Section 6 Hazard Identification, Profiling, and Ranking

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1 Section 6 Hazard Identification, Profiling, and Ranking Contents of this Section 6.1 Interim Final Rule Requirement for Hazard Identification and Profiling 6.2 Hazard Identification 6.3 Overview of Type and Location of Hazards That Can Affect Morris County Dam and Levee Failure Drought Earthquake/Geological Extreme Temperatures Cold Extreme Temperatures Heat Flood Hail Hazardous Materials Release Fixed Site Hazardous Materials Release Transportation High Wind Straight-Line winds High Wind Tornado Ice Storm Landslide (non-seismic) Severe Storm Lightning Severe Storm Winter Weather Wildfire 6.4 Methodology for Identifying Hazards of Concern 6.1 Interim Final Rule Requirement for Hazard Identification and Profiling Requirement 201.6(c)(2)(i): [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. Note that Appendix D includes general descriptions of all selected hazards that can affect Morris County. The present section addresses the specific requirements of the Interim Final Rule (IFR) with regard to hazards in the planning area. Page 6-1

2 6.2 Hazard Identification In accordance with IFR requirements, and as part of its efforts to support and encourage hazard mitigation initiatives, Morris County s Hazard Mitigation Steering Committee (MCHMSC) prepared this general assessment of the hazards that have the potential to impact the county. The following subsections provide an overview of past hazard events in the county and brief descriptions of the potential for future losses. Section 7 (Risk Assessment) includes much more detailed information about past and potential losses (risk) from a subset of the most significant hazards in Morris County. The term planning area is used frequently in this section. This term refers to the geographic limits of Morris County. The Risk Assessment section (Section 7) addresses the potential future damages of hazards on Morris County and its citizens. Overview of Morris County s History of Hazards Numerous federal agencies maintain a variety of records regarding losses associated with natural hazards. Unfortunately, no single source offers a definitive accounting of all losses. The Federal Emergency Management Agency (FEMA) maintains records on federal expenditures associated with declared major disasters. The US Army Corps of Engineers and the Natural Resources Conservation Service collect data on losses during the course of some of their ongoing projects and studies. Additionally, the National Oceanic Atmospheric Administration s (NOAA) National Climatic Data Center (NCDC) database collects and maintains data about natural hazards in summary format. The data includes occurrences, dates, injuries, deaths, and costs. According to the NCDC database, between 1950 and June 2008, Morris County has experienced the following hazard events. 204 thunderstorm and high wind events (11 exceeding 69 mph) 142 winter storms (five major blizzards/ severe winter storms) 79 wildfires (average of 80 acres burned per year) 69 floods/flash floods 31 significant lightning events 28 hail storms (14 of which had hailstones with 1 diameter or greater) 22 extreme heat events 17 extreme cold temperature events 11 droughts 11 hurricanes or tropical storms 6 tornadoes (three F1s, one F2, and two F3s) 2 ice storms (12 freezing rain events, eight snow/ice events, and 32 wintry mix events) In addition to the events recorded in the NCDC database other sources identified three earthquakes, and 15 partial dam failures and one complete dam failure. A number of these events caused property damage, injuries, and loss of life. 1 These figures are discussed in more detail in the hazard-specific subsections that follow. 1 NOAA/NCDCD database Page 6-2

3 In the absence of definitive data on some of the hazards that may occur in Morris County, illustrative examples are useful. Table provides brief descriptions of particularly significant hazard events occurring in the county s recent history. This list is not meant to capture every event that has affected the area, rather lists some of the more significant events that have occurred here in the past. Morris County has received ten major Presidential Disaster Declarations and eight Emergency Declarations since Five of the ten major disaster declarations were the result of significant flooding. 2 The more recent major and emergency declarations are included as part of the summary in Table below. Table Recent Hazards and Declared Emergency and Major Disasters in Morris County, New Jersey ( ) (Sources: NOAA/NCDC; FEMA; and the New Jersey Office of Emergency Management) Date & Disaster (DR) 3/13/1993 (EM 3106) 1/7/1996 (DR 1088) 10/19/1996 (DR 1145) 9/18/1999 (DR 1295) Nature of Event SEVERE STORMS AND FLOODING (Emergency Declaration) Event known as the Storm of the Century affected as many as 26 States from Florida to Maine, the Gulf Coast, and the Ohio Valley. This storm was one of the most intense nor easters to ever affect the United States. Snow became very heavy, changed to sleet, then back to snow. The Storm of the Century label was given to the event due to the record low pressure, wind speeds, temperature and snowfall. All 21 counties in New Jersey were included in the Presidentially Declared Disaster. Snowfall totals ranged from 13" to 20" in Morris County. BLIZZARD The winter storm event known as the Blizzard of 96 resulted in severe conditions throughout much of the east coast. In New Jersey, blizzard conditions grew stronger as high northeast winds developed around the intensifying low pressure. Road conditions were dangerous due to the high winds and drifts. Both government and contract snow plowing operations were running at a maximum. Local roads were impassable. A State of Emergency was declared and more than 400 National Guard personnel were activated for transport assistance, primarily for medic missions. In Morris County snowfall totals ranged from 23" to 28. A little more than a week after the blizzard, strong southerly winds ushered in very mild and moisture laden air that resulted in heavy rains and flash flooding. Street flooding became a major problem early on due to the rains and significant snowmelt. In Morris County, dozens of people were evacuated along the Rockaway River in Denville Township and Boonton. There were also numerous road washouts in Washington Township. FLASH FLOOD Heavy rains caused considerable urban and local drainage flooding as well flooding of most of the rivers and streams in the Passaic River Basin. The Netcong, Passaic, Rockaway, and Whippany Rivers all exceeded flood stage. The hardest hit municipalities included the Townships of Denville, Hanover, Harding, Roxbury, Long Hill and the Boroughs of Florham Park and Hopatcong. The Stirling section of Long Hill Township was hard hit by flooding where four main roads were flooded. In Roxbury Township, basements in Succasunna and Port Morris had water up to 6' deep. Elsewhere in Roxbury Township, flooding along Ledgewood Circle reached some historical buildings for the first time in 20 years. Damages countywide were estimated at $1 million. HURRICANE FLOYD This downgraded fall hurricane put the entire Eastern Seaboard on flood watch, including every county in New Jersey. Although downgraded from a hurricane by the time it hit New Jersey, the storm lasted approximately 18 hours. Tropical Storm Floyd battered New Jersey and brought with it torrential and in some areas unprecedented and record breaking, rains, damaging winds and flash flooding. Rainfall totals in Morris County were highest in Pequannock Township with 11" and Morris Plains Borough and Morristown, each with nearly 9". In the Passaic River Basin in Morris County, the Rockaway River above the Boonton Reservoir crested 6.3', estimated to be 1.3' above flood stage. In Pine Brook, the Passaic River crested at 20.8 with flood stage estimated at Public Entity Risk Institute disaster database Page 6-3

4 Date & Disaster (DR) 8/12/2000 (DR 1337) 2/16/2003 (EM 3181) 4/2/2005 (DR 1588) 4/15/2007 (DR 1694) Nature of Event SEVERE STORMS, FLOODING, AND MUDSLIDES A nearly unprecedented series of thunderstorms with torrential downpours produced rainfall totals of around 15 along the Morris/Sussex County border. Two to three inches of rain fell per hour at times and caused considerable, widespread and devastating flooding across southeastern Sussex County and western Morris County. Mud and rock slides exacerbated the damage. This was approximately a one in a thousand year event. In Morris County, three bridges were destroyed, two dams were badly damaged, four others suffered some damage and about two dozen roads were closed or damaged. The torrential rain caused a record rise in Lake Hopatcong and lakeside flooding in Jefferson and Roxbury Townships. About 1,000 homes and businesses were damaged. Two houses were destroyed, 75 suffered major damage while 727 others suffered minor damage. Vehicles drove into flood waters after several roadways collapsed. About 150 persons were rescued from flood waters. Damage in the county was estimated at $12 million. HEAVY SNOW (Emergency Declaration) The most powerful storm to affect New Jersey since the Blizzard of 1996 struck during the President's Day Weekend in February, The combination of the very cold temperatures and the approach of a strong storm system caused widespread snow to break out, starting before sunrise on Sunday, February 16. Snow continued during the day Sunday, heavy at times, and continued into Sunday night. Precipitation continued on Monday, before finally coming to an end on Tuesday. New Jersey requested and was granted a Snow Emergency Declaration for all 21 counties. The President's Day snowstorm tied or set records in all 21 New Jersey counties including Morris. Statewide, the event resulted in damages estimated at approximately $30.2 million. In Morris County, specific snow accumulations totaled 27.0 in Green Pond and 23.5 in Morristown. SEVERE STORMS AND FLOODING On April 2nd and 3rd heavy rains from an intense low pressure system caused widespread flooding throughout northern New Jersey. The New Jersey Office of Emergency Management estimated that the flooding forced 6,000 residents from their homes and caused a total of $60 million in damages. More than 3 of rain was recorded by rain gages in Morris, Passaic, and Sussex Counties. Contributing to widespread flooding was rapid snowmelt, brought on by a series of moderate to heavy rainfalls that lasted for two weeks. In Morris, Sussex, Warren, Hunterdon, and Mercer counties, about 1,800 homes and businesses were flooded and 25 homes were destroyed. The northeastern part of Morris County was hit the hardest by flooding along the Pequannock, Pompton and Passaic Rivers. Property damage in Morris County was estimated at around $1 million. SEVERE STORMS AND INLAND AND COASTAL FLOODING A 7-day nor easter deluged New Jersey with over nine inches of rain, causing millions of dollars of damage and killing three residents. Statewide damage was estimated at $180 million. Flooding from the event forced about 1,000 people to be evacuated in Morris County. About 100 businesses along New Jersey State Route 23 suffered flood damage. In Lincoln Park Borough, flooding along the Pompton River severely affected the area. About 1,000 homes were damaged with water up to five feet in some homes. An estimated 24 roads were temporarily closed including access roads to New Jersey State Routes 23 and Interstate 80. Weather-Related Deaths and Injuries According to the NCDC, Morris County has experienced 51 deaths and 348 injuries from natural hazards in the period from 1950 to June, NOAA/NCDCD database Page 6-4

5 Section 6.3 Overview of the Type and Location of Hazards that can affect Morris County In the initial phase of the planning process, MCHMSC considered 24 natural and technological hazards and the risks they create for the county and its material assets, operations, and staff. The hazards initially considered are shown in Table Table Preliminary Hazard List Morris County Hazard Type (1) Morris County EOP Mitigation 20/20 NJSHMPU (2) Include in MC HMP Civil Disturbance I No Crime I No Dam and Levee Failure T Yes Drought N Yes Earthquake/Geological (3) N Yes Economic Crisis T No Enemy Attack /Terrorism I No Extreme Temperature Cold N Yes Extreme Temperature Heat N Yes Flood (4) N Yes Hail N Yes Hazardous Materials Release Fixed Site T Yes Hazardous Materials Release Transportation T Yes High Wind Straight-Line Winds (5) N Yes High Wind Tornado N Yes Ice Storm N Yes Landslide (non-seismic) N Yes Pandemic Disease / Infestation B No Radiological Incident T No Severe Storm Lightning N Yes Severe Storm Winter Weather N Yes Utility Failure (gas, power, sewer, telecom, water) T No Urban Fire I No Wildfire N Yes Notes: 1. Type Legend: B = Biological; I = Intentional Acts; N = Natural; T = Technological/Manmade. 2. NJSHMPU = State of New Jersey Hazard Mitigation Plan Update (Approved by FEMA in April 2008). 3. Earthquake/Geological includes effects of surface faulting, ground shaking, earthquake induced landslides and liquefaction. 4. Flood includes tidal, flash, sheet, and riverine flooding. Page 6-5

6 5. High Wind Straight-Line Winds includes winds due to Nor easters, coastal storms, hurricanes, and severe storms, but not tornadoes. In the initial identification process, the MCHMSC catalogued potential hazards to identify those with the most chance to significantly affect the county. The hazards include those that have occurred in the past and may occur in the future. A variety of sources were used in the investigation. These included national, regional, and local sources such as emergency operations plans, the State Hazard Mitigation Plan, websites, published documents, databases, and maps, as well as discussion with the MCHMSC. The MCHMSC reviewed the 24 hazards and determined that 8 of these hazards were the result of intentional acts or were due to biological or technological hazards that were not consistent with traditional hazard mitigation planning and implementation processes. These 8 hazards were referred to the Morris County Office of Emergency Management for further action as part of appropriate preparedness activities (e.g., emergency operations planning). The remaining 16 hazards, listed below, were selected for inclusion in the Morris County Multi-Jurisdictional Hazard Mitigation Plan (the Plan) by the MCHMSC. 1. Dam and Levee Failure 2. Drought 3. Earthquake/Geological 4. Extreme Temperature Cold 5. Extreme Temperature Heat 6. Flood 7. Hail 8. Hazardous Materials Release Fixed Site 9. Hazardous Materials Release Transportation 10. High Wind Straight-Line Winds 11. High Wind Tornado 12. Ice Storm 13. Landslide (non-seismic) 14. Severe Storm Lightning 15. Severe Storm Winter Weather 16. Wildfire The following section profiles each of the 16 hazards listed above and includes a description of the hazard, location and extent of the hazard, severity of the hazard, impact on life and property, and past occurrences of the hazard. Page 6-6

7 6.3.1 Dam and Levee Failure Description of the Dam and Levee Failure Hazard A dam is defined by the New Jersey Department of Environmental Protection (NJDEP) as any artificial dike, levee or other barrier that is constructed for the purpose of impounding water on a permanent or temporary basis, that raises the water level five feet or more above the usual, mean, low water height when measured from the downstream toe-ofdam to the emergency spillway crest or, in the absence of an emergency spillway, the top-of-dam. 4 Dam failures can result from a variety of causes including lack of maintenance, seismic activity, improper design or construction, or the effects of large storms. Significant rainfall can quickly inundate an area and cause floodwaters to overwhelm a reservoir. If the spillway of the dam cannot safely pass the resulting flows, water will begin flowing in areas not designed for such flows and failure may occur. 5 See Appendix D for a more detailed description and definition of the dam failure hazard. To prevent, or reduce the probability of a failure, existing dams are periodically inspected by professional engineers on a regular basis. Table summarizes the dam inspection schedule for New Jersey, including Morris County. Table New Jersey Dam Inspection Schedule (Source: NJDEP Dam Safety and Flood Control) Dam Class Regular Inspection Formal Inspection Class I Large Dam annually once every three years Class I Dam once every two years once every six years Class II Dam once every two years once every ten years Class III Dam once every four years only as required Class IV Dam once every four years only as required A levee is a natural or artificial slope or wall, either earthen or concrete and often parallels the course of a river. The main purpose of a man-made levee is to prevent flooding to adjacent development or farmland. Engineered levees are often reinforced with concrete and rip-rap to prevent erosion or failure. Levee failure can occur in numerous ways but the most common is breaching. A breach occurs when part of the levee actually fails and breaks away, leaving an opening for water to flood surrounding areas. A breach can occur suddenly or gradually, and can be caused either by surface erosion or by a subsurface failure of the levee. Failure can also occur when water overtops the crest of a levee. This is known as overtopping, where floodwaters exceed the lowest crest of a levee, flooding the surrounding area. 4 NJDEP 5 NJDEP Page 6-7

8 Location of the Dam and Levee Failure Hazard According to the NJDEP, there are a total of 225 dams in Morris County. The NJDEP Bureau of Dam Safety separates New Jersey dams into three hazard classifications. These hazard classifications include high hazard, significant, and low and are based upon the guidelines outlined in the New Jersey Administrative Code Dam Safety Standards (NJAC: 7-20): Dam Classifications. Of the 225 dams in Morris County, 32 are classified as high hazard. The following table lists the high hazard dams, including the municipality name, hazard classification, the river or stream the dam is located along, the last inspection date and the name of the dam. The NJDEP database does not include the data points listed as na in the table. The complete inventory of Morris County dams can be found in Appendix E. Page 6-8

9 Table Morris County High Hazard Dams (Source: NJDEP Bureau of Dam Safety and Flood Control) Municipality Name Dam Name River/Stream Height (feet) Length (feet) Last Date Inspected Kinnelon Borough Kakeout Dam Stonehouse Brook /9/2006 Jefferson Township Lake Winona Dam Musconetcong River /26/2006 Jefferson Township Oak Ridge Reservoir Dam Pequannock River /7/2006 Jefferson Township Mount Paul Dam Russia Brook-TR /14/2006 Kinnelon Borough Kakeout Dike Kakeout Brook /9/2006 Dover Town Denmark Lake Dam Green Pond Brook-TR /10/2006 Dover Town Picatinny Lake Dam Green Pond Brook /10/2006 Jefferson Township Swannanoa Lake #2 (North) Dam Rockaway River /19/2003 Jefferson Township Swannanoa Lake #1 (South) Dam West Branch Rockaway River /9/2005 Kinnelon Borough Untermeyer Dam East Ditch /4/2007 Rockaway Township Split Rock Pond Dam Beaver Brook /9/2007 Mount Olive Township Saxton Falls Dam Musconctcong River /17/2007 Mendham Township Clyde Potts Reservoir Dam Harmony Brook /10/2008 Morristown Town Speedwell Dam Whippany River /16/2007 Rockaway Township Mount Hope Lake Dam White Meadow Brook /18/2008 Rockaway Township White Meadow Lake Dam White Meadow Brook /17/2007 Mountain Lakes Borough Mountain Lake Dam Troy Brook /31/2003 Montville Township Valhalla Lake Dam Morris Canal-TR /3/2007 Denville Township Lake Estling Dam Den Brook /18/2006 Parsippany-Troy Hills Township Rainbow Lakes Dam Whippany River /20/2006 Randolph Township Shongum Lake Dam Den Brook /18/2006 Parsippany-Troy Hills Township Boonton Dam Rockaway River /8/2008 Netcong Borough Lake Hopatcong Dam Muscontcong River /12/2007 Parsippany-Troy Hills Township Powder Mill Pond Dam Whippany River-TR /20/2006 Parsippany-Troy Hills Township Parsippany Dike Rockaway River /8/2008 Mountain Lakes Borough Wildwood Lake Dam Troy Brook /31/2003 Mountain Lakes Borough Crystal Lake Dam Troy Brook /30/2003 Morristown Town Pocahontas Dam Whippany River /12/2007 Page 6-9

10 Municipality Name Dam Name River/Stream Height (feet) Length (feet) Last Date Inspected Mountain Lakes Borough Birchwood Lake Dam Troy Brook /15/2003 Netcong Borough Lake Musconetcong Dam Musconetcong River /17/2007 Mendham Township Pleasant Valley Lake Dam McVickers Brook /28/2006 Parsippany-Troy Hills Township Lake Parsippany Dam Eastmans Brook /7/2007 Page 6-10

11 The following map identifies the locations for 209 of the 225 dams in Morris County. The inventory of dams was provided by the NJDEP - Bureau of Dam Safety and Flood Control. The latitude and longitude coordinates were missing for 16 of the dams and therefore not identified on the map. Figure Morris County Dams (Source: NJDEP Bureau of Dam Safety and Flood Control) Note: 16 dams without latitude and longitude coordinates were excluded from the map: Elwood Headley Pond Dam, Jefferson Pond Dam, Lower Camp Mason Dam, Memorial Pond Dam, Mill Brook Dam, Mill Pond Dam, Moore Estate Dam, Rock Creek Crossing Detention Dam, Suntan Lake Dam, Tanners Brook Pond Dam, Triumph Square D/B #2 Dam, Triumph Square D/B #3 Dam, Upper Great Bay Dam, Upper Camp Mason Dam, Upper Mount Hope Lake Dam, and Ute Place Detention Dam. Page 6-11

12 A variety of open sources were reviewed to identify an inventory and location of levees in Morris County. Although no levees were identified, the USACE is currently in the process of developing a National Levee Database (NLD) that will inventory all federal levees in the United States. The NLD is currently in development by the USACE and any levees identifying from this effort will be included in the next scheduled Plan update. Severity of Dam and Levee Failure Hazard In 1921, the New Jersey Legislature created the Bureau of Dam Safety and Flood Control, which instituted laws relating to the construction, repair, and inspection of existing and proposed dam structures. The law was amended in 1981, and became known as the Safe Dam Act. New Jersey's Dam Safety program is administered by NJDEP s Division of Engineering & Construction, Dam Safety Section. 6 The severity of a dam failure event can depend on various aspects related to the size of the dam, the extent of the failure, the velocity of the floodwaters released, and the intensity of downstream development. The severity of the levee failure hazard can range from minor cracks along the levee wall to a complete breach. The severity of failure can be influenced by a variety of factors, such as the topography of a region, population densities, volume, depth and velocity of water released from behind the levee. After Hurricane Katrina in 2005 (in which New Orleans flooded, due mainly to failures of the levees that surround the City), Congress directed the USACE and FEMA to determine which levees in the United States pose an unacceptable risk of failure during a flood. The USACE inspected approximately 2,000 levees nationwide and in February 2007, indicated there were 122 levees in the United States that posed an unacceptable risk of failing in a major flood (mainly due to poor maintenance).7 Though many levees identified were in rural areas, some were in metropolitan regions including the District of Columbia, Springfield, Massachusetts, Stockton and Sacramento, California, and some suburbs of San Francisco. The list did not include any levees in New Jersey. Impact on Life and Property According to the National Inventory of Dams as of 2005 there were 79,500 dams in the United States. Approximately one third of these pose a "high" or "significant" hazard to life and property if failure occurs. Dam or levee failure has the potential for catastrophic impact on life and property. This risk can be reduced by proper design, construction and routine maintenance and inspection. Occurrences of the Dam and Levee Failure Hazard The NJDEP indicates there have been no previous catastrophic dam failures in New Jersey, but the number of small failures has risen over the past few years. This has been primarily due to a combination of lack of inspection and the number of dams nearing the end of their design life. 8 The NJDEP Bureau of Dam Safety and Flood Control lists dam failures in New Jersey from several major flooding events including Hurricane Floyd in September of 1999 and the Sparta storm in August, Review of these floods indentified 15 partial dam failures and one complete failure in Morris County. 9 6 NJDEP Bureau of Dam Safety and Flood Control 7 Insurance Journal. Levees in 27 States at Risk of Failing; Could Trigger Flood Mandate. Beverly Lumpkin. February 5, NJDEP Bureau of Dam Safety and Flood Control 9 NJDEP Bureau of Dam Safety and Flood Control-Historical Events Page 6-12

13 The dam failures are listed below in Table Note that with the exception of Spencer Detention Basin Dam (which completely failed), all are partial failures. See Figure for the location of the dam failures listed in the table. Table Dam Failures after Hurricane Floyd in 1999 and the Sparta Flood in 2000 (Source: NJDEP Bureau of Dam Safety and Flood Control) Dam Name Municipality Name Event Name Event Date Cozy Lake Dam Jefferson Township Sparta Flood 8/12/2000 Elwood Headley Pond Dam Jefferson Township Sparta Flood 8/12/2000 Hudsonia Dam Rockaway Township Floyd 9/16/1999 Lake Hartung Dam Jefferson Township Sparta Flood 8/12/2000 Lake Winona Dam Jefferson Township Floyd 9/16/1999 Lower Waterloo Dam Mount Olive Sparta Flood 8/12/2000 New Jersey No Name No 51 Jefferson Township Sparta Flood 8/12/2000 Oak Ridge Lake Dam Jefferson Township Sparta Flood 8/12/2000 Saffin Pond Dam Jefferson Township Sparta Flood 8/12/2000 Shawnee Lake Dam Jefferson Township Sparta Flood 8/12/2000 Shongum Lake Dam Randolph Township Floyd 9/16/1999 Spencer Detention Basin Dam (1) Morris Township Floyd 9/16/1999 Swannanoa South Dam Jefferson Township Sparta Flood 8/12/2000 Upper Waterloo Dam Mount Olive Sparta Flood 8/12/2000 Washington Forge Pond Dam Wharton Sparta Flood 8/12/2000 Winona Lake Dam Jefferson Township Sparta Flood 8/12/2000 (1) Complete dam failure occurred at this dam. No failures were identified from other events. Based on the 16 previous dam failure events in Morris County, the likelihood of a major failure occurring in the future is considered moderate. The MCHMSC determined that seven high-hazard dams should be addressed in the risk assessment (Section 7) of this Plan. See Section 7.3.4, Dam Failure Risk in Morris County, for a more detailed analysis of seven high hazard dams selected for the risk assessment. The dams analyzed include the following: Boonton Dam Kakeout Dam Kakeout Dike Lake Hopatcong Dam Swannanoa Lake #1 (South) Dam Swannanoa Lake #2 (North) Dam Valhalla Lake Dam No past levee failure events were identified for Morris County. Page 6-13

14 6.3.2 Drought Description of the Drought Hazard A drought is an extended dry climate condition when there is not enough water to support urban, agricultural, human, or environmental water needs. It usually refers to a period of below-normal rainfall, but can also be caused by drying bores or lakes, or anything that reduces the amount of liquid water available. Drought is a recurring feature of nearly all the world's climatic regions. See Appendix D for a more detailed description and definition of the drought hazard. Location of the Drought Hazard Droughts may occur anywhere in the United States. Effects seen in different regions vary depending on normal meteorological conditions such as precipitation and temperature, as well as geological conditions such as soil type and subsurface water levels. Drought is possible throughout the planning area. Severity of the Drought Hazard A drought s severity depends on numerous factors, including duration, intensity, and geographic extent as well as regional water supply demands by humans and vegetation. The severity of drought can be aggravated by other climatic factors, such as prolonged high winds and low relative humidity. 10 Due to its multi-dimensional nature, drought is difficult to define in exact terms and also poses difficulties in terms of comprehensive risk assessments. Impact on Life and Property The NCDC database indicates there have been no known deaths or injuries from past droughts in the planning area. The database also indicates no property damage from drought, but does identify $80 million in crop damages from a single event in the summer of Occurrences of the Drought Hazard According to the NCDC database, Morris County has experienced 35 drought events in the period from 1950 to All 35 events occurred between 1995 and The database provides no indication as to why there are no events prior to 1995, although presumably occurrences follow the same pattern and frequency as shown in the NCDC list. The events are listed by month. For example, if a drought lasts several continuous months, it is listed in the database as a separate event. If the continuous months are combined into single events, the number of events is reduced from 35 to FEMA, 1997 Page 6-14

15 Based on the 11 events between 1995 and 2007, on average, a drought event occurs in Morris County approximately once a year. From these previous occurrences, it is reasonable to assume that droughts will continue in Morris County, but with no previous injuries, deaths, or property damage the impacts will probably be minimal Earthquake/Geological (Includes surface faulting, ground shaking, earthquake induced landslide, subsidence, and liquefaction) Description of the Earthquake Hazard An earthquake is a sudden release of energy from the earth s crust that creates seismic waves. Tectonic plates become stuck, putting a strain on the ground. When the strain becomes so great that rocks give way, fault lines occur. At the Earth's surface, earthquakes may manifest themselves by a shaking or displacement of the ground, which may lead to loss of life and destruction of property. Size of an earthquake is expressed quantitatively as magnitude and local strength of shaking as intensity. The inherent size of an earthquake is commonly expressed using a magnitude. See Appendix D for a more detailed description of the earthquake hazard. Subsidence is the motion of the Earth s surface as it shifts downward, relative to sea-level. Land subsidence, the loss of surface elevation due to the removal of subsurface support, ranges from broad, regional lowering of the land surface to localized collapse. Page 6-15

16 Location of the Earthquake Hazard The entire planning area is susceptible to the effects of earthquakes. Figure displays the northeast portion of a United States Geological Survey (USGS) earthquake hazard map produced in The map shows peak ground acceleration (pga) with a 10% exceedence probability over 50 years is highest in northeastern New Jersey (6%g) and decreases to the south (2%g). The FEMA How-To guidance, Understanding Your Risks, FEMA 386-2, p. 1-7, suggests the earthquake hazard should be profiled if the pga is greater than 3%g.The map shows Morris County is located in the 3%g range, a slightly higher risk area than the southern part of the state. Figure New Jersey Seismic Hazard Map, showing Peak Ground Acceleration in Percent of g, with 10 % exceedance in 50 years. (Source: USGS, 2008) Morris County In November, 2005 the New Jersey Geologic Survey (NJGS) completed an Earthquake Loss Estimation Study for Morris County. The NJGS acquired and analyzed geologic, topographic and test-boring data in order to map seismic soil class, liquefaction susceptibility, and landslide susceptibility for Morris County. The soil class, liquefaction, and landslide susceptibility were then entered into the FEMA HAZUS (Hazards US) model for each census track in the county. The study completed by the NJGS identified and mapped the distribution and thickness of 12 surface materials for Morris County. Mapping the soil type for each census track identifies areas that are susceptible to soil liquefaction. Figure below is a soil liquefaction map for Morris County. The map identifies the southeastern region of Morris County as the main area of higher susceptibility for soil liquefaction. Page 6-16

17 Figure Morris County, New Jersey Soil Liquefaction Susceptibility (Source: Earthquake Loss Estimation Study for Morris County, New Jersey: Geologic Component (NJGS, 2005) Additional information about the results of the Earthquake Loss Estimation Study for Morris County can be found in Section 7.3 (Risk Assessment) of this Plan. Page 6-17

18 Land subsidence is generally found in areas of very distinct geography, such as places where there is extensive gas or groundwater (that has been extracted), or in areas of karst topography or mines. The Association of New Jersey Environmental Commissions indicates that the New Jersey Highlands area is susceptible to subsidence due to the presence of carbonate rocks. These rock formations, consisting primarly of limestone, dolmonite, and marble and may contain surface depressions and open drainage passages making such areas unstable and vulnerable to surface collapse. According to the NJDEP 59 of the 88 municipalities within the highlands region contain carbonite rocks. In Morris County 14 municipalities contain carbonite rocks and therefore considered to be the area of the County most susceptible to land subsidence. Severity of the Earthquake Hazard Although most past earthquakes in northern New Jersey have been of low magnitude, there have been several significant historical earthquake events (See Figure ). As shown in Table , the area has experienced a few events in the last 75 years, although even the most significant one (in 1927) was not particularly damaging. 11 As discussed in Appendix D, the severity of earthquakes is influenced by several factors, including the depth of the quake, the geology in the area, and the soils. The severity of liquefaction depends on various factors related to the soil, including grain size, thickness, compaction, and degree of saturation. 12 The severity of land subsidence has no generally established measure, except that it can be described in terms of change in ground elevation relative to sea level. Subsidence is generally permanent, although it can be abated with proper management methods. Land subsidence occurs slowly and continuously over time or on abrupt occasions, as in the case of sudden formation of sinkholes. Procedures for determining the probability or frequency of land subsidence have not been recommended. Impact on Life and Property There are no known deaths or injuries from earthquakes in Morris County. Some of the past earthquake events were severe enough to cause minor property damage such as broken windows or contents falling from shelves. Although the probability of a significant earthquake occurring in this region is relatively small, the effects on life and property in the area could be significant, so this hazard is included in the risk assessments in Section 7. The Mitigation Strategies in Section 9 also includes specific actions related to earthquake risk. The highlands area of Morris County is at a higher risk from land subsidence than other areas of the County. Land subsidence can impact life and property by causing the collapse or subsidence of structures, including buildings, roadways and underground utilities. As noted in Section 7.5, Morris County Future Development Trends, the Highlands Water Protection and Planning Act of 2004 divides the Highlands Region into the Highlands Preservation Area and the Highlands Planning Area, each area representing approximately half of the entire Region. In the Preservation Area, future development is severely limited. 13 With minimal development in this area, the impact from subsidence on life and property in the highlands region of Morris County is most likely minimal. 11 USGS and NJGS New Jersey earthquake history 12 NJGS 13 Morris County Comprehensive Farmland Preservation Plan - December 2007 Page 6-18

19 Occurrences of the Earthquake Hazard To identify past earthquake occurrences that have potentially impacted Morris County, the map titled Earthquake Epicenters displaying historical earthquakes was reviewed. Figure displays historical earthquake epicenters spatially across the northeast from 1737 to Although the map highlights historical earthquakes in New York State, the map also shows earthquake occurrences for surrounding states, including northern New Jersey. The map indicates there have been six historical earthquakes of 5.0 magnitude, or greater, within the New Jersey region during the period of record. This map was prepared by the Geographical Information System (GIS) division of the New York State Emergency Management Office (SEMO) using New York State Geological Survey/National Institute of Building Sciences data. Figure Earthquake Epicenters for the Northeast United States, (Sources: New York State Geological Survey, National Institute of Building Sciences) In addition to the Earthquake Epicenters map prepared by the New York SEMO, the USGS also offers earthquake history for each state. The USGS earthquake history for New Jersey indicates that there have been nine earthquakes statewide since Of the nine events in New Jersey, the earthquake descriptions provided by the USGS indicate that three have affected Morris County. Table below summarizes the past earthquake events that have impacted the planning area. Page 6-19

20 Table Morris County Earthquake History (Source: USGS) Event Date Epicenter Description June 1, 1927 Asbury Park, New Jersey The highest intensity earthquake ever observed in New Jersey occurred on June 1, 1927, in the Asbury Park area. Three shocks were felt along the coast from Sandy Hook to Toms River. Several chimneys fell, plaster cracked, and articles were thrown from shelves. September 3, 1951 Rockland County, New York Northeastern New Jersey experienced minor effects from an earthquake on September 3, 1951 that was apparently centered in Rockland County, New York. March 23, 1957 High Bridge, New Jersey On March 23, 1957, a shock affected west-central New Jersey, near the site of the 1895 earthquake. Chimneys cracked (intensity VI), windows and dishes broke, and pictures fell at Lebanon. A cracked chimney was also reported from Hamden. At Long Valley some walls were cracked and plaster fell. The felt area was small in comparison with the other shocks previously described. On average, an earthquake has impacted Morris County every 26 years, so based on the historical record, the probability of earthquakes of all magnitudes occurring in the future is moderate in the planning area. Section 7 of this Plan includes a more detailed discussion of the earthquake risk in Morris County, including HAZUS simulation results from the NJGS, and probability-based risk estimates that were performed using the FEMA Full-Data Earthquake Benefit-Cost Analysis Module. A variety of open source documents were researched to identify past land subsidence events in Morris County, The primary areas where land subsidence has occurred is at abandoned underground mines located in the highlands region of the County. The NJDEP maintains abandoned mine maps for 36 sites in Morris County. The mine maps can be useful to assist in the remediation of any subsidence or collapse events, pollution tracking and remediation, historical research, land development and open space purchases. 14 The Department of Energy (DOE) indicates that land subsidence occurred at several abandoned mines in Rockaway Township. The DOE report titled Remediation of Abandoned Iron Ore Mine Subsidence in Rockaway Township, New Jersey identified significant subsidence at the following mine locations White Meadow Mine Mt. Hope Road Green Pond Mine (Township Compost Storage Facility) 15 The degree of subsidence at the sites listed above was considered a public safety hazard and the DOE began subsidence remediation in September, The project was completed in Prior to the next scheduled Plan update, past land subsidence activity in Morris County will be further studied to research the possibility of additional events in Morris County. Any additional events identified will be incorporated into the 2013 Plan update. 14 New Jersey Department of the Environment Map Archive of New Jersey s Abandoned Mines 15 Department of Energy (DOE) The Remediation of Abandoned Iron Ore Mine Subsidence in Rockaway Township, New Jersey. Page 6-20

21 6.3.4 Extreme Temperature Cold Description of the Extreme Temperature (Cold) Hazard Temperatures that are significantly below normal are considered extreme cold temperatures. What constitutes extreme cold and its effect varies across different areas of the United States. In areas unaccustomed to winter weather, near freezing temperatures are considered "extreme cold." Freezing temperatures can cause severe damage to citrus fruit crops and other vegetation. Pipes may freeze and burst in homes that are poorly insulated or without heat. In the northeast, below zero temperatures may be considered as "extreme cold. 16 The consequences of extreme cold on humans are intensified by high winds which increase the rate of heat loss and has the effect of making it feel colder than the actual air temperature. Extreme cold temperatures combined with high winds can lead to frostbite, permanent damage to the body, or even death. See Appendix D for a more detailed description and definition of the extreme cold hazard. Location of the Extreme Temperature (Cold) Hazard The entire planning area is subject to the hazards associated with extreme cold temperatures. Severity of Extreme Temperature (Cold) The severity of extreme cold temperature events is measured by temperature, duration, and humidity. Most events are less than a week in duration but can occasionally last for longer periods up to several weeks. Impact on Life and Property The NCDC database combines the extreme cold and extreme heat into a single category called temperature extremes. The database indicates there have been seven deaths and seven injuries from 17 extreme cold events. Damages from extreme cold temperatures are generally confined to effects on humans (described above), although occasionally there may be relatively minor effects on infrastructure such as freezing pipes or electrical grids. Table lists the extreme temperature events from the NCDC for Morris County that resulted in at least one death. Periodically throughout Section 6.3, the output from the NCDC database queries has been included to summarize past events for specific hazards. 16 NOAA Winter Storms The Deceptive Killers Page 6-21

22 Table Reported Extreme Temperature Events Resulting in Deaths, Morris County, 1950 through June 2008 (Source: NOAA/NCDC) Note: Coded letters and numbers under Location or County column are a result of output from the NCDC query. Several of the column headings (the five farthest to the right) within the NCDC table above have been abbreviated and are defined as follows: Mag = Magnitude of the event for applicable hazards (Hailstorms, Tornadoes, etc.) Dth = Number of deaths Inj = Number of Injuries PrD = The dollar amount of reported property damage CrD = The dollar amount of reported crop damage Occurrences of Extreme Temperature (Cold) The NCDC database indicates there have been 17 recorded extreme cold temperature events in Morris County during the period 1950 through June, Although the query results begin in 1950, the first reported event was in Several of these events are reported within a few days of each other and were most likely from one cold air mass lingering over the area for an extended period of time, and can be combined into a single event. If these cold spells are considered one event, the number of events identified in the NCDC database is reduced from 17 to 12. There are most likely additional extreme cold events prior to 1996 that are not captured in the database. Page 6-22

23 No indication is given in the database as to why there are no events identified prior to 1996, although the pattern is most likely similar with an extreme cold temperature event occurring about once per year. Based on the 12 events between 1996 and June, 2008, an extreme cold temperature event occurs on average approximately once per year. Taking into account the historical data from the NCDC database, the probability of future extreme cold temperature events can be considered moderate to high. However, the impact on life and property in the planning area will most likely be minimal Extreme Temperature Heat Description of the Extreme Temperature (Heat) Hazard Temperatures that are significantly above normal are considered extreme temperatures. There is no specific point when air temperatures are defined as significantly above normal. However, the National Weather Service (NWS) will initiate alert procedures such as special weather statements when the heat index is expected to exceed 105 F-110 F (depending on local climate), for at least two consecutive days. 17 Heat stress can be indexed by combining the effects of temperature and humidity. See Appendix D for a more detailed description and definition of the extreme heat hazard. Location of the Extreme Temperature (Heat) Hazard The entire planning area is subject to the hazards associated with extreme temperatures from high heat. Severity of Extreme Temperature (Heat) The severity of extreme temperature events is measured by temperature, duration and humidity. Most events are less than a week in duration. In the northeastern United States periods of warmer than normal temperatures typically occur several times a summer. Extreme heat waves may occur about once every five years or so where maximum daily temperatures exceed 100 F for an extended period of time. The passing of a cold front usually moderates temperatures after a few days to a week. Impact on Life and Property The structure of the NCDC database combines the extreme cold and extreme heat into temperature extremes. The database indicates there have been 33 deaths and 256 injuries in Morris County from excessive heat-related events. Ten of the 33 reported deaths were from one event that occurred from July 4 July 6, From the description provided in the NCDC database, the 12 deaths appear to cover all parts of New Jersey impacted by the event, not just Morris County. During the July 4 July 6 heat wave, the NCDC database indicates no deaths occurred in Morris County. The combination of the temperature and humidity during this event produced heat indices of around 110 F during the afternoon of each day. 17 NOAA Heat Wave Description Page 6-23

24 Damages from the extreme high temperature hazard are generally confined to effects on humans, although occasionally there may be relatively minor effects on infrastructure such as electrical grids. Table lists the extreme temperature events from the NCDC for Morris County that resulted in injuries. Table Reported Extreme Temperature Events Resulting in Injuries, Morris County, 1950 through June 2008 (Source: NOAA/NCDC) Notes: Coded letters and numbers under Location or County column is a result of output from the NCDC query. See bullets following Table for column heading definitions. Occurrences of Extreme Temperature (Heat) The NCDC database indicates there have been 60 recorded extreme temperature events related to high heat in Morris County during the period 1950 through June, Although the query results begin in 1950 the first reported event was in There are most likely additional extreme heat events prior to 1994 that are not captured in the NCDC database. The database provides no indication as to why there are no events prior to 1994, although presumably occurrences follow the same pattern and frequency as shown in the NCDC list. Similar to droughts and other hazards, the events are listed by month. If the continuous months are combined into single events, the number of events is reduced from 60 to 22. As mentioned above, one of the worst extreme heat-related events occurred in July, A very strong and oppressive high pressure system that extended from the surface to aloft gave New Jersey a brutal heat wave that included the entire Independence Day weekend. High temperatures reached the 90s for the first time on July 3, but sweltering humidity and record breaking maximum temperatures of around 100 F occurred from Independence Day through the July 6 of the month. 18 Based on the 22 events between 1994 and June, 2008, on average, an extreme heat event occurs approximately once every 1.5 years. Based on the historical data from the NCDC database, extreme heat events will continue to occur in the county at about this frequency, but with relatively minor impacts on life and property. 18 NOAA/NCDC database Page 6-24