Document cayugacounty_gov_doc_a7d3cc099d

SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-1 August 2013 5.4.2 GROUND FAILURE This section provides a profile and vulnerability assessment for the ground failure hazard, including landslides, land subsidence, and sinkholes. HAZARD PROFILE This section provides profile information including description, extent, location, previous occurrences and losses and the probability of future occurrences. Description Landslide A landslide is the process that results in the downward and outward movement of slope-forming materials (NYS Geological Survey, Date Unknown). Landslide materials can be composed of natural rock, soil, artificial fill or any combination of these materials (NYS HMP, 2011). The materials move by falling, toppling, sliding, spreading, or flowing (NYS Geological Survey, Date Unknown). Landslides are caused by one or a combination of the following factors: change in slope of the terrain, increased load on the land, shocks and vibrations, change in water content, groundwater movement, frost action, weathering of rocks, and removing or changing the type of vegetation covering slopes. Landslide hazard areas are where the land has characteristics that contribute to the risk of the downhill movement of material, such as the following:  A slope greater than 33-percent  A history of landslide activity or movement during the last 10,000 years  Stream or wave activity, which has caused erosion, undercut a bank or cut into a bank to cause the surrounding land to be unstable  The presence or potential for snow avalanches  The presence of an alluvial fan, indicating vulnerability to the flow of debris or sediments  The presence of impermeable soils, such as silt or clay, which are mixed with granular soils such as sand and gravel. Landslides are typically triggered by other natural hazards, such as earthquakes, heavy rain, floods or wildfires. Frequency of landslides is often related to the frequency of these other hazards. They can occur suddenly or slowly. Assessing the geology, vegetation, and amount of predicted precipitation for an area can assist in predicting landslides. Warning signs for landslide activity include:  Springs, seeps or saturated ground in areas that have not typically been wet before  New cracks or unusual bulges in the ground, street pavement or sidewalk  Soil moving away from foundations  Ancillary structures, such as decks and patios, tilting and/or moving relative to the main house  Tilting or cracking of concrete floors and foundations  Broken water lines and other underground utilities  Leaning telephone poles, trees, retaining walls or fences  Offset fence lines  Sunken or down-dropped road beds  Rapid increase in creek water levels, possibly accompanied by increased turbidity ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-2 August 2013  Sudden increase in creek water levels though rain is still failing or just recently ended  Sticking doors and windows, and visible open spaces indicating jambs and frames out of plumb  A faint rumbling sound that increases in volume as the landslide nears  Unusual sounds, such as trees cracking or boulders knocking together (USGS, 2009). Land Subsidence/Sinkholes Land subsidence can be defined as the sudden sinking or gradual downward settling of the earth’s surface with little or no horizontal motion, owing to the subsurface movement of earth materials (USGS, 2007). Subsidence often occurs through the loss of subsurface support, which may result from a number of natural and human-caused occurrences. Sinkholes are a natural and common geologic feature in areas with underlying limestone, carbonate rock, salt beds, or other rocks that are soluble in water. Over periods of time measured in thousands of years, the carbonate bedrock can be dissolved through acidic rain water moving in fractures or cracks in the bedrock. This creates larger openings in the rock through which water and overlying soil materials will travel. Over time, the deposited soils compromise the strength of the bedrock, until it is unable to support the land surface above, and a collapse or sinkhole occurs. In this example the sinkhole occurs naturally, but in other cases the root causes of a sinkhole are anthropogenic, especially those that involve changes to the water balance of an area including: over-withdrawal of groundwater, diverting surface water from a large area and concentrating it in a single point, artificially creating ponds of surface water, and drilling new water wells. These actions can also serve to accelerate the natural processes of bedrock degradation, which can have a direct impact on sinkhole creation. Karst is a distinctive topography in which the landscape is largely shaped by the dissolving action of water on carbonate bedrock (usually limestone, dolomite, or marble). Therefore, any area defined by Karst topography is likely to experience land subsidence, generally in the form of sink holes brought on by sinking soils resulting from voids below. The karst landscape in New York State stretches in a narrow band along the Helderberg Escarpment in Schoharie and Albany counties. These landscapes include typical karst characteristics such as caves and sinkhole lakes (NYS HMP, 2011). According to the the triggering events for subsidence in areas of karst development include periods of heavy precipitation and/or rapid snowmelt. Periods of flooding are associated with aggressive erosion, both from chemical and physical forces, and the dissolution of carbonate rock or removal of supporting in-filled sediments triggers new collapses. Subsidence may be initiated in mining areas by weakness in the roof rocks due to previous ore removal and by the process of active mining. Both natural and man-made sinkholes can occur without warning. Slumping or falling fence posts, trees, or foundations; sudden formation of small ponds; wilting vegetation; discolored well water; and/or structural cracks in walls and floors, are all specific signs that a sinkhole is forming. They can form into steep-walled holes to bowl or cone shaped depressions. When sinkholes occur in developed areas they can cause severe property damage, injury and loss of life, disruption of utilities, and damage to roadways. In urban and suburban areas, sinkholes can destroy highways and buildings. Land subsidence can also occur on areas underlain by highly organic peat and muck soils. New development activity in peat soils can exceed its relatively low load bearing capacity. The signs of failure can occur without warning and are similar to those listed for sinkholes. ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-3 August 2013 Coastal Erosion According to the NYS Department of Environmental Conservation (NYS DEC) Rules and Regulations (6 Part 505.2 – Coastal Erosion Management), coastal erosion means the loss or displacement of land along the coastline due to the action of waves, currents, tides, wind-driven water, waterborne ice, or other impacts associated with storms. It also means the loss or displacement of land due to the action of wind, runoff of surface waters, or groundwater seepage. The principal natural causes of erosion are wave action, wind action, and overland runoff groundwater seepage through intense precipitation and natural sorting of beach sediment through loss of fines. Other contributing factors that can significantly increase erosion of a natural protective feature include length of fetch (length of water over which a given wind has blown), wind direction and speed, wave length, height and period, nearshore water depth, tidal influence, increased lake or sea levels, overall strength and duration of storm events and variability in sediment supply to the littoral zone. Combinations of these factors and events can exacerbate the effects of these processes by increasing water levels, storm rise, wave run up and wind setup, producing damaging waves, driving ice "plates" along the shore scouring beaches and bluff areas, reducing sand from beaches, and allowing water and wave action further inland that intensifies erosion of dunes and bluffs (NYS DEC). In addition, erosion can be exacerbated by man-made influences, such shoreline hardening, seawalls, groins, jetties, navigation inlets, boat wakes, dredging and other interruptions of physical coastal processes which reduce or interrupt longshore sediment transport. Primary forms of coastal erosion include beach erosion, dune scarping/dune erosion, overwash, and bluff erosion, as described below: Beach Erosion: A beach is the accumulation of sand, gravel, silt or clay located at the transition zone between land and water. Beach erosion occurs through the removal of beach sediment caused by wind, wave action and longshore currents, causing offshore movement of sand from the sub- aerial beach during storms. Beach erosion is a recurring, long-term problem and it is a precursor of dune erosion, dune overwash, bluff erosion, failure of shoreline protection structures and destruction of shoreline development. Dune Erosion/Scarping: A dune is a hill of sand built by wind-related or man-made processes found in deserts or near lakes and oceans. Dune erosion is caused by wave-attack during a storm or a large swell or by wind action. This process, generally known as scarping, releases sand that was stored in the dune to the active beach or to the zone just landward of the dune. The influx of this dune sand to the active beach is often carried offshore to build temporary sand bars, which help attenuate incoming wave energy and can assist in post storm low profile beach recovery. Overwash/Washover: Overwash/washover are terms related to the transport of sediment landward of the active beach, which occurs from coastal flooding during a hurricane, nor’easter or other event with extreme waves. Overwash occurs where the flow of water (from wave and storm surge) over the upper part of the beach profile causes beach sediment, to advance over the crest of the beach, dune or berm and where this beach sediment does not directly return to the generating water body such as ocean, sea, bay or lake after water level fluctuations return to normal. There are two kinds of overwash: overwash by run up and overwash by inundation. Overwash begins when the run up level of waves, usually coinciding with a storm surge, exceeds the local beach or dune crest height. As the water level in the ocean rises such that the beach or dune crest is inundated, a steady sheet of water (called sheetwash) and sediment runs over (overwashes) the barrier. Washover is the sediment deposited inland of a beach by overwash. Washover can be deposited onto the berm crest or as far as the back barrier bay, estuary, or lagoon (USACE, 2004). Bluff Erosion: A bluff is a cliff with a broad face, or a relatively long strip of land rising abruptly above surrounding land or water. Typically, it rises at least 25 feet above the water body at an average slope of 30 percent or greater. Bluff erosion is the erosion of these cliffsides or broad ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-4 August 2013 faces as a result of high waves, wind, groundwater or surface runoff and can lead to significant loss of land to the sea. Bluff erosion takes place from the top of the bluff down to the sea. Several processes can lead to erosion on bluffs. Groundwater can leak out the face of a bluff to create wet areas that wash sediments down the bluff face. Surface water may flow directly over the face of a bluff or down a gully on a bluff and carry soil and sediment to the sea. Seasonal freeze-thaw cycles can loosen sediment in a bluff that slumps downhill in the spring. At the base of the bluff, high tides, coastal flooding and wave action can scour the bluff toe to remove sediment and undercut the slope. Oversteepened slopes can move downward under the pull of gravity. Coastal bluffs can be affected by all of these processes to some extent. The rate of bluff erosion may vary from one location to the next. Over time, erosion is often episodic with significant land loss one year and less the next. Bluff erosion leads to net land loss and the landward migration of the shoreline as well as the top of the bluff. Actively eroding bluffs are unstable and potentially unsafe for development near the bluff top (Maine Geological Survey, 2005). Erosion can impact beaches, dunes, bluffs, barriers, bays, cliffsides, wetlands, marshes, parks, and other natural landforms and can lead to destructive forces upon nearby manmade structures. One of the major impacts of erosion processes is the permanent breaching or creation of inlets along barrier beaches and islands. Impacts associated with new inlets could include increased flooding and erosion on the mainland shoreline due to increased water levels and wave action in the bays, changes in shoaling patterns, water circulation, temperature and salinity that could significantly alter existing bay ecosystems, and disruption of the longshore transport of sand along the ocean shoreline that would result in increased downdrift erosion. It is noted that these stabilized inlets do provide benefits for recreational and commercial navigation, which is the trade-off. There are a variety of natural- and human-induced factors that influence the erosion process. For example, shoreline orientation and exposure to prevailing winds, open ocean swells and storm surges, and waves all influence erosion rates. Beach composition influences erosion rates as well. For example, a beach composed of a finer sand and silt is easily eroded compared to beaches primarily consisting of course sand, boulders, gravel or large rocks, which are more resistant to erosion. Other factors may include: Shoreline type Geomorphology of the coast Structure types along the shoreline Density of development Amount of encroachment into the high hazard zone Proximity to erosion inducing coastal structures Nature of the coastal topography Elevation of coastal dunes and bluffs Shoreline exposure to wind and waves The causes of erosion are often difficult to determine and usually require a skilled interpretation of the processes and activities affecting a particular area. However, common contributing factors to coastal erosion include, but are not limited to, the following: Coastal Storms (Tropical and Extra-tropical) Human Influence / Intervention (Poor land use practices, failed erosion control methods) Reduction in Sand/Sediment Supply (through littoral sand transport, sand mining, weather patterns) ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-5 August 2013 Rising Sea Levels (potentially exacerbated by global warming) Extent Landslides To determine the extent of a landslide hazard, the affected areas need to be identified and the probability of the landslide occurring within some time period needs to be assessed. Natural variables that contribute to the overall extent of potential landslide activity in any particular area include soil properties, topographic position and slope, and historical incidence. Predicting a landslide is difficult, even under ideal conditions. As a result, the landslide hazard is often represented by landslide incidence and/or susceptibility, defined below:  Landslide incidence is the number of landslides that have occurred in a given geographic area. High incidence means greater than 15-percent of a given area has been involved in landsliding; medium incidence means that 1.5 to 15-percent of an area has been involved; and low incidence means that less than 1.5-percent of an area has been involved. (Geological Hazards Program, Date Unknown).  Landslide susceptibility is defined as the probable degree of response of geologic formations to natural or artificial cutting, to loading of slopes, or to unusually high precipitation. It can be assumed that unusually high precipitation or changes in existing conditions can initiate landslide movement in areas where rocks and soils have experienced numerous landslides in the past. Landslide susceptibility depends on slope angle and the geologic material underlying the slope. Landslide susceptibility only identifies areas potentially affected and does not imply a time frame when a landslide might occur. High, medium, and low susceptibility are delimited by the same percentages used for classifying the incidence of landsliding (Geological Hazards Program, Date Unknown). Figure 5.4.2-1 depicts the landslide incidence and susceptibility of the northeastern U.S., identifying areas that have the potential for landslides. These areas are determined by correlating some of the principal factors that contribute to landsliding, such as steep slopes, weak geologic units that lose strength when saturated, and poorly drained rock or soil, with the past distribution of landslides. ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-6 August 2013 Figure 5.4.2-1 Landslide Incidence and Susceptibility in the Northeast U.S. Source: USGS, 1982 Note: The circle indicates the approximate location of Cayuga County. Figure 5.4.2-1 was created by including two primary characteristics that define landslide probability: terrain slopes and soil makeup or type. Most of New York State’s soils consist of dense glacial till which stands up well to landslide tendency. However, certain types of soil exist throughout the State that has a risk of landslide susceptibility and incidence. For example, glacial lake clay soils which are abundant throughout New York State have a higher risk for landslide occurrence. As for the terrain, typically, the steeper the slope, the higher the risk for landslide occurrence, assuming other conditions that leads to landslides are present. However, according to the New York State Geological Survey, landslides can occur with very little slope. Cayuga County has an overall low landslide incidence; however, the northern-most parts of Cayuga County have moderate susceptibility/low incidence (NYS HMP, 2011). Land Subsidence/Sinkholes The predominant conditions that lend to the overall risk of land subsidence occurrence include, as mentioned previously, underlying soil and rock type, natural and human impact on ground water, and occurrence of underground mining (natural and human caused). These conditions affect the location and probability of where a subsidence event would occur, and can be generally classified as either underlying rock type or triggers. ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-7 August 2013 Other significant factors in land subsidence occurrence include aquifer-system compaction, drainage of organic soils (e.g. peats and mucks), and natural and hydro-compaction. The USGS estimates that 80% of the identified subsidence in the U.S. is a consequence of human impact on subsurface water. However, the USGS also notes that Cayuga County is not made up of unconsolidated aquifer systems, hence it is unlikely that there will be permanent subsidence and related ground failures (NYS HMP, 2011). Location Landslides The entire U.S. experiences landslides, with 36 states having moderate to highly severe landslide hazards. Expansion of urban and recreational developments into hillside areas leads to more people being threatened by landslides each year (USGS, 2011). Figure 5.4.2-2 illustrates the potential for landslides in the U.S. Figure 5.4.2-2 Landslide Potential of the Conterminous U.S. Source: USGS, 2005 Note: Red areas have very high potential, yellow areas have high potential, and green areas have moderate potential. Landslides can and do occur in the black areas, but the potential is low. Map not to scale. Circle indicates the approximate location of Cayuga County. The potential for landslides does exist throughout the entire northeast U.S., which includes New York State. Scientific and historical landslide data indicate that some areas of northern and eastern New York State have a substantial landslide risk. However, compared to other states, New York State is not identified as a state with having a serious landslide threat. According to information provided by USGS and it is estimated that 80-percent of New York State has a low susceptibility to landslide hazard. In general, the highest potential for landslides can be found along major rivers and lake valleys ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-8 August 2013 that were formerly occupied by glacial lakes resulting in glacial lake deposits (glacial lake clays) and usually associated with steeper slopes. A good example of this is the Hudson and Mohawk River Valley (NYS HMP, 2011). Figure 5.4.2-3 shows the landslide susceptibility overview map of New York State. Overall, Cayuga County has a low landslide incidence; however, the northern portion has a moderate susceptibility/low incidence and the far northern-most portion of Cayuga County bordering Lake Ontario has a high susceptibility/moderate incidence (NYS HMP, 2011). Figure 5.4.2-3 Landslide Susceptibility in New York State Source: NYS HMP, 2011 Figure 5.4.2-4 shows the location of landslide incidents in New York State. ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-9 August 2013 Figure 5.4.2-4 Location of Landslides in New York State. Source: NYS HMP, 2011 Note: The circle indicates the approximate location of Cayuga County. The NYS HMP indicates that Cayuga County has not had any landslide occurrences from 1837 to 2007. As previously stated, areas with steep slopes are more prone to landslide occurrences. Erodible soils with steep slopes are common in Southern Cayuga County, especially along the shorelines of Cayuga, Owasco and Skaneateles Lakes, plus Little and Big Salmon Creeks, Pine Hollow Brook, Hemlock Creek, Dresserville Creek and Dutch Hollow Brook (County Input, 2013). Coastal Erosion The Lake Ontario lakeshore is prone to sudden bank collapse, due to the deep sand deposits exposed to wave, wind and frost action. In undeveloped areas, the Cayuga County coast is characterized by sand spires and sand bluffs. When roads and houses are built too close to the shore on the sand deposits, the sand can give way suddenly (County Input, 2013). Land Subsidence/Sinkholes The potential for land subsidence exists across New York State, and some historical land subsidence event data exists to indicate areas having a higher land subsidence risk. Certain areas of Cayuga County contain the conditions needed for subsidence events, including underlying carbonate and evaporite rock, ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-10 August 2013 and the occurrence of underground mining. In general, data suggests that future land subsidence occurrence can be expected where it has occurred in the past. Figure 5.4.2-5 Subsidence Due to Sinkholes and Evaporative Rock Source: USGS Fact Sheet-165-00, December 2000, Land Subsidence in the United States. (NYS HMP) Note: Salt and gypsum underlie about 40% of the contiguous U.S. Carbonate karst landscapes constitute about 40% of the U.S. east of Tulsa, OK. Figure 5.4.2-5 above also indicates the existence of evaporite rock (salt and gypsum) in areas of western and central New York State. Evaporite rock is soluble in water, allowing large cavity formations to occur, and is especially susceptible to sink holes. There is an additional area of karstic materials not shown on this map. In areas where the Tully Limestone is near the ground surface, conditions exist for the dissolution of carbonates within the limestone. This has led to numerous disappearing streams existing in Moravia, Ledyard, and Genoa. These disappearing streams can contribute to flash flooding, sinkhole formation and drinking water contamination (County Input, 2013). Carbonate rock (limestone and dolomite) is also prone to void formation, but over a much longer period of time that evaporite rock. Also, the presence of glacial till in many areas of the State seems to prevent sudden collapses in carbonate rock. As a result, collapses are relatively rare in in New York, even in the regions characterized by karst topography (NYS HMP, 2011). Figure 5.4.2-6 illustrates the karst environments across the U.S. ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-11 August 2013 Figure 5.4.2-6 Karst Areas across the U.S. Source: Davies et al, 1984 High organic content peat and muck soils exist in several areas in Cayuga County. The three main areas are associated with the large wetlands along the Seneca River, Bear Swamp in Sempronius and Cedar Swamp in Owasco (County Input, 2013). Figure 5.4.2-7, below, was created by the to emulate the USGS map showing the location of rock type and minerals that are generally susceptible to natural land subsidence. Locating mineral resources helps to indicate areas where the potential exists for human caused land subsidence due to mining collapse, which is often cited as a causal element of land subsidence (NYS HMP, 2011). Salt and gypsum are abundant across western and central New York State, including southern Cayuga County, and a number of underground salt and gypsum mines exist in this part of the State. This figure also indicates mining in Cayuga County, including clay mines in the southern part. ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-12 August 2013 Figure 5.4.2-7 Mineral Resources of New York State. Source: NYS HMP Note: The circle indicates the location of Cayuga County Previous Occurrences and Losses Between 1837 and 2008, 326 landslides occurred and were reported in New York State. According to the NYS HMP, Cayuga County has not experienced any federally declared landslide or land subsistence disasters in the past. However, there have been at least two areas impacted by landslides in Cayuga County over the past 20 years. Landslide Seneca River Landslide In February of 2003, in the Town of Cato, about 1000 feet of the Seneca River bank failed and slid down and/or into the River. The Seneca River had been lowered by the New York State Canal Corps for work on the next dam/lock complex in Baldwinsville, and extreme cold froze the natural springs in the Sloan soil type. This soil type is rated as having “poor stability and low shear strength” with banks subject to failure if drained (Cayuga County Soil Survey, 1971). This frost heave resulted in a 100-foot long muddy fissure some 20 feet high in places. Two homes had to be condemned and eight to twelve ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-13 August 2013 property owners lost lawns, septic systems, boat houses, sheds, docks and/or shoreline. Approximately 4.8 miles of the Seneca River banks in Cayuga County contains these same Sloan soils, which means that about 20 to 30 houses and two commercial properties may be vulnerable to future similar events (County Input, 2013). Coastal Erosion Lake Ontario Shore Landslides The Lake Ontario shoreline is vulnerable to collapse due to constant wind, wave and winter ice action against the deep sandy soils. Cayuga County’s eight miles of Lake Ontario shoreline is roughly 60% County and state parkland with about 1.4 miles of residential development. The State rated the coastal erosion rates in 1989 in the “Coastal Erosion Hazard Area Map, Town of Sterling, Cayuga County.” Over the past 20 years, lakeshore landslides have destroyed about ten homes and/or summer cottages in the Moon Beach hamlet in Sterling. At least eight additional homes and a half-mile of Town road remain very vulnerable for future landslides (County Input, 2013). Figures Figure 5.4.2-8 through Figure 5.4.2-10 show the effects of this landslide event. Figure 5.4.2-8 February 2003 Landslide Event, Moon Beach (Town of Sterling) Source: Cayuga County Planning Committee, 2013 ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-14 August 2013 Figure 5.4.2-9 February 2003 Landslide Event, Moon Beach (Town of Sterling) Source: Cayuga County Planning Committee, 2013 Figure 5.4.2-10 February 2003 Landslide Event, Moon Beach (Town of Sterling) Source: Cayuga County Planning Committee, 2013 Land Subsidence/Sinkholes ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-15 August 2013 There have been at least three documented cases of land subsidence/sinkholes with significant damage over the past 20-40 years in Cayuga County. Two have occurred on peat and muck soils, while one occurred in the Karst geology in Central Cayuga County (County Input, 2013). Spring Lake Road aka “Sunken Bridge Road”, Conquest Around 2001, Cayuga County replaced the culvert where Spring Lake Road crosses a wetland underlain by muck soils. The additional load imposed by the construction unexpectedly destabilized the muck. The resulting subsidence deflected and decoupled the new culvert, followed by cracking and sinking of the pavement, resulting in road closure. It took approximately $250,000 and 3 years to reopen the road, with another $100,000 in additional repairs scheduled for 2013 (County Input, 2013). Hartnett Road, Sempronius Due to adjacent beaver activity, the Town of Sempronius tried to raise the road level by adding additional gravel top coating. This additional loading destabilized the muck/peat under the roadway, which then sank and cracked causing an extended road closure (County Input, 2013). Central Cayuga County Karst geology that lies about 50 to 150 feet below a former solvent disposal pit at an industrial site just west of Auburn has led to a federal Superfund clean-up known as the “Cayuga County Groundwater Contamination Superfund Site.” Sinkholes and karst features in the Aurelius area allowed contamination to reach the regional aquifer, showing up in the Village of Union Springs drinking water, seven miles away. In 2012, a $24.4 million clean-up alternative was proposed by the United States Environmental Protection Agency. This projected present worth does not include the cost of work already completed to provide clean drinking water in the Village of Union Springs and the Town of Springport (County Input, 2013). There are also three areas where less developed karst has contributed to property losses and/or well contamination. The events have occurred along the Tully limestone interface with the ground surface in four different towns in Southern Cayuga County (County Input, 2013).  Moravia Area (FEMA-DR-1095) - The rapid snowmelt and rainfall in January 1996 overwhelmed at least three “disappearing streams” in the Tully limestone interface upslope of the Village of Moravia. This led to extensive street flooding especially in areas where culverts plugged with shaley debris. Damages are included in the flood risk assessment section in DR- 1095 (County Input, 2013).  King Ferry Station, Genoa (FEMA-DR-1335) - The southwestern portion of Cayuga County experienced heavy thunderstorms that led to Tompkins County being federally declared in June of 2000. The storms overwhelmed one or more disappearing streams in the Tully limestone, sending excess flows cascading over Firelanes 5, 6 and 7, causing property damage to lakeview and lakeshore houses (County Input, 2013).  Private Well Contamination - Several shallow residential wells in the Towns of Ledyard and Scipio may have been contaminated around 2002. The wells are located near the Tully Limestone interface just downslope from a dairy farm (County Input, 2013). ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-16 August 2013 Probability of Future Events Landslide/Coastal Erosion As indicated in the NYS HMP, given the history of landslide occurrences in New York State, it is certain that future landslides will occur. Therefore, the probability of future landslides in New York State is considered high. However, the severity of landslides cannot be determined. Using documented historical occurrences from the New York State Geological Survey’s Landslide Inventory Study to estimate the probability of future landslides, New York State can expect on average approximately two major landslides each year, a greater number of smaller but still significant slides/slumps/flows each year and at least one landslide causing a fatality, is expected once every 12 years. Although historical data indicates a high frequency of landslide occurrence, the estimates that 80-percent of the State has a low susceptibility to landslides. The frequency of damaging landslides within and adjacent to Cayuga County has been and can be classified as low. However, the fact that high landslide susceptibility exists in the northern part of Cayuga County and that two landslides have occurred in the northern portions of Cayuga County in the past suggests that infrastructure and people are at risk from damaging ground failure hazards in Cayuga County. Land Subsidence and Sinkholes Sinkhole occurrence is a rare phenomenon in Cayuga County, and while land subsidence often goes undocumented, the probability land subsidence in Cayuga County is low. As areas underlain by evaporite and carbonate rock become increasingly developed or mined, the threat for sinkholes in those areas may increase resulting from groundwater depletion. In Section 5.3, the identified hazards of concern for Cayuga County were ranked. The probability of occurrence, or likelihood of the event, is one parameter used for ranking hazards. Based on historical records and input from the Planning Committee, the probability of occurrence for the landslide or subsidence hazards in Cayuga County is considered ‘Frequent’ (likely to occur more than once every 25 years, as presented in Table 5.3-3). Based on geological conditions, subsidence events are likely to occur in the future for the areas of Cayuga County underlain by carbonate bedrock and experiencing increased development and/or mining. The future occurrence of subsidence and sinkholes is considered unlikely as defined by the Risk Factor Methodology probability criteria (refer to Section 5.1). ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-17 August 2013 VULNERABILITY ASSESSMENT To understand risk, a community must evaluate what assets are exposed or vulnerable in the identified hazard area. The following section discusses the potential impact of the ground failure hazard on Cayuga County including:  Overview of vulnerability  Data and methodology used for the evaluation  Impact to: life, safety and health of County residents, general building stock, critical facilities, economy and future growth and development  Effect of climate change on vulnerability  Further data collections that will assist understanding of this hazard over time Overview of Vulnerability Vulnerability to ground failure hazards is a function of location, soil type, geology, type of human activity, use, and frequency of events. The effects of ground failure on people and structures can be lessened by total avoidance of hazard areas or by restricting, prohibiting, or imposing conditions on hazard-zone activity. Local governments can reduce ground failure effects by educating themselves on past hazard history of the site and by making inquiries to planning and engineering departments of local governments (National Atlas, 2007). Data and Methodology In an attempt to estimate Cayuga County’s vulnerability to ground failure due to landslides, the Geology - Landslide Incidence and Susceptibility GIS layer from National Atlas was used to coarsely define the general landslide susceptible area (Figure 5.4.2-3 earlier in this profile). The Geology - Landslide Incidence and Susceptibility GIS layer was overlaid upon the 2010 Census population data, custom building inventory and Cayuga County’s critical facility inventory to estimate exposure. According to Radbruch-Hall et.al., the Landslide Incidence and Susceptibility GIS layer from National Atlas ‘….was prepared by evaluating formations or groups of formations shown on the geologic map of the United States (King and Beikman, 1974) and classifying them as having high, medium, or low landslide incidence (number of landslides) and being of high, medium, or low susceptibility to landsliding. Thus, those map units or parts of units with more than 15 percent of their area involved in landsliding were classified as having high incidence; those with 1.5 to 15 percent of their area involved in landsliding, as having medium incidence; and those with less than 1.5 percent of their area involved, as having low incidence. This classification scheme was modified where particular lithofacies are known to have variable landslide incidence or susceptibility. In continental glaciated areas, additional data were used to identify surficial deposits that are susceptible to slope movement. Susceptibility to landsliding was defined as the probable degree of response of the areal rocks and soils to natural or artificial cutting or loading of slopes or to anomalously high precipitation. High, medium, and low susceptibility are delimited by the same percentages used in classifying the incidence of landsliding. For example, it was estimated that a rock or soil unit characterized by high landslide susceptibility would respond to widespread artificial cutting by some movement in 15 percent or more of the affected area. We did not evaluate the effect of earthquakes on slope stability, although many catastrophic landslides have been generated by ground shaking during earthquakes. Areas susceptible to ground failure under static conditions would probably also be susceptible to failure during earthquakes’ (Radbruch-Hall, 1982). ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-18 August 2013 To estimate Cayuga County’s vulnerability to ground failure due to karst environments, the Engineering Aspects of Karst GIS layer from National Atlas, released in April 2005, was used. This national data set shows areas of karst, as well as features analogous to karst (sometimes referred to as "pseudokarst", which is karst-like terrain produced by processes other than the dissolution of rocks). Also included are lines showing the limits of areas of subsidence caused by karst-related problems; although there are no areas of subsidence caused by karst-related problems identified in Cayuga County. This data set is a digital representation of USGS Open-File Report 2004-1352. This GIS layer was overlaid upon the 2010 Census population data, custom building inventory and Cayuga County’s critical facility inventory to estimate exposure. The limitations of this analysis are recognized and are only used to provide a general estimate. Over time additional data will be collected to allow better analysis for this hazard. Available information and a preliminary assessment are provided below. ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-19 August 2013 Figure 5.4.2-11 Landslide Hazard Areas in Cayuga County Source: Godt, 2011 (Geology WMS Layer from the National Atlas of the United States) ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-20 August 2013 Figure 5.4.2-12 Karst Areas in Cayuga County Source: Tobin and Weary, 2005 ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-21 August 2013 Table 5.4.2-1 Karst Types Karst 11Type Description Short 4 Fissures, tubes and caves generally less than 1,000 ft. (300 m) long; 50 ft. (15 m) or less vertical extent; In gently dipping to flat-lying beds of carbonate rock Short 5 Fissures, tubes and caves generally less than 1,000 ft. (300 m) long; 50 ft. (15 m) or less vertical extent; In gently dipping to flat-lying beds of carbonate rock beneath an overburden of noncarbonate material 10 ft. (3 m) to 200 ft. (60 m) thick Short 7 Fissures, tubes and caves generally less than 1,000 ft. (300 m) long; 50 ft. (15 m) or less vertical extent; in gently dipping to flat-lying beds of gypsum Source: Tobin and Weary, 2005 Impact on Life, Health and Safety To estimate the population located within the ground failure hazard areas, the approximate hazard area boundaries were overlaid upon the 2010 Census population data (U.S. Census, 2010). The Census blocks with their center (centroid) within the boundary of the landslide incidence and susceptibility/incidence hazard areas, and the karst environments, were used to calculate the estimated population considered exposed to this hazard. Tables Table 5.4.2-2 and 5.4.2-3 summarize the population within each identified area by municipality (U.S. Census 2010). Impact on General Building Stock In general, the built environment located in the high susceptibility zones and the population, structures and infrastructure located downslope are vulnerable to this hazard. In an attempt to estimate the general building stock vulnerable to this hazard, the building replacement values (buildings and contents) were determined for the buildings with their centroids within the approximate landslide and karst hazard areas. Tables Table 5.4.2-4 and 5.4.2-5 list the number of buildings and replacement cost value (structure and contents) of the general building stock exposed to this hazard. ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-22 August 2013 Table 5.4.2-2 Estimated Population Exposed to Landslides in Cayuga County Municipality Total U.S. 2010 Population Landslide Incidence Landslide Susceptibility/Incidence High Moderate Low High/Moderate High/Low Moderate/Low Pop. Exposed % Total Pop. Exposed % Total Pop. Exposed % Total Pop. Exposed % Total Pop. Exposed % Total Pop. Exposed % Total Auburn 27,687 0 0.0% 0 0.0% 27,687 100.0% 0 0.0% 0 0.0% 0 0.0% Aurelius 2,243 0 0.0% 0 0.0% 2,243 100.0% 0 0.0% 0 0.0% 0 0.0% Aurora 724 0 0.0% 0 0.0% 724 100.0% 0 0.0% 0 0.0% 0 0.0% Brutus 2,649 0 0.0% 0 0.0% 2,649 100.0% 0 0.0% 0 0.0% 0 0.0% Cato 2,020 0 0.0% 0 0.0% 1,537 76.1% 0 0.0% 0 0.0% 483 23.9% Cato 533 0 0.0% 0 0.0% 0.0% 0 0.0% 0 0.0% 533 100.0% Cayuga 549 0 0.0% 0 0.0% 549 100.0% 0 0.0% 0 0.0% 0 0.0% Conquest 1,819 0 0.0% 0 0.0% 1,343 73.8% 0 0.0% 0 0.0% 476 26.2% Fair Haven 703 0 0.0% 563 80.1% 0.0% 0 0.0% 0 0.0% 0 0.0% Fleming 2,636 0 0.0% 0 0.0% 2,636 100.0% 0 0.0% 0 0.0% 0 0.0% Genoa 1,935 0 0.0% 0 0.0% 1,935 100.0% 0 0.0% 0 0.0% 0 0.0% Ira 1,881 0 0.0% 0 0.0% 0.0% 0 0.0% 0 0.0% 1,881 100.0% Ledyard 1,158 0 0.0% 0 0.0% 1,158 100.0% 0 0.0% 0 0.0% 0 0.0% Locke 1,951 0 0.0% 0 0.0% 1,951 100.0% 0 0.0% 0 0.0% 0 0.0% Mentz 1,096 0 0.0% 0 0.0% 1,096 100.0% 0 0.0% 0 0.0% 0 0.0% Meridian 309 0 0.0% 0 0.0% 0.0% 0 0.0% 0 0.0% 309 100.0% Montezuma 1,277 0 0.0% 0 0.0% 1,277 100.0% 0 0.0% 0 0.0% 0 0.0% Moravia 2,347 0 0.0% 0 0.0% 2,347 100.0% 0 0.0% 0 0.0% 0 0.0% Moravia 1,279 0 0.0% 0 0.0% 1,279 100.0% 0 0.0% 0 0.0% 0 0.0% Niles 1,194 0 0.0% 203 17.0% 991 83.0% 0 0.0% 0 0.0% 0 0.0% Owasco 3,793 0 0.0% 913 24.1% 2,880 75.9% 0 0.0% 0 0.0% 0 0.0% Port Byron 1,282 0 0.0% 0 0.0% 1,282 100.0% 0 0.0% 0 0.0% 0 0.0% Scipio 1,713 0 0.0% 0 0.0% 1,713 100.0% 0 0.0% 0 0.0% 0 0.0% Sempronius 890 0 0.0% 0 0.0% 890 100.0% 0 0.0% 0 0.0% 0 0.0% ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-23 August 2013 Municipality Total U.S. 2010 Population Landslide Incidence Landslide Susceptibility/Incidence High Moderate Low High/Moderate High/Low Moderate/Low Pop. Exposed % Total Pop. Exposed % Total Pop. Exposed % Total Pop. Exposed % Total Pop. Exposed % Total Pop. Exposed % Total Sennett 3,595 0 0.0% 0 0.0% 3,595 100.0% 0 0.0% 0 0.0% 0 0.0% Springport 1,176 0 0.0% 0 0.0% 1,176 100.0% 0 0.0% 0 0.0% 0 0.0% Sterling 2,337 0 0.0% 722 30.9% 0.0% 0 0.0% 0 0.0% 1,613 69.0% Summerhill 1,222 0 0.0% 0 0.0% 1,222 100.0% 0 0.0% 0 0.0% 0 0.0% Throop 1,990 0 0.0% 0 0.0% 1,990 100.0% 0 0.0% 0 0.0% 0 0.0% Union Springs 1,195 0 0.0% 0 0.0% 1,195 100.0% 0 0.0% 0 0.0% 0 0.0% Venice 1,368 0 0.0% 0 0.0% 1,368 100.0% 0 0.0% 0 0.0% 0 0.0% Victory 1,660 0 0.0% 0 0.0% 0.0% 0 0.0% 0 0.0% 1,660 100.0% Weedsport 1,815 0 0.0% 0 0.0% 1,815 100.0% 0 0.0% 0 0.0% 0 0.0% Cayuga County 80,026 0 0.0% 2,401 3.0% 70,528 88.1% 0 0.0% 0 0.0% 6,955 8.7% Source: U.S. Census 2010; Godt, 2011 (Geology WMS Layer from the National Atlas of the United States) Pop. = Population ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-24 August 2013 Table 5.4.2-3 Estimated Population Located in Karst Areas in Cayuga County Municipality Total U.S. Census 2010 Population Population Exposed % Total Auburn 27,687 27,687 100.0% Aurelius 2,243 1,400 62.4% Aurora 724 0 0.0% Brutus 2,649 0 0.0% Cato 2,020 925 45.8% Cato 533 533 100.0% Cayuga 549 144 26.2% Conquest 1,819 1,478 81.3% Fair Haven 703 0 0.0% Fleming 2,636 2,458 93.2% Genoa 1,935 235 12.1% Ira 1,881 1,849 98.3% Ledyard 1,158 133 11.5% Locke 1,951 910 46.6% Mentz 1,096 0 0.0% Meridian 309 309 100.0% Montezuma 1,277 0 0.0% Moravia 2,347 2,283 97.3% Moravia 1,279 1,279 100.0% Niles 1,194 509 42.6% Owasco 3,793 2,578 68.0% Port Byron 1,282 0 0.0% Scipio 1,713 497 29.0% Sempronius 890 397 44.6% Sennett 3,595 2,394 66.6% Springport 1,176 1,176 100.0% Sterling 2,337 131 5.6% Summerhill 1,222 87 7.1% Throop 1,990 504 25.3% Union Springs 1,195 1,195 100.0% Venice 1,368 592 43.3% Victory 1,660 1,660 100.0% Weedsport 1,815 0 0.0% Cayuga County 80,026 53,343 66.7% Source: U.S. Census 2010; Source: Tobin and Weary, 2005 ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-25 August 2013 Table 5.4.2-4 General Building Stock Exposed to Landslides in Cayuga County Municipality GBS Count Total GBS RCV Landslide Incidence Landslide Incidence/Exposure Low Moderate Moderate/Low GBS Count % of Total RCV % of Total GBS Count % of Total RCV % of Total GBS Count % of Total RCV % of Total Auburn 8,279 $1,878,218,032 8,279 100.0% $1,878,218,032 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Aurelius 924 $235,842,408 924 100.0% $235,842,408 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Aurora 204 $78,145,146 204 100.0% $78,145,146 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Brutus 737 $137,559,741 737 100.0% $137,559,741 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Cato 1,045 $123,559,352 797 76.3% $92,528,215 74.9% 0 0.0% $0 0.0% 248 23.7% $31,031,137 25.1% Cato 203 $25,489,778 0 0.0% $0 0.0% 0 0.0% $0 0.0% 203 100.0 % $25,489,778 100.0% Cayuga 218 $30,622,602 218 100.0% $30,622,602 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Conquest 858 $80,886,230 595 69.3% $57,988,585 71.7% 0 0.0% $0 0.0% 263 30.7% $22,897,645 28.3% Fair Haven 663 $81,256,714 0 0.0% $0 0.0% 510 76.9% $66,154,264 81.4% 0 0.0% $0 0.0% Fleming 1,128 $224,901,456 1,128 100.0% $224,901,456 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Genoa 991 $157,595,339 991 100.0% $157,595,339 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Ira 773 $141,248,229 0 0.0% $0 0.0% 0 0.0% $0 0.0% 773 100.0 % $141,248,229 100.0% Ledyard 666 $121,217,136 666 100.0% $121,217,136 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Locke 654 $80,900,298 654 100.0% $80,900,298 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Mentz 427 $70,917,868 427 100.0% $70,917,868 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Meridian 116 $13,281,419 0 0.0% $0 0.0% 0 0.0% $0 0.0% 116 100.0 % $13,281,419 100.0% Montezuma 493 $50,517,527 493 100.0% $50,517,527 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Moravia 654 $139,466,396 654 100.0% $139,466,396 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Moravia 495 $110,235,862 495 100.0% $110,235,862 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Niles 905 $134,855,774 718 79.3% $103,554,474 76.8% 187 20.7% $31,301,300 23.2% 0 0.0% $0 0.0% Owasco 1,741 $392,636,885 1,283 73.7% $283,516,911 72.2% 458 26.3% $109,119,975 27.8% 0 0.0% $0 0.0% Port Byron 414 $74,854,644 414 100.0% $74,854,644 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Scipio 740 $115,757,295 737 99.6% $115,463,997 99.7% 3 0.4% $293,298 0.3% 0 0.0% $0 0.0% Sempronius 457 $55,409,787 457 100.0% $55,409,787 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-26 August 2013 Municipality GBS Count Total GBS RCV Landslide Incidence Landslide Incidence/Exposure Low Moderate Moderate/Low GBS Count % of Total RCV % of Total GBS Count % of Total RCV % of Total GBS Count % of Total RCV % of Total Sennett 1,383 $421,576,376 1,383 100.0% $421,576,376 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Springport 561 $101,711,905 561 100.0% $101,711,905 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Sterling 1,136 $111,783,180 0 0.0% $0 0.0% 399 35.1% $46,001,000 41.2% 675 59.4% $62,609,980 56.0% Summerhill 498 $62,016,044 498 100.0% $62,016,044 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Throop 782 $117,821,212 782 100.0% $117,821,212 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Union Springs 440 $96,036,680 440 100.0% $96,036,680 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Venice 570 $94,806,303 570 100.0% $94,806,303 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Victory 677 $70,156,430 0 0.0% $0 0.0% 0 0.0% $0 0.0% 677 100.0 % $70,156,430 100.0% Weedsport 658 $121,709,134 658 100.0% $121,709,134 100.0% 0 0.0% $0 0.0% 0 0.0% $0 0.0% Cayuga County 30,490 $5,752,993,179 25,763 84.5% $5,115,134,074 88.9% 1,557 5.1% $252,869,837 4.4% 2,955 9.7% $366,714,619 6.4% Source: Cayuga GIS; Godt, 2011 (Geology WMS Layer from the National Atlas of the United States) Notes: GBS = General Building Stock; RCV = Replacement Cost Value. The total building count and total replacement values are the sum of all seven general occupancy classifications (residential, commercial, industrial, agricultural, religious, government and educational) for that jurisdiction. The valuation of general building stock and loss estimates determined in Cayuga County were based on the custom general building stock inventory generated for this project. ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-27 August 2013 Table 5.4.2-5 General Building Stock Exposed to Karst Areas in Cayuga County Municipality Total Number of Buildings Total GBS RCV Number of Buildings Exposed % of Buildings Exposed Exposed RCV % of RCV Exposed Auburn 8,279 $1,878,218,032 8,279 100.0% $1,878,218,032 100.0% Aurelius 924 $235,842,408 584 63.2% $192,061,644 81.4% Aurora 204 $78,145,146 0 0.0% $0 0.0% Brutus 737 $137,559,741 0 0.0% $0 0.0% Cato 1,045 $123,559,352 585 56.0% $65,544,222 53.0% Cato 203 $25,489,778 203 100.0% $25,489,778 100.0% Cayuga 218 $30,622,602 48 22.0% $5,617,800 18.3% Conquest 858 $80,886,230 674 78.6% $64,001,541 79.1% Fair Haven 663 $81,256,714 0 0.0% $0 0.0% Fleming 1,128 $224,901,456 997 88.4% $198,194,587 88.1% Genoa 991 $157,595,339 252 25.4% $45,086,857 28.6% Ira 773 $141,248,229 765 99.0% $140,462,829 99.4% Ledyard 666 $121,217,136 178 26.7% $28,860,635 23.8% Locke 654 $80,900,298 258 39.4% $33,096,683 40.9% Mentz 427 $70,917,868 0.0% $0 0.0% Meridian 116 $13,281,419 116 100.0% $13,281,419 100.0% Montezuma 493 $50,517,527 0 0.0% $0 0.0% Moravia 654 $139,466,396 621 95.0% $135,618,787 97.2% Moravia 495 $110,235,862 495 100.0% $110,235,862 100.0% Niles 905 $134,855,774 396 43.8% $51,538,274 38.2% Owasco 1,741 $392,636,885 1,127 64.7% $251,255,136 64.0% Port Byron 414 $74,854,644 0 0.0% $0 0.0% Scipio 740 $115,757,295 266 35.9% $34,781,379 30.0% Sempronius 457 $55,409,787 247 54.0% $31,857,017 57.5% Sennett 1,383 $421,576,376 999 72.2% $332,187,008 78.8% Springport 561 $101,711,905 561 100.0% $101,711,905 100.0% Sterling 1,136 $111,783,180 74 6.5% $7,116,600 6.4% Summerhill 498 $62,016,044 35 7.0% $4,268,531 6.9% Throop 782 $117,821,212 211 27.0% $36,559,471 31.0% Union Springs 440 $96,036,680 440 100.0% $96,036,680 100.0% Venice 570 $94,806,303 219 38.4% $40,601,040 42.8% Victory 677 $70,156,430 677 100.0% $70,156,430 100.0% Weedsport 658 $121,709,134 0 0.0% $0 0.0% Cayuga County 30,490 $5,752,993,179 19,307 63.3% $3,993,840,146 69.4% ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-28 August 2013 Impact on Critical Facilities To estimate exposure, the approximate ground failure hazard areas (landslide and karst areas) were overlaid upon the essential and municipal facilities. Table 5.4.2-6 lists these facilities police, fire, EOCs and hospitals) and which approximate hazard area they are located in. ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-29 August 2013 Table 5.4.2-6 Emergency Critical Facilities Exposed to Landslides and Karst Areas in Cayuga County Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility Allen St Pump Station Auburn X X Appleton Disposal - Auburn Hauling Hazmat Auburn X X Auburn Substation Auburn X X Auburn Substation Auburn X X AUBURN ARMORY User Defined Auburn X X Auburn Community Hospital Medical Auburn X X Auburn Correctional Facility User Defined Auburn X X Auburn Fire Department #1 Afd Fire/EMS Auburn X X Auburn Fire Department #3 Afd Fire/EMS Auburn X X Auburn High School Schools Auburn X X AUBURN HIGH SCHOOL User Defined Auburn X X Auburn Junior High School Schools Auburn X X AUBURN JUNIOR HIGH SCHOOL User Defined Auburn X X Auburn Landfill G & E Generator Power Plant Auburn X X Auburn Memorial Hospital Airport Auburn X X Auburn Nursing Home Senior Auburn X X Auburn Nursing Home User Defined Auburn X X Auburn Police Department Police Auburn X X Bimbo Bakeries, USA - Auburn Facility Hazmat Auburn X X BJ's Wholesale Club (0314) Hazmat Auburn X X Bluefield Manor Senior Auburn X X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-30 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility Bluefield Manor User Defined Auburn X X Boyle Center Senior Auburn X X Boyle Center User Defined Auburn X X Canoga St Pump Station Auburn X X CASEY PARK ELEMENTARY User Defined Auburn X X Casey Park Elementary School Schools Auburn X X Cayuga County Community College Schools Auburn X X Cayuga County Highway Department User Defined Auburn X X Cayuga County Office Building EOC Auburn X X CAYUGA SENECA COMMUNITY ACTION AGENCY User Defined Auburn X X CAYUGA/ONONDAGA BOCES User Defined Auburn X X Centro Auburn Facility Hazmat Auburn X X Centro-Auburn User Defined Auburn X X City Court User Defined Auburn X X City Hall User Defined Auburn X X City of Auburn User Defined Auburn X X City of Auburn CSO (029A) Wastewater Facilities Auburn X X City of Auburn CSO (05) Wastewater Facilities Auburn X X City of Auburn CSO (07) Wastewater Facilities Auburn X X City of Auburn CSO (17) Wastewater Facilities Auburn X X City of Auburn Sewage Plant Wastewater Facilities Auburn X X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-31 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility City of Auburn Sewerage Facility Wastewater Facilities Auburn X X City of Auburn Water Purification Plant Hazmat Auburn X X County Court House User Defined Auburn X X Emergency Radio CommTower Communications Auburn X X Faatz-Crofut Home Senior Auburn X X Faatz-Crofut Home User Defined Auburn X X Finger Lakes Center For Living Senior Auburn X X Finger Lakes Center For Living User Defined Auburn X X Fingerlakes Medical Care Center Medical Auburn X X FIRST PRESBYTERIAN CHURCH User Defined Auburn X X First Student, Inc. #20658 Hazmat Auburn X X Genesee Elementary School Schools Auburn X X GENESEE ELEMENTARY SCHOOL User Defined Auburn X X HERMAN AVE ELEMENTARY SCHOOL User Defined Auburn X X Herman Avenue Elementary School Schools Auburn X X John Walsh Blvd (Walmart) Pump Station Auburn X X Lowe's of Auburn (#0561) Hazmat Auburn X X McQuay International Hazmat Auburn X X Mercy Health And Rehab Ctr. Senior Auburn X X Mercy Health And Rehab Ctr. User Defined Auburn X X Mill Street Dam Power Plant Auburn X X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-32 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility New York State DOT User Defined Auburn X X North Division Street Dam Power Plant Auburn X X Apartments Senior Auburn X X Apartments User Defined Auburn X X Heights Home For Adults Senior Auburn X X Heights Home For Adults User Defined Auburn X X Northeast Battery 04 Hazmat Auburn X X NYSEG - Auburn Service Center Hazmat Auburn X X NYSEG Peaking Plant Power Plant Auburn X X Onondaga Coach User Defined Auburn X OWASCO ELEMENTARY SCHOOL User Defined Auburn X X Penske Truck Leasing Co., LP Hazmat Auburn X X Public Safety Building - Heliport Airport Auburn X Restmour Home For Adults Senior Auburn X X Restmour Home For Adults User Defined Auburn X X Rural Metro Fire/EMS Auburn X X SCAT Van Transportation User Defined Auburn X X Schwartz Towers Senior Auburn X X Schwartz Towers User Defined Auburn X X SENNETT FEDERATED CHURCH User Defined Auburn X SENNETT FIRE DEPARTMENT User Defined Auburn X X SEWARD ELEMENTARY SCHOOL User Defined Auburn X X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-33 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility Ss. Peter & Paul School Schools Auburn X X St. Joseph School Schools Auburn X X Homes Senior Auburn X X Homes User Defined Auburn X X Substation (Clark St) Substation Auburn X X Substation Green St) Substation Auburn X X Substation (Swift St) Substation Auburn X X Suburban Heating Oil Partners Hazmat Auburn X X Suburban Propane Hazmat Auburn X X THE HOME DEPOT STORE #6846 Hazmat Auburn X X TLC Ambulance Fire/EMS Auburn X X Treatment Plant & Storage Tank Potable Water Facility Auburn X X TRW Automotive Hazmat Auburn X X TUBE CITY IMS - AUBURN Hazmat Auburn X X Tyburn Academy Schools Auburn X X Verizon CO (NY73300) Hazmat Auburn X X West Middle School Schools Auburn X X Westminster Manor Senior Auburn X X Westminster Manor User Defined Auburn X X William H. Seward Elementary School Schools Auburn X X Xylem Inc. Water Systems U.S.A., LLC Hazmat Auburn X X Cayuga Sewage Facility Wastewater Facilities Aurelius X Cayuga Sewage Plant Wastewater Facilities Aurelius X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-34 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility Aurelius Fire Department #1 Fire/EMS Aurelius X X Aurelius Fire Department #2 Fire/EMS Aurelius X Aurelius Sewer Pump Station Pump Station Aurelius X X Cayuga-Onondaga BOCES School Schools Aurelius X X Intake Potable Water Facility Aurelius X X New York State Police Airport Aurelius X X New York State Police Barracks Police Aurelius X X Tower Communications Aurelius X X Town Hall User Defined Aurelius X Treatment Plant Potable Water Facility Aurelius X X Aurora Sewage Plant Wastewater Facilities Aurora X Aurora Fire Department Fire/EMS Aurora X Peachtown Elementary School Schools Aurora X SOUTHERN CAYUGA HIGH SCHOOL User Defined Aurora X Storage Tank Potable Water Facility Aurora X Village Hall User Defined Aurora X Village of Aurora User Defined Aurora X Village Of Aurora Fire Department Fire/EMS Aurora X Wells College Schools Aurora X DIRT Ambulance (Boundless Racing, Inc.) Fire/EMS Brutus X Storage Tank Potable Water Facility Brutus X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-35 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility Storage Tank Potable Water Facility Brutus X Weedsport Junior-Senior High School Schools Brutus X Town of Brutus User Defined Brutus X New York Thruway User Defined Brutus X Pump Road CCSWA Pump Station Brutus X Emergency Radio CommTower Communications Cato X X Town of Cato User Defined Cato X X Village Of Meridian Fire Department #2 Fire/EMS Cato X Well Potable Water Facility Cato X X Whitfords Airport Cato X (CIMVAC) Ambulance Corp., Inc. Fire/EMS Cato X X CATO MERIDIAN HIGH SCHOOL User Defined Cato X X Cato Substation And Village Garage Fire/EMS Cato X X Hillview Terrace User Defined Cato X Hillview Terrace Senior Cato X X Ira Town Hall User Defined Cato X X Storage Tank Potable Water Facility Cato X X Treatment Plant Potable Water Facility Cato X X Village Hall (Cato) User Defined Cato X X Village of Cato User Defined Cato X X Village Of Cato Fire Department Fire/EMS Cato X X Village of Cayuga User Defined Cayuga X X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-36 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility Cayuga Substation Cayuga X Cayuga Elementary School Schools Cayuga X Cayuga Fire Department Fire/EMS Cayuga X Salato Gardens Senior Cayuga X Salato Gardens User Defined Cayuga X Storage Tank Potable Water Facility Cayuga X Village Hall User Defined Cayuga X Village Of Cayuga Fire Department Fire/EMS Cayuga X Cayuga County Regional Digester Power Plant Cayuga County X Conquest Fire Company, Inc. Fire/EMS Conquest X X Conquest Fire Department Fire/EMS Conquest X X Conquest Parochial School Schools Conquest X X Town Hall User Defined Conquest X X Town of Conquest User Defined Conquest X X Fair Haven Ambulance Fire/EMS Fair Haven X Fair Haven Senior Apartments User Defined Fair Haven X X Fair Haven Senior Apartments Senior Fair Haven X FAIR HAVEN VOLUNTEER FIRE COMPANY User Defined Fair Haven X Morning Glory Home For Adults Senior Fair Haven X Morning Glory Home For Adults User Defined Fair Haven X Storage Tank-Main St. East Potable Water Facility Fair Haven X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-37 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility Village Hall User Defined Fair Haven X Village of Fair Haven User Defined Fair Haven X Village Of Fair Haven Fire Department Fire/EMS Fair Haven X Fair Haven Sewer Pump Station Pump Station Fair Haven(V) X Fleming Fire Company #1 Fire/EMS Fleming X X Fleming Fire Company #2 Fire/EMS Fleming X X Fleming Fire Department #1 Fire/EMS Fleming X X Fleming Fire Department #2 Fire/EMS Fleming X X Storage Tank Potable Water Facility Fleming X X Storage Tank #1-Mill St. Potable Water Facility Fleming X X Storage Tank #2-Stone School Rd. Potable Water Facility Fleming X X Town Hall User Defined Fleming X X Town of Fleming User Defined Fleming X X Treatment Plant Potable Water Facility Fleming X X Amerigas Propane Hazmat Genoa X Amerigas Propane Hazmat Genoa X DiSanto Propane 9 Hazmat Genoa X Genoa Substation Genoa X Genoa Fire Department Fire/EMS Genoa X King Ferry Fire Department Fire/EMS Genoa X Storage Tank-Genoa Potable Water Facility Genoa X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-38 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility Storage Tank-King Ferry Potable Water Facility Genoa X Town Hall User Defined Genoa X Town of Genoa User Defined Genoa X Treatment Plant &Well #2A, #2B Potable Water Facility Genoa X Well #4 Potable Water Facility Genoa X Cato-Meridian Elementary School Schools Ira X X Cato-Meridian Middle School Schools Ira X X Cato-Meridian Senior High School Schools Ira X X Cayuga County Highway Department User Defined Ira X X Ira Fire Department Fire/EMS Ira X X Town of Ira User Defined Ira X X Amerigas Propane Hazmat King Ferry X Intake Potable Water Facility Ledyard X Ledyard Substation Ledyard X Match Mate Airport Ledyard X Storage Tank Potable Water Facility Ledyard X Town Hall User Defined Ledyard X Town of Ledyard User Defined Ledyard X Treatment Plant Potable Water Facility Ledyard X HEWITT BROTHERS, INC. Hazmat Locke X Emergency Radio CommTower Communications Locke X X Locke Substation Locke X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-39 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility Locke Fire Department Fire/EMS Locke X LOCKE TOWN HALL & FIRE STATION User Defined Locke X South Well-Main Well & WWT Plant Potable Water Facility Locke X Storage Tank Potable Water Facility Locke X Town Clerk’s Office User Defined Locke X Water Utility and Treatment Potable Water Facility Locke X A.A. Gates Elementary School Schools Mentz X Leslie B. Lehn Middle School Schools Mentz X New York Thruway User Defined Mentz X Port Byron Senior High School Schools Mentz X Town of Mentz User Defined Mentz X Village of Meridian User Defined Meridian X X Village Of Meridian Fire Department #1 Fire/EMS Meridian X X Well 8 & Storage Tank & WWT Plant Potable Water Facility Meridian X X Town/Village Hall User Defined Meridian Cato X X Montezuma Fire Department Fire/EMS Montezuma X MONTEZUMA FIRE DEPARTMENT User Defined Montezuma X Storage Tank Potable Water Facility Montezuma X Town Hall User Defined Montezuma X Town of Montezuma User Defined Montezuma X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-40 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility Treatment Plant Potable Water Facility Montezuma X Verizon CO (NY70300) Hazmat MORAVIA X X Cayuga Correctional Facility User Defined Moravia X X Storage Tank Potable Water Facility Moravia X X Storage Tank Potable Water Facility Moravia X X Four Town First Aid Squad, Inc. Fire/EMS Moravia X X Glen House Eldercare Senior Moravia X X Glen House Eldercare User Defined Moravia X Millard Fillmore Elementary School Schools Moravia X X Court Senior Moravia X X Court User Defined Moravia X X Moravia Substation Moravia X X MORAVIA CENTRAL SCHOOLS User Defined Moravia X X Moravia Junior-Senior High School Schools Moravia X X Moravia Justice Center Police Moravia X X Moravia Sewage Plant Wastewater Facilities Moravia X X New York State DOT User Defined Moravia X X Northwoods Senior Moravia X X Northwoods User Defined Moravia X X Town Hall User Defined Moravia X X Town of Moravia User Defined Moravia X X Village Elder Care Senior Moravia X X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-41 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility Village Elder Care User Defined Moravia X X Village Hall User Defined Moravia X Village of Moravia User Defined Moravia X X Village Of Moravia Fire Department Fire/EMS Moravia X X Well & Treatment Plant Potable Water Facility Moravia X X Emergency Radio CommTower Communications Niles X X Maus Marineland Airport Niles X X Microwave Communications Niles X X Murphy Field Airport Niles X New Hope Fire Department #1 Fire/EMS Niles X X Niles Town Hall User Defined Niles X X Town Hall User Defined Niles X X Town of Niles User Defined Niles X X West Niles Fire Department Fire/EMS Niles X Emergency Radio CommTower Communications Onondaga County X Tower Communications Ovid X X Verizon CO (NY70858) Hazmat Owasco X Archie St. Severe High Flow Pump Pump Station Owasco X X Burtis Point Pump Station Owasco X Intake Potable Water Facility Owasco X X Intake Potable Water Facility Owasco X X Martin Point Pump Station Owasco X X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-42 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility Owasco Substation Owasco X X Owasco and Oakridge Pump Station Owasco X X Owasco Elementary School Schools Owasco X X Owasco Fire Department #1 Fire/EMS Owasco X X Owasco Fire Department #1 Fire/EMS Owasco X X Owasco Fire Department #2 Fire/EMS Owasco X Owasco Rd. and Pump Station Owasco X X Storage Tank-Martin Rd. Potable Water Facility Owasco X Storage Tank-Melrose Rd. Potable Water Facility Owasco X X Town Hall User Defined Owasco X X Town of Owasco User Defined Owasco X Treatment Plant Potable Water Facility Owasco X X Verizon CO (NY70574) Hazmat POPLAR RIDGE X Port Byron Service Area Hazmat Port Byron X X Port Byron Sewage Plant Wastewater Facilities Port Byron X Church Street Apartments Senior Port Byron X Church Street Apartments User Defined Port Byron X CONQUEST FIRE DEPARTMENT User Defined Port Byron X X CONQUEST MUNICIPAL COURT User Defined Port Byron X X Port Byron Substation Port Byron X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-43 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility PORT BYRON CENTRAL SCHOOL DISTRICT User Defined Port Byron X Port Byron Fire Department Fire/EMS Port Byron X Port Byron Village Hall Police Port Byron X Storage Tank Potable Water Facility Port Byron X Town Hall User Defined Port Byron X Village Hall User Defined Port Byron X Village of Port Byron User Defined Port Byron X Village Of Port Byron Fire Department Fire/EMS Port Byron X Cayuga County Highway Department User Defined Scipio X X Killian Airfield Airport Scipio X Scipio Substation Scipio X Scipio Fire Department Fire/EMS Scipio X Town Hall User Defined Scipio X Town of Scipio User Defined Scipio X Sempronius Fire Department Fire/EMS Sempronius X Town Hall User Defined Sempronius X X Town of Sempronius User Defined Sempronius X Emergency Radio CommTower Communications Seneca County X X 388 Grant Avenue Road Pump Station Sennett X X Cayuga County Jail User Defined Sennett X Cayuga County Nursing Home User Defined Sennett X X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-44 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility Cayuga County Nursing Home Senior Sennett X Cayuga County Public Safety Building Police Sennett X E-911 County Public Safety Building EOC Sennett X Emergency Radio CommTower Communications Sennett X Hillside Children’s Center Schools Sennett X X Montessori School Schools Sennett X X Quincy Hill Drive Pump Station Sennett X X Sennett Substation Sennett X X Sennett Fire Department #1 Fire/EMS Sennett X Sennett Fire Department #2 Fire/EMS Sennett X X Storage Tank Potable Water Facility Sennett X X Storage Tank Potable Water Facility Sennett X X Storage Tank Potable Water Facility Sennett X Town Hall User Defined Sennett X X Town of Sennett User Defined Sennett X X Niles Substation Substation Skaneateles X Tower Communications Spafford X Springport Substation Springport X X St Bernard Field Airport Springport X X Storage Tank Potable Water Facility Springport X X Town Hall User Defined Springport X Town of Springport User Defined Springport X X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-45 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility Suburban Propane Hazmat Sterling X Emergency Radio CommTower Communications Sterling X Storage Tank Potable Water Facility Sterling X Town Hall User Defined Sterling X Town of Sterling User Defined Sterling X Well #3 & Treatment Plant Potable Water Facility Sterling X Emergency Radio CommTower Communications Summerhill X Town Hall User Defined Summerhill X Town of Summerhill User Defined Summerhill X Throop Fire Department Fire/EMS Throop X X Throop Fire Department Fire/EMS Throop X X Town Hall User Defined Throop X X Town of Throop User Defined Throop X Castelli's Marina Inc. Hazmat Union Springs X X Verizon CO (NY70596) Hazmat UNION SPRINGS X X Union Springs Sewage Plant Wastewater Facilities Union Springs X X Andrew J. Smith Elementary School Schools Union Springs X X Fox Lane Apartments Senior Union Springs X X Fox Lane Apartments User Defined Union Springs X North & South Well & WWT Plant Potable Water Facility Union Springs X X Storage Tank Potable Water Facility Union Springs X X Storage Tank-Center St. Potable Water Facility Union Springs X X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-46 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility TRINITY UNITED CHURCH OF CHRIST User Defined Union Springs X X Union Springs Academy Schools Union Springs X X UNION SPRINGS ACADEMY User Defined Union Springs X X Union Springs Fire Department Fire/EMS Union Springs X X Union Springs Fire Department Fire/EMS Union Springs X X Union Springs Middle School High School Schools Union Springs X X Village Hall User Defined Union Springs X X Village of Union Springs User Defined Union Springs X X Long Hill Fire Department Fire/EMS Venice X Owasco Airport Airport Venice X Poplar Ridge Fire Department Fire/EMS Venice X Southern Cayuga High School Schools Venice X Southern Cayuga Instant Aid, Inc. Fire/EMS Venice X Southern Cayuga Middle School Schools Venice X Tower Communications Venice X Town Hall User Defined Venice X X Town of Venice User Defined Venice X X 802344-LEDYARD Hazmat Venice Center X X New York State DOT User Defined Victory X X Paradise Airport Victory X X Town Hall User Defined Victory X Town of Victory User Defined Victory X X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-47 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility Victory Substation Victory X X Victory Substation Victory X X Victory Fire Department Fire/EMS Victory X X DiSanto Propane 6 Hazmat Weedsport X Verizon CO (NY70684) Hazmat Weedsport X Weedsport Maintenance Facility Hazmat Weedsport X Weedsport Sewage Plant Wastewater Facilities Weedsport X Evergreen Heights W/De Paul Senior Weedsport X Evergreen Heights W/De Paul User Defined Weedsport X Town Hall (Brutus) User Defined Weedsport X Village Hall User Defined Weedsport X X Village Manor Apartments Senior Weedsport X Village of Weedsport User Defined Weedsport X Village Of Weedsport Fire Department Fire/EMS Weedsport X Weedsport Substation Weedsport X WEEDSPORT CENTRAL HIGH SCHOOL User Defined Weedsport X Weedsport Elementary School Schools Weedsport X Weedsport Fire Department Fire/EMS Weedsport X Weedsport Village Hall Police Weedsport X Lauren Hopkins Dam Dam X Mill Dam Dam X X Mill Street Dam Dam X X ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-48 August 2013 Name Type Municipality Landslide Karst Area High Incidence Moderate Incidence Low Incidence High/ Moderate Susceptibility High/ Low Susceptibility Moderate/ Low Susceptibility Mud Lock Dam Dam X New Hope Glen Dam X X NORTH DIVISION ST DAM Dam X X Owasco Lake Outlet Dam Dam X X Robert Alcorn Dam Dam X Seneca Falls Dams Dam X X Source: Cayuga GIS; Godt, 2011 (Geology WMS Layer from the National Atlas of the United States); Tobin and Weary, 2005 Note: indicates the facility’s presence in the identified area. ---PAGE BREAK--- SECTION 5.4.2: RISK ASSESSMENT – GROUND FAILURE DMA 2000 Hazard Mitigation Plan – Cayuga County, New York 5.4.2-49 August 2013 Impact on the Economy Ground failure’s impact on the economy and estimated dollar losses are difficult to measure. As stated earlier, ground failure can impose direct and indirect impacts on society. Direct costs include the actual damage sustained by buildings, property and infrastructure. Indirect costs, such as clean-up costs, business interruption, loss of tax revenues, reduced property values, and loss of productivity are difficult to measure. Additionally, ground failure threatens transportation corridors, fuel and energy conduits and communication lines (USGS, 2003). Estimated potential damages to general building stock can be quantified as discussed above. For the purposes of this analysis, general building stock damages are discussed further. Direct building losses are the estimated costs to repair or replace the damage caused to the building. There are zero buildings located in the high incidence and high/moderate susceptibility/incidence landslide hazard areas. A total risk exposure of $253 Million or nearly 5% of Cayuga County’s total inventory is estimated for the buildings located in the landslide moderate incidence area. The replacement value of buildings in the landslide moderate susceptibility/low incidence area is an additional $367 Million or approximately 6% of Cayuga County’s total inventory. The estimated replacement value of the building stock located in the karst areas is approximately $4 Billion or nearly 70% of Cayuga County’s total inventory. These dollar value losses to Cayuga County’s total building inventory replacement value would impact Cayuga County’s tax base and the local economy. Future Growth and Development As discussed in Section 4 and Volume II, Section 9, areas targeted for future growth and development have been identified across Cayuga County. It is anticipated that new development within the identified hazard area will be exposed to such risks. Additional Data and Next Steps Obtaining historic damages to buildings and infrastructure incurred due to ground failure will help with loss estimates and future modeling efforts, given a margin of uncertainty. More detailed landslide susceptibility zones can be generated so that communities can more specifically identify high hazard areas. A pilot study was conducted for Schenectady County, New York as described in the 2011 Draft New York State Hazard Mitigation Plan to develop higher resolution landslide susceptibility zones. The methodology included using the Natural Resource Conservation Services (NRCS) Digital Soil Survey soil units and their associated properties including the American of State Highway Transportation Officials (AASHTO) rating, liquid limit, hydrologic group, percentage of silt and clay, erosion potential and slope derived from high resolution digital elevation models. Further, research on rainfall thresholds for forecasting landslide potential may also be an option for Cayuga County.