Community Risk Assessment Village of Seneca Risk Assessment Tornadoes
Floods
Winter Storms
LaSalle County
Elevated
Elevated
High
Elevated
High
Guarded
Elevated
Elevated
Seneca
Guarded
Guarded
High
Elevated
Elevated
Guarded
Elevated
Guarded
Communities
Extreme Temps.
Dangerous Winds
Lightning
Drought
Hail
Location: The Village of Seneca is located 14.4 miles east of the City of Ottawa along U.S. Route 6 in LaSalle County. Population: 2,371 (2010 Census) Major Storm Events since February 2008:
June 2015 Heavy Rain and Flooding: The village has been experiencing flash flooding coming off the hill from the north end of town. The water flows through a trailer park, the BP gas station at the corner of 170 and Jackson, across the railroad tracks and onward to Crotty Creek and Rat Run. April 17-19, 2013 Flood: A slow-moving storm dropped as much as 10 inches of rain across the region causing widespread flooding along the Illinois River and local creeks to swell. There was minor surface water flooding east of Main Street near Shipyard Road. Flooding from Rat Run, a creek that runs east to west through town, nearly flooded the waste water treatment plant on West Union Street. The street was also closed preventing access to the village’s garages. When the Illinois River floods, water backups onto the creek. On the north side of town, Crotty Creek flooded and pushed water into a subdivision on Valley View Drive, placing 100 homes at risk; however, none of the homes were damaged. Scouring of road aprons occurred.
Tornado Risk: The Village of Seneca has a “Guarded” risk of tornadoes. A memorandum of understanding has been entered into between Grundy County, LaSalle County, and the Village of Seneca for the Conditional Dual Control of outdoor early warning sirens that are owned and
Community Risk Assessment maintained by Exelon Nuclear. The outdoor warning sirens are part of the LaSalle Nuclear Power Station Prompt Notification System. Exelon Nuclear has no objections to Dual Control of the sirens. Under the agreement, when the Village of Seneca requests that the sirens be activated, the village will give the public prompt notification through radio stations as to why the sirens were activated. The village will ensure that the LaSalle County Emergency Management Agency and the LaSalle County Dispatch have been notified. For non-radiological activation of the sirens, the village will contact the Grundy County Dispatch Center for activation. For radiological-related activity and testing, the sirens will be activated by the LaSalle County Dispatch. The sirens will be tested on the first Tuesday of each month at 10:00 and again at 10:30. The memorandum of understanding was a significant undertaking by all parties involved. From a planning perspective, North Central Illinois Council of Governments would recommend that as a long-term goal the village consider purchasing separate outdoor early warning sirens for severe weather to eliminate any confusion between a nuclear activity situation and a severe weather event. NCICG recognizes that at the current time, the village may not have the financial resources to pursue the purchase of new sirens. Flood Risk: The Village of Seneca has a “Guarded” risk of flooding. Type(s) of Flooding: Riverine Flooding/ Urban Drainage- Surface Water Runoff Area of Risk: The FEMA Flood Insurance Rate Map (FIRM) for the village shows that the 100year floodplains for Rat Run and Crotty Creek pose the greatest threat of flooding to the community. Rat Run traverses east to west through town and threatens to flood Seneca High School’s athletic fields, sections of Commerce and Main Streets, and the village’s waste water treatment plant. The creek swells when the Illinois River floods. Agricultural lands bordering the creek become inundated with water. The 100-year floodplain for Crotty Creek starts near East Jackson Street and runs south to Vaughey Street until it meets the Illinois and Michigan Canal. The creek has the potential to flood multiple homes in the Valley View Drive Subdivision. The village monitors Crotty Creek when heavy rains is expected or occurs. Spring Brook Marina and its creek have consistent flooding issues when the river gets too high. Road closures, culvert issues, and home flooding have occurred. The marina has also been closed at times. Critical Facilities at Risk: The village’s waste water treatment plant on West Union Street is located in a 100-year floodplain. National Flood Insurance Program Participant: Yes Community Rating System Participant: No Winter Storm Risk: The Village of Seneca has a “High” risk of experiencing winter storms including blizzards, heavy snowstorms, and ice storms. Early frost and freeze events are another form of winter weather that are factored into determining the winter storm risk level.
Community Risk Assessment Extreme Temperatures Risk: Extreme heat and cold can have detrimental effects on the human body including illness and death. Exposure to extreme heat can lead to heat rash, exhaustion, and stroke. When exposed to extremely cold temperatures, the human body loses heat quickly. Unable to replace utilized energy, the body is susceptible to hypothermia and frostbite. Extreme heat and cold can also be problematic for public water systems. Although water main breaks are thought to occur more frequently during the winter, they can happen anytime of the year. According to AccuWeather.com, prolonged hot and cold temperatures cause the ground to shift more abruptly, which leads to water main breaks. The age and condition of water mains can also play a factor. The Village of Seneca has an “Elevated” risk for extreme temperatures. Dangerous Winds Risk: This category includes thunderstorm winds, high winds, and strong winds. LaSalle County has a “High” risk of having dangerous winds that can lead to property damage and crop damage. During high winds, people are at a greater risk for injury and death as a result of flying debris and falling trees and power lines. The Village of Seneca has an “Elevated” risk of dangerous winds. Lightning Risk: Lightning is caused by the buildup and release of atmospheric electricity. Whenever there is a thunderstorm, lightning has occurred. Lightning can strike anywhere and has the potential to cause fatalities, injury, and property damage. The Village of Seneca has a “Guarded” risk of lightning that could result in property damage or bodily harm. Drought Risk: Drought is caused by a lack of precipitation over an extended period of time. A prolonged drought can have a devastating impact on a region’s economy and quality of life. LaSalle County’s last reported drought was between June 2005 and February 2006. The impact of the drought is not known. The Village of Seneca and LaSalle County have an “Elevated” risk of drought. Hail Risk: Hailstones can be found within the middle and upper portions of most thunderstorms. Hailstones are compacted layers of ice and snow that look like snowballs. Hailstones may be as small as marbles or as large as softballs. Hailstones cause damage to property and crops. There have been 130 hail events in LaSalle County since 1965. LaSalle County has an “Elevated Risk” of hail and the Village of Seneca has a “Guarded” risk. Additional Information:
The village adopted a comprehensive plan in 2008. It does not address natural hazards. The village’s most recent zoning ordinance was adopted in 2009. It does not address natural hazards. The village has adopted International Building Code 2003. The village does not have a storm water management ordinance. The village has at least 95 percent of the sanitary and storm sewer systems separated. The village’s library can serve as a heating and cooling center during extreme temperatures. The village has cleared various areas in town that collected debris and silt. Upsized drainage tiles have also been constructed by the high school. A backflow check and valve compliance survey is currently being worked on with the water department. Bids have been put out for work on the sewer system in Valley View Subdivision to address infiltration issues. The work should help with flooding and erosion issues.
Community Risk Assessment
A great number for ash borer diseased trees have been identified that could fall and plug the flow of the Illinois & Michigan Canal. There is some risk of mine subsidence on the north side of the village where coal mines once were located. In January 2014, a procedure was developed for a short-term cooling and warming center at Seneca High School during extreme weather conditions. This is not a shelter, but a center until further arrangements can be made.
Mitigation Activities: 1. Mitigation Strategy: Encourage the Illinois Department of Natural Resources to dredge the Illinois and Michigan Canal. Responsible Entity or Person: Village Board/ Village Building and Zoning Official Priority: High Cost: Staff Time Revenue Source: Local Funds Resources: Local Legislators Benefits: Increase flow of water and reduce flooding caused by the canal. Deadline: 1-5 Years (Ongoing) 2. Mitigation Strategy: Assess the waste water treatment plant’s risk of flooding and implement projects and activities to minimize risk. Responsible Entity or Person: Village Building and Zoning Official/ Village Engineer Priority: Very High Cost: Depends on activities and projects pursued Revenue Source: Local Funds Resources: Village Engineer Benefits: Protection of a critical facility and reduce the likelihood of an environmental and public health disaster. Deadline: 3 Years 3. Mitigation Strategy: Identify and implement activities and projects to minimize the impact of flooding on homes in the Valley View Drive Subdivision. Responsible Entity or Person: Village Building and Zoning Official Priority: High Cost: Staff Time/ Varies depending on activities and projects pursued Revenue Source: Local Funds Resources: Village Engineer/ Village Building and Zoning Official Benefits: Minimize the impact of flooding in the subdivision. Deadline: 4 Years 4. Mitigation Strategy: Inform residents on the importance of understanding their flood insurance policy. Responsible Entity or Person: Village Board Priority: High Cost: Minimal/Letters to residents
Community Risk Assessment Revenue Source: Local Funds Resources: Insurance agencies/ Federal Emergency Management Agency Benefits: Residents should be aware that their flood insurance policy may not cover basement backups. A separate sewer and drain policy may be required. Deadline: 1 Year 5. Mitigation Strategy: Engage in a regional discussion on the implementation of best practices for activating early warning sirens during storm events. Responsible Entity or Person: A regional group consisting of County Emergency Management Agencies for Bureau/ LaSalle/ Marshall/ Putnam/ and Stark Counties, Local Fire Departments, Fire Protection Districts, County Sheriff’s Departments, Local Police Departments, and Local Officials Priority: Very High Cost: Staff Time Revenue Source: Local Funds Resources: NOAA/ Illinois Emergency Management Agency/ Policies for other communities Benefits: Regional guidelines on activating early warning sirens can lessen public confusion and save lives. Deadline: 1 Year 6. Mitigation Strategy: Participate in the development of a building inspector training program with neighboring communities and/or a mutual agreement to share trained building inspectors. Responsible Entity or Person: Village Board Priority: Medium Cost: Staff Time/ Cost of Building Inspector Revenue Source: Local Funds Resources: International Code Council Benefits: Communities unable to afford a full-time building inspector will have a resource for building inspections. Deadline: 3 Years 7. Mitigation Strategy: Improve local hazardous weather operations by becoming a StormReady community. Responsible Entity or Person: Village Board Priority: Medium Cost: Staff Time Revenue Source: Local Funds Resources: Weather Spotters/ Emergency Responders –Fire, Police, Paramedics/ Emergency Management Personnel Benefits: Immediate disbursement of information to residents during severe weather. Deadline: 1 Year 8. Mitigation Strategy: Participate in the National Flood Insurance Program’s Community Rating System to help residents save on flood insurance premiums.
Community Risk Assessment Responsible Entity or Person: Village Board/ Village Building and Zoning Official/ Village Engineer Priority: Medium Cost: Varies depending on activities pursued Revenue Source: Local Funds Resources: Insurance Services Office/ Illinois Department of Natural Resources/ Illinois Emergency Management Agency Benefits: Lower flood insurance premiums for residents/ Activities reduce the impact of flooding. Deadline: 1 Year
