FLDWAV, National Weather Service, 1996 (manual only).
Graham, Wayne. A Procedure for Estimating Loss of Life Due to Dam Failure, 1997 ASDSO Annual
Conference, pp. 629-640.
U.S. Bureau of Reclamation. Safety Evaluation of Existing Dams (SEED Manual), 1992. 178 pp.
U.S. Bureau of Reclamation. Training Aids for Dam Safety, Denver, 1988.
Wang, Z. (2010). “Ground Motion for the Maximum Credible Earthquake in Kentucky.” Report of
Investigations 22, Series XII, prepared for the Kentucky Geological Survey.
Wang, Z., Harik, I. E., Woolery, E. W., Shi, B., and Peiris A. (2012). “Seismic Hazard Maps and Time
Histories for the Commonwealth of Kentucky.” Report No. KTC-07-07/SPR246-02-6F,
prepared for the Kentucky Transportation Center.
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Assessment
Appendix D.1: Locations of Kentucky Dams
Appendix D.2: Dam Conditions Assessments
Appendix D.3: Inundation Mapping
Appendix D.4: HAZUS Results
Appendix D.5: NRCS-USBR Risk Assessment
Appendix D.6: Mitigation Screening
Dam - 28

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2018 Kentucky Hazard Mitigation

Plan Update – Dam Risk

This Risk Assessment will be used to understand Kentucky’s dam-related

KDOW Dam Safety Program

Dam Hazard Classifications

Figure 1. Regulated dams in Kentucky.

State Owned Dam Repair (SODR) Program

• KY Department of Fish and Wildlife – 26 dams

Figure 2. Locations of state owned dams.

National Dam Safety Program

National Inventory of Dams

Dam Conditions Assessments

Types of Dam Failures

3) Cracking caused by natural settling of the dam

Signs of Potential Dam Failure

• Seepage. The appearance of seepage on the downstream slope, abutments, or downstream

Impacts of Dam Failures

Long-Term Recovery Plans

Table 1. Dam incidents in Kentucky.

NRCS Risk Assessment Spreadsheet Tool

Seismic Risk Assessment

Seismic Failure Index Methods

Modified USBR Method

Seismic Failure Index Results

Modified USBR Method

Table 2. Seismic Failure Indices for dams in high seismic areas.

Results of Dam Risk Assessment

Mitigation Action Identification

Table 3. Sources of characterization.

Characteristic of Inundation Area Source

Table 4. Level of potential for mitigation options.

Mitigation Option Level 1 Level 2 Level 3

Conveyance/ Storage – Road crossings are Treatment plants or

References and Resources

Appendix D.1: Locations of Kentucky Dams

Appendix D.2: Dam Conditions Assessments

Appendix D.3: Inundation Mapping

Appendix D.4: HAZUS Results

Appendix D.5: NRCS-USBR Risk Assessment

Appendix D.6: Mitigation Screening

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