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LINCOLN COUNTY AND MINNEHAHA COUNTY MULTI-HAZARD
PRE-DISASTER MITIGATION PLAN 2011 UPDATE
Prepared By:
Lincoln and Minnehaha Counties Pre-Disaster Mitigation Planning Committee
As Directed By:
Lincoln County Emergency Management 128 N. Main Street
Canton, SD 57013-1703
Minnehaha County Emergency Management 608 Sigler Ave.
Sioux Falls, SD 57104
Contact: Lincoln County EM Harold Timmerman (605) 764-5746,
Minnehaha County EM Lynn DeYoung (605) 367-4290, [email protected]
Prepared With The Technical Assistance Of:
South Eastern Council of Governments 500 N Western Ave., Suite 100
Sioux Falls, SD 57104
Contact: Seth Hyberger, Planner (605) 367-5390, [email protected]
Submitted to:
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Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Table of Contents…………………………………………………………………. i
Introduction and Purpose…………………………………………………………1
Purpose…………………………………………………………………...… 1
Background………………………………………………………………… 1
Jurisdictions………………………………………………………………... 2
Organizations………………………………………………………………. 2
Chapter I Perquisites and Community Profile
1.1 Adoption by Local Governing Body………………………………………….. 4
1.2 Multi-Jurisdictional Plan Adoptions…………………………………………... 4
1.3 Multi-Jurisdictional Planning Participation…………………………………… 5
Jurisdictions……………………………………………………………….. 5
Organizations……………………………………………………………… 5
1.4 Community Profile……………………………………………………………. 6
Population………………………………………………………………….. 6
Physical Description……………………………………………………….. 7
Social and Economic Description………………………………………….. 8
Transportation and Utility Infrastructure………………………………….. 11
Medical and Emergency Services………………………………………….. 11
Chapter II Planning Process
2.1 Documentation of the Planning Process……………………………………….. 13
2.2 Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster
Mitigation Planning Committee………………………………………………... 14
Local Collaboration………………………………………………………... 15
State and Federal Collaboration…………………………………………… 17
Public Participation………………………………………………………… 17
Drafting the Plan…………………………………………………………… 17
Chapter III Hazard Assessment
3.1 Hazard Identification…………………………………………………………... 18
3.2 Profiling Hazards & Assessing Vulnerability………………………………….. 24
3.3 Hazard Assessment…………………………………………………………….. 28
3.3.1 Severe Summer Storms (including excess rain, lightning and hail)…………. 29
Probability of Occurrence………………………………………………….. 29
Vulnerability and Loss Potential…………………………………………… 30
Vulnerability Summary…………………………………………………….. 33
Existing Capabilities……………………………………………………..… 33
Future Development……………………………………………………….. 33
History………………………………………………………………………34
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3.3.2 Severe Winter Storms (including freezing and extreme cold)……………….. 34
Probability of Occurrence………………………………………………….. 34
Vulnerability and Loss Potential…………………………………………… 35
Vulnerability Summary…………………………………………………….. 37
Existing Capabilities……………………………………………………….. 38
Future Development……………………………………………………….. 38
History…………………………………………………………………....... 39
3.3.3 Tornados and High Winds…………………………………………………… 39
Probability of Occurrence………………………………………………….. 39
Vulnerability and Loss Potential…………………………………………… 40
Vulnerability Summary…………………………………………………….. 43
Existing Capabilities……………………………………………………….. 44
Future Development……………………………………………………….. 44
History……………………………………………………………………... 44
3.3.4 Flooding……………………………………………………………………… 45
Probability of Occurrence………………………………………………….. 45
Vulnerability and Loss Potential…………………………………………… 48
Vulnerability Summary…………………………………………………….. 53
Existing Capabilities……………………………………………………….. 54
Future Development……………………………………………………….. 54
History………………………………………………………………………55
3.4 National Flood Insurance Program Participation………………………………. 55
3.5 Population Density & Building Exposure Vulnerability to All Hazards………. 57
3.6 Lincoln County and Communities Future Growth and Development………… 59
3.7 Minnehaha County and Communities Future Growth and Development...…… 61
Chapter IV Hazard Mitigation Strategy
4.1 Hazard Mitigation Goals and Objectives………………………………………. 63
Background………………………………………………………………… 63
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster
Hazard Mitigation Plan 2011 Update - Problem Statements………………. 64
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster
Hazard Mitigation Plan 2011 Update - Goals and Objectives………..……. 65
4.2 Hazard Mitigation Actions…………………………….………………………. 66
4.3 Lincoln County and Minnehaha County HMGP Project Applications 2011…...71
Chapter V Plan Maintenance
5.1 Plan Maintenance Process………………………………………………………72
5.2 Plan Monitoring, Evaluation, and Updating………………………………….. 72
5.3 Plan Integration……………………………………………………………….. 74
Figures:
Figure 1-1: Lincoln County and Minnehaha County Infrastructure……………..… 10
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Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Figure 3-1: South Dakota Seismic Hazard Map………………………………….... 21
Figure 3-2: Lincoln County and Minnehaha County Expansive Soils…………….. 22
Figure 3-3: South Dakota Land Slide Incidence and Susceptibility……………… 23
Figure 3-4: Wind Zones in the United States……………………………………… 39
Figure 3-5: Vulnerability in Flood Prone Areas - Lincoln County……………..…. 52
Figure 3-6: Vulnerability in Flood Prone Areas - Minnehaha County………..…… 53
Tables:
Table 1-1: Lincoln County Population Characteristics…………………………….. 6
Table 1-2: Minnehaha County Population Characteristics………………………… 7
Table 1-3: Monthly Climatic Conditions in Minnehaha and Lincoln Counties
Region…………………………………………………………………... 8
Table 1-4: Income, Job Earnings, and Poverty - Lincoln County………………… 9
Table 1-5: Income, Job Earnings, and Poverty - Minnehaha County……………… 9
Table 2-1: Participation in Plan Development (2011 Update) and
Meeting Attendance…………………………………………………..… 14
Table 2-2: Summary of the Planning Process……………………………………… 15
Table 3-1: Presidential Disaster Declarations in Lincoln County…………………. 26
Table 3-2: Presidential Disaster Declarations in Minnehaha County……………… 27
Table 3-3: Hazard Risk Assessment Matrix……………………………………….. 28
Table 3-4: Impact of Severe Summer Storms - Lincoln County…………………. 30
Table 3-5: Impact of Severe Summer Storms - Minnehaha County……………… 30
Table 3-6: Crop Loss Due to Severe Summer Storms (2000-2009) -
Lincoln County…………………………………………………………. 32
Table 3-7: Crop Loss Due to Summer Storms (2000-2009) -
Minnehaha County……………………………………………………… 32
Table 3-8: Impact of Severe Winter Storms - Lincoln County…………………..... 35
Table 3-9: Impact of Severe Winter Storms - Minnehaha County……………….... 35
Table 3-10: Crop Loss Due to Winter Weather - Lincoln County……………..….. 36
Table 3-11: Crop Loss Due to Winter Weather - Minnehaha County……………. 37
Table 3-12: Impact of Tornados and High Wind - Lincoln County………………. 41
Table 3-13: Impact of Tornados and High Winds - Minnehaha County…………. 41
Table 3-14: Crop Loss Due to High Winds (2000-2009) - Lincoln County……… 42
Table 3-15: Crop Loss Due to High Winds (2000-2009) - Minnehaha County….... 42
Table 3-16: Lincoln County and Minnehaha County Dams Inventory……………. 47
Table 3-17: Impact of Flooding - Lincoln County……………..………………….. 48
Table 3-18: Impact of Flooding - Minnehaha County……………………...……… 49 Table 3-19: HAZUS-MH Base Flood (1 Percent Chance) Loss Estimation Results:
Impacts on Lincoln County and Minnehaha County………………………… 50 Table 3-20: Crop Loss Due to Flooding (2000-2009) - Lincoln County…………... 50
Table 3-21: Crop Loss Due to Flooding (2000-2009) - Minnehaha County………. 51
Table 3-22: National Flood Insurance Program Participation - Lincoln County….. 56
Table 3-23: National Flood Insurance Program Participation - Minnehaha County. 56
Table 3-24: Building Exposure……………………………………………………. 57
Table 3-25: Population Density…………………………………………………… 58
Table 3-26: Lincoln County Total Property Evaluation & Population Density…… 58
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Table 3-27: Minnehaha County Total Property Evaluation & Population Density... 59
Table 3-28: Lincoln County and Communities Future Growth and
Development Trends………………………………………………….. 60
Table 3-29: Minnehaha County and Communities Future Growth and
Development Trends………………………………………………….. 61
Table 4-1: Status of Mitigation Projects included in the revised 2005
“Multi-Hazard Pre-Disaster Mitigation Plan - Serving the
Jurisdictions and Communities of Minnehaha and Lincoln
Counties and City of Sioux Falls”……………………………………. 66
Table 4-2: Status of Mitigation Projects included in the revised 2005
“Multi-Hazard Pre-Disaster Mitigation Plan - Serving the
Jurisdictions and Communities of Minnehaha and Lincoln
Counties and City of Sioux Falls”……………………………………. 68
Table 4-3: Lincoln and Minnehaha County HMGP Project
Applications 2011……………………………………………………… 71
Table 5-1: Plan Monitoring, Evaluation, and Updating Schedule 2011-2016……. 73
Appendix A: County and Community Adoption Resolutions, and FEMA
Acceptance Letter
Appendix B: Meeting Sign-In Sheets, Agendas, and Minutes
Appendix B-1: Meeting 1, August 31, 2010, Sign-In Sheet 1……………………... B-1
Appendix B-2: Meeting 1, August 31, 2010, Sign-In Sheet 2…………………….. B-2
Appendix B-3: Meeting 1, August 31, 2010, Agenda……………………………... B-3
Appendix B-4: Meeting 1, August 31, 2010, Minutes……………………………... B-4
Appendix B-5: Meeting 2, November 16, 2010, Sign-In Sheet…………………….B-6
Appendix B-6: Meeting 2, November 16, 2010 Agenda…………………………. B-7
Appendix B-7: Meeting 2, November 16, 2010, Minutes…………………………. B-8
Appendix B-8: Meeting 3, January 25, 2011, Sign-In Sheet………………………. B-10
Appendix B-9: Meeting 3, January 25, 2011, Agenda…………………….………. B-11
Appendix B-10: Meeting 3, January 25, 2011, Minutes……………………..…….. B-12
Appendix B-11: Meeting 4, March 15, 2011, Sign-In Sheet………………………. B-14
Appendix B-12: Meeting 4, March 15, 2011, Agenda…………………………….. B-15
Appendix B-13: Meeting 4, March 15, 2011, Minutes…………………………..… B-17
Appendix B-14: Meeting 5, August 31, 2011, Sign-In Sheet………………………B-19
Appendix B-15: Meeting 5, August 31, 2011, Agenda……………………………. B-20
Appendix B-16: Meeting 5, August 31, 2011, Minutes……………………………. B-21
Appendix B-17: Public Forum Lincoln County, September 27, 2011,
Sign-In Sheet……..………………………………………………………………… B-23
Appendix B-18: Public Forum Lincoln County, September 27, 2011, Agenda…… B-24
Appendix B-19: Public Forum Minnehaha County, September 28, 2011,
Sign-In Sheet……..………………………………………………………………… B-25
Appendix B-20: Public Forum Minnehaha County, September 28, 2011, Agenda.. B-26
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Appendix C: Press Releases and Public Notices
C-1: Press Release 1, Meeting 2, November 16, 2011…………………………….. C-1
C-2: Press Release 2, Meeting 3, January 25, 2011………………………………... C-3
C-3: Press Release 3, Meeting 4, March 15, 2011…………………………………. C-4
C-4: Press Release 4, Public Forums Lincoln and Minnehaha
Counties, September 12, 2011…………………………………………………….. C-5
C-5: Public Notice, The Hartford Area News, Meeting 4, March 15, 2011……….. C-6
C-6: Public Notice, Beresford Republic, Meeting 4, March 15, 2011…………….. C-7
C-7: Public Notice, The Sioux Valley News, Meeting 4, March 15, 2011…….….. C-8
C-8: Public Notice, Argus Leader, Meeting 4, March 15, 2011……………..…….. C-9
C-9: Public Notice, Argus Leader Media, Meeting 4, March 15, 2011…………… C-10
C-10: Public Notice, Argus Leader, Public Forums, September 27 and 28, 2011… C-11
C-11: Public Notice, Argus Leader Media, Public Forums,
September 27 and 28, 2011………………………………………………………… C-12
C-12: Public Notice, Lennox Independent, Public Forums,
September 27 and 28, 2011………………………………………………………… C-13
C-13: Public Notice, Tea Weekly, Public Forums,
September 27 and 28, 2011………………………………………………………… C-14
Appendix D: History of Significant Weather Events in Lincoln County
D-1: History of Significant Weather Events in Lincoln County…………………....D-1
Appendix E: History of Significant Weather Events in Minnehaha County
E-1: History of Significant Weather Events in Minnehaha County……………..… E-1
Appendix F: Community Critical Facilities Listings
F-1: City of Baltic Critical Facilities…………………………………………….… F-1
F-2: City of Beresford Critical Facilities………………………………………...… F-2
F-3: City of Brandon Critical Facilities………………………………………….… F-3
F-4: City of Canton Critical Facilities……………………………………………... F-4
F-5: City of Colton Critical Facilities……………………………………………… F-5
F-6: City of Crooks Critical Facilities………………………………………….….. F-6
F-7: City of Dell Rapids Critical Facilities………………………………………… F-7
F-8: Town of Fairview Critical Facilities………………………………………….. F-8
F-9: City of Garretson Critical Facilities………………………………………….. F-9
F-10: City of Harrisburg Critical Facilities………………………………………… F-10
F-11: City of Hartford Critical Facilities………………………………………...… F-11
F-12: City of Hudson Critical Facilities…………………………………………… F-12
F-13: City of Humboldt Critical Facilities………………………………………… F-13
F-14: City of Lennox Critical Facilities…………………………………………… F-14
F-15: City of Sioux Falls Clinics………………………………………………….. F-15
F-16: City of Sioux Falls City Hall and Courthouses……………………………... F-16
F-17: City of Sioux Falls Emergency Response Services…………………………. F-17
F-18: City of Sioux Falls Hospitals………………………………………………... F-18
F-19: City of Sioux Falls Nursing Homes………………………………………… F-19
F-20: City of Sioux Falls Schools…………………………………………………. F-20
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F-21: Town of Sherman Critical Facilities………………………………………… F-21
F-22: City of Tea Critical Facilities……………………………………………….. F-22
F-23: City of Valley Springs Critical Facilities……………………………………. F-23
F-24: City of Worthing Critical Facilities………………………………………..… F-24
Appendix G: Community Flood Zones Maps
G-1: City of Baltic Flood Zones Map…………………………………………….... G-1
G-2: City of Beresford Flood Zones Map………………………………………… G-2
G-3: City of Brandon Flood Zones Map………………………………………….. G-3
G-4: City of Canton Flood Zones Map……………………………………………. G-4
G-5: City of Colton Flood Zones Map……………………………………………. G-5
G-6: City of Crooks Flood Zones Map…………………………………………… G-6
G-7: City of Dell Rapids Flood Zones Map………………………………………. G-7
G-8: Town of Fairview Flood Zones Map………………………………………… G-8
G-9: City of Garretson Flood Zones Map………………………………………… G-9
G-10: City of Harrisburg Flood Zones Map……………………………………….. G-10
G-11: City of Hartford Flood Zones Map………………………………………….. G-11
G-12: Town of Hudson Flood Zones Map………………………….……………… G-12
G-13: City of Humboldt Flood Zones Map…………………………...…………… G-13
G-14: City of Lennox Flood Zones Map…………………………………………... G-14
G-15: Town of Sherman Flood Zones Map……………………………………….. G-15
G-16: City of Sioux Falls Flood Zones Map……………………………………… G-16
G-17: City of Tea Flood Zones Map………………………………………………. G-17
G-18: City of Valley Springs Flood Zones Map………………………...…………. G-18
G-19: City of Worthing Flood Zones Map………………………………………… G-19
Appendix H: Lincoln County, Minnehaha County, and its Communities
Proposed Mitigation Actions……………………………………... H-1
Appendix I: Bibliography……………………………………………………...… I-1
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Introduction
Purpose
The purpose of the Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster
Mitigation Plan 2011 Update is:
1) To guide Lincoln County and Minnehaha County’s mitigation programs to
reduce the impacts of or remove the effects of significant hazards from these
jurisdictions e.g., threats to life and property.
2) To serve as a public and private sector reference document and management
tool for mitigation activities throughout Lincoln and Minnehaha Counties.
3) To meet the local planning requirements of the Robert T. Stafford Disaster
Relief and Emergency Assistance Act, as amended by Public Law 106-390,
October 30, 2000 UNITED STATES CODE Title 42. THE PUBLIC
HEALTH AND WELFARE CHAPTER 68. DISASTER RELIEF [As
amended by Pub. L. 103-181, Pub. L. 103-337, and Pub. L. 106- 390] (Pub.
L. 106-390, October 30, 2000, 114 Stat. 15521575) hereafter referred to as
the Disaster Mitigation Act of 2000 (DMA 2000).
FEMA published an Interim Final Rule (44 CFR Part 201) in the Federal Register on February
26, 2002, to implement the DMA 2000 planning requirements. This Lincoln County and
Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update includes the
requirements set forth by this rule.
Background
The “Multi-Hazard Pre-Disaster Mitigation Plan - Serving the Jurisdictions and Communities of
Minnehaha and Lincoln Counties and the City of Sioux Falls” was completed and approved by
FEMA on January 21, 2004. The plan was forged to prevent and minimize the costs incurred by
businesses, property owners, private non-profits, and governmental entities due to past hazard
events. The plan identified hazards and assessed the risks historically faced by Lincoln and
Minnehaha Counties and incorporated a mitigation strategy that encompassed a set of goals,
objectives, and action steps to help mitigate against and minimize damages imposed by those
hazards. The 2004 plan was later updated and improved upon in April of 2005 to account for the
severe flash floods and rainfall that occurred during the summer months of 2004. The storm
damages inflicted upon the counties of Lincoln and Minnehaha resulted in a presidential
declaration (FEMA-DR-1531-SD).
The Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011
Update is a multi-jurisdictional plan. The following jurisdictions and organizations participated
in the plan’s development by attending at least one planning meeting, sharing information, and
by offering its time and support during the planning process. East Dakota Water Development
District, Lincoln County Rural Water System, Minnehaha Community Water Corporation, and
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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the South Lincoln Rural Water System participated in the planning process, but did not formally
adopt the plan.
Jurisdictions
City of Baltic
City of Beresford
City of Brandon
City of Canton
City of Colton
City of Crooks
City of Dell Rapids
City of Garretson
City of Harrisburg
City of Hartford
City of Humboldt
City of Lennox
City of Sherman
City of Sioux Falls
City of Tea
City of Worthing
Lincoln County
Minnehaha County
Organizations
East Dakota Water Development District
Lincoln County Rural Water System
Minnehaha Community Water Corporation
Sioux Valley Energy
South Eastern Electric Cooperative
South Lincoln Rural Water System
This plan illustrates Lincoln County, Minnehaha County, and its communities/jurisdictions’
current and future mitigation actions and strategies in accordance with the guidance materials
provided by FEMA and the State of South Dakota’s Office of Emergency Management. The
reviewer will note that the section headings and subheadings follow the organization of the Local
Mitigation Plan Review Crosswalk. Several appendices accompany this plan. They contain
technical data and other supporting documents to meet 44 CFR Part 201 local multi-hazard
planning requirements.
Chapter 1 demonstrates the legal authority of the Lincoln County and
Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
through the adoption of the plan by the legislative body of each participating
jurisdiction.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Chapter 2 documents the planning process for developing this plan.
Chapter 3 outlines the identified hazards, profiles vulnerabilities, and assesses
the risk for each hazard for Lincoln County, Minnehaha County, and its
participating jurisdictions.
Chapter 4 details the mitigation strategy for Lincoln County, Minnehaha
County, and its participating jurisdictions based on the local vulnerability
analyses and risk assessments.
Chapter 5 outlines the plan maintenance process.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Chapter I
Prerequisites and Community Profile
1.1 Adoption by the Local Governing Body
The “Multi-Hazard Pre-Disaster Mitigation Plan - Serving the Jurisdictions and Communities of
Minnehaha and Lincoln Counties and the City of Sioux Falls” was completed and approved by
FEMA on January 21, 2004.
On May 16, 2012 the Lincoln and Minnehaha Counties Hazard Mitigation Planning committee,
led by the Minnehaha County Emergency Manager Lynn DeYoung and Lincoln County
Emergency Manager Harold Timmerman recommended that this 2011 revised and updated
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan be adopted
by the Minnehaha County Commission on June 12, 2012 and the Lincoln County Commission
on June 7, 2012. The Minnehaha County Commission adopted the revised and updated plan by
resolution on June 12, 2012 and the Lincoln County Commission adopted the revised and
updated plan by resolution on June 7, 2012. The resolutions to adopt the plan can be found in
Appendix A.
1.2 Multi-Jurisdictional Plan Adoptions
In accordance with 44 CFR Part §201.6(c) (5), the City of Baltic, the City of Beresford, the City
of Brandon, the City of Canton, the City of Colton, the City of Crooks, the City of Dell Rapids,
the City of Garretson, the City of Harrisburg, the City of Hartford, the City of Humboldt, the
City of Lennox, the Town of Sherman, the City of Sioux Falls, the City of Tea, and the City of
Worthing have adopted the 2011 revised and updated Lincoln County and Minnehaha County
Multi-Hazard Pre-Disaster Mitigation Plan. The following two organizations adopted the revised
and updated 2011 plan; Sioux Valley Energy, and South Eastern Electric Cooperative. These
aforementioned community and organization resolutions to adopt the revised and updated 2011
plan can be found in Appendix A.
The following aforementioned communities and organizations are adopting the Lincoln County
and Minnehaha County Multi-Hazard Pre-Disaster Hazard Mitigation Plan Update 2011 in order
to comply with 44 CFR §20.6(d) (3) that requires each jurisdiction to review, revise, and
resubmit their plan to their State Office of Emergency Management and the Federal Emergency
44 CFR Part §201.6(c) (5): Requirement
[The local hazard mitigation plan shall include] documentation that the plan has been
formally adopted by the governing body of the jurisdiction requesting approval of the
plan (e.g., City Council, County Commissioner, Tribal Council).
44 CFR Part §201.6(c) (5): Requirement
For multi-jurisdictional plans, each jurisdiction requesting approval of the plan must
document that it has been formally adopted.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Management Agency for approval once every five years in order to continue to remain eligible
for federal mitigation project funding (Hazard Mitigation Grant Program, Pre-Disaster
Mitigation Grant Program, Flood Mitigation Assistance Program, and the Severe Repetitive Loss
Program).
1.3 Multi-Jurisdictional Planning Participation
The following jurisdictions and organizations participated in the planning process. East Dakota
Water Development District, Lincoln County Rural Water System, Minnehaha Community
Water Corporation, and the South Lincoln Rural Water System participated in the planning
process, but did not formally adopt the plan. The non-incorporated communities or areas were
represented by Lincoln County and Minnehaha County.
Jurisdictions
City of Baltic
City of Beresford
City of Brandon
City of Canton
City of Colton
City of Crooks
City of Dell Rapids
City of Garretson
City of Harrisburg
City of Hartford
City of Humboldt
City of Lennox
City of Sherman
City of Sioux Falls
City of Tea
City of Worthing
Lincoln County
Minnehaha County
Organizations
East Dakota Water Development District
Lincoln County Rural Water System
Minnehaha Community Water Corporation
Sioux Valley Energy
South Eastern Electric Cooperative
South Lincoln Rural Water System
44 CFR Part §201.6(a) (3): Requirement
Multi-jurisdictional plans (e.g., watershed plans) may be accepted, as appropriate, as
long as each jurisdiction has participated in the process…Statewide plans will not be
accepted as multi-jurisdictional plans.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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1.4 Community Profile
Population
Lincoln County is located in southeastern South Dakota. The county covers approximately 579
square miles and has a population of 44,828 according to the US Census 2010. Canton is the
county seat, and the County’s most populous city is Sioux Falls (Lincoln County) with a
population of 21,095.1 Lincoln County has nearly doubled in size from 24,131 in 2000 to 44,828
in 2010. All indicators are the population will continue to grow and expand in the coming years.
Table 1.1: Lincoln County Population Characteristics
Jurisdiction Population
1990
Population
2000
Population
2010
Median Age
2000
Minority %
2000
Lincoln County 15,427 24,131 44,828 34 2.45%
Beresford 349 427 359 39.1 1.1%
Canton 2,787 3,110 3,057 36.2 2.8%
Fairview 73 94 60 31 3.2%
Harrisburg 727 958 4,089 30.1 1.4%
Hudson 332 402 296 37.3 2%
Lennox 1,767 2,037 2,111 37.7 1.3%
Sioux Falls City
(Lincoln County)
1,409 6,618 21,095 N/A N/A
Tea 786 1,742 3,806 28.2 3.3%
Worthing 371 585 877 29 1%
Minnehaha County is located in southeastern South Dakota. The county covers approximately
810 square miles and is South Dakota’s most populous county with a population of 169,4681
according to the US Census 2010. Sioux Falls is the county seat and the state’s most populous
city with a population of 153,888.2 Minnehaha County and its communities have experienced
significant population growth over the last 20 years. Some communities within the Sioux Falls
Metropolitan Area have experienced population increases of 50% or more from 2000 to 2010.
All indicators are that the population will continue to grow and expand over the next twenty
years.
1 US Census 2010, www.census.gov
2 US Census 2010, www.census.gov
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Table 1.2: Minnehaha County Population Characteristics
Jurisdiction Population
1990
Population
2000
Population
2010
Median
Age 2000
Minority %
2000
Minnehaha County 123,809 148,281 169,468 34 6.97%
Baltic 666 811 1,089 30 1.11%
Brandon 3,545 5,693 8,785 31 1.77%
Colton 657 662 687 37 .91%
Crooks 671 859 1,269 30 1.86%
Dell Rapids 2,484 2,980 3,633 36 1.31%
Garretson 924 1,165 1,166 37 2.4%
Hartford 1,262 1,844 2,534 32 2.44%
Humboldt 468 521 589 32 3.26%
Sherman 66 87 78 28 2.3%
Sioux Falls 99,405 117,355 132,793 33 11.1%
Valley Springs 739 792 759 32 1.52%
Physical Description
The geography of the Lincoln County and Minnehaha County Region is heavily settled and
urban within in the Sioux Falls Metropolitan Area (SFMA), but the land outside of the SFMA is
mostly rural and devoted to the raising of crops such as corn, wheat, and soybeans. The land
primarily consists of what is referred to as Coteau De Prairies3 which is made of low lying
prairie and glacial lakes. The only major river within the region is the Big Sioux River. The Big
Sioux River acts as the eastern border for Lincoln County and runs through the center of
Minnehaha County. There are areas within the region in which drainage presents a major issue,
especially along the Big Sioux River Basin and other low lying areas.
Lincoln County and Minnehaha County are both located in the Big Sioux River Basin. The Basin
is formed within a topographic feature known as the Coteau de Prairies. The Coteau has what is
known as a flatiron shape lying in a general northwest to southeast direction. It is about 200
miles long and 80 miles wide at the widest point. The northern part of the Coteau de Prairies has
geologically developed features of potholes, sloughs, and lakes. During periods of low
precipitation, these features tend to hold backwater and do not contribute to the drainage of the
Big Sioux River. Conversely, during wet years, this area can accumulate enough moisture to
greatly increase the water supply to the drainage basin. These wet years pose a higher risk for
flood hazards in Lincoln County and Minnehaha County.
In general, most soil in the region is fertile with adequate rainfall to meet agricultural production
needs. In terms of precipitation, the average annual rainfall is 24.7 inches and is concentrated
during the warm summer months. Snowfall occurs mostly in light to moderate amounts during
the winter, and the annual average is at 39.3 inches. The climate of the region is considered a
humid continental climate which is characterized by hot, relatively humid summers and cold,
3 USGS – The Coteau de Prairies, http://www.nationalatlas.gov/tapestry/features/38coteau.html
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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drier winters. From mid-January to mid-July, highs range from 24 to 86 °F (-4 to 30 °C) and
lows from 2 to 61 °F (-17 to 16 °C).
Table 1.3: Monthly Climate Conditions in Minnehaha and Lincoln Counties Region4
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Ave.
High
(F°) 24.3 29.6 42.3 59.0 70.7 80.5 86.3 83.3 73.1 61.2 43.4 28.0
Ave.
Low (F°)
3.3 9.7 22.6 34.8 45.9 56.1 62.3 59.4 48.7 36.0 22.6 8.6
Ave.
Percip.
(Inches) .5 .6 1.6 2.5 3.0 3.4 2.7 2.9 3.0 1.8 1.1 .7
Ave.
Snow (Inches)
6.8 8.2 2.8 0 0 0 0 0 0 .8 5.8 7.2
Social and Economic Description
The economy of the Lincoln County and Minnehaha County Region is heavily influenced by its
Sioux Falls Metropolitan Area (SFMA). The SFMA economy is comprised of diverse sectors
that include finance, healthcare, retail, agriculture, tourism, distribution, and trade. This
diversification has lead to the creation of high paying jobs within the region. As shown in Table
1.4, Lincoln County, as a whole, posts a higher median household income with $65,922 than the
national average of $51,425. The communities within Lincoln County have household incomes
that range from a low of $25,750 in the City of Hudson to a high of $67,717 in the City of
Harrisburg. The percentage of families living below the poverty level in Lincoln County is only
2.6% compared to the national average of 9.9%.
As shown in Table 1.5, Minnehaha County’s median household income of $50,671 was slightly
less than the national average of $51,425. The communities within Minnehaha County have
median household incomes that range from a low of $41,875 in Valley Springs to a high of
$72,113 in Crooks. The percentage of families living below the poverty level in Minnehaha
County is 6.4%, which is less than the national average of 9.9%.
4 Climate Information Sioux Falls Area, http://www.climate-zone.com/climate/united-states/south-dakota/sioux-
falls/
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Table 1.4: Income, Job Earnings, and Poverty - Lincoln County5
Entity Median Household
Income (2009 Est.)
Per Capita Income
(2009 Est.)
% of Families Living
Below Poverty Level
Beresford $47,725 $25,518 4.9%
Canton $47,146 $22,980 2.9%
Fairview $51,875 $17,885 3.3%
Harrisburg $67,717 $24,699 .5%
Hudson $25,750 $15,501 3.4%
Lennox $53,558 $18,708 5%
Sioux Falls $49,157 $26,306 7.1%
Tea $66,213 $26,222 6.3%
Worthing $50,547 $20,231 2.7%
Lincoln County $65,992 $28,307 2.6%
South Dakota $44,828 $23,445 8.8%
United States $51,425 $27,041 9.9%
Table 1.5: Income, Job Earnings, and Poverty - Minnehaha County6
Entity Median Household
Income (2009 Est.)
Per Capita Income
(2009 Est.)
% of Families Living
Below Poverty Level
Baltic $55,708 $22,845 .7%
Brandon $63,295 $25,591 1.9%
Colton $49,531 $22,014 5%
Crooks $72,113 $27,417 2.1%
Dell Rapids $61,033 $26,490 4.4%
Garretson $44,138 $20,621 7%
Hartford $58,594 $22,450 5.2%
Humboldt $52,031 $26,746 0%
Sherman $55,000 $27,158 0%
Sioux Falls $49,157 $26,306 7.1%
Valley Springs $41,875 $16,722 7.7%
Minnehaha County $50,671 $25,836 6.4%
South Dakota $44,828 $23,445 8.8%
United States $51,425 $27,041 9.9%
5 US Census Bureau, American Community Survey, 2005-2009, www.census.gov
6 US Census Bureau, American Community Survey, 2005-2009, www.census.gov
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Figure 1-1: Lincoln County and Minnehaha County Infrastructure
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Transportation and Utility Infrastructure
The Lincoln County and Minnehaha County Region’s main routes are I-29 and I-90. Other
highways include I-229, US Hwy 46, SD Hwy 11, SD Hwy 115, SD Hwy 19, and SD Hwy 17.
The region is served by four railroad lines. These rail lines include the Burlington Santa Fe
Railroad Line, the D & I Railroad Line (Private), the D & I Rail Line (State Owned), and the Elis
and Eastern Rail Line. The region’s main airport is the Joe Foss Field Sioux Falls Regional
Airport. Additional airports are also located in Tea (large general aviation services provided) and
Canton (small general aviation services provided).
Most of the communities within Lincoln County and Minnehaha County own and operate their
water and sanitary sewer systems. Some communities belong to water or sanitary sewer system
districts. For rural customers, water service is provided primarily by Lincoln County Rural Water
System, Minnehaha Community Water Corporation, the South Lincoln Rural Water System, and
the Lewis and Clark Rural Water System. Rural residences often use individual septic tanks and
drain fields. Residential development is expected to continue in both Lincoln County and
Minnehaha County. Development into new areas needs to be controlled through planning and
development guidelines to help ensure growth is not occurring in hazard prone areas such as
floodways or wetlands.
Electric power in the region is provided through investor owned companies such as Xcel Energy
and rural electric cooperatives. Some communities operate and own their electric utilities. The
main phone companies serving the region are MidContinent Communication, CenturyLink, and
SPN Communications. The main cellular companies providing services within the region are
Version Wireless, AT&T, and Sprint.
Medical and Emergency Services
The hospitals and health centers serving the Lincoln County and Minnehaha County Region are
listed below:
Avera McKennan Hospital & University Center – Sioux Falls
Sanford – USD Medical Center – Sioux Falls
VA Medical Center – Sioux Falls
Canton-Inwood Memorial Hospital – Canton
Dells Area Health Center – Dell Rapids
The main hospitals serving the region are the Avera McKenna Heart Hospital & University
Center and Sanford – USD Medical Center. Both hospitals provide a full range of emergency
and medical services to the region.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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The fire departments in the Lincoln County and Minnehaha County Region are as follows:
Baltic Volunteer Fire Department
Beresford Volunteer Fire Department
Brandon Volunteer Fire Department
Canton Volunteer Fire Department
Colton Volunteer Fire Department
Crooks Volunteer Fire Department
Dell Rapids Volunteer Fire Department
Fairview Volunteer Fire Department
Garretson Volunteer Fire Department
Harrisburg Volunteer Fire Department
Hartford Area Fire and Rescue Incorporated
Hudson Volunteer Fire Department
Humboldt Volunteer Fire Department and Ambulance
Lennox Volunteer Fire Department
Lyons Volunteer Fire Department
Renner Fire and Rescue
Sherman Volunteer Fire Department
Sioux Falls Fire Department
Split Rock Volunteer Fire Department
Valley Springs Volunteer Fire Department
Tea Fire and Rescue Department
Worthing Community Fire Department Incorporated
Each department has the capability to respond to both structural and wild land fires. All
departments have training, expertise, and equipment at various levels in regard to hazardous
materials response.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Chapter II
Planning Process
2.1 Documentation of the Planning Process
The “Multi-Hazard Pre-Disaster Mitigation Plan - Serving the Jurisdictions and Communities of
Minnehaha and Lincoln Counties and the City of Sioux Falls” was completed in 2004 and
revised in 2005. The plan was developed by Lincoln and Minnehaha Counties Multi-Hazard Pre-
Disaster Planning Committee. The committee participated in discussions to identify, categorize,
and prioritize issues relevant to each historical and current hazard event in Lincoln and
Minnehaha Counties. During the 2004 and 2005 planning process, the only multi-jurisdictional
participants were from Lincoln County, Minnehaha County, and the City of Sioux Falls. All
three jurisdictions continued to remain participating jurisdictions for the development of the
2011 plan update.
This section demonstrates the planning process used to develop this 2011 update for The Lincoln
County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan. The planning
process began in late 2010, continued through the adoption of the plan, and will remain in effect
as the plan is maintained. This process has provided and continues to provide all relevant
stakeholders the opportunity to actively participate in the development/revision of this plan.
Production of the plan was led by Minnehaha County Emergency Manager Lynn DeYoung and
Lincoln County Emergency Manager Harold Timmerman. They both served as the main points
of contact for all activities associated with the plan’s development. Input was also received by
44 CFR Part §201.6(b): Requirement
An open public involvement process is essential to the development of an effective
plan. In order to develop a more comprehensive approach to reducing the effects of
natural hazards, the planning process shall include:
1) An opportunity for the public to comment on the plan during the drafting stage and
prior to plan approval;
2) An opportunity for neighboring communities, local and regional agencies involved
in hazard mitigation activities, and agencies that have the authority to regulate
development, as well as businesses, academia and other private and non-profit interests
to be involved in the planning process; and
3) Review and incorporation, if appropriate, of existing plans, studies, reports, and
technical information.
44 CFR Part §201.6(c) (1): Requirement
[The plan shall document] the planning process used to develop the plan, including
how it was prepared, who was involved in the process, and how the public was
involved.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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the Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Planning
Committee whose membership is listed in Table 2.1 Participation in Plan Development (2011
Update) and Meeting Attendance (1-5). Lincoln County and Minnehaha County contracted
with South Eastern Council of Governments (SECOG) staff to provide technical assistance and
guidance with the drafting and overall development of the 2011 plan update.
2.2 Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster
Mitigation Planning Committee
The communities and jurisdictions of Lincoln and Minnehaha Counties were notified by letter to
send at least one representative to participate in the planning process and attend the Lincoln
County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Planning Committee Kick-
Off Meeting for the 2011 update held on August 31, 2010. Each representative acted as a local
liaison to relay information obtained from the hazard mitigation meetings back to local staff,
elected officials, fire districts, and other local personnel associated with emergency, planning,
and mitigation activities. A core planning committee was formed by those who were in
attendance at the kick-off meeting. A list of the planning committee members can be found in
Table 2.1.
Table 2.1: Participation in Plan Development (2011 Update) and Meeting Attendance
Name Entity Represented M
1 M
2 M
3 M
4 M 5
Ryan Fods City of Baltic X X
Mike Wendland City of Baltic X X
Elaine Hendrickson City of Baltic X
Jim Fedderson City Beresford X X X X
Jerry Zeimetz City of Beresford X X X X
Bryan Reed City of Brandon X X X X
Amy Nelson City of Canton X X X
Erik Miller City of Colton X
Jeanne Hisek City of Crooks X X X X X
Scott Fiegen City of Dell Rapids X
Justin Weiland City of Dell Rapids X X X
Ann Uhl City of Garretson X X X
Albert Schmidt City of Harrisburg X X X X
Teresa Sidel City of Hartford X X X X X
Kira Schmeichel City of Humboldt X X X X X
Judy Finnell City of Lennox X
Roland VanDerWerff City of Lennox X X
Robin Berg City of Sherman X X X X
Andrew Berg City of Sioux Falls X X
Regan Smith City of Sioux Falls X X X X
Jason Kjenstad City of Tea/ HDR Engineering X X
Kevin Nissen City of Tea X X X X
Carrie McDannel City of Worthing X
Jeff Tanner City of Worthing X X
Jay Gilbertson East Dakota Water Development District X X
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Table 2.1: Participation in Plan Development (2011 Update) and
Meeting Attendance – Continued
Jon Peters Lincoln County X X X X X
Harold Timmerman Lincoln County EM X X X X X
Robin Dykstra Lincoln County Rural Water System X
Scott Anderson Minnehaha County X
Robert Wilson Minnehaha County X
Lynn DeYoung Minnehaha County EM X X X X
Scott Buss Minnehaha Community Water Cooperation X
Tom Neville Sioux Valley Energy X
Michele Nielson Sioux Valley Energy X X X X X
Jay Cleveland Southeastern Electric Coop. X X X X X
Ralph Hammer South Lincoln Rural Water System X
In addition to assisting in the writing, editing, and coordination of the 2011 plan update, the
specific requirements and responsibilities of the planning committee include:
1. Meeting periodically to review and update the Multi-Hazard Pre-Disaster
Mitigation Plan as needed or at least once every 5 years
2. Establishing county-wide hazard mitigation goals, objectives, and action items
3. Reconfirming priorities for categories of hazard mitigation projects
Local Collaboration
The planning process involved five planning meetings, communication via e-mail and digital
data sharing. A summary of the meetings and collaboration is presented in Table 2.2: Summary
of the Planning Process. The South Eastern Council of Governments (SECOG) also ensured
regional collaboration occurred by sharing data, ideas, and information collected simultaneously
from both Lincoln and Minnehaha Counties during the 2011 plan update process.
Table 2.2: Summary of the Planning Process
August 31, 2010 – Multi-Hazard Pre-Disaster Mitigation Planning Committee
Minnehaha and Lincoln Counties (Update 2011) Meeting 1
Meeting 1 was facilitated by SECOG, Minnehaha County EM and Lincoln County EM -
(1) Introduction, (2) Purpose of PDM Plan (3) Roles and Responsibilities, (3) PDM
Planning Process, and (4) Review of Existing Plan
November 16, 2010 – Multi-Hazard Pre-Disaster Mitigation Planning Committee
Minnehaha and Lincoln Counties (Update 2011) Meeting 2
Meeting 2 was facilitated by SECOG, Minnehaha County EM and Lincoln County EM -
(1) Review of Planning Process, (2) Reviewing Location of Critical Infrastructure, (3)
Identification of Hazards Most Affecting the Counties and Impacts, (4) Identifying Areas
of Flooding and Poor Drainage, (5) Valuing Property and Infrastructure in Flood-Prone
Areas, and (6) Discussion of Mitigation Actions Already Taken
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Table 2.2: Summary of the Planning Process – (Continued)
January 24, 2011 – Multi-Hazard Pre-Disaster Mitigation Planning Committee
Minnehaha and Lincoln Counties (Update 2011) Meeting 3
Meeting 3 was facilitated by SECOG, Minnehaha County EM and Lincoln County EM -
(1) Review of Draft PDM Report, (2) Discussion and Identification of Mitigation Goals
and Objectives, (3) Initial Discussion of Potential Mitigation Projects to Include in the
PDM, (4) Review and Assessment of Progress of Mitigation Projects Identified in the
Previous PDM Plan, and (5) Discussion of Next Steps
March 15, 2011 - Multi-Hazard Pre-Disaster Mitigation Planning Committee
Minnehaha and Lincoln Counties (Update 2011) Meeting 4
Meeting 4 was facilitated by SECOG, Minnehaha County EM and Lincoln County EM –
(1) Review of Committee’s Prior Work, (2) Review Draft PDM, (3) Review Mitigation
Projects in Prior PDM, (4) Discussion and Identification of New Mitigation Strategies,
(5) Prioritizing Mitigation Projects, (6) Disaster Mitigation Project Grant Application
Process, and (7) Discussion/ Next Steps
August 31, 2011 - Multi-Hazard Pre-Disaster Mitigation Planning Committee
Minnehaha and Lincoln Counties (Update 2011) Meeting 5
(1) Review complete draft PDM Plan (2) Establish Dates for Public Forum
Meeting 5 was facilitated by SECOG, Minnehaha County EM and Lincoln County EM –
(1) Review of Committee’s Prior Work, (2) Review Complete Draft PDM, (3)
Established Dates for Public Forums, and (4) Discussion/ Next Steps
September 27, 2011 - Public Forum in Lincoln County to Discuss Complete Draft
(1) Power Point Presentation, (2) Question and Answer Session with the Public
September 28, 2011 - Public Forum in Minnehaha County to Discuss Complete Draft
(1) Power Point Presentation, (2) Question and Answer Session with the Public
October 11, 2011 - Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster
Mitigation Plan (2011 Update) SD State Office of Emergency Management - Review of
Complete Draft
February 9, 2012 Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster
Mitigation Plan (2011 Update) FEMA - Review of Complete Draft
June 7 and June 12, 2012 Lincoln County and Minnehaha County Multi-Hazard Pre-
Mitigation Plan (2011 Update) – Adoption
May 16, 2012 Final Plan Submittal to FEMA
August 1, 2012 FEMA Final Plan Approval
A copy of the Agendas, Minutes, and Sign-In Sheet from each of the planning meetings is
included in Appendix B.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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State and Federal Collaboration
The State Office of Emergency Management provided additional support and information during
the entire planning process. The US Army Corps of Engineers, Federal Emergency Management
Agency (FEMA), the South Dakota Department of Environment and Natural Resources, and the
South Dakota Department of Transportation were unable to attend or send representatives to any
of the planning meetings. However, the majority of the aforementioned state and federal
agencies agreed to share information and participate in the planning process though phone
conversations and email.
Public Participation
To invite the public and private sector to attend meetings and participate in the planning process,
press releases were sent out to newspapers, radio and news outlets throughout the two counties
on November 11, 2010, January 21, 2011, and March 10, 2011, for the November 16th
, January
25th
, and March 15th
core planning meetings. A public notice was placed in the following
publications: Argus Leader - Sioux Falls, Hartford Area News - Hartford, Dell Rapids Tribune –
Dell Rapids, Sioux Valley News - Harrisburg, Sioux Valley News – Canton, Garretson Gazette -
Garretson, Humboldt Journal – Humboldt, Lennox Independent – Lennox, Beresford Republic –
Beresford, and the Tea Weekly – Tea, to invite the public to attend the fourth planning meeting
and give them the opportunity to provide input on the plan’s goals, objectives, and action steps.
The second public notice was placed in the same aforementioned publications on September 12,
2011 to invite the public to attend public forums held in Lincoln and Minnehaha Counties to
provide comments on the draft plan. The public was given an opportunity to comment both
during the drafting stage of the plan and prior to plan approval. A copy of the press releases and
public notices are included in Appendix C.
The South Eastern Council of Governments also maintained a Multi-Hazard Pre-Disaster
Mitigation web page on its website at http://www.secog.org/disaster_mitigation/
disastermitigation.htm. The web site contained meeting information, PDM maps, PDM plan draft
components, and other useful information detailing the multi-hazard pre-disaster mitigation
planning process.
Drafting the Plan
Based on the collaboration among the planning committee, the SD State Office of Emergency
Management, and FEMA, the South Eastern Council of Governments drafted the updated 2011
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan for review by
the planning committee. Each section of the plan was reviewed, analyzed and thoroughly
updated. Comments and required actions noted in FEMA’s previously completed crosswalk
(reviewing the original 2005 Pre-Disaster Minnehaha and Lincoln Counties Multi-Jurisdictional
Hazard Mitigation Plan) were addressed and incorporated.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Chapter III
Hazard Assessment
3.1 Hazard Identification
Background
The risk assessment acts as the foundation for the Lincoln County and Minnehaha County
The Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011
Update establishes a framework for identifying mitigation goals and prioritizing actions to help
make Lincoln and Minnehaha Counties’ residents more disaster resilient and safe. The planning
committee reviewed a variety of potential hazards and assessed their potential impacts on
Lincoln and Minnehaha Counties. The list of potential hazards was narrowed down to focus on
hazards that have the most significant impact on the area and hazards where potential pre-
disaster mitigation activities would result in the most substantial benefit. As part of this
assessment, data was compiled and maps produced that help analyze the potential impacts of
various hazards.
“The Federal Emergency Management Agency (FEMA) defines risk assessment terminology as
follows:
Hazard—A hazard is an act or phenomenon that has the potential to produce
harm or other undesirable consequences to a person or thing.
Vulnerability—Vulnerability is susceptibility to physical injury, harm,
damage, or economic loss. It depends on an asset’s construction, contents, and
economic value of its functions.
Exposure—Exposure describes the people, property, systems, or functions
that could be lost to a hazard. Generally, exposure includes what lies in the
area the hazard could affect.
Risk—Risk depends on hazards, vulnerability, and exposure. It is the
estimated impact that a hazard would have on people, services, facilities, and
structures in a community. It refers to the likelihood of a hazard event
resulting in an adverse condition that causes injury or damage.
Risk Assessment—Risk assessment is the process of measuring the potential
loss of life, personal injury, economic injury, and property damage resulting
from hazards.”7
The planning committee began the risk assessment by reviewing the State of South Dakota
Hazard Mitigation Plan – Basic Plan (April, 2008) and the recently updated draft State of South
Dakota Hazard Mitigation Plan – Basic Plan (January, 2011). These plans provided useful
7 State of South Dakota Hazard Mitigation Plan (2008 Update), Section 3, Pg. 1
44 CFR Part §201.6(c) (2): Requirement
The plan shall include a risk assessment that provides the factual basis for activities
proposed in the strategy to reduce losses from identified hazards. Local risk
assessments must provide sufficient information to enable the jurisdiction to identify
and prioritize appropriate mitigation actions to reduce losses from identified hazards.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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information about potential hazards that represent a significant risk on a statewide basis. In
addition, planning committee participants reviewed the prior Lincoln and Minnehaha Multi-
Hazard Pre-Disaster Mitigation Plan and determined that a complete re-write of the risk
assessment section was appropriate given that more than five years had passed since the previous
plan was approved.
Planning committee participants reviewed historical information about natural hazards that have
occurred over the past 60 years, including information reported in the Spatial Hazard Events and
Losses Database for the United States (SHELDUS)8, as well as weather events data compiled by
the National Climatic Data Center’s Storm Events Database (NCDCSED).9
A list of historical hazard events for Lincoln County is included in Appendix D. A list of
historical hazard events for Minnehaha County is included in Appendix E. The information
included in these appendices is derived primarily from SHELDUS with descriptive information
from the NCDCSED incorporated where available (1993 and later). In addition, since
SHELDUS information is only current through 2009, information through September 2010 from
the NCDCSED was also included when the event resulted in injury, death, or monetary damage.
After reviewing this information, the planning committee began assessing which types of
hazards would likely result in the most significant impact on the area. Planning committee
members reviewed an extensive list of potential hazards including those covered in the statewide
Multi-Hazard Pre-Disaster Mitigation Plan, as well as the previous plan for Lincoln and
Minnehaha Counties (April 2005).
In particular, the following hazards were discussed by the planning committee as potential
hazards to address in the Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster
Mitigation Plan 2011 Update, including:
1) Flooding
2) Winter Storms
3) Wild Fires
4) Drought
5) Tornado
6) Wind
7) Hazardous Materials
8) Landslides and mudflows
9) Earthquakes
10) Hail
11) Terrorism / Civil Disorder
12) Urban Fire
13) Nuclear Incident
14) Transportation Incident
8 SHELDUS database - http://webra.cas.sc.edu/hvri/products/sheldus.aspx
9 National Climatic Data Center database - http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?wwEvent~Storms
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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The planning committee decided to focus on natural hazards in the Lincoln County and
Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update. The planning
committee felt that disaster mitigation projects would be most effective in addressing and
mitigating against the impact of natural hazards. Man-made hazards such as terrorism were
considered to have a low probability of occurrence. No known incident of terrorism has
occurred in the two-county area. In addition, man-made hazards such as transportation incidents
and hazardous materials are covered in both of the Lincoln County and Minnehaha County
Hazardous Materials Plans.
Drought was considered as a hazard for the two counties and several droughts have been
recorded in the area over the past 60 years. However, the area has not been subject to a
Presidential Declaration related to drought. A review of USDA Risk Management Agency data
shows that over the past 10 years, about $8.9 million in crop damages occurred in Lincoln
County and $3.3 million in crop damages occurred in Minnehaha County as a result of drought
conditions. While this hazard has a significant impact on the agricultural economy and on local
economies reliant on the agricultural sector, the planning committee concluded that there are
minimal measures that can be taken to mitigate against the impacts of this hazard.
The other primary impact of drought conditions is lower water levels. While this is a potential
threat to the area, jurisdictions within the area have already implemented policies that mitigate
against the impacts of this threat, including restrictive water usage policies during drought and
non-drought periods. These restrictions relate primarily to limits on lawn watering and other
heavy uses of water.
Several natural hazards such as avalanches, coastal erosion, coastal storms, earthquakes,
expansive soils, hurricanes, land subsidence, mudflows, land slides, tsunamis, volcanoes, and
wildfires were excluded from further consideration due to the non-existent or limited
vulnerability of the area to the aforementioned hazards. For example, there are limited forested
areas within the two counties. Consequently, wildfire has a low probability of occurrence. Only
one incidence of wildfire was noted in a review of more than 60 years of data in the NCDCSED,
with this single event resulting in only $50,000 in damage.
Earthquakes were also excluded as a hazard even though this hazard is included in the State’s
Multi-Hazard Pre-Disaster Mitigation Plan. As illustrated in Figure 1-1: South Dakota Seismic
Hazard Map, the vulnerability of Lincoln and Minnehaha Counties to earthquakes is considered
minimal. According to the State’s plan, no major earthquakes have been reported in South
Dakota since 1967, and South Dakota is geologically stable. The U.S. Geological Survey
estimates only a 10 percent chance of an earthquake occurring exceeding a 5.1 magnitude in any
one 50-year period. Minor earthquakes that have been observed in the state have resulted in very
limited damage such as displaced foundations, stuck doors and windows, etc.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Figure 3-1: South Dakota Seismic Hazard Map10
Some areas within Lincoln County, Minnehaha County, and the majority of South Dakota are
listed as having over 50 percent of their land area underlain with abundant clays of high swelling
or potential for expansive soils. As indicated in Figure 3-2, there are areas within Lincoln
County and Minnehaha County that have the potential to contain expansive soils, but the
planning committee decided not to profile the expansive soils hazard due to a lack of historical
damage information and modern building practices that often take this hazard into account
already.
The planning committee gave further consideration to other types of geological hazards
including landslides and land subsistence. However, after further consideration, these hazards
were identified as having a low probability of occurrence and low vulnerability factor. While
landslides and land subsidence are discussed in the State’s plan, Lincoln County and Minnehaha
County have fairly level topography, and based on the United States Geological Survey’s
Landslide Incidence and Susceptibility Map, the area’s vulnerability to landslides is low. As a
result of these assessments, both of these hazards were excluded from further consideration by
the planning committee. Figure 3-3 illustrates that Lincoln County and Minnehaha County have
a low incidence and susceptibility to landslides.
10
Draft State of South Dakota Hazard Mitigation Plan (January, 2011), Section 3, Pg. 121
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Figure 3-2: Lincoln County and Minnehaha County Expansive Soils11
11
Draft State of South Dakota Hazard Mitigation Plan (January, 2011), Section 3, Pg. 112
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Figure 3-3: South Dakota Land Slide Incidence and Susceptibility12
Source: U.S. Geological Survey, map generated by www.nationalatlas.gov
Dam Failure and Levee Failure will be profiled as a type of flood hazard. The National Inventory
of Dams database13
indicated that there are 13 dams listed in Lincoln County and 12 dams in
Minnehaha County.
12
Draft State of South Dakota Hazard Mitigation Plan (January, 2011), Section 3, Pg. 101 13 National Inventory of Dams Database - http://crunch.tec.army.mil/nidpublic/webpages/nid.cfm
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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After reviewing a broad list of hazards and excluding those hazards where the area has limited or
no vulnerability, the planning committee decided to focus specifically on four hazard categories:
1) Severe Summer Storms (including excess rain, lightning, and hail);
2) Severe Winter Storms (including freezing and extreme cold);
3) Tornadoes and High Winds; and
4) Flooding
Hazards such as hail, excess precipitation, lightning, freezing and extreme cold were all
considered as hazards, but are incorporated under the broader headings of either severe summer
storms or severe winter storms.
3.2 Profiling Hazards & Assessing Vulnerability
44 CFR Part §201.6(c) (2) (i): Requirement
[The risk assessment shall include a] description of the….location and extent of all
natural hazards that can affect the jurisdiction. The plan shall include information on
previous occurrences of hazard events and on the probability of future hazard events.
44 CFR Part §201.6(c) (2) (ii) (A) & (B) & (C): Requirement
The plan should describe vulnerability in terms of the types and numbers of existing
and future buildings, infrastructure, and critical facilities located in the identified
hazard areas…
[The plan should describe vulnerability in terms of an] estimate of the potential dollar
losses to vulnerable structure identified in paragraph (c) (2) (i) A of this section and a
description of the methodology used to prepare the estimate…
[The plan should describe vulnerability in terms of] providing a general description of
land uses and development trends within the community so that mitigation options can
be considered in future land use decisions.
44 CFR Part §201.6(c) (2) (i): Requirement
For multi-jurisdictional plans, the risk assessment must assess each jurisdiction’s risks
where they vary from the risks of the entire planning area
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Scope of Analysis
The four hazard categories to be discussed in this Plan were analyzed based on five factors
including probability, vulnerability, existing capabilities, future development, and history.
Probability: The likelihood that a disaster event will take place within a defined period.
For purposes of this analysis, the probability of a hazard is considered “high” if it were
likely to occur five times in a ten-year period, “medium” if it were to occur one to two
times in a ten-year period, and “low” if it were likely to occur less than one time in a ten-
year period. The planning committee assessed the probability of an event occurring in
the future after reviewing data from SHELDUS and the NCDCSED to track the history of
such events, in addition to local experience with dealing with these types of hazard
events.
Vulnerability: The potential impact of a hazard in terms of monetary impact, disruption,
and potential to result in injury or loss of life. For purposes of this analysis, a “high”
vulnerability assessment is a hazard that is likely to threaten human life and a substantial
amount of property. A “medium” vulnerability assessment is a hazard that this is
unlikely to threaten human life but some risk exists and the hazard may pose a significant
risk to property. A “low” vulnerability assessment is a hazard that is unlikely to threaten
human life or pose a risk to property.
Vulnerability was assessed based on a variety of factors including:
(1) Historical hazard data provided through SHELDUS and the NCDCSED. In
particular, the incidence of property damage, loss of life, and injuries was
reviewed to assess potential vulnerability.
(2) Flood plain maps were reviewed to determine the vulnerability of particular
jurisdictions to flooding events.
(3) Information was collected on the number, type and value of properties located
in flood prone areas. This information is shown in Tables 3-22 and 3-23.
(4) Information pertaining to population density and building exposure
vulnerability to all hazards can be found in Section 3.4.
In particular, vulnerability is assessed based on its potential impact on critical
infrastructure. Maps showing the location of critical infrastructure such as hospitals,
schools, police stations, etc. are shown for each jurisdiction and are included in
Appendix F. These community assets play a vital role during any natural disaster and
their susceptibility to being impacted by a particular hazard factors heavily in the
community’s vulnerability to such hazards.
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Existing Capabilities: Existing capabilities or previously implemented actions of a
jurisdiction to mitigate against the impact of a hazard event. In the following section,
each hazard category is analyzed in more detail, including a discussion of the existing
capabilities of various jurisdictions to mitigate against each hazard category.
Future Development: Development trends factor into the potential impact of particular
hazards. For example, development within flood prone areas may result in increased
vulnerability. The impact on property and life increases as development within these
areas occurs. In addition, development within flood prone areas may expand the
vulnerability of flooding to adjacent areas that may not have been previously vulnerable
to flooding. The impact of development trends was assessed by reviewing population
projections for the area, reviewing building permit activity, the reviewing of
comprehensive plans and zoning regulations, as well as feedback provided by planning
committee participants.
History: Historical information of various hazards and their occurrence in Lincoln
County and Minnehaha County was reviewed as a part of this analysis. Table 3-1 below
shows previous Presidential Disaster Declarations for Lincoln County. Since 1960, there
have been nine disaster declarations that have occurred in Lincoln County. The total
damage figures shown represent the total damages for the entire disaster-declared area,
which included Lincoln County. Since 1960, eight of the nine disaster declarations in
Lincoln County involved flooding, two were related to severe summer storms, two were
related to severe winter storms, and two involved tornadoes.
Table 3.1: Presidential Disaster Declarations in Lincoln County
Date
Disaster
Dec # Type
Total Damage
(2009 Dollars)
4/8/1960 99 Flooding $983,088
7/27/1962 132 Flooding and Tornadoes $3,843,478
4/18/1969 257 Flooding $4,599,306
7/19/1984 717 Severe Storms and Flooding $4,432,207
7/19/1993 999 Severe Storms, Tornadoes and Flooding $53,068,748
5/26/1995 1052 Flooding $35,649,349
1/10/1997 1156 Severe Winter Storms and Blizzard Conditions $19,455,263
4/7/1997 1173 Severe Flooding, Severe Winter Storm $87,069,429
9/23/2010 1938 Severe Storms and Flooding $4,078,772
Source: Public Entity and Risk Institute (www.peripresdecusa.org)
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Table 3-2 shows previous Presidential Disaster Declarations for Minnehaha County. Since
1960, there have been eight disaster declarations that included Minnehaha County. The total
damage figures shown represent the total damages for the entire disaster-declared area, which
included Minnehaha County. Since 1960, five of the eight disaster declarations in Minnehaha
County involved flooding, three were related to severe summer storms, three were related to
severe winter storms, and one involved tornadoes. In addition, six of the disasters covered both
Lincoln and Minnehaha Counties.
Table 3-2: Presidential Disaster Declarations in Minnehaha County
Date
Disaster
Dec # Type
Total Damage
(2009 Dollars)
4/8/1960 99 Flooding $983,088
4/18/1969 257 Flooding $4,599,306
7/19/1993 999 Severe Storms, Tornadoes and Flooding $53,068,748
1/10/1997 1156
Severe Winter Storms and Blizzard
Conditions $19,455,263
2/28/1997 1161
Severe Winter Storms and Blizzard
Conditions $2,666,554
4/7/1997 1173 Severe Flooding, Severe Winter Storm $87,069,429
7/21/2004 1531 Severe Storms and Flooding $2,286,912
9/23/2010 1938 Severe Storms and Flooding $4,078,772
Source: Public Entity and Risk Institute (www.peripresdecusa.org)
Appendix D and Appendix E each provide a comprehensive list of weather related events over
the past 60 years for Lincoln County, Minnehaha County, and their communities. The list
includes events that resulted in significant property or crop damages, injuries, or loss of life. The
list was derived primarily from information compiled by the Spatial Hazard Events and Losses
Database of the United States (SHELDUS), with descriptive information incorporated, when
available. Events occurring since 1993 were also included from the NCDCSED. In addition,
due to SHELDUS information only being current through 2009, information through September
of 2010 was incorporated using the NCDCSED when the event resulted in injury, death, or
monetary damage. It is important to note that the damage figures shown in these appendices are
estimated and reflect the total amount of reported damages caused by the event divided by the
number of counties impacted.
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3.3 Hazard Assessment
As part of the process of identifying which hazards to include in the report, the planning
committee developed a risk assessment matrix to summarize the probability of each hazard’s
occurrence in relation to each hazard’s identified vulnerability. While the occurrence and
vulnerability of any particular hazard may vary from jurisdiction to jurisdiction, the Risk
Assessment Matrix included in Table 3-3 aggregates the information to determine the
vulnerability and probability of a hazard for the entire area. The Risk Assessment was made by
the planning committee considering the past incidence and impacts of these events, in addition to
their own knowledge of prior impacts for local jurisdictions.
Table 3-3: Hazard Risk Assessment Matrix
Vulnerability
Low Medium High
Pro
bab
ilit
y o
f O
ccu
rren
ce
Low Dam Failure;
Landslide
Medium
Tornado
High
Severe Summer Storms
Severe Winter Storm;
Flooding
For the purpose of discussion, the planning committee created Table 3-3: Hazard Risk
Assessment Matrix, with the categories of Low, Medium, and High defined as follows:
Probability of Occurrence:
Low – historically, the listed hazard has been analyzed with a frequency of one or fewer
noteworthy events within the last decade. This category also includes rare hazard events
that may occur only once every century.
Medium – the occurrence of the listed hazard has been noted more frequently than once
in a decade, but less frequently than twice every five year period on average.
High – the listed hazard has taken place more than twice every five years, and is
comprised of annual event hazards, and even multiple times per year hazards. To be
assigned this ranking, the hazard does not have to occur each year, but when considered
over a five year period, the hazard is observed three or more times within a five-year
period.
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Vulnerability: Potential to Impact People, Structure, Infrastructure, and the Economy
Low – the occurrence of the listed hazard has a low probability of negatively impacting
critical resources based on the risk exposure to developments and population centers,
coupled with concerns in regard to available resources to respond to these threats. The
risk exposure potentially impacts no lives and less than 25 structures when it is recorded.
Medium- the occurrence of the listed hazard has moderate potential to negatively impact
critical resources based on the exposure to developments and population centers, coupled
with considerations for available resources to respond to these threats. The risk exposure
potentially impacts fewer than five lives or less than 50 structures when it is recorded.
High – the occurrence of the listed hazard has high potential to negatively impact critical
resources based on the exposure to developments and population centers, coupled with
considerations for available resources to respond to these threats. The risk exposure
potentially impacts more than five lives or more than 50 structures per occurrence.
Maps showing the location of critical community infrastructure are included in Appendix F.
This is particularly important as it relates to flooding, where the geographic impact is more
predictable. Alternatively, tornadoes, severe winter storms and severe summer storms are as
likely to occur anywhere in the region geographically and are less predictable in terms of their
overall impacts.
The remainder of this section discusses each of the four hazard categories (Severe Summer
Storms, Tornadoes, Severe Winter Storms, and Flooding) within the context of the five criteria
outlined previously including probability, vulnerability, existing capabilities, future
development, and history.
3.3.1 Severe Summer Storms (including excess rain, lightning and hail)
Probability of Occurrence
Severe Summer Storms, as defined for purposes of this report, include all storms occurring
during spring, summer, and fall with damages that may result from excess rain or thunderstorms,
lightning, and hail. The impact of tornadoes and high winds, which usually occur in conjunction
with summer storms (high winds and tornadoes) or winter storms (high winds), are considered as
separate hazards for the purposes of this report.
Severe summer storms are typically associated with unstable weather conditions and are not
geographically predictable. All portions of Minnehaha County and Lincoln County are equally
susceptible to these types of events, although the type and amount of damages will vary
depending on the location. For example, hail can result in significant agricultural damage in the
rural parts of the county, but the urbanized area of Sioux Falls is more vulnerable to significant
property damage due to having higher density population, housing, and commercial districts.
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Planning committee participants identified the following potential impacts resulting from severe
summer storms:
1. Damage to trees and other physical property (homes and building, cars, etc.);
2. Knock down overhead power lines and result in power outages;
3. Negative impact on utilities and physical property due to power outages;
4. Lightning strikes starting fires (homes, grass fires, etc.) and causing power outages;
5. Crop damage in agricultural areas; and
6. Possible physical injuries due to hail and lack of appropriate shelter.
The probability of severe summer storms occurring in any given year is high. Based on
information compiled by the NCDCSED, 120 lightning/thunderstorm events occurred in Lincoln
County and 224 lightning/thunderstorm events occurred in Minnehaha County during the 17-
year period between 1994 and 2010. This is an average of seven events per year for Lincoln
County and 13 events per year for the geographically larger Minnehaha County. Similarly,
there have been 128 recorded hail events in Lincoln County and 334 hail events in Minnehaha
County between 1959 and 2010 or approximately 2.5 hail events per year in Lincoln County and
6.5 hail events per year in Minnehaha County. The likelihood of future severe summer storms
including hail, excess rain, lightning, and thunderstorms is inevitable.
Vulnerability and Loss Potential
All jurisdictions included in this plan are vulnerable to the impacts of summer storms,
particularly storms that include hail, lightning, or excess rain. Tables 3-4 and 3-5 show the
number of events and estimated damages from hail and lightning/thunderstorm events occurring
in Lincoln County and Minnehaha County.
Table 3-4: Impact of Severe Summer Storms -
Lincoln County
Type
Years
Covered
Nu. of
Events Deaths Injuries
Total
Physical
Damage*
Total
Crop
Damage*
Total
Damage*
Avg.
Damage
Per
Event*
Hailstorms 1959-2010 128 0 0 $4,006 $300 $4,306 $34
Lightning & Thunderstorms 1994-2010 120 0 1 $3,386 $0 $3,386 $28
*In Thousands Source: National Climatic Data Center’s Storm Events Database
Table 3-5: Impact of Severe Summer Storms -
Minnehaha County
Type
Years
Covered
Nu. of
Events Deaths Injuries
Total
Physical
Damage*
Total
Crop
Damage*
Total
Damage*
Avg.
Damage
Per
Event*
Hailstorms 1959-2010 334 0 0 $23,761 $3,006 $26,767 $80
Lightning & Thunderstorms 1994-2010 224 3 6 $3,766 $51 $3,817 $17
*In Thousands Source: National Climatic Data Center’s Storm Events Database
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Based on this data source, it is somewhat difficult to assess the true damage caused by these
events as the damage figures shown in the tables above are aggregated for all counties impacted
by particular hazard events, which may extend far beyond Lincoln County or Minnehaha County
individually. The data does, however, provide perspective on the probability of events occurring
and potential vulnerability. For example, between 1959 and 2010, the total damages resulting
from hailstorms were $4.3 million for events that included Lincoln County and $26.8 million for
events that include Minnehaha County.
It is not entirely surprising that Minnehaha County would sustain much higher damages relative
to Lincoln County. First, the City of Sioux Falls is the largest population center in the two
counties, and while the City of Sioux Falls extends into both counties, a majority of the City is in
Minnehaha County. With a higher population density, it is not unexpected that hail-related
damages would be higher for Minnehaha County since hail can exert significant damage on
physical property such as homes, buildings, and vehicles.
Hail can also cause significant monetary damage to agricultural areas, which would suggest that
Lincoln County, which is primarily agricultural, would have more monetary crop losses due to
hail events than what is shown in the NCDCSED. It appears that the NCDCSED estimates for
crop damages are highly speculative and unreliable. A more accurate estimate of crop damages
resulting from hail was generated from the United States Department of Agriculture’s (USDA)
Risk Management Agency. Table 3-4 is able to demonstrate that crop damage for the 10 year
period between 2000 and 2009 from hail was nearly $2 million for Lincoln County, whereas the
NCDCSED only reported total crop damages from hail events impacting Lincoln County at
$300,000 for the 52-year period ending in 2010.
The primary conclusions that can be drawn from the information included in the NCDCSED is
that:
1) On average, a lightning/thunderstorm event is more likely to occur in a given year
compared with hail events;
2) Typically, hail events result in more monetary damage compared to
lighting/thunderstorm events, but hail events are unlikely to result in death or injury
as there are no such injuries/deaths reported in the database; and
3) Lightning/thunderstorm events are more likely to result in injury or death, but the
likelihood of this occurring is still relatively low.
Tables 3-6 and 3-7 provide more insight into the potential impact of summer storms as they
relate to the agricultural sector. A majority of the land area in Lincoln County and Minnehaha
County is devoted to agricultural production such as field crops. According to the USDA Risk
Management Agency, over a ten-year period ending in 2009, crop losses due to hail storms was
nearly $2 million for Lincoln County and about $500,000 for Minnehaha County. Crop losses
due to excess rain were much higher in both counties and totaled nearly $7.5 million in Lincoln
County and $5.3 million in Minnehaha County during this ten-year period.
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Table 3-6: Crop Loss Due to Severe Summer Storms (2000-2009) -
Lincoln County
Hail Excess Rain
2000 $474,787 $10,694
2001 $7,421 $267,388
2002 $881,062 $13,591
2003 $11,820 $419,424
2004 $102,435 $226,001
2005 $88,417 $2,343,141
2006 $58,668 $46,415
2007 $108,953 $519,105
2008 $229,449 $3,184,523
2009 $23,606 $445,463
Total $1,986,618 $7,475,745
Annual Avg. $198,662 $747,575 Source: U.S. Department of Agriculture Risk Management Agency
Table 3-7: Crop Loss Due to Severe Summer Storms (2000-2009) -
Minnehaha County
Hail Excess Rain
2000 $87,603 $87,748
2001 $93,771 $825,281
2002 $9,675 $31,192
2003 $36,720 $266,780
2004 $2,228 $182,109
2005 $4,937 $754,546
2006 $0 $316,270
2007 $0 $582,085
2008 $44,244 $1,960,533
2009 $209,932 $312,722
Total $489,110 $5,319,266
Annual Avg. $48,911 $531,927
Source: U.S. Department of Agriculture Risk Management Agency
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Vulnerability Summary
Severe Summer Storms (lightning, hail, or severe heat) in Lincoln County from 1959 – 2010
have resulted in annual damages of approximately $150,823 (non-adjusted for inflation) to
property and infrastructure. The annual losses caused by severe summer storms (2000 – 2009) to
the agricultural sector for Lincoln County is approximately $946,237 (non-adjusted for
inflation). The frequency of severe summer storm events is high. Hail storm events in Lincoln
County occur on average 2.5 times per year, and thunderstorm events occur 7.5 times per year.
Severe Summer Storms (lightning, hail, or extreme heat) incidents in Minnehaha County from
1959 – 2010 have resulted in annual damages of approximately $539,745 (non-adjusted for
inflation) to property and infrastructure. The annual crop losses caused by past severe summer
storms (2000 – 2009) within Minnehaha County are approximately $580,838 (non-adjusted for
inflation). The frequency of severe summer storm events is high. Hail storm events in Minnehaha
County occur on average six times per year and thunderstorm events occur 14 times per year.
Existing Capabilities
Planning committee participants identified several strategies already being utilized to mitigate
the impact of severe summer storms including:
1) Use of sirens and early warning systems;
2) Burying overhead power lines;
3) Identifying emergency shelters;
4) Installing backup generators for community utilities and other critical facilities (i.e. pump
stations);
5) Instant communication system for emergency management notification;
6) Established method for announcing alerts;
7) Regular maintenance of alert systems;
8) Establishing appropriate building codes to ensure new structures can withstand storm
damage;
9) Enforcement of nuisance ordinances;
10) Replacing and upgrading culverts;
11) Storm sewer improvements; and
12) Tree trimming.
Future Development
Since the geographic impact of severe summer storms is impossible to predict, severe summer
storms, as defined in this report, have minimal impact on land use planning and development.
However, each jurisdiction continues to assess the capacity of its utilities, such as storm sewers,
to determine where different types of development can take place, and ensuring that storm sewer
and other related utilities are capable of withstanding severe summer storms, particularly as it
relates to excess rain and localized flooding.
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History
The two costliest severe summer storm events in Lincoln County and Minnehaha County region
occurred on 5/22/1993 in Minnehaha County with approximately $5,000,000 in property
damages and on 6/12/2001 in Minnehaha County, Lincoln County, and the City of Sioux Falls
with approximately $20,000,000 in total property damages. Damages in both incidents were
caused by hail.
This historical incidence of severe summer storms is discussed in the vulnerability section. It is
also appropriate to note that three Presidential Disaster Declarations within the two counties
reference severe summer storms as part of the disaster declaration, although these events
typically involved other hazards such as flooding and/or tornadoes.
3.3.2 Severe Winter Storms (including freezing and extreme cold)
Probability of Occurrence
Severe winter storms, as defined for the purposes of this report, include blizzards, as well as
freezing temperatures, and extreme cold. These storms tend to occur in the late fall, winter, and
early spring seasons. Similar to severe summer storms, severe winter storms are typically
associated with unstable weather conditions and are not geographically predictable. All areas
within Minnehaha County and Lincoln County are equally susceptible to the impact of these
events. Impacts can include hazardous driving conditions, loss of life or injury for individuals
without proper shelter, damage to agricultural crops, and budgetary issues for local governments
to clear snow from roadways.
Planning committee participants identified the following potential impacts resulting from severe
winter storms:
1) Excessive snow blocking roads, limited access for emergency personnel and
transportation access for residents;
2) Hazardous driving conditions resulting in potential loss of life or injury during winter
storm events;
3) Power outages due to damage to overhead power lines resulting in loss of heat to homes
and life safety issues, as well as loss of power damaging community infrastructure such
as lift stations;
4) Damage to community infrastructure such as freezing water mains and water towers,
resulting in loss of access to water for residents and businesses;
5) Budgetary pressure for local jurisdictions due to removing snow and ice from roadways
and repairing broken infrastructure as a result of extreme cold and winter storm events;
6) Ice jams on rivers leading to potential flooding; and
7) Negative impact on economic activity due to school and business closings during severe
winter storms.
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The probability of a severe winter storm event occurring in any given year is high. Based on the
information available through the NCDCSED, there were 41 winter storm events in Lincoln
County during the 17-year period beginning in 1994 and ending in 2010. There were 90
recorded winter storm events impacting Minnehaha County during this same period. Based on
this data, it is likely that a severe winter storm will occur in this region on average of two to five
times annually. Typically, the storm events are widespread effecting larger geographic areas.
There is a high likelihood that there will be severe winter storms occurring every year in Lincoln
County and Minnehaha County.
Vulnerability and Loss Potential
All of the jurisdictions included in this plan are vulnerable to the impacts of severe winter
storms. Tables 3-8 and 3-9 summarize the number of winter storm events recorded in the
NCDCSED for both Lincoln County and Minnehaha County between 1994 and 2010. Based on
this data source, there were 41 events occurring during this period in Lincoln County, resulting
in 12 deaths and 160 injuries. Average damage per event is estimated at $184,000. Some of the
damage and injuries may have occurred outside Lincoln County as the information provided
through this data source aggregates the damages for all counties affected. By comparison, there
were 90 events reported for the geographically larger Minnehaha County resulting in 12 deaths,
123 injuries, and average monetary damages of $90,000 per event.
Table 3-8: Impact of Severe Winter Storms -
Lincoln County
Type
Years
Covered
Nu. of
Events Deaths Injuries
Total
Physical
Damage*
Total
Crop
Damage*
Total
Damage*
Avg.
Damage
Per
Event*
Winter Storms 1994-2010 41 12 160 $7,535 $0 $7,535 $184
*In Thousands Source: National Climatic Data Center’s Storm Events Database
Table 3-9: Impact of Severe Winter Storms -
Minnehaha County
Type
Years
Covered
Nu. of
Events Deaths Injuries
Total
Physical
Damage*
Total
Crop
Damage*
Total
Damage*
Avg.
Damage
Per
Event*
Winter Storms 1994-2010 90 12 123 $8,080 $0 $8,080 $90
*In Thousands Source: National Climatic Data Center’s Storm Events Database
Compared with other hazards discussed in this plan, winter storms are far more likely to result in
the loss of life or injuries. Since one of the primary impacts of winter storms is hazardous
driving conditions, it is likely that most of the deaths and injuries resulting from winter storms
were a result of traffic accidents on icy or snow covered roadways, or poor driving conditions
resulting from blowing snow.
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Data available through the USDA Risk Management Agency over the ten-year period ending in
2009 was also reviewed to determine the impact of winter storms on the agricultural sector. The
impact of winter storms is relatively low for agricultural crop production as most crops are
harvested prior to the onset of the winter season. The primary impact of winter storms on the
agricultural sector are the delays it causes in planting crops due to an extended winter season, or
issues with harvesting crops due to the early onset of winter weather, neither of which is
reflected in the data available through the USDA Risk Management Agency. Cold weather and
freezing temperatures are more likely to shorten the growing season and reduce agricultural
production. The impact on the agricultural sector due to cold winters and freezing temperatures
is depicted in Tables 3-10 and 3-11 for Lincoln County and Minnehaha County. Overall, the
data provided by the USDA Risk Management Agency suggests limited overall monetary impact
of either cold winters or freezing temperatures during the past ten years.
Table 3-10: Crop Loss Due to Winter Weather (2000-2009) -
Lincoln County
Cold Winter Freeze / Frost
2000 $0 $0
2001 $4,772 $0
2002 $294 $0
2003 $0 $0
2004 $1,126 $3,256
2005 $0 $1,949
2006 $0 $0
2007 $0 $0
2008 $0 $371
2009 $5,606 $0
Total $11,798 $5,576
Annual Avg. $1,180 $558 Source: U.S. Department of Agriculture Risk Management Agency
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Table 3-11: Crop Loss Due to Winter Weather (2000-2009) -
Minnehaha County
Cold Winter Freeze / Frost
2000 $0 $0
2001 $16,700 $1,850
2002 $2,540 $817
2003 $0 $0
2004 $0 $22,715
2005 $0 $0
2006 $0 $0
2007 $0 $0
2008 $0 $0
2009 $33,924 $27,743
Total $53,164 $53,125
Annual Avg. $5,316 $5,313 Source: U.S. Department of Agriculture Risk Management Agency
The primary conclusions that can be drawn from the information provided by the NCDCSED
and the USDA Risk Management Agency related to winter storms are:
1) The likelihood of a winter storm event occurring in the region is high in any given year;
2) Winter storms are more likely to result in death and injury compared to other potential
natural hazards affecting the region, which is most likely due to treacherous driving
conditions;
3) The monetary impact of severe winter storms can be significant; and
4) The impact on crop production is limited compared to other types of natural hazards such
as severe summer storms, high winds, and flooding.
Vulnerability Summary
Severe winter storms in Lincoln County from 1994-2010 resulted in annual damages of
approximately $470,937 (non-adjusted for inflation) to property and infrastructure. The annual
losses caused by severe winter storms (2000 – 2009) to the agricultural sector for Lincoln
County are approximately $1,738 (non-adjusted for inflation). The frequency of severe winter
storm events is high. Severe winter weather events in Lincoln County occur on average 2.5 times
per year.
Severe winter storms in Minnehaha County from 1994-2010 have resulted in annual damages of
approximately $505,000 (non-adjusted for inflation) to property and infrastructure. The annual
losses caused by severe winter storms (2000 – 2009) to the agricultural sector for Lincoln
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
38
County are approximately $10,629 (non-adjusted for inflation). The frequency of severe winter
storm events is high. Severe winter storm events in Minnehaha County occur on average 5.5
times per year.
Existing Capabilities
Planning committee participants identified several strategies already being utilized in some
jurisdictions to mitigate against the impact of severe winter storms including:
1) Burying power lines;
2) Identifying emergency routes to be cleared first in the event of a winter storm to
maximize transportation access for emergency responders and residents;
3) Established communication channels for identifying snow emergencies and getting
information out to residents during severe winter events;
4) Identification of emergency shelters to assist residents that are without power or have
limited access to shelter during winter storms;
5) Utilizing back up generators at critical infrastructure sites to mitigate the impact of
power outages on utility systems;
6) Utilizing back up generators at emergency shelters to ensure access to safe shelter
during winter storm events and power outages;
7) Tree trimming ordinances enforced to limit impact of falling trees and branches for
overhead power lines and roadways;
8) Closing certain transportation corridors during severe winter events to limit travel and
reduce potential for loss of life and injury; and
9) Keeping infrastructure and emergency equipment up-to-date and in working condition in
order to properly withstand and respond to severe winter events.
Future Development
Similar to severe summer storms, the geographic impact of severe winter storms is difficult to
predict and all areas of the region are equally likely to be impacted by severe winter events. As a
result, severe winter storms have minimal impact on land use planning and development. The
primary impact of severe winter storms is a continued effort to bury exposed overhead power
lines to limit future vulnerability. In addition, the identification of emergency snow routes is
reassessed based on development trends and the location of new businesses and homes in the
community.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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History
The most severe winter storm impacting the Lincoln County and Minnehaha County region
occurred from November 14 – November 18, 1996, that resulted in $2,000,000 in property
damages. The storm event involved more than twenty counties and resulted in three traffic
fatalities due to the road conditions caused by the storm. The historical incidence of severe
winter storms is discussed in the vulnerability section. Two of the previous Presidential Disaster
Declarations for Lincoln County and three of the Presidential Disaster Declarations for
Minnehaha County were a result of severe winter storms.
3.3.3 Tornadoes and High Winds
Figure 3-4: Wind Zones in the United States14
Probability of Occurrence
Similar to the other natural hazards identified in this plan, tornadoes and high winds have the
potential to significantly impact the region. Based on historical information provided in the
NCDCSED, the likelihood of tornadoes or high wind events occurring in any given year is less
than the incidence of severe summer or winter storms. However, based on the nature of wind
and tornado events, they are likely to result in more damage than severe summer or winter
storms. As indicated in Figure 3-4: Wind Zones in the United States, sections of both Lincoln
County and Minnehaha County are located in a Wind Zone 4 (250 mph).
14
Draft State of South Dakota Hazard Mitigation Plan (January, 2011), Section 3, Pg. 83
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Similar to severe summer and winter storms, tornadoes and high wind events are associated with
unstable weather patterns and are geographically unpredictable. As a result, all areas within the
region are equally susceptible to the potential of tornadoes and high wind events. Planning
committee members identified the following potential impacts resulting from tornadoes and high
wind events:
1) Power outages due to damages to overhead power lines;
2) Loss of life and injury due to disrupted electrical service, disrupted utilities such as water
and sewer services, and physical destruction to business and residential structures;
3) Loss of life and injury due to a lack of adequate shelter;
4) Damage to vehicles and personal property;
5) Financial burden for local governments to clean up after tornadoes and high wind events;
6) Blocked roadways and transportation systems due to downed trees, power lines, and other
debris created by tornadoes and high wind events; and
7) Damage to and loss of critical infrastructure such as lift stations, utility stations,
communication towers, emergency response facilities, etc.
Based on information available through the NCDCSED, 50 tornadoes occurred between 1954
and 2010 for Lincoln County, or less than one event per year on average. By comparison, there
were 41 recorded tornado events in Minnehaha County during this same period, again equating
to less than one per year. As will be noted in the next section, however, the impact of these
events is likely to be greater than severe summer and winter storms on an individual basis.
High wind events are as likely to occur as tornadoes based on the information recorded in the
NCDCSED. Historical information on these wind events covers a slightly shorter time period
compared with historical information recorded for tornadoes. Between 1994 and 2010, the
NCDCSED recorded 15 high wind events/storms occurring in Lincoln County and Minnehaha
County, or slightly less than one incidence per year. This appears to coincide with the likelihood
of a tornado occurring in either county, which is also slightly less than one time per year on
average.
Vulnerability and Loss Potential
While tornadoes and high wind events are less likely to occur in any given year compared to
severe winter and summer storms, their impact is often greater given the severity of the
widespread damage that can result from these types of events. The incidence and impact of
tornadoes and high wind events are summarized in Tables 3-12 and 3-13 for Lincoln County
and Minnehaha County.
In Lincoln County, over the 57-year period in which tornadoes have been recorded in the
NCDCSED, total damages from tornadoes exceeded $31 million, or about $630,000 per
occurrence. It is important to note that not all of this damage may have occurred in Lincoln
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
41
County since the damage figures shown in the data are aggregated for all of the counties
impacted by a particular recorded event. By comparison, high wind events resulted in more than
$3 million in damages during the 17-year period in which data is available, or approximately
$200,000 per occurrence. In this case, high wind events were less likely to result in as much
damage as tornadoes, but on average, result in more monetary damage than either severe winter
or summer storms. There is also a higher likelihood of loss of life or injury, particularly for
tornadoes, resulting from the lack of appropriate shelter during these events.
In Minnehaha County, during the 57-year period in which information is available for tornadoes,
there was more than $12 million in physical damage as a result of tornadoes or about $300,000
per occurrence. This is less than the amount reported for Lincoln County, but still significant.
High wind events caused more than $3 million in damages during the 17-year period between
1994 and 2000, similar to Lincoln County. Average physical damage per wind storm event was
about $200,000 per occurrence, again very similar to Lincoln County.
Table 3-12: Impact of Tornadoes and High Winds -
Lincoln County
Type
Years
Covered
Nu. of
Events Deaths Injuries
Total
Physical
Damage*
Total
Crop
Damage*
Total
Damage*
Avg.
Damage
Per
Event*
Tornadoes 1954-2010 50 2 8 $31,522 $0 $31,522 $630
Wind Storms 1994-2010 15 0 1 $3,025 $0 $3,025 $202
*In Thousands Source: National Climatic Data Center’s Storm Events Database
Table 3-13: Impact of Tornadoes and High Winds -
Minnehaha County
Type
Years
Covered
Nu. of
Events Deaths Injuries
Total
Physical
Damage*
Total
Crop
Damage*
Total
Damage*
Avg.
Damage
Per
Event*
Tornadoes 1954-2010 41 0 4 $12,143 $0 $12,143 $296
Wind Storms 1994-2010 15 0 1 $3,105 $0 $3,105 $207
*In Thousands Source: National Climatic Data Center’s Storm Events Database
Similar to the impact of severe summer storms, the NCDCSED appears to underestimate the
impact of tornadoes and high winds on crop damages. Information from the USDA Risk
Management Agency on crop damages due to winds is summarized in Tables 3-14 and 3-15
below. Based on the information provided by the USDA Risk Management Agency,
approximately $36,000 in crop damages occurred in Lincoln County as a result of high winds
over the ten-year period ending in 2009. By comparison, slightly more than $190,000 in crop
damages is noted during the same period for Minnehaha County. While high winds have an
impact on crop production in the region, the overall impact of this hazard appears to be
negligible based on this data source.
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Table 3-14: Crop Loss Due to High Winds (2000-2009) -
Lincoln County
Winds
2000 $1,306
2001 $0
2002 $0
2003 $1,427
2004 $143
2005 $3,728
2006 $0
2007 $11,049
2008 $18,203
2009 $0
Total $35,856
Annual Avg. $3,586 Source: U.S. Department of Agriculture Risk Management Agency
Table 3-15: Crop Loss Due to High Winds (2000-2009) -
Minnehaha County
Winds
2000 $802
2001 $24,792
2002 $12,372
2003 $0
2004 $108,260
2005 $411
2006 $0
2007 $0
2008 $43,928
2009 $0
Total $190,565
Annual Avg. $19,057 Source: U.S. Department of Agriculture Risk Management Agency
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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The primary conclusions that can be drawn from the information provided by the NCDCSED
and USDA Risk Management Agency are:
1) On average, there is typically one or less tornado and one or less high wind event
occurring in either Lincoln County or Minnehaha County annually;
2) While the incidence of tornado and high wind events is lower, the impact is
significant in terms of physical damage compared to severe summer and winter
storms;
3) Tornadoes and high wind events are more likely to result in the loss of life and injury
compared to severe summer storms, but less likely to result in the loss of life or injury
compared to severe winter storms;
4) The loss of life and injury from tornadoes and high wind events is likely due to the
lack of adequate shelter; and
5) The impact of tornadoes and wind events on crops is less than the impact resulting
from severe summer storms.
Vulnerability Summary
Tornadoes and high winds in Lincoln County from 1954 - 2010 have resulted in annual damages
of approximately $616,910 (non-adjusted for inflation) to property and infrastructure. The annual
losses caused by tornadoes or high winds (2000 – 2009) to the agricultural sector for Lincoln
County are approximately $3,586 (non-adjusted for inflation). The frequency of tornadoes or
high wind events is moderate. High wind events in Lincoln County occur on average less than
once per year and tornado events occur less than once per year.
Tornadoes and high winds in Minnehaha County from 1954-2010 resulted in annual damages of
approximately $272,285 (non-adjusted for inflation) to property and infrastructure. The annual
losses caused by tornadoes and high winds (2000 -2009) to the agricultural sector for Minnehaha
County are approximately $19,057 (non-adjusted for inflation). The frequency of tornadoes or
high wind events is moderate. High wind events in Minnehaha County occur on average less
than once per year and tornado events occur less than once per year.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Existing Capabilities
Planning committee participants identified several strategies already being utilized by some
jurisdictions to mitigate the impact of tornado and high wind events including:
1. Use of sirens and other warning systems;
2. Continuing efforts to bury overhead power lines;
3. Identification of emergency shelters to assist residents that are without power or have
limited access to shelter during tornadoes and wind storms;
4. Utilizing back up generators at critical infrastructure sites to mitigate the impact of power
outages on utility systems;
5. Utilizing back up generators at emergency shelters to ensure access to safe shelter during
tornado/wind events and resulting power outages;
6. Use of ordinances to require shelters in trailer parks;
7. Establishing building codes so that newly built or renovated structures can better
withstand the impact of tornadoes and high winds;
8. Tree trimming ordinances enforced to limit the impact of falling trees and branches for
overhead power lines and roadways; and
9. Keeping infrastructure and emergency equipment up-to-date and in good working
condition so they can withstand and help respond to tornadoes and high wind events.
Future Development
Similar to severe summer and winter storms, the incidence of tornadoes and high wind events is
not geographically predictable, and therefore, makes it difficult to implement land use strategies
that mitigate the impact of these events. Primary strategies for mitigating against the impact of
tornadoes and high wind events include burying power lines in newly developed areas to avoid
power outages, requiring access to shelters in areas such as trailer parks, implementing more
restrictive building codes to ensure newly developed commercial and residential structures can
better withstand the impact of high wind events, and ensuring that early warning systems, such
as sirens, are constructed in newly developed areas.
History
The two most significant tornado/high winds events in Lincoln County occurred on July 14,
1970 that resulted in $25 million in total damages and on April 26, 1986, that resulted in $2.5
million in total damages. For Minnehaha County the two most significant tornado/high wind
events occurred on June 19, 1979, with $5 million in total damages and on June 16, 1992 that
resulted in $2.5 million in total damages.
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The community of Hartford was also impacted by an F1 tornado on June 24, 2003, that resulted
in $2.5 million in property damages. During that storm event, 20 homes in the City of Hartford
were heavily damaged due to the incident.
The historical incidence of tornadoes and high wind events are discussed in the vulnerability
section. Two of the previous Presidential Disaster Declarations for Lincoln County and one of
the previous Presidential Disaster Declarations for Minnehaha County were related to tornadoes.
3.3.4 Flooding
Probability of Occurrence
Flooding and excess precipitation can significantly impact local communities, residents, and the
economy in general. Unlike the other hazards discussed in this Plan, flooding is more
geographically predictable. While flooding, particularly flash flooding, can potentially occur
anywhere during periods of excess precipitation, predictive modeling is done to determine areas
that are most at risk for flooding, and designating those areas as flood hazard areas.
In South Dakota, flooding is typically a result of runoff from excess rainfall during the spring,
summer and fall seasons, or runoff from melting snow during the spring. Flooding can occur as
a result of localized precipitation, or flooding can occur due to excess precipitation occurring
outside the region but resulting in elevated river levels flowing down stream from areas where
the excess precipitation occurred.
There are generally four types of flooding affecting the region based on information included in
the previous South Dakota Multi-Hazard Mitigation Plan:
1) Flash Flooding: Results when several inches of rain and precipitation occur within a
short period of time. This type of excess precipitation generally occurs as part of a
severe summer storm and may be compounded by other hazards such as high winds,
hail, and tornadoes. Flash flooding usually occurs in a smaller geographic area and
results in excessive runoff which can exceed the capacity of the community’s sanitary
sewer system. This type of flooding is less predictable geographically.
2) Long-Rain Flooding: Occurs when there is a significant amount of precipitation or
rainfall over an extended period of days or weeks. Often, the intensity of the rainfall
is low, but cumulatively that amount of precipitation is larger and exceeds the
capacity of the ground to absorb the precipitation. Often the ground becomes “water
logged” or the rainfall can no longer infiltrate. This typically occurs over a
widespread geographic area due to the extended period of time in which the
precipitation occurs. Flooding can occur for several days or weeks depending on the
severity of the event. Water that is unable to infiltrate the soil runs off into low lying
areas, can enter homes and commercial facilities through windows and doors, and
results in devastating impacts for property owners.
Stagnant water that cannot infiltrate the ground can also lead to health issues and a
higher incidence of mosquitoes. Excess moisture in the ground can seep into
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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basements of homes and businesses, creating additional damage. Water seepage can
exceed the capacity of sump pumps and storm sewer systems to transfer the water out
of homes, businesses, and developed areas in general.
3) Flooding as a result of Snow Melt: Typically occurs in the spring and has
characteristics similar to flash floods and long-range floods. The impacted area is
typically larger than that of flash floods, but smaller than long-rain floods. The areas
impacted are more geographically predictable and center on low lying areas and areas
adjacent to rivers, streams, and other water bodies. Generally, flooding can last for
several days to several weeks. The flooding is compounded if the ground is frozen,
resulting in more runoff of precipitation to the lower lying areas and streams/rivers.
Recently, flooding from snow melt has become a major challenge for the region due
to the large amounts of snow received locally and in surrounding areas.
4) Dam or Levee Failure: There are several dams located within the region which could
result in flooding and economic loss if physical damage were to occur to the dam
structure or levee structure. Lincoln County has approximately 13 dams and
Minnehaha County has 12 dams according to the National Inventory of Dams. The
State defines a dam as follows: “a structure is a dam if the height to the dam crest is
greater than or equal to 25 feet and the storage at the dam crest (not at the spillway
elevation) is greater than 15 acre feet or if the height to the dam crest is greater than 6
feet and the storage at the dam crest (not at the spillway elevation) is greater than or
equal to 50 acre feet. The height of the dam is the difference in elevation between the
natural bed of the watercourse or the lowest point on the toe of the dam, whichever is
lower, and the crest elevation of the dam.”15
In “Federal Guidelines for Dam Safety: Hazard Potential Classification Systems for
Dams (FEMA 2004),” dams are classified as follows:
Low Hazard Potential—Dams assigned the low hazard potential classification are those
where failure or incorrect operation result in no probable loss of human life and low
economic and/or environmental losses. Losses are principally limited to the owner’s
property.
Significant Hazard Potential—Dams assigned the significant hazard potential
classification are those dams where failure or incorrect operation result in no probable
loss of human life but can cause economic loss, environmental damage, disruption of
lifeline facilities, or can impact other concerns. Significant hazard potential classification
dams are often located in predominantly rural or agricultural areas but could be located in
areas with population and significant infrastructure.
High Hazard Potential—Dams assigned the high hazard potential classification are those
where failure or incorrect operation will probably cause loss of human life as well as
economic, environmental, and lifeline losses.
15
State of South Dakota’s Hazard Mitigation Plan (2008), State Office of Emergency Management - Section 3, Page
10).
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Of the total 25 dams listed for both Lincoln County and Minnehaha County, no dams are
listed as high hazard dams. However, Lincoln County has one significant hazard dam that
is located near Canton, SD, and Minnehaha County has two significant hazard dams that
are located near Sioux Falls. The remaining 22 dams are classified as low hazard dams
Table 3-16: Lincoln and Minnehaha County Dams Inventory16
Dam Name Legal Description County
Hazard
Class-
ification
Dam
Height
Alvin SE NE SEC.34-T100N-R49W Lincoln L 36
Evenson NW SW SEC.23-T100N-R49E Lincoln L 27
Canton Dam No. 1 NWSE SEC.13-098N-49W Lincoln S 27
Pattee Creek Watershed Dam
N0.4 NW SE SEC.28-T96N-R48W Lincoln L 27
Pattee Creek Watershed Dam P-2 NE SE SEC.32-T97N-R48W Lincoln L 41
Brule Creek Watershed DT Dam
B-1 SW SE SEC.35-T97N-R49W Lincoln L 25
Brule Creek Watershed DT Dam
B-7 SE SEC.20-T96N-R49W Lincoln L 27
Pattee Creek Watershed Dam P-3 NW SE SEC.34-T97N-R48W Lincoln L 34
Juel Dam NE SW SEC.31-T99N-R48W Lincoln L 22
Lakota Dam NW SE SEC.19-T98N-R48W Lincoln L 46
Brule Creek Watershed DT Dam
B-4 SE NW SEC.14-T96N-R49W Lincoln L 25
Jensen Dam SE NW SEC.25-T96N-R51W Lincoln L 21
Klondike Dam NE NW SEC.21-T99N-R48W Lincoln L 7
Nordstrom SW NE SEC.19-T102N-R48W Minnehaha L 27
Assam SW SE SEC.17-T101N-R48W Minnehaha L 30
Sioux Falls Diversion N SEC.32-T102-R49 Minnehaha S 21
Sioux Falls Diversion Weir NW SEC.33-T102-R49 Minnehaha S 27
Harr Dam SW SE SEC.19-T101N-R48W Minnehaha L 28
Silver Creek Watershed DT #1 SE SW SEC.22-T104N-R49W Minnehaha L 19
Silver Creek Watershed DT Dam
#2 SE SW SEC.34-T104N-R49W Minnehaha L 24
Silver Creek Watershed DT Dam
#4 NW SW SEC.3-T103N-R49W Minnehaha L 22
Silver Creek Watershed DT Dam
S-3 SW SEC.34-T104N-R49W Minnehaha L 27
Silver Creek Watershed DT Dam
S-5 SW SE SEC.4-T103N-R49W Minnehaha L 22
Silver Creek Watershed DT Dam
S-6 SE SEC.10-T103N-R49W Minnehaha L 24
Eros Data Center Dam SE SEC.8-T103N-R48W Minnehaha L 31
16
National Inventory of Dams Database, http://crunch.tec.army.mil/nidpublic/webpages/nid.cfm
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Planning committee Members identified the following potential impacts resulting from flooding
and excess precipitation:
1) Property damage to roads, homes, businesses, community infrastructure, and personal
property;
2) Displacement of residents from flooded homes;
3) Reduced economic activity due to flooded businesses;
4) Health hazards due to contaminated water;
5) Personal injury and possible death due to moving waters;
6) Excess precipitation exceeding the capacity of the community infrastructure system,
resulting in failure of the infrastructure, sewage back-ups, damage to wastewater
treatment facilities, lagoon overflows, etc.;
7) Erosion of soils exposing buried infrastructure; and
8) Negative impact on development when areas are reclassified as flood hazard areas.
Based on information included in the NCDCSED, there were 24 incidents of flooding in Lincoln
County during the 18-year period from 1993 to 2010. For Minnehaha County, there were 43
flooding events listed for the same period. The likelihood of a flooding event occurring in each
county typically varies from 1.3 to 2.4 flooding events annually.
Vulnerability and Loss Potential
While the incidence of flooding is less than severe summer or winter storms in general, the
impact of flooding can be widespread and significant in terms of physical damage. According to
the Storm Event Database, physical damage from flooding for Lincoln County over the past 18
years totaled $850,000 or about $35,000 per event. For Minnehaha County, total damages
during the same period exceeded $69 million, or $1.7 million per event. The NCDCSED
historical information for flooding in Lincoln County and Minnehaha County is summarized in
Tables 3-17 and 3-18.
Table 3-17: Impact of Flooding -Lincoln County
Type
Years
Covered
Nu. of
Events Deaths Injuries
Total
Physical
Damage*
Total
Crop
Damage*
Total
Damage*
Avg.
Damage
Per
Event*
Flooding 1993-2010 24 0 0 $850 $0 $850 $35
*In Thousands Source: National Climatic Data Center’s Storm Events Database
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Table 3-18: Impact of Flooding -Minnehaha County
Type
Years
Covered
Nu. of
Events Deaths Injuries
Total
Physical
Damage*
Total
Crop
Damage*
Total
Damage*
Avg.
Damage
Per
Event*
Flooding 1993-2010 43 0 0 $69,852 $2,205 $72,057 $1,676
*In Thousands Source: National Climatic Data Center’s Storm Events Database
According to the FEMA, “Policy and Loss Data by Community with County and State Data,”
June 3, 2010, there were 112 recorded flood insurance losses in Minnehaha County between
1978 and 2010 that resulted in payouts of $836,205 from the National Flood Insurance Program
(NFIP). For Lincoln County, there were 46 incidents of losses for NFIP insured properties
totaling over $413,000.
Repetitive loss properties are those properties which NFIP defines as any insurable building for
which two or more claims of more than $1,000 were paid by NFIP within any rolling 10-year
period since 1978. At least two of the claims must be more than 10-days apart. Minnehaha
County has 10 repetitive loss properties and Lincoln County has none.18
Neither county has any severe repetitive loss properties. According to the Flood Insurance
Reform Act of 2004, a severe repetitive loss property is defined as, “a single family property
(consisting of one-to-four residences) that is covered under flood insurance by the NFIP and has
incurred flood-related damage for which four or more separate claims payments have been paid
under flood insurance coverage with the amount of each claim payment exceeding $5,000 and
with cumulative amount of such claims payments exceeding $20,000; or for which at least two
separate claims payments have been made with the cumulative amount of such claims exceeding
the reported value of the property.”17
The State Office of Emergency Management conducted a HAZUS-MH impact analyses on all 66
counties within the state to determine direct economic losses for buildings and potential societal
impacts caused by a flooding event. Based upon a 1% chance loss estimation scenario, it is
projected that Lincoln County would have 26 buildings damaged with 524 persons displaced and
Minnehaha County is projected to have 719 buildings damaged with 7,482 persons displaced.
The primary indicators used to assess flood losses were:
• Direct building losses combined with income losses;
• Loss ratio of the direct building losses compared to overall building inventory;
• Loss ratio of building contents compared to overall building inventory; and
• Population displaced by the flood and shelter needs.18
17
State of South Dakota Multi-Hazard Mitigation - Basic Plan (2011) 18
State of South Dakota Multi-Hazard Mitigation - Basic Plan (2011)
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Table 3-19: HAZUS-MH Base Flood (1 Percent Chance) Loss Estimation Results:
Impacts on Lincoln and Minnehaha County
County Building
Damage
Count
Building
Damage
Loss
($K)
Building
Damage
Loss
Ratio*
Contents
Damage
Loss
($K)
Contents
Loss
Ratio
Total
Direct
Economic
Bldg.
Loss
**($K)
Short
Term
Shelter
Needs
Displaced
Population
Lincoln 26 7,275 0.5% 6,826 0.7% 14,514 210 524
Minnehaha 719 162,527 1.6% 252,358 3.6% 432,484 6,159 7,482
Source: FEMA Region VIII HAZUS-MH MR2 Notes:
*Loss ratio is the percent of the total building inventory value that could be damaged from flooding in any given year.
**Total Direct Economic loss includes relocation loss, capital-related loss, wages loss, rental income loss and building loss.
Tables 3-20 and 3-21 show the amount of crop damages resulting from flooding for the 10-year
period ending in 2009. According the USDA Risk Management Agency, total crop damage for
Lincoln County during this period was nearly $300,000. Crop damage for Minnehaha County
was minimal at slightly more than $16,000.
Table 3-20: Crop Loss Due to Flooding (2000-2009) -
Lincoln County
Flooding
2000 $356 2001 $16,127 2002 $17,775
2003 $122,113 2004 $25,772
2005 $19,133 2006 $0 2007 $5,391 2008 $90,602
2009 $0 Total $297,269 Annual Avg. $29,727
Source: U.S. Department of Agriculture Risk Management Agency
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Table 3-21: Crop Loss Due to Flooding (2000-2009) -
Minnehaha County
Flooding
2000 $0
2001 $0
2002 $0
2003 $4,793
2004 $9,136
2005 $2,368
2006 $0
2007 $0
2008 $0
2009 $0
Total $16,297
Annual Avg. $1,630 Source: U.S. Department of Agriculture Risk Management Agency
The vulnerability of each county and participating jurisdiction was analyzed using FEMA’s
HAZUS software to develop maps for Lincoln County and Minnehaha County’s Flood Prone
Areas. Maps indicated flood prone areas for the communities of Baltic, Beresford, Brandon,
Canton, Colton, Crooks, Dell Rapids, Fairview, Garretson, Harrisburg, Hartford, Hudson,
Humboldt, Lennox, Sherman, Sioux Falls, Tea, Valley Springs, and Worthing can be found in
Appendix G.
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Figure 3-5: Vulnerability in Flood Prone Areas Lincoln County
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Figure 3-6: Vulnerability in Flood Prone Areas Minnehaha County
Vulnerability Summary
Flooding in Lincoln County from 1993-2010 has resulted in annual damages of approximately
$50,000 (non-adjusted for inflation) to property and infrastructure. The annual losses caused by
flooding (2000–2009) to the agricultural sector for Lincoln County are approximately $29,727
(non-adjusted for inflation). The frequency of severe flooding events is high. Flooding events in
Lincoln County occur on average 1.4 times per year.
Flooding in Minnehaha County from 1993-2010 resulted in annual damages of approximately
$4,108,941 (non-adjusted for inflation) to property and infrastructure. The annual losses caused
by flooding (2000-2009) to the agricultural sector for Minnehaha County are approximately
$1,630 (non-adjusted for inflation). The frequency of severe flooding events is high. Flooding
events in Minnehaha County occur on average 2.5 times per year.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Existing Capabilities
Planning committee participants identified several strategies already being utilized in some
jurisdictions to mitigate the impact of flooding and excess precipitation including:
1) Cleaning culverts to ensure flow of excess precipitation;
2) Designation of emergency shelters for displaced residents due to flooding;
3) Completion of drainage studies and storm sewer improvements to address deficiencies in
waste water infrastructure;
4) Requiring detention ponds in newly developed areas to reduce flooding impacts;
5) Creating greenways and linear open spaces in floodplain areas; and
6) Implementation of flood damage, flood plain management, and other ordinances to
reduce the impact of flooding and limiting development in flood prone areas.
Future Development
Because the impact of flooding is typically more geographically predictable and because of the
recent severity that floods have had on the region, mitigating against future flooding is often
emphasized as part of land use planning. As noted above, several participating jurisdictions have
established flood plain management and development ordinances that prevent or limit
development in flood hazard areas. In addition, managing storm water run off is a major
consideration in the development of new wastewater infrastructure and replacement of existing
wastewater infrastructure.
A major challenge impacting the region over the past two years was the release of the new Flood
Insurance Rate Maps (FIRM) for Lincoln County (2008) and Minnehaha County (2009). As a
result of new predictive flood modeling completed by FEMA, several areas that were not
previously part of the flood hazard area are now within the floodplain. This has created
significant issues for residents whose homes are within the newly expanded floodplain.
Homeowners and businesses within this expanded floodplain are now often required by lending
institutions to purchase flood insurance creating a financial burden, limiting marketability of the
properties in the event of sale, and limiting the ability to expand the facilities within the
floodplain. This is particularly an issue for commercial structures within the expanded
floodplain that would like to expand but can not because of the cost of purchasing flood
insurance or ordinances that restrict further development within the flood plain.
The City of Sioux Falls is undertaking a two-year project to improve the levees along the Big
Sioux River and construct a dam at Skunk Creek. Once completed, the City will work with
FEMA to review the existing FIRM for the City, with the intent of reducing the expanded flood
hazard area and removing several commercial and residential properties that were included in the
flood hazard area as a result of the FIRM issued in 2009.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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History
The most significant flooding event to occur in the Lincoln County and Minnehaha County
region happened in the City of Sioux Falls on May 22, 1993, that resulted in $50 million in total
damages. During the flash flood event in Sioux Falls, nearly 200 homes had water in their
basements, 2,600 households were without power, and flooding in the Silver Glen area had
turned a normally three-feet wide creek into a 100 feet wide creek in some places. A second
flooding event in Sioux Falls occurred on June 16, 2004, that resulted in $10 million in damages.
Another significant flooding event impacted the community of Valley Springs on June 12, 2001.
Most of the town was flooded, with widespread damages to basements and first floors of homes.
The flooding left a layer of mud over much of the town. The sewer system backed up, leaving
sewage in several houses and apartments. A mobile home park was also hard hit, with damages
to the mobile home structures and contents. Flooding and debris left some roads in the area
closed for three days.
The historical incidence of flooding in Lincoln County and Minnehaha County is discussed in
the previous vulnerability section. A majority of the Presidential Disaster Declarations since
1960 for Lincoln County and Minnehaha County have involved flooding, including eight of nine
declarations for Lincoln County and six of eight declarations for Minnehaha County.
3.4 National Flood Insurance Program Participation
Existing Capabilities
Tables 3-22 and 3-23 summarize the status of various jurisdictions within Lincoln County and
Minnehaha County participating in the National Flood Insurance Program (NFIP). According to
FEMA BureauNet, Lincoln County and five of its municipalities are participating in the NFIP.
Minnehaha County and nine of its municipalities are participating in the NFIP.
44 CFR Part §201.6(c) (3) (ii): Requirement
[The mitigation strategy] must also address the jurisdiction’s participation in the
NFIP, and continued compliance with NFIP requirements as appropriate.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Table 3-22: National Flood Insurance Program Participation -
Lincoln County
Jurisdiction CID # NFIP Status
Entry
Date Into
Regular
Program
FIRM
Effective
Date
Policies
in
Place
Amount of
Insurance
Lincoln County 460277 Participating 10/1/1986 7/2/2008 104 $26,471,300
Beresford 460155 Not Participating
7/2/2008
Canton 460047 Participating 9/4/1985 7/2/2008 2 $420,000
Fairview 460048 Not Participating
7/2/2008
Harrisburg 460114 Participating 6/8/1998 7/2/2008 6 $970,000
Hudson 460049 Suspended 12/18/1985 7/2/2008
Lennox 460192 Participating 6/8/1998 7/2/2008 1 $70,000
Tea 460143 Participating 4/25/1997 7/2/2008 15 $3,326,000
Worthing 460151 Participating 4/25/1997 7/2/2008 2 $350,000
Source: Federal Emergency Management Agency Community Status Book Report; FEMA BureauNet web site.
Insurance policy information as of 11/30/2010.
Table 3-23: National Flood Insurance Program Participation -
Minnehaha County
Jurisdiction CID # NFIP Status
Entry
Date Into
Regular
Program
FIRM
Effective
Date
Policies
in
Place
Amount of
Insurance
Minnehaha
County 460057 Participating 9/5/1979 9/2/2009 129 $21,665,000
Baltic 460058 Participating 11/19/1980 9/2/2009 3 $259,600
Brandon 460296 Participating 7/10/1979 9/2/2009 4 $875,000
Colton 460166 Participating 6/8/1998 9/2/2009 0 $0
Crooks 460314 Not Participating
9/2/2009
Dell Rapids 460059 Participating 8/15/1980 9/2/2009 32 $3,702,500
Garretson 460177 Participating 1/30/1984 9/2/2009 1 $175,000
Hartford 460180 Participating 4/25/1997 9/2/2009 14 $2,596,600
Humboldt 460118 Participating 6/8/1998 9/2/2009 0 $0
Sherman 460313 Not Participating
9/2/2009
Sioux Falls 460060 Participating 1/17/1979 9/2/2009 1242 $318,931,200
Valley Springs 460221 Participating 7/16/1980 9/2/2009 1 $210,000
Source: Federal Emergency Management Agency Community Status Book Report; FEMA BureauNet web site.
Insurance policy information as of 11/30/2010.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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3.5 Population Density & Building Exposure Vulnerability to All Hazards
Lincoln County, Minnehaha County, and their communities are all at risk to the hazards of
severe summer storms, severe winter storms, flooding, and tornadoes. Areas with a higher
population or a higher degree of building exposure will have a higher risk of being impacted by
the aforementioned hazards.
Building Exposure — To best compare the vulnerability of one community or county to
another, it is necessary to consider the total assets vulnerable to loss. This rating is based on total
building exposure from total property valuations (residential, commercial, industrial,
agricultural, religion, government, and education) for each community and county. The total
range of building exposure ($59,332,000 to $11,610,000,000) was divided into 10 ranges as
shown in Table 3-24. The ranges were numbered 1 through 10 in ascending order and assigned a
vulnerability ranking of low, moderate, or high.
Table 3-24: Building Exposure
Building Exposure ($000)
Ranking Vulnerability
59,332 – 100,000 1 Low 100,001 - 2,079,144 2 Moderate 2,079,145 - 3,089,051 3 Moderate 3,089,052 - 4,098,957 4 Moderate 4,098,958 - 5,108,863 5 Moderate 5,108,864 - 6,118,769 6 Moderate 6,118,770 - 7,128,675 7 Moderate 7,128,676 - 8,138,582 8 High 8,138,583 - 9,148,488 9 High 9,148,489 – 11,610,000 10 High
Population Density — In order to compare the vulnerability of one community or county to
another, it is necessary to examine a location’s population density. This rating is based on the
number of persons per square mile for each community and county. The total range of population
density (75 to 3,000) was divided into 10 ranges as shown in Table 3-25. The ranges were
numbered 1 through 10 in ascending order and assigned a population density ranking of low,
moderate, or high.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Table 3-25: Population Density
Population Density Ranking Vulnerability
75-300 1 Low
301-600 2 Moderate
601-900 3 Moderate
901-1200 4 Moderate
1201-1500 5 Moderate
1501-1800 6 Moderate
1801-2100 7 Moderate
2101-2400 8 High
2401-2700 9 High
2701-3000 10 High
As illustrated in Tables 3-26 and 3-27, in terms of building exposure vulnerability, Minnehaha
County and the City of Sioux Falls are most at risk to the hazards of severe summer storms,
severe winter storms, flooding, and tornadoes with building exposure vulnerability rankings of
ten and eight. The communities of Baltic, Beresford, Colton, Crooks, Fairview, Garretson,
Humboldt, Hudson, Lennox, Sherman, Worthing, and Valley Springs with less than
$100,000,000 in building exposure vulnerability have the least building exposure within the
region.
The communities of Brandon, Crooks, Sioux Falls, and Tea with more than 2,101 persons per
square mile are most vulnerable, based on population density, to the hazards of severe summer
storms, severe winter storms, flooding, and tornadoes. Lincoln County, Minnehaha County, and
the community of Sherman have the least population density with less than 300 persons per
square mile.
Table 3-26: Total Property Evaluation & Population Density -
Lincoln County
Jurisdiction Total Property
Valuation
(Exposure) (2009)19
Building
Exposure
Ranking
Population
2010
Population
Density per
Square Mile
Population
Density
Ranking
Lincoln County $4,059,264,827 4 44,828 77.8 1
Beresford $11,600,595 1 359 1,114.4 4
Canton $114,428,778 2 3,057 1,019 4
Fairview $1,353,110 1 60 600 2
Harrisburg $183,197,083 2 4,089 1,648.8 6
Hudson $6,566,383 1 296 986.6 4
Lennox $71,878,170 1 2,111 1,919 7
Sioux Falls City
(Lincoln County)
$1,912,390,135
2 21,095 2,306.5 8
Tea $168,794,285 2 3,806 2,903 10
Worthing $31,023,357 1 877 1,754 6
19
SD Department of Revenue, http://www.state.sd.us/drr2/propspectax/booklets/CITY_TAX_PAY2010.pdf
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Table 3-27: Total Property Evaluation & Population Density -
Minnehaha County
Jurisdiction Total
Property
Valuation
(Exposure)
(2009)20
Building
Exposure
Rating
Population
2010
Population
Density
Ranking
Population
Density
Ranking
Minnehaha
County
$11,609,473,010 10 169,468 209.2 1
Baltic $42,404,400 1 1,089 1,555.7 6
Brandon $470,532,463 2 8,785 2,311.8 8
Colton $23,873,473 1 687 981.4 4
Crooks $57,937,026 1 1,269 2,115 8
Dell Rapids $163,077,780 2 3,633 1,816.5 7
Garretson $45,307,051 1 1,166 777.3 3
Hartford $108,704,944
2 2,534 1,689.3 6
Humboldt $22,653,643 1 589 981.6 4
Sherman $2,595,960 1 78 260 1
Sioux Falls $7,823,188,044 8 132,793 2,306.5 8
Valley Springs $26,533,275 1 759 975 4
3.6 Lincoln County and Communities Future Growth and Development
Trends
From 2000 to 2010, Lincoln County’s population increased 86% from 24,131 to 44,828, making
it one of the fastest growing counties in the United States. The majority of this growth has
occurred in Sioux Falls. The population of Sioux Falls in Lincoln County has more than tripled
from 6,620 in 2000 to 21,095 in 2010. Much growth has also occurred in the communities of Tea
and Harrisburg as well. This rapid transformation of what once was agricultural land into
commercial and residential developments has occurred with proper planning and land use
policies in place. During 2011, Lincoln County has been in the process of updating its drainage
ordinances and drafting a drainage management plan. Future development is anticipated to occur
within southern Sioux Falls, Tea, and Harrisburg. Each of these communities is using previously
developed drainage master plans to address future development and flood plains concerns.
20
SD Department of Revenue, http://www.state.sd.us/drr2/propspectax/booklets/CITY_TAX_PAY2010.pdf
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Table 3-28: Lincoln County and Communities Future Growth and Development Trends
Jurisdiction Future Growth 2011-2020
Lincoln County Lincoln County has grown 86% in the last ten years, nearly doubling in size
from 24,131 in 2000 to 44,828 in 2010. The majority of this growth has
occurred within the municipalities of Harrisburg, Sioux Falls, and Tea. Over
the next decade, future growth is anticipated to occur on the fringes of
Harrisburg, Sioux Falls, and Tea. Growth is also expected to occur along the I-
29 corridor.
Beresford Beresford’s population has remained steady over the last decade. No major
future projects or development are anticipated.
Canton The City of Canton’s population has decreased 1.7% from 3,110 in 2000 to
3,057 in 2010. Future industrial expansion is expected to occur over the next
decade for businesses along US Hwy 18.
Fairview The Town of Fairview’s population has decreased significantly from 94
persons in 2000 to 60 persons in 2010. Future growth within the Town of
Fairview is anticipated to be minimal.
Harrisburg The City of Harrisburg has quadruped in population from 958 in 2000 to 4,089
in 2010.The number of housing units has increased from 318 to 1,507 as well.
In order to keep up with the influx of growth, the City has had to make system-
wide improvements to its drinking water and sanitary sewer infrastructure. In
2012, the City will undertake the Columbia Basin Storm Sewer Project to make
much needed drainage improvements at the south end of the Columbia Basin.
These infrastructure improvements are being undertaken in response to
recommendations provided by the City of Harrisburg’s Master Drainage Plan.
Growth has slowed with the downturn in the housing market and the United
States (US) economy post the US 2008-2009 recession. Growth and future
development is expected to continue in a northwestern general direction, as
planned by the 2011 revised Comprehensive Plan for the City of Harrisburg.
Hudson The population of Hudson has decreased from 402 in 2000 to 296 in 2010.
Future growth in Hudson is anticipated to be minimal over the next decade.
Lennox The population of Lennox has increased 3.6% from 2,037 in 2000 to 2,111 in
2010. Additional growth along the City’s fringe is anticipated to occur over the
next decade.
Sioux Falls City
(Lincoln County)
The population of Sioux Falls within Lincoln County limits has increased
318.7% from 6,620 in 2000 to 21,095 in 2010. The number of housing units
has increased dramatically from 2,154 to 8,700. The southern fringe of Sioux
Falls is anticipated to grow over the next decade with the majority of the
development occurring southeast of existing city limits. According to the
Shape Sioux Falls 2035 Comprehensive Plan, two drainage basin areas in
Southeastern Sioux Falls are slated as a high priority for future storm water
infrastructure projects. The City of Sioux Falls’ growth management policies
advocate for infill development and contagious growth along the City’s fringe.
Adequate City services, including storm sewer, must be in place prior to the
approval of future development.
Tea The City of Tea’s population has increased 118.48% from 1,742 in 2000 to
3,806 in 2010. The number of housing units has increased from 600 in 2000 to
1,354 in 2010. The majority of Tea’s future growth over the next decade is
anticipated to occur north and east of Tea’s City Limits toward I-29. In the near
future, a large commercial and residential development is planned south of Tea
City Hall.
Worthing The population of Worthing has increased nearly 50% from 585 persons in
2000 to 877 in 2010. The majority of Worthing’s future growth over the next
decade is anticipated to occur west of Worthing’s City Limits toward I-29.
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3.7 Minnehaha County and Communities Future Growth and Development
Trends
Minnehaha County’s population has increased by 14.3% from 148,281 in 2000 to 169,468 in
2011. Much of this growth has occurred within the communities of Baltic, Brandon, Crooks, Dell
Rapids, Hartford, and Sioux Falls. Drainage has been a primary concern within Minnehaha
County since the first drainage districts were created in the early 1900s. The prevention of
downstream impacts and the importance of maintaining wetlands are policies advocated by
Minnehaha County’s Drainage Plan (August, 2011). The county revised its drainage ordinance in
2010 to better address drainage complaints/concerns and to ensure that South Dakota Codified
Law and local laws are followed during the issuance of drainage permits.21
Table 3-29: Minnehaha County and Communities Future Growth
and Development Trends
Jurisdiction Future Growth 2011-2020
Minnehaha County The population of Minnehaha County has increased 14.3% from 148,281 in
2000 to 169,468 in 2010. The majority of this growth has occurred within the
municipalities of Brandon, Crooks, Dell Rapids, Hartford, and Sioux Falls.
Over the next decade, future growth is anticipated to occur on the fringes of the
aforementioned cities. Growth is also expected to occur along the I-29, I-229,
and I-90 corridors.
Baltic The City of Baltic’s population has increased 34.2% from 811 in 2000 to 1,089
in 2010. Additional future residential growth is anticipated along the City’s
fringe.
Brandon The City of Brandon’s population has increased 54.3% from 5,693 in 2000 to
8,785 in 2010. Growth is restrained by the Big Sioux River to the west, Split
Rock Creek to the east, and Beaver Creek to the south and east of Brandon.
Growth over the next decade will likely occur along the southern and western
fringes of Brandon that are not designated as floodplain conservation areas.
Colton Colton’s population has increased from 662 in 2000 to 667 in 2010. Growth is
expected to be minimal over the next decade.
Crooks Crook’s population has increased 47.7% from 859 in 2000 to 1,269 in 2010.
Growth is anticipated to occur along the City’s fringe residential areas.
Dell Rapids The City of Dell Rapids population has increased 21.9% from 2,980 in 2000 to
3,633 in 2010. Growth will occur to the west and north of the existing city
limits. The southeast corner of the City is located in the 100-year flood plain.
Garretson Garretson’s population remained steady from 2000 to 2010. Minimal future
growth is anticipated over the next decade.
Hartford The City of Hartford’s population increased by 37.4% from 1,844 in 2000 to
2,534 in 2010. Additional growth is expected to occur along the City’s fringe.
Humboldt The population of Humboldt has increased 13.05% from 521 in 2000 to 589 in
2010. Additional growth is expected to occur along the City’s fringe.
Sherman Sherman’s population fell 10.3% from 87 in 2000 to 78 in 2010. Growth is
expected to be minimal over the next decade.
21
Minnehaha County – 2010 Drainage Ordinance:
http://www.minnehahacounty.org/dept/pl/pl_ordinances/2010_revised_drainage.pdf
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Table 3-29: Minnehaha County and Communities Future Growth
and Development Trends (continued)
Jurisdiction Future Growth 2011-2020
Sioux Falls
(City-Wide)
The City of Sioux Falls has increased 24.13% from $123,975 in 2000 to
$153,888 in 2010. Over the next decade growth is anticipated to occur along
the City’s fringe, with the majority of the growth occurring to the south and
west of existing city limits.
As indicated previously, the Shape Sioux Falls 2035 Comprehensive Plan
identified two drainage basin areas in Southeastern Sioux Falls that are slated
as a high priority for future storm water infrastructure projects. As indicated in
the Comprehensive Plan, drainage will be addressed utilizing two methods:
“(1) on-site drainage ponds, and, (2) regional drainage basins. On-site drainage
ponds will need to provide for the rainfall and snow melt needs of the
development site and detain it on the site. Regional drainage basins will have
one or several drainage facilities which serve large drainage basin areas; these
basin areas drain naturally through low areas into settlement facilities to
improve the overall water quality.”22
Valley Springs Valley Springs’ population decreased 4% from 792 in 2000 to 759 in 2010.
Minimal growth is expected over the next decade.
22
The Shape Sioux Falls 2035 Comprehensive Plan (December 2009) Section, Page 33.
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63
Chapter IV
Hazard Mitigation Strategy
4. 1 Hazard Mitigation Goals and Objectives
Background
The previous chapters of this plan discussed the potential hazards impacting both Lincoln
County and Minnehaha County. This chapter discusses the mitigation goals and objectives
established by the planning committee for the joint jurisdiction, followed by a discussion of the
mitigation projects identified for implementation, and concluding with a discussion for how the
proposed mitigation projects were prioritized.
Mitigation Goals and Objectives
The planning committee began the process of developing mitigation goals and objectives by
reviewing the mitigation goals and objectives included in the draft State of South Dakota Hazard
Mitigation Plan – Basic Plan (January, 2011). The committee wanted to ensure that the goals
and objectives identified in this updated plan would complement the goals and objectives
identified in the statewide plan, while specifically focusing on the impact of hazards for Lincoln
County and Minnehaha County. In addition, the planning committee reviewed the goals and
priorities established for a nearby jurisdiction in its recently updated PDM Plan to use as a guide
and reference for discussion. After reviewing these reference materials and further discussion,
an initial draft set of goals and objectives was identified by the planning committee.
To further flesh out the goals and objectives and ensure that the goals and objectives fully
represented the issues identified in the Hazard Risk Assessment, planning committee members
split into several small working groups with each group being assigned a specific hazard
category to be discussed in the report (i.e. severe summer storms, severe winter storms,
tornadoes/high winds, and flooding). Each group was tasked with developing a set of problem
statements that would recognize the impact, vulnerability, and challenges faced by the region as
a result of the specific hazard events. To help facilitate this process, groups were given a copy of
the problem statements identified in the draft State of South Dakota Hazard Mitigation Plan –
Basic Plan (January, 2011) to utilize as a guide for conceptualizing problem statements for the
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Hazard Mitigation Plan 2011
Update. Once each group had completed its work, the group reported its draft problem
statements to the entire planning committee.
It became apparent that while each group focused on a particular hazard category, many of the
problem statements identified by various groups were similar and were not always specifically
unique to a particular hazard. A summarized consolidated list of problem statements identified
by the planning committee was then developed.
44 CFR Part §201.6(c) (3) (i): Requirement
[The hazard mitigation strategy shall include a] description of mitigation goals to
reduce or avoid long-term vulnerabilities to the identified hazards.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
64
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Hazard Mitigation
Plan 2011 Update - Problem Statements
1) There are an insufficient number of shelters to accommodate residents without power
or needing protective shelter during and after hazard events.
2) Need to better maintain existing shelters.
3) Residents are often not aware of the location of protective shelters.
4) Power outages due to freezing or heavy rains, lightning, high winds, tornadoes, or
blizzard events have a significant negative impact on resident safety, provision of
emergency services, and operation of critical community infrastructure.
5) Need to make sure that warning systems are adequate, appropriately maintained, and
operational during power outages.
6) Ensure emergency notification systems are adequate, appropriately maintained, and
operational during hazard events.
7) There are not enough resources to clear emergency routes during blizzards and large
snow events resulting in public safety issues for emergency responders and an
inability of people to travel to work and access critical services.
8) In extreme cold conditions, the water distribution system is at risk of failure.
9) Drainage and infrastructure are insufficiently capable of handling heavy rains
resulting in infiltration and contamination of storm sewer systems.
10) In response to winter storms, local governments are financially burdened by increased
costs for clearing snow from roads including costs related to gravel, salt, employee
wages, etc.
11) Significant property and crop damage resulting from severe storms including
blizzards, heavy rains, flooding, tornadoes, heavy winds, lightning, etc.
12) Need to ensure that structures such as mobile homes and storage sheds are property
anchored to withstand the impact of hazards and that anchoring systems continue to
be maintained. There is a lack of inspection and enforcement of building codes.
13) Communities need defined action plans for preparing and responding to disaster or
hazard events to mitigate against the impact of the hazards.
14) Residents lack knowledge of flood insurance coverage and an appropriate
understanding of what is covered and what is not covered.
15) There is a general lack of enforcement and knowledge by local communities
regarding flood plain management.
16) Erosion of waterways causes infrastructure such as waterlines to be exposed during
flooding and heavy rains resulting in defective infrastructure.
17) There is a need for more coordinated responses to mitigating, preparing, and
responding to hazards and disaster events at a county-wide and joint county level.
After completing the exercise of developing problem statements, planning committee members
again reviewed their previously identified goals and objectives and further refined the goals and
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
65
objectives to ensure that they represented the problem statements identified by the planning
committee. The final list of goals and objectives for the plan are listed below.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Hazard Mitigation
Plan 2011 Update - Goals and Objectives
Goal 1: Reduce injuries and loss of life from natural hazards
Objective: Reduce the number of injuries/fatalities caused by severe weather related
hazards
Objective: Ensure that people have adequate warning when violent weather is imminent
Objective: Ensure that people have access to adequate shelter from hazardous weather
conditions and are aware of the location of shelters
Goal 2: Reduce damage to existing and future structures within hazard areas
Objective: Reduce the number of repetitive and non-repetitive loss structures
Objective: Reduce flood damage to flood prone properties, structures, and critical
facilities through property acquisition, property relocation, or elevating
structures at least one foot above the base flood elevation
Objective: Reduce damage by better maintaining and replacing aging infrastructure
Goal 3: Reduce the losses to critical facilities, utilities, and infrastructure from natural
hazards
Objective: Reduce the number of power outages
Objective: Reduce negative impacts to water supply and sewage treatment systems by
indentifying and implementing storm water drainage and infrastructure
projects as needed
Objective: Improve reliability of communications during/following hazard events
Goal 4: Reduce impacts to the economy, the environment, and cultural resources from
hazards
Objective: Reduce loss to environment and cultural resources
Objective: Reduce agricultural losses
Goal 5: Better coordinate efforts to mitigate, prepare, manage, and respond to all hazard
events across jurisdictions in Lincoln and Minnehaha Counties.
Objective: Establish a centralized Emergency Operations Center (EOC)/Multi-Agency
Coordinating Center (MACC) to coordinate emergency management services
for both Lincoln County and Minnehaha County and the communities located
therein.
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66
4.2 Hazard Mitigation Actions
The planning committee then began the process of identifying specific mitigation projects that
reflect the goals, objectives and problem statements identified in this chapter, and that if
implemented, would mitigate the impact of future hazard events. At the Multi-Hazard Pre-
Disaster Mitigation Planning Committee Minnehaha and Lincoln Counties (Update 2011)
Meeting 4 on March 15, 2011, the planning committee first assessed the status of mitigation
projects included in the prior 2005 Multi-Hazard Pre-Disaster Mitigation Plan.
Table 4.1: Status of Mitigation Projects included in the revised 2005 “Multi-Hazard Pre-
Disaster Mitigation Plan - Serving the Jurisdictions and Communities of Minnehaha and
Lincoln Counties and the City of Sioux Falls”
Hazard Area of Concern Potential Project Status Wildfire Threat Sioux Falls / Brandon
Future development in the NE
corner of the City of Sioux
Falls between Great Bear
Recreation Park and the City
of Brandon
Ordinance for development area,
suggesting the placement of
vegetation & debris to that of the
residential structure. The distance
between the structure and any
nearby tree or outbuilding should be
greater than the height of the mature
tree or building or at least 10 feet.
Building codes, which advice of
appropriate roofing materials. For
instance, instead of using wooden
shingles, use asphalt, fiberglass,
metal or ceramic tile.
Building codes, which advise of
appropriate and safer landscaping
techniques. For instance, instead of
using heavy vegetation next to the
structure, use stones, pavers, or rock
features.
Enforce the existing and/or new
ordinances and codes in both
existing and future residential and
commercial development areas.
Debris clean up off future
development sites to ensure lack of
fuel for potential fire.
No Progress
Reason: No
progress has
occurred regarding
this identified hazard
mitigation action
due to lack of time
and resources, as
well as low
perceived
vulnerability to the
hazard.
44 CFR Part §201.6(c) (3) (ii): Requirement
[The mitigation strategy shall include a] section that identifies and analyzes a
comprehensive range of specific mitigation actions and projects being considered to
reduce the effects of each hazard, with the particular emphasis on new and existing
buildings and infrastructure.
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67
Hazard Area of Concern Potential Project Status
Steep Slope
Development /
Landslide
Sioux Falls / Brandon
Future development in the NE
corner of the City of Sioux
Falls between Great Bear
Recreation Park and the City
of Brandon
Use retention walls when
developing hillsides to prevent
landslide.
Educate developers and
homeowners of emergency response
problems that could occur within
the area.
No Progress
Reason: No
progress has
occurred regarding
this identified hazard
mitigation action
due to a lack of time
and resources.
Rail lines
carrying
hazardous
materials
Lincoln and Minnehaha
Counties
Countywide area, but
especially throughout
municipalities
Develop communications plan with
rail companies and emergency
management officials to ensure that
emergency management officials
have knowledge of what and when
hazardous materials are being
transported by rail.
No Progress
Reason: After
conducting basic
research, it became
apparent that this
hazard mitigation
action could not be
feasibly
implemented.
Gas pipeline
explosion Lincoln and Minnehaha
Counties
Countywide area, but
especially throughout
municipalities
Project in which all pipelines
throughout the City would be
identified and mapped. This project
would also include a
communications plan between city
officials and gas companies so that
city officials (especially emergency
responders) are aware of what type
of product is being carried in each
pipe and what the type of pipe in
which the product is being
transported.
Completed
State Pipeline
Association /
Industry Group have
met with local
leaders and
emergency
responders to
discuss the location
of pipelines and
responding to
pipeline hazards.
Power outages
due to electrical
storms
Sioux Falls
Busy Intersections within the
City of Sioux Falls
Back up power supplies within
traffic signals at busy intersections.
Completed
Back up power
supplies now go into
every traffic signal
Storm water
discharge Sioux Falls Funding is needed for the design
and construction of facilities.
On-going
Creek Slope
Failure Sioux Falls
Along Skunk Creek, below
12th
Street within the City of
Sioux Falls
Soft bank stabilization, which will
create fish habitat and stop slope
failure along the creek in critical
areas.
On-going
High Wind and
Tornado Entire County
Countywide area, and
especially throughout
municipalities
Enforcement of tougher building
codes for tornado shelters
Aggressive education of public on
debris clean up and tree thinning.
The project would provide free
debris pick-up more often in return
for participation in the event.
No Progress
Reason: It became
difficult to
implement this
hazard mitigation
action due to lack of
time and resources.
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68
Hazard Area of Concern Potential Project Status
Storm water
discharge Dell Rapids City of Dell Rapids,
particularly at 12th
Street from
Clarke Avenue to Garfield
Avenue
Construction of storm water
detention area and improvement to
storm sewer in the vicinity.
Completed
Storm water
discharge Humboldt
Town of Humboldt Funding needed for construction of
storm water detention area and
improvements to storm sewer in the
vicinity.
No Progress
Reason: This Hazard
Mitigation action is
still being
considered.
Lack of accurate
data needed to
support
emergency
response actions
and hazard
mitigation
analysis
Lincoln and Minnehaha
Counties The City will include the feature
compilation projection with the
aerial photo project in 2004 in
which the City will provide the
additional GIS work necessary to
join attribute information to the
building footprint features.
Completed
Lack of agreed
upon evacuation
routes for rural
municipalities
Lincoln and Minnehaha
Counties and their Rural
municipalities
Evacuation routes will be developed
by County Planning & GIS
personnel and copies of the routes
will be given to the local
municipalities to adopt.
Completed
Cities were later
covered under plans.
Table 4.2: Status of Mitigation Projects included in the revised 2005 “Multi-Hazard Pre-
Disaster Mitigation Plan - Serving the Jurisdictions and Communities of Minnehaha and
Lincoln Counties and the City of Sioux Falls”
Hazard Area of Concern Potential Project Status Wildfire Threat Lincoln and Minnehaha
Counties
Countywide grasslands
Enforcement of burn ban as deemed
appropriate by officials.
No Progress
Reason: No
progress has
occurred regarding
this identified
hazard mitigation
action due to a lack
of time and
resources.
Gas pipeline
explosion Lincoln and Minnehaha
Counties Countywide area, but
especially throughout
municipalities
Project in which all pipelines
throughout the cities would be
identified and mapped. This project
would also include a
communications plan between city
officials and gas companies so that
city officials (especially emergency
responders) are aware of what type
of product is being carried in each
pipe and what the type of pipe in
which the product is being
transported.
Completed
State Pipeline
Association /
Industry Group
have met with local
leaders and
emergency
responders to
discuss the location
of pipelines and
responding to
pipeline hazards.
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69
Hazard Area of Concern Potential Project Status Power outages
due to electrical
storms
Sioux Falls
Busy Intersections within the
City of Sioux Falls
Back up power supplies within
traffic signals at busy intersections.
Completed
Back up power
supplies now go in
every traffic signal
High Wind and
Tornado Lincoln and Minnehaha
Counties
Countywide area, and
especially throughout the
municipalities
Enforcement of tougher building
codes for tornado shelters.
Aggressive education of public on
debris clean up and tree thinning.
The project would provide free
debris pick-up more often in return
for participation in the event.
Progress
Reason: The cities
of Harrisburg and
Tea did conduct
storm damage
debris pickup, but
the other cities have
not.
Storm water
discharge Harrisburg
(NE side of town) Funding will be needed to provide
an appropriate storm sewer drainage
system in the Northeast portion of
the City. An engineering study has
been completed and an application
for funds is the next step.
Completed
Flooding Hudson
Northern portion of the Town
of Hudson
Flooding is occurring in the northern
portion of Hudson. A buyout of
flooded cropland would solve the
flooding problem. However, the
town and the property owner have
not yet negotiated a buyout.
On-Going
Reason: Issue has
been worked on, but
land owner
continues to refuse
to sell the property.
Lack of agreed
upon evacuation
routes for rural
municipalities
Rural municipalities
in Lincoln and Minnehaha
Counties
Evacuation routes will be developed
by County Planning & GIS
personnel and copies of the routes
will be given to the local
municipalities to adopt.
Completed
Cities were later
covered under the
hazardous materials
plan.
At the Multi-Hazard Pre-Disaster Mitigation Planning Committee Minnehaha and Lincoln
Counties (Update 2011) Meeting #4 on March 15, 2011, the planning committee members
divided into five small groups with 4-5 jurisdictions represented per group to prioritize and rank
potential hazard mitigation projects for their communities. Prior to the meeting, representatives
for each community submitted a list of potential hazard mitigation projects. The list of projects
included the name of the jurisdiction, rating (high, medium, or low), responsible party,
timeframe, cost, and hazard type.
Later, each small group member was given a ledger sheet detailing the aforementioned project
information regarding potential hazard mitigation projects for 2011. Each small group was then
tasked with ranking and prioritizing each project utilizing the following categories: Overall
Benefit (High, Medium, or Low); Cost Effective (Yes, No); Politically Feasible (Yes, No);
Technically Feasible (Yes, No); Environmentally Feasible (Yes, No); Revised Rating (High,
Medium, or Low); Funding Resources (FEMA, SD Office of Emergency Management, SD
Department of Environment and Natural Resources, etc.); and Included on the South Dakota’s
Hazard Mitigation Project List (Yes, No). Each small group deliberated and ranked each project
using the criteria previously mentioned. After 30 minutes of discussion, each small group
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
70
reported back to the entire group. This activity gave each planning committee member the
opportunity to see what other communities are undertaking in terms of potential hazard
mitigation projects, and planning committee members were able to take a second look at the
potential hazard mitigation projects that they plan on submitting to the state. A table listing the
proposed mitigation actions/projects for Lincoln County, Minnehaha County, and their
communities can be found in Appendix H. Hazard Mitigation projects that are being submitted
to the state will be reviewed for their cost effectiveness and must have a benefit cost analysis
ratio of 1.0 or greater to be considered for submission. SECOG will work with Lincoln County,
Minnehaha County, and their communities to help them determine whether or not a project is
cost effective.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
71
4.3 Lincoln and Minnehaha County HMGP Project Applications 2011
Lincoln County, Tea Tributary Project Area, Redwood Avenue looking East
July 2010, photo taken by Lincoln County GIS
Table 4-3: Lincoln and Minnehaha County HMGP Project Applications 2011
July – 2011,
Lincoln County
Spring Creek
Tributary Project
The Lincoln County – Spring Creek Tributary Project will permanently
remove 20 residences from the 100-year flood plain through the use of
increased culverts sizes and channel improvements.
July – 2011,
Lincoln County
Tea Tributary
Project
The Lincoln County – Tea Tributary Project will permanently remove 70
residences from the 100-year flood plain through the use of increased
culverts sizes, channel improvements, and the creation of water detention
areas.
July – 2011, City
of Canton
Holiday Drive
Drainage Project
The City of Canton – Holiday Drive Project through the construction of
channel improvements and storm sewer inlets will provide increased flood
protection to a home and nearby residences along Holiday Drive.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Chapter V
Plan Maintenance
5.1 Plan Maintenance Process
In order to be an effective hazard mitigation tool, the Lincoln County and Minnehaha County
Multi-Hazard Pre-Disaster Hazard Mitigation Plan must be updated on an annual basis or after
the occurrence of a hazard event. It must also be flexible enough so that it can be used with
existing planning and emergency management documents at both the city and county level. This
chapter will address how local officials within Lincoln County and Minnehaha County, and their
communities intend to ensure the following:
The plan’s goals and objectives address current and expected conditions.
The plan has addressed the nature, magnitude, and/or type of risks that have changed.
The current resources available are appropriate for implementing the plan.
The plan has addressed implementation issues such as technical, political, legal or
coordination issues with other agencies.
The plan has measured the outcomes that have occurred and the progress that has been
made regarding meeting hazard mitigation goals and objectives.
5.2 Plan Monitoring, Evaluation, and Updating
The Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011
Update is an open document that will be evaluated and updated as needed. The Lincoln County
Emergency Management Director and the Minnehaha County Emergency Management Director
are both responsible for ensuring the plan is maintained. They will both work with the Multi-
Hazard Pre-Disaster Mitigation Planning Committee throughout the plan’s maintenance process.
Each year, the Multi-Hazard Pre-Disaster Mitigation Planning Committee will assemble as a
group at an annual review meeting to evaluate the overall effectiveness of the hazard mitigation
plan. The group will scrutinize each chapter and individually discuss hazard mitigation actions
that have been undertaken to indicate what has worked and not worked for their communities. At
each annual review meeting, the group shall acknowledge: The occurrence of a significant event,
funding availability, changes in local priorities, and technological advancements.
When the review meeting concludes, the group will make changes to the current mitigation
strategy, goals, and objectives as needed. If no changes are proposed, it is anticipated that the
plan would not be updated until required (within five years).The emergency managers will be
responsible for ensuring that the plan updates are incorporated into the plan document. Each
44 CFR Part §201.6(4) (3) (i): Requirement
[The plan maintenance process shall include a] section describing the method and
schedule of monitoring, evaluating, and updating the mitigation plan within a five-
year cycle.
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Multi-Hazard Pre-Disaster Mitigation Planning Committee member will then be tasked with
reporting their findings back to their local government officials.
Each year the emergency managers for both Lincoln County and Minnehaha County will be
tasked with annually reporting the Lincoln County and Minnehaha County Multi-Hazard Pre-
Disaster Mitigation Plan 2011 Update’s effectiveness to its County Commission. At each annual
review meeting, an update on the progress of current and ongoing hazard mitigation projects and
priorities will be discussed. Each participating jurisdiction represented in the plan will be invited
to send a representative to each county’s review meeting of the County Commission. This will
help ensure local jurisdiction input is a part of the annual plan review process.
Table 5.1: Plan Monitoring, Evaluation, and Updating Schedule 2011-2016
2011 2012 2013 2014 2015 2016
January-
October
Conduct
meetings
with Pre-
Disaster
Mitigation
Planning
Committee
to Update
PDM Plan
2011
October –
Annual Pre-
Disaster
Mitigation
Planning
Committee
meeting to
discuss Plan
October –
Annual Pre-
Disaster
Mitigation
Planning
Committee
meeting to
discuss Plan
October –
Annual Pre-
Disaster
Mitigation
Planning
Committee
meeting to
discuss Plan
October –
Annual Pre-
Disaster
Mitigation
Planning
Committee
meeting to
discuss Plan
January –
October
Conduct
meetings with
Pre-Disaster
Mitigation
Planning
Committee to
Update PDM
Plan 2016
November–
Meetings
with
Lincoln
County
Commission
and
Minnehaha
County
Commission
to approve
updated
PDM Plan
2011
November –
Annual
Meetings with
Lincoln
County
Commission
and
Minnehaha
County
Commission
November –
Annual
Meetings with
Lincoln
County
Commission
and
Minnehaha
County
Commission
November –
Annual
Meetings with
Lincoln
County
Commission
and
Minnehaha
County
Commission
November –
Annual
Meetings with
Lincoln
County
Commission
and
Minnehaha
County
Commission
November–
Meetings with
Lincoln
County
Commission
and
Minnehaha
County
Commission
to approve
updated PDM
Plan 2016
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
74
5.3 Plan Integration
The Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011
Update will be used as a blueprint to address hazards within Lincoln County, Minnehaha County,
and their communities. The plan is designed to work with other local planning and emergency
management documents, tools, and systems at both the city and county level. The plan’s
effectiveness hinges on incorporating local plans and policy documents. For example, addressing
the flood hazard can easily be done at the city or county level through tools such as local
comprehensive plans, zoning, and floodplain ordinances. Future property losses can be prevented
or mitigated against at no cost by simply directing development to areas that are less prone to the
flood hazard. The Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation
Plan acts as another tool in addressing hazard mitigation concerns.
It is highly critical that the goals, objectives, and actions highlighted in the hazard
mitigation plan build upon existing information that is currently included in existing local
comprehensive plans, emergency operations plans, land use plans, zoning ordinances, flood
plain ordinances, and emergency response plans. Listed below are some of the local planning
and emergency planning documents that the Lincoln County and Minnehaha County Multi-
Hazard Pre-Disaster Mitigation Plan 2011 Update is designed to work with. Each document was
analyzed and reviewed as the plan was being drafted:
Lincoln County Local Emergency Operations Plan
Proposed Lincoln County Drainage Plan 2011
Minnehaha County Local Emergency Operations Plan
Sioux Falls EM Plan 2007
2010 Revised Drainage Ordinance of Minnehaha County
Minnehaha County Drainage Plan
Lincoln County Comprehensive Plan (2005-2025)
Minnehaha County Compressive Development Plan (December 1998)
Baltic Comprehensive Plan (2005-2025)
Brandon Comprehensive Plan (2000-2025)
Beresford Comprehensive Plan (2003-2025)
Colton Comprehensive Plan (2000-2025)
Crooks Comprehensive Plan (2000-2025)
Dell Rapids Comprehensive Plan (2000-2025)
Hartford Comprehensive Plan (2006-2026)
Humboldt Comprehensive Plan (2003-2025)
Shape Sioux Falls Comprehensive Plan (2010-2035)
Canton Comprehensive Plan (2000-2020)
Harrisburg Comprehensive Plan (2005-2025)
Lennox Comprehensive Plan (1995-2015)
Tea Comprehensive Plan (2005-2030)
Drainage Master Plan for the City of Tea, South Dakota (2007)
Worthing Comprehensive Plan (2010-2030)
Valley Springs Comprehensive Plan (1978)
Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation Plan 2011 Update
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Reviewing the comprehensive plans and zoning ordinances was a highly useful activity during
the development of the Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster
Mitigation Plan 2011 Update because the plans and ordinances are able to demonstrate where
growth is occurring within Lincoln County and Minnehaha County and what policies are in place
to direct future growth. The integration between existing plans is critical; otherwise the plans
will not work together effectively if they each contain contradicting goals or policy
recommendations.
To ensure the Lincoln County and Minnehaha County Multi-Hazard Pre-Disaster Mitigation
Plan 2011 Update’s usefulness, local policy makers need to be familiar with the goals and
actions that are indentified in this plan, and these items need to be incorporated into local
priorities. This can be accomplished by aligning local capital improvements with mitigation
improvements during each community’s annual budgeting process. This will allow local
jurisdictions to better plan for future hazard mitigation projects and activities.
It is also imperative that County Officials and City Officials within Lincoln County, Minnehaha
County, and their municipalities work together as a region when confronting the flooding hazard
and other hazards. As Sioux Falls and its surrounding municipalities continue to grow,
cooperation at all levels must occur.