HomeMy WebLinkAboutRESOLUTION - 46-20 - 7/7/2020 - Cook County Multi-Jurisdictional Hazard PlanRESOLUTION NO.46-20
A RESOLUTION OF THE VILLAGE OF ELK GROVE VILLAGE AUTHORIZING
THE ADOPTION OF THE UPDATE OF THE COOK COUNTY MULTI -
JURISDICTIONAL HAZARD MITIGATION PLAN (CCMJHMP)
WHEREAS, the Village of Elk Grove Village recognizes the threat that natural hazards
pose to people and property within our community; and
WHEREAS, the Village of Elk Grove Village recognizes the importance of reducing or
eliminating vulnerability to disasters caused by natural hazards for the overall good andwelfare
of the community, and
WHEREAS, on October 10, 2000, the U.S. Congress passed the Disaster Mitigation Act
of 2000 ("Act") which provides the legal framework for the Federal Emergency Management
Agency (FEMA) mitigation, planning requirements for state, local, and tribal governments as a
condition of mitigation grant assistance emphasizing the need for pre -disaster mitigation of
potential hazards; and
WHEREAS, as a condition of future funding for mitigation projects, the Act requires
jurisdictions to prepare and adopt a hazard mitigation plan to identify and address certain
vulnerabilities that exist prior to and during a disaster; and
WHEREAS, FEMA supports post -disaster grant funding through the Hazard Mitigation
Plan Grant program, which has as a condition of funding eligibility, a requirement for jurisdictions
to prepare and adopt a hazard mitigation plan; and
WHEREAS, to maintain continued eligibility for FEMA mitigation grant assistance
programs the Act requires a hazard mitigation plan be updated every five years; and
WHEREAS, in accordance with the Act's requirements, 121 Cook County jurisdictions
engaged in the FEMA-prescribed mitigation planning process to prepare the 2019 Plan and its
associated local hazard mitigation plan annexes; and
WHEREAS, the 2019 Plan has been approved by the Illinois Emergency Management
Agency and Federal Emergency Management Agency, Region V.
NOW, THEREFORE, BE IT RESOLVED that the Village of Elk Grove Village
hereby:
1. Accepts, approves and adopts in its entirety, Volume 1, the Countywide Mitigation Actions
in Volume 2; and the Elk Grove Village Jurisdictional Annex of Volume 2 of the 2019
Cook County Multi -Jurisdictional Hazard Mitigation Plan.
2. Will continue to participate in the updating and revision of the 2019 Plan with another plan
review and revision to occur within a five year cycle, and designated staff will provide
annual progress reports on the status of implementation of the 2019 Plan to the Mayor and
Board of Trustees.
VOTE: AYES: 5 NAYS: 0 ABSENT: 1
PASSED this 7th day of July 2020.
APPROVED this 7th day of July 2020.
APPROVED:
Mayor Craig B. Johnson
Village of Elk Grove Village
ATTEST:
Loretta M. Murphy, Village Clerk
Cook County Multi -Jurisdictional Hazard Mitigation Plan Update
Executive Summary - July 2019
Hazard mitigation is the use of long-term and short-term policies, programs, projects, and other
activities to alleviate the death, injury, and property damage that can result from a disaster. Cook
County and a coalition of 121 municipal planning partners prepared and updated the 2019 Cook County
Multi -Jurisdictional Hazard Mitigation Plan in order to identify the risks posed by hazards and find ways
to reduce their impacts. The plan reduces risks for those who live in, work in, and visit the County.
1. Cook County Profile
Cook County is located in northeast Illinois on the western shore of Lake Michigan. It is the most
populous of the 102 counties in Illinois, with a 2018 estimated population of 5.18 million. In terms of
area, it is the sixth largest county, covering approximately 945 square miles. Cook County makes up
roughly 41 percent of the population of Illinois. The surrounding counties are Lake and McHenry to the
north, Kane, and DuPage to the west, and Will to the southwest. Lake Michigan is the county's eastern
border along with the State of Indiana.
Cook County is the second most populous county in the United States, after Los Angeles County. The
county contains 135 municipalities, covering about 85 percent of the area of the county. The remaining
unincorporated areas are under the jurisdiction of the Cook County Board of Commissioners, a 17-
member board elected by district.
The planning area's economy is strongly based in the educational services, health care, and social
assistance industry, followed by the professional, scientific, management, administrative, and waste
management industries. Major businesses include, but are not limited to, the U.S. Government,
Advocate Health System, JPMorgan Chase, Jewel-Osco, United Airlines, Abbott Laboratories, American
Airlines, and Walgreens. Major educational and research institutions in the county include Northwestern
University, Loyola University, DePaul University, the University of Chicago, and the University of Illinois
at Chicago.
Cook County has experienced 19 hazard events since 1967 for which federal disaster declarations were
issued. The Spatial Hazard Events and Losses Database for the United States (SHELDUS), maintained by
the University of South Carolina, includes many more hazard events. For Cook County, SHELDUS lists 851
instances of direct property, crop, monetary, or human loss due to a hazard event from 1960 through
2017 - an average of approximately 15 various direct loss events per year.
2. Participating Partners and the Planning Area
The responsibility for hazard mitigation lies with many, including private property owners; business and
industry; and local, state, and the federal government. Through multi -jurisdictional partnerships, local
jurisdictions within an area that has uniform risk exposure can pool resources and eliminate redundant
planning activities. Cook County opened this planning effort to all municipalities within the County. The
table, Planning Partners, lists the planning partners that participated in the planning process and are
covered under this plan. The planning area was defined as all incorporated and unincorporated areas of
Cook County as well as the incorporated areas of cities that cross county boundaries. The planning area
boundary is shown in the figure below (Figure: Planning Area).
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Municipalities that are partially in Cook County and are participating in the mitigation planning efforts of
adjacent counties are also included in the table below. Future efforts are already underway to include
these jurisdictions in future updates of the plan. Six jurisdictions that had not previously participated in
the 2014 Cook County MJ-HMP are now part of the 2019 Cook County MJ-HMP.
TABLE: PLANNING PARTNERS
PLANNING PARTNERS COVERED BY THIS HAZARD MITIGATION PLAN
Arlington Heights Bellwood Alsip
Barrington
Berkeley
Bedford Park
Bartlett
Berwyn
Blue Island
Des Plaines
Broadview
Bridgeview
Elk Grove Village
Brookfield
Burbank
Evanston
City of Chicago
Burnham
Glencoe
Cicero
Calumet City
Glenview
Countryside
Calumet Park
Golf
Elmwood Park
Chicago Heights
Hanover Park
Forest Park
Chicago Ridge
Hoffman Estates
Forest View
Country Club Hills
Inverness
Franklin Park
Crestwood
Kenilworth
Harwood Heights
Dixmoor
Lincolnwood
Hillside
Dolton
Morton Grove
Hodgkins
East Hazel Crest
Mount Prospect
Indian Head Park
Evergreen Park
Niles
LaGrange
Flossmoor
Northbrook
LaGrange Park
Ford Heights
Northfield
Lyons
Glenwood
Palatine
Maywood
Harvey
Park Ridge
McCook
Hazel Crest
Prospect Heights
Melrose Park
Hickory Hills
Rolling Meadows
Norridge
Hometown
Schaumburg
Northlake
Homewood
Skokie
North Riverside
Justice
South Barrington
Oak Park
Lansing
Streamwood
River Forest
Lemont
Wheeling
River Grove
Lynwood
Wilmette
Riverside
Markham
Winnetka
Rosemont
Matteson
Schiller Park
Merrionette Park
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Stickney
Midlothian
Stone Park
Oak Forest
Summit
Oak Lawn
Westchester
Olympia Fields
Western Springs
Orland Hills
Orland Park
Palos Heights
Palos Hills
Palos Park
Park Forest
Phoenix
Posen
Richton Park
Riverdale
Robbins
Sauk Village
South Chicago Heights
South Holland
Steger
Thornton
Tinley Park
University Park
Willow Springs
Worth
Not Participating in 2019
Cook County MJ-HMP
Not Participating in 2019 Cook
County MJ-HMP
Not Participating in 2019
Cook County MJ-HMP
Barrington Hills
Bensenville
Frankfort
Buffalo Grove
Burr Ridge
Woodridge
Deerfield
Elmhurst
Deer Park
Hinsdale
East Dundee
Oak Brook
Elgin
Roselle
3. Plan Development and Organization
The 2019 Cook County MJ-HMP was updated by a planning team of Cook County Department of
Homeland Security and Emergency Management staff and expert consultants, with guidance from a
steering committee representing the planning partners and other local stakeholders. The key steps in
updating the plan were as follows:
1. Determine the Planning Area and Resources
2. Build and Reconvene the Planning Team
3. Outreach Strategy
4. Review and Update Community Capabilities
5. Update and Conduct the Risk Assessment
6. Update the Mitigation Strategy
7. Keep the Plan Current
8. Review and Adopt the Plan
9. Create a Safe and Resilient Community
4. Mission Goals and Objectives
The defined mission for the 2019 Cook County MJ-HMP is to "Identify risks and sustainable,
cost-effective actions to mitigate the impact of natural hazards to protect the life, health, safety,
welfare, and economy of the communities of Cook County." Mitigation goals were established as
follows:
1. Develop and implement sustainable, cost-effective, and environmentally sound risk -reduction
(mitigation) projects.
2. Protect the lives, health, safety, and property of the citizens of Cook County from the impacts of
natural hazards.
3. Protect public services and critical facilities, including infrastructure, from loss of use during
natural hazard events and potential damage from such activities.
4. Involve stakeholders to enhance the local capacity to mitigate, prepare for, and respond to the
impacts of natural hazards.
5. Develop, promote, and integrate mitigation action plans.
6. Promote public understanding of and support for hazard mitigation.
Thirteen objectives were established for the plan that meets multiple goals, serving as stand-alone
measurements of the effectiveness of the mitigation action. Proposed mitigation actions were evaluated
in part based on how many goals and objectives they would help to fulfill.
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1. Eliminate or minimize disruption of local government operations caused by natural hazards
through all phases of emergency management.
2. Increase the resilience of (or protect and maintain) infrastructure and critical facilities.
3. Consider the impacts of natural hazards on future land uses in the planning area, including
possible impacts from climate change.
4. Integrate hazard mitigation policies into land use plans in the planning area.
5. Develop, improve, and protect systems that provide early warnings, emergency response
communications, and evacuation procedures.
6. Use the best available data, science and technologies to educate the public and to improve
understanding of the location and potential impacts of natural hazards, the vulnerability of
building types and community development patterns, and the measures needed to protect life
safety.
7. Retrofit, purchase, or relocate structures in high hazard areas, including those known to be
repetitively damaged.
8. Establish partnerships among all levels of local government, the private sector, and/or
nongovernmental organizations to improve and implement methods to protect people and
property.
9. Provide or improve flood protection on a watershed basis with flood control structures and
drainage maintenance plans.
10. Strengthen codes and land use planning and their enforcement, so that new construction or
redevelopment can avoid or withstand the impacts of natural hazards.
11. Encourage mitigation through incentive -based programs, such as the Community Rating System,
Firewise, and StormReady programs.
12. Reduce natural hazard -related risks and vulnerability to potentially isolated populations within
the planning area.
13. Encourage hazard mitigation measures that result in the least adverse effect on the natural
environment and that use natural processes.
5. Hazards Addressed
The steering committee considered the full range of natural hazards that could impact the planning area
and identified the following hazards as presenting the most significant concern:
• Dam or levee failure
• Drought
• Earthquake
• Flood
• Severe weather
• Severe winter weather
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• Tornado
Detailed risk assessments were performed for each of these hazards of concern. Also, a brief qualitative
review was conducted of technological and human -caused hazards of interest, which included the
following: epidemic or pandemic, nuclear power plant incident, secondary impacts from incoming
evacuees, widespread power outage, hazardous material incident, and coastal erosion. Climate Change
was addressed for each hazard, as applicable.
6. Risk Assessment Methodology
The risk assessments of the identified hazards of concern describe the risks associated with each hazard.
The following steps were used to define the risk of each hazard:
Profile and update each hazard, describing the geographic area it affects, its frequency and
severity, and the warning time provided before a hazard event occurs.
Use maps of hazard impact areas, as appropriate, to determine and update how many
structures, facilities, and systems are exposed to each hazard.
Assess the vulnerability of exposed structures and infrastructure based on exposure and the
probability of occurrence of a hazard event. Tools such as the Federal Emergency Management
Agency's (FEMA's) hazard modeling program called Hazus-MH were used to perform this
assessment for flood, dam failure, earthquake hazards, and tornado. Outputs similar to those
from Hazus-MH were generated for other hazards, using maps generated by the Hazus-MH
program.
A detailed inventory of critical facilities and infrastructure were reevaluated for this plan using GIs
applications. Over 6,000 facilities were inventoried and uploaded into the Hazus-MH model to support
the risk assessment.
7. Profiles of Cook County Hazards of Concern
The following hazards are addressed in the 2019 Cook County MJ-HMP. A brief description of each
hazard is included in this section of the Executive Summary.
7.1 Dam and Levee Failure
There are 40 dams in Cook County, all regulated by the Water Resources Division of the Illinois
Department of Natural Resources (IDNR). Importantly, 24 of these dams are classified as "high" (10) or
"significant" (14) hazard, which means they have significant downstream populations at risk if the dam
should fail. Flooding as a result of a dam and levee failure would significantly impact properties and
communities in the inundation zones. No records of dam failures in the planning area are available,
however.
There are also nine levee systems in Cook County. Although there is no history of levee failures in the
planning area, it should be noted that the State of Illinois experienced levee failures in 1993 and 2008. In
1993, 17 levee systems breached along the Mississippi River and the Illinois Riverjust north of where it
meets the Mississippi River. Over 237,000 acres along the rivers were flooded.
Warning time for dam or levee failure varies depending on the cause of the failure. In events of extreme
precipitation or massive snowmelt, evacuations can be planned with sufficient time. In the event of a
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structural failure due to an earthquake, there may be no warning time. Cook County and its planning
partners have established protocols for flood warning and response for dam failure in the flood warning
portion of its adopted emergency operations plan. These protocols are tied to the emergency action
plans created by the dam owners.
Important issues associated with dam and levee failure include the following:
• Federally regulated dams have an adequate level of oversight and sophistication in their
emergency action plans. However, the protocol for notifying downstream citizens of imminent
failure needs to be tied to local emergency response planning.
• Mapping that estimates inundation depths is needed for non -federal -regulated dams to better
assess the risk associated with dam failure from these facilities.
• Most dam failure mapping required at federal levels requires determination of the probable
maximum flood, which is a worst -case scenario and generally the event with the lowest
probability of occurrence. For non -federal -regulated dams, mapping of dam failure scenarios
that are less extreme than the probable maximum flood but have a higher probability of
occurrence could better illustrate areas potentially impacted by more frequent events to
support emergency response and preparedness.
• The concept of residual risk associated with structural flood control projects should be
considered in the design of capital projects and the application of land use regulations.
• Addressing security concerns and the need to inform the public of the risk associated with dam
failure is a challenge for public officials. Not all levees are reflected in the current flood mapping,
which makes complete delineation of the hazard area difficult.
7.2 Drought
Droughts originate from a deficiency of precipitation resulting from an unusual weather pattern. If the
weather pattern lasts a short time (a few weeks or a couple of months), the drought is considered short-
term. If the weather pattern becomes entrenched and the precipitation deficits last for several months
or years, the drought is considered to be long-term. Drought generally affects large geographic areas, so
drought descriptions in the hazard mitigation plan are usually for the entire State of Illinois rather than
the immediate planning area of Cook County.
The most severe droughts in Illinois occurred in the summer of 1934, the summer of 1931 and 1954. All
three of these events were categorized as extreme droughts. More recently, in September 1983, all 102
counties were declared state disaster areas because of high temperatures and insufficient precipitation.
In 1988, 54 percent of the state was impacted by drought -like conditions, resulting in disaster relief
payments to landowners and farmers exceeding $382 million. Historical drought data for the planning
area indicate there have been at least seven (7) significant droughts in the last 115 years, which equates
to a drought every 16 years on average, or a minimum of a 6.25-percent chance of a drought in any
given year.
Drought can have a widespread impact on the environment and the economy, although it typically does
not result in loss of life or damage to property, as do other natural disasters. The National Drought
Mitigation Center describes likely drought impacts as those affecting agriculture, water supplies, and the
risk of fire.
Scientists at this time do not know how to predict drought more than a month in advance for most
locations. How long a drought lasts depends on interactions between the atmosphere and the oceans,
soil moisture and land surface processes, topography, internal dynamics, and the accumulated influence
of weather systems on the global scale.
Crucial issues associated with drought include the following:
• Identification and development of alternative water supplies
• Use of groundwater recharge techniques to stabilize the groundwater supply
• The probability of increased drought frequencies and durations due to climate change
• The promotion of active water conservation even during non -drought periods.
7.3. Earthquake
An earthquake is the vibration of the earth's surface following a release of energy in the earth's crust.
Earthquakes tend to occur along faults, which are zones of weakness in the crust. Earthquakes occur
throughout Illinois, with most in the southern third of the state. Over 360 earthquakes have occurred in
Illinois during the past 20 years, with 32 resulting in damage. Fifteen events have been recorded in Cook,
DuPage, Kane, Kendall, and Will Counties since 1704. Cook County has experienced three earthquakes
ranging from a magnitude of 3 (categorized as "minor") to 4.9 (categorized as "light").
The actual movement of the ground in an earthquake is seldom the direct cause of injury or death.
Casualties generally result from falling objects and debris, because the shocks shake, damage or
demolish buildings and other structures. Disruption of communications, electrical power supplies and
gas, sewer and water lines should be expected. Earthquakes may trigger fires, dam failures, or releases
of hazardous material, compounding their effects. Any seismic activity of 6.0 or greater on faults within
the planning area would have significant impacts throughout the county. Earthquakes of this magnitude
or higher would lead to a massive failure of structures built on loose soils. Levees and revetments
constructed on such soils would likely fail, representing a loss of critical infrastructure. These events
could cause secondary hazards, including mudslides, that would further damage structures.
There is currently no reliable way to predict an earthquake at any given location with any significant
warning time. Research is being done with warning systems that use the low energy waves that precede
major earthquakes to give approximately 40 seconds notice that a major earthquake is about to occur.
The warning time is very short but it could allow for someone to get under a desk, step away from a
hazardous material they are working with or shut down a computer system.
Important issues associated with earthquakes include the following:
The public perception of the earthquake risk within the planning area is low. It can be difficult to
get the public to think about earthquake mitigation with little or no perceived risk.
Most of the planning area's building stock was built prior to 1975 when seismic provisions
became uniformly applied through building code applications. A building stock analysis that
looks at the potential fragility of the older building stock constructed without building code
influence would be beneficial in the identification of seismic mitigation projects.
• More earthquake mapping is needed for the planning area.
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• Critical facility owners/operators should be encouraged to create or enhance continuity of
operations plans using the information on risk and vulnerability contained in the Cook County
hazard mitigation plan.
• Geotechnical standards should be established that take into account the probable impacts of
earthquakes in the design and construction of new or enhanced facilities.
• The County has over 6 miles of earthen levees and revetments on soft, unstable soil. These soils
are prone to liquefaction, which would severely undermine the integrity of these facilities.
• There are a large number of earthen dams within the planning area. Dam failure warning and
evacuation plans and procedures should be reviewed and updated to reflect the dams' risk
potential associated with earthquake activity in the region.
7.4 Flood
Flood Types and History
Two types of flooding are typical in Cook County: riverine flooding when water overflows the banks of a
stream; and stormwater/urban drainage flooding, when storm runoff exceeds the capacity of local
drainage systems in place to convey stormwater to a receiving body. 231 flooding events (including
flood, flash flood, coastal flood, and heavy rains) have occurred in Cook County from 1996 to 2019.
Flood events of historical significance occurred in the Cook County region in 1849, 1855, 1885, 1938,
1952, 1954, 1957, 1961, 1973, 1979, 1986, 1987, 1996, 2001, 2004, 2010, 2011, and 2013. Since 1972,
13 presidential -declared flood events in the County have caused over $628.5 million in property
damage.
In the past 20 years, stormwater/urban drainage flooding has become the principal cause of flood losses
in the Cook County planning area. Urban portions of the county annually experience nuisance flooding
related to drainage issues. After flooding in August 2010, FEMA provided more than
$435 million in disaster recovery, response, and mitigation in Cook and DuPage Counties, and more than
75 percent of this went to individual homeowners, most of whom suffered sewer back-ups and
basement flooding caused by stormwater/urban drainage flooding. The frequency and the magnitude of
stormwater/urban drainage flooding in Cook County dictated the assignment of stormwater
management within the County to a single entity —the Metropolitan Water Reclamation District of
Greater Chicago (MWRD).
Cook County experiences numerous episodes of the river and urban flooding every year; massive floods
that can cause significant property damage typically occur every three to seven years.
Flood Mapping
Flood studies use historical records to determine the probability of occurrence for different river
discharge (flow) levels. The flood frequency equals 100 divided by the discharge probability. For
example, the 100-year discharge has a 1-percent chance of being equaled or exceeded in any given year.
The extent of flooding associated with a 1-percent annual probability of occurrence (the base flood or
100-year flood) is used as a regulatory boundary by many agencies. This boundary is a convenient tool
for assessing risk in flood -prone communities. For most communities participating in the National Flood
Insurance Program (NFIP), FEMA has prepared a detailed Flood Insurance Study that presents water
surface elevations for the 1- percent annual chance flood and the 0.2-percent annual chance flood (the
500-year flood). The boundaries of the 100- and 500-year floodplains are shown on Flood Insurance
Rate Maps.
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FEMA has mapped over 78 square miles of the 100-year floodplain and 99 square miles of 500-year
floodplain along 172 watercourses in the Cook County planning area. Approximately 8 percent of the
County is located within mapped 100-year floodplains. As is the case for many communities, there is a
need for updated maps that better reflect the actual flood risk. MWRD has created inundation maps,
which may be a good resource for some communities.
It should be noted that mapping showing areas of urban flooding is limited in the County
Flood Severity
The principal factors affecting flood damage are flood depth and velocity. The deeper and faster flood
flows become, the more damage they can cause. Shallow flooding with high velocities can cause as
much damage as deep flooding with slow velocity, is especially true when a channel migrates over a
broad floodplain, redirecting high -velocity flows and transporting debris and sediment.
The worst -case scenario for flooding in the Cook County planning area has happened numerous times in
the past. It involves intense rainstorms that stall over the planning area, dropping rainfall totals in excess
6 inches over 48 hours (this scenario is significantly exacerbated by the presence of snowpack on the
ground), which leads to both riverine and stormwater/urban drainage flooding that can overwhelm
flood response capabilities in the planning area. Significant roads can be blocked, preventing critical
access for many residents and critical functions. High in -channel flows can cause water courses to scour,
possibly washing out roads and creating more isolation problems.
Flood Warning
The Cook County flood threat system consists of a network of precipitation gages throughout the
watershed and stream gages at strategic locations that continuously monitor and report stream levels.
All of this information is analyzed by agencies such as the Cook County Department of Homeland
Security and Emergency Management (DHSEM) and Metropolitan Water Reclamation District to
evaluate the flood threat and possible evacuation needs.
Floods are generally classed as either slow -rise or flash floods. Due to the sequential pattern of
meteorological conditions needed to cause serious slow -rise flooding, it is unusual for a slow -rise flood
to occur without warning. Slow -rise floods may be preceded by a warning time from several hours, to
days, to possibly weeks. Evacuation and sandbagging for a slow -rise flood may lessen flood damage.
Flash floods are more difficult to prepare for, due to the extremely short warning time given, if any.
Flash flood warnings usually require evacuation within an hour. However, potential hazard areas can be
warned in advance of potential flash flooding danger.
Participation in Federal Flood Programs
The NFIP makes federally backed flood insurance available to homeowners, renters, and business
owners in participating communities. Cook County entered the NFIP on April 15, 1981. The effective
date for the current countywide Flood Insurance Rate Map is August 19, 2008. In addition to the County,
most Cook County municipalities participate in the NFIP. As of October 2018, Cook County had 14,790
flood insurance policies providing $3.092 billion in insurance coverage. According to FEMA statistics, in
the State of Illinois, there were 51,246 total losses (claims) between January 1, 1978, and January 31,
2019, for a total of approximately $545.36 million, an average of roughly $10,642 per claim.
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Twenty-four communities in the planning area also participate in the Community Rating System (CRS) a
voluntary program that encourages floodplain management activities that exceed the NFIP
requirements. The CRS requires participating communities to identify repetitive loss areas, where flood
insurance claims have been paid multiple times for individual properties. There are 1,775 such
properties in Cook County as of October 2018.
Issues
Important issues associated with flooding include the following:
• The 2-D, unsteady -state modeling performed by the Metropolitan Water Reclamation District is
considered to be the best available flood risk data for the planning area, but it is not the basis of
FEMA's current effective Flood Insurance Rate Map. The District's flood hazard data should be
formatted so that can be used to support risk assessment and thus validate best available data.
• The planning area has a large percentage of policies and losses outside a mapped hazard area.
Basement flooding is a common problem.
• The stormwater/urban drainage flooding risk is not mapped, which makes it difficult to assess
this hazard, other than looking at historical loss data.
• The risk associated with the flood hazard overlaps the risk associated with other hazards such as
an earthquake. This provides an opportunity to seek mitigation alternatives with multiple
objectives that can reduce the risk for multiple hazards.
• There is no consistency of land -use practices and regulatory floodplain management within the
planning area. It is unclear how potential climate change may impact flood conditions in the
planning area.
• The concept of residual risk should be considered in the design of future capital flood control
projects and should be communicated with residents living in the floodplain.
• More information is needed on flood risk to support the concept of risk -based analysis of capital
projects.
• There needs to be a sustained effort to gather historical damage data, such as high water marks
on structures and damage reports, to measure the cost-effectiveness of future mitigation
projects.
• Ongoing flood hazard mitigation will require funding from multiple sources.
• There needs to be a coordinated hazard mitigation effort between jurisdictions affected by flood
hazards in the county.
• Floodplain residents need to continue to be educated about flood preparedness and the
resources available during and after floods.
• The promotion of flood insurance as a means of protecting private property owners from the
economic impacts of frequent flood events should continue.
• The economy affects a jurisdiction's ability to manage its floodplains. Budget cuts and personnel
losses can strain the resources needed to support floodplain management.
7.5 Severe Weather
Severe weather refers to any dangerous meteorological phenomena with the potential to cause
damage, serious social disruption, or loss of human life. It includes hail, heat, excessive heat, lightning,
hail, fog, and high, strong, and thunderstorm winds. Severe -weather events can happen anywhere in the
planning area. Severe local storms are probably the most common widespread hazard. They affect large
numbers of people throughout Cook County and the surrounding region when they occur. The heat
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wave of July 1995 was one of the worst disasters in Illinois history, with over 700 deaths statewide over
five -days.
Records from the National Climatic Data Center indicate approximately 1,386 severe weather events
(not including heat and excessive heat events) in the planning area between 1950 and 2018 occurring
between 503 separate days. NCDC data from 1996 to 2018 also records 57 heat or excessive heat
events. This means that Cook County can expect approximately 9 days every year where at least one
severe weather event is occurring. More specifically, this represents an average of approximately 11
thunderstorm wind, 7 hail, 3 heat or excessive heat, 1 lightning, and 1 high or strong wind event every
year. According to the 2018 Illinois Natural Hazard Mitigation Plan, the planning area is designated as
severely vulnerable to severe storms, with a high vulnerability to extreme heat as well. There were no
significant fog events recorded for Cook County in the NCDC - NOAA data.
The most common problems associated with severe storms are immobility and loss of utilities. Roads
may become impassable due to flooding, downed trees, or a landslide. Power lines may be downed due
to high winds, and services such as water or phone may not be able to operate without power. Lightning
can cause severe damage and injury. A worst -case severe -weather event would involve prolonged high
winds during a thunderstorm. Such an event would have both short-term and longer -term effects.
Initially, schools and roads would be closed due to power outages caused by high winds and downed
tree obstructions. In more rural areas, some subdivisions could experience limited ingress and egress.
Prolonged rain could produce flooding and overtopped culverts with ponded water on roads. Flooding
could further obstruct roads and bridges, further isolating residents.
Meteorologists can often predict the likelihood of a severe storm or other severe weather events, which
can give several days of warning time. The Chicago Office of the National Weather Service issues severe
storm watches and warnings when appropriate to alert government agencies and the public of possible
or impending weather events. The watches and warnings are broadcast over NOAA weather radio and
are forwarded to the local media for re -transmission using the Emergency Alert System.
Important issues associated with severe weather include the following:
Redundancy of power supply throughout the planning area must be evaluated. The capacity for
backup power generation is limited.
Public education on dealing with the impacts of severe weather needs to be provided and debris
management (downed trees, etc.) must be addressed.
The effects of climate change may result in an increase in the frequency of extreme heat events.
7.6 Severe Winter Weather
The severe winter weather hazard encompasses heavy snow, lake -effect snow, blizzards, ice storms,
sleet, cold/windchill, extreme cold temperatures and wind chill, frost/freeze, general winter weather,
and winter storms. Severe winter weather events can happen anywhere in the planning area. NOAA
identifies 178 of these severe winter weather events in the planning area from 1950 - 2018, excluding
snowstorms classified as less than major snowstorms. The planning area typically receives 34 inches of
snow each year and can expect to experience exposure to a severe winter weather event at least
annually.
178 severe winter weather events were reported between 01/01/1950 and 06/01/2019, although
Cold/Windchill and Extreme Cold/Windchill were not recorded in available data sets until 1997 and
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2006, respectively. There have likely been many more of these events before those dates that were not
recorded by the NCDC data. All events totaled $700,000 in property damage, 156 direct deaths and 8
indirect deaths, and 5 direct injuries and 3 indirect injuries.
Severe winter weather impacts can be significant. Roads may become impassable due to ice or snow.
Power lines may be downed due to high winds or ice accumulation, and services such as water or phone
may not be able to operate without power. Physical damage to homes and facilities can occur from wind
damage or accumulation of snow or ice. Freezing rain can cause the most dangerous conditions. Ice
buildup can bring down trees, communication towers, and wires, creating hazards for property owners,
motorists, and pedestrians alike. Many severe winter weather events in the planning area have resulted
in the loss of life.
Meteorologists can often predict likely severe winter weather, giving several days of warning time. The
National Weather Service provides public warnings on storm, snow and ice events as appropriate to
alert government agencies and the public of possible or impending weather events. Watches and
warnings are broadcast over NOAA weather radio and are forwarded to local media for re -transmission
using the Emergency Alert System.
Important issues associated with severe winter weather in the planning area include the following:
• The older building stock in the planning area is built to low code standards or none at all. These
structures could be highly vulnerable to severe winter weather events such as windstorms.
• Redundancy of power supply must be evaluated.
• The capacity for backup power generation is limited.
• Isolated population centers are at significant risk.
7.7 Tornado
Tornadoes are the most violent of all atmospheric storms, and all of Illinois is susceptible to them,
including Cook County. The tornado season runs March through August, although a tornado can occur in
the state at any time. Many tornadoes have struck Cook County, including several within the Chicago
city limits. According to NCDC data, there were 54 tornado and three funnel cloud events from 1954 to
2018, which totaled $118,337,750 in property damage, 39 deaths, and 770 injuries. The F4-rated Oak
Lawn tornado in April 1967 was the deadliest tornado in the planning area, with 33 fatalities. The only
F5 tornado to ever strike the Chicago area was on August 28, 1990, which additionally impacted Will and
Kendall Counties. In total, 29 direct deaths, 350 injuries, and 250 million in property damage was
recorded.
Tornadoes can cause fatalities and devastate a neighborhood in seconds. Winds can reach 300 mph, and
damage paths can be more than a mile wide and 50 miles long. If a major tornado were to strike within
the populated areas of Cook County, the damage could be widespread. Businesses could be forced to
close for an extended period or permanently, fatalities could be high, many people could be homeless
for an extended period, and routine services such as telephone or power could be disrupted. Buildings
can be damaged or destroyed.
The local NWS office issues a tornado watch when tornadoes are possible in an area and a tornado
warning when a tornado has been sighted or indicated by weather radar. The current average lead time
for tornado warnings is 13 minutes. The National Weather Service has established a goal of 15 minutes
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in its strategic plan. Occasionally, tornadoes develop so rapidly that little, if any, advance warning is
possible.
Important issues associated with tornadoes in the planning area include the following:
• The older building stock in the planning area is built to low code standards or none at all. These
structures could be highly vulnerable to tornadoes.
• Redundancy of power supply must be evaluated. The capacity for backup power generation is
limited.
• The amount of the tornado zone that contains vacant, developable land is not known and would
be valuable information for gauging the future development potential of the tornado zone.
• Declining growth rate makes it difficult for code standards to have impacts on new
development. The planning area has insufficient suitable tornado shelters.
• Public awareness of tornado response protocols is a concern, given the area's many visitors.
8. Planning Area Risk Ranking
Risk rankings were performed by each planning partner to compare the probable impacts of the
hazards of concern. For each community, the rankings assessed the probability of each hazard's
occurrence as well as its likely impact on people, property, and the economy. The results of the
countywide ranking, which were used in establishing mitigation action and priorities, are
summarized below.
TABLE: HAZARD RISK RANKING
Hazard Ranking
Hazard Event
Category
1
Severe Winter Weather
High
2
Severe Weather
High
3
Flood (including urban flooding)
High
4
Earthquake
Medium
5
Tornado
Medium
6
Drought
Low
7
Dam Failure
Low
9. Mitigation Strategies
The heart of the mitigation plan is the mitigation strategy, which serves as the long-term blueprint for
reducing the potential losses identified in the risk assessment. The mitigation strategy describes how
Cook County and the participating jurisdictions will accomplish the overall purpose, or mission, of the
planning process. As part of the update process, mitigation goals and objectives were reevaluated; and
mitigation actions/projects were updated/amended, identified, evaluated, and prioritized. A total of 367
new mitigation projects were identified by the County and participating jurisdictions.
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10. Plan Maintenance Strategy
The hazard mitigation plan includes a formal process to ensure that the 2019 Cook County MJ-HMP
remains an active and relevant document and that the planning partners maintain their eligibility for
relevant funding sources. The plan's format allows sections to be reviewed and updated when new data
become available, resulting in a plan that will remain current and relevant. The strategy for ongoing
maintenance of the plan includes the following components:
Plan Implementation —Plan implementation and evaluation will be a shared responsibility among all
planning partners and agencies identified as lead agencies in the mitigation action plans. Cook County
DHSEM will assume lead responsibility for implementing the plan maintenance strategy.
Steering Committee —It is recommended that a steering committee remain a viable body involved in
key elements of the plan maintenance strategy. The steering committee will strive to include
representation from the planning partners, as well as other stakeholders in the planning area.
Annual Progress Report —The steering committee will convene to perform annual reviews. DHSEM will
then prepare a formal annual report on the progress of the plan.
Plan Update —The planning partnership intends to update the hazard mitigation plan on a five-year
cycle from the date of initial plan adoption.
Continuing Public Involvement —The public will continue to be apprised of the plan's progress through
the Cook County hazard mitigation website and by copies of annual progress reports provided to the
media. DHSEM has agreed to maintain the hazard mitigation plan website, and each planning partner
has agreed to provide links to the website on their jurisdictional websites.
Incorporation into Other Planning Mechanisms —All municipal planning partners are committed to
creating a linkage between the hazard mitigation plan and their comprehensive plans by identifying a
mitigation action as such and giving that action a high priority. As information becomes available from
other planning mechanisms that can enhance this plan, that information will be incorporated via the
update process.
11. Plan Adoption
The 2019 Cook County MJ-HMP will be submitted for a pre -adoption review to the Illinois Emergency
Management Agency and FEMA before adoption by Cook County. Once pre -adoption approval has been
provided, all planning partners will formally adopt the plan.
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