How to Prepare for Seiche Events: The Inland Tsunami Most People Don’t See Coming

When most people think of water-related disasters, hurricanes, floods, and tsunamis typically come to mind. However, seiche events—pronounced “saysh”—represent a lesser-known but potentially devastating natural phenomenon that can strike inland bodies of water with little warning. These “standing waves” in enclosed or semi-enclosed water bodies can cause rapid water level fluctuations that mimic tsunamis, sometimes rising several feet in minutes and causing significant flooding, property damage, and even loss of life. Despite affecting the Great Lakes region, reservoirs, and large inland lakes across America, seiche preparedness remains overlooked in many emergency planning discussions.

At Batten Home Security, we’ve observed that homeowners living near large lakes or reservoirs often focus their emergency preparations on more common threats while remaining unaware of seiche risks that could directly impact their properties. This guide aims to close that knowledge gap by providing comprehensive preparation strategies for these unique standing wave events.

Understanding Seiche Events: The Science Behind Inland Standing Waves

A seiche occurs when strong winds, rapid atmospheric pressure changes, or seismic activity causes water in an enclosed or semi-enclosed basin to oscillate like water sloshing in a bathtub. Unlike normal waves that pass through water, seiches involve the entire water body moving back and forth, creating dramatic water level changes at shorelines. According to the National Oceanic and Atmospheric Administration (NOAA), seiches can cause water levels to fluctuate by several feet within minutes, with documented cases showing rises of up to 10 feet in extreme scenarios. The Great Lakes region experiences seiches most frequently, with Lake Erie particularly susceptible due to its relatively shallow depth and elongated shape that allows wind to push water effectively from one end to the other.

The most devastating seiche in U.S. history struck Lake Michigan in 1954, when a 10-foot wall of water suddenly inundated Chicago’s shoreline, sweeping people off piers and resulting in eight fatalities. More recently, in 2017, a seiche on Lake Erie caused water levels to rise nearly 8 feet at Buffalo, New York, while simultaneously dropping by similar amounts at Toledo, Ohio—demonstrating the see-saw effect characteristic of these events.

Common Causes of Seiche Events

Meteorological triggers: Sudden strong winds, squall lines, or rapid changes in atmospheric pressure (often associated with severe thunderstorms or weather fronts)
Seismic activity: Earthquakes that create energy transfer through the water body
Tsunami interaction: In coastal areas, tsunamis can generate seiches in harbors and bays
Human activities: Large vessels, water management operations, or dam releases can sometimes trigger smaller seiches

Identifying If You’re in a Seiche-Prone Area

Determining your vulnerability to seiche events requires understanding both your proximity to susceptible water bodies and the historical patterns of seiche activity in your region. The Great Lakes region represents America’s most seiche-prone area, with Lake Erie experiencing approximately 5-10 significant seiches annually according to NOAA data. However, many residents near large reservoirs, elongated lakes, or bays remain unaware of their risk. Based on our work with lakefront homeowners, we’ve found that many property owners who’ve experienced unexplained shoreline flooding were actually witnessing minor seiche events without recognizing them as such.

Water Bodies Most Susceptible to Seiches

The Great Lakes: Particularly Lake Erie, but also Lakes Michigan, Superior, Ontario, and Huron
Large reservoirs: Especially those with elongated shapes or oriented along prevailing wind directions
Fjord-like lakes: Long, narrow lakes with steep sides that can amplify wave action
Coastal bays and harbors: Semi-enclosed areas connected to oceans where tsunami energy can be transferred
Large inland lakes: Including Lake Tahoe, Lake Champlain, and other substantial bodies of water

To determine your specific risk level, check with local emergency management agencies, which often maintain records of historical seiche events. The NOAA Great Lakes Environmental Research Laboratory also provides resources for Great Lakes residents to understand seiche patterns and frequency in their area.

Creating an Early Warning System for Seiche Events

Unlike hurricanes or river floods that often provide days of advance warning, seiches can develop rapidly—sometimes in less than an hour. This makes establishing reliable early warning mechanisms crucial for at-risk properties. The National Weather Service has improved seiche forecasting in recent years, particularly for the Great Lakes region, where meteorological conditions that frequently trigger seiches (such as strong cold fronts or derecho wind events) can sometimes be predicted 12-24 hours in advance. However, many homeowners we’ve consulted with near inland lakes report having no formal warning system in place for these events.

Essential Components of a Personal Seiche Warning System

Weather alerts: Enable emergency alerts on your phone and consider a NOAA Weather Radio with specific area message encoding (SAME) technology that can be programmed for your county
Specialized apps: The Great Lakes Coastal Forecasting System offers predictions and real-time monitoring for Great Lakes water levels
Visual monitoring: Install a water level gauge visible from your property if you’re directly on a shoreline
Community networks: Join local social media groups focused on weather and lake conditions where members often share real-time observations
Meteorological indicators: Learn to recognize weather patterns that commonly precede seiches in your area, such as rapidly falling barometric pressure or approaching squall lines

For those in high-risk areas, particularly around Lake Erie or other frequently affected water bodies, consider installing water level sensors that can alert you to unusual fluctuations. These systems have become more affordable in recent years and can provide crucial extra minutes of warning.

Protecting Your Property from Seiche Flooding

Seiche flooding differs from typical riverine or coastal flooding in several important ways that affect property protection strategies. The rapid onset, relatively short duration, and potentially powerful wave action require specific mitigation approaches. According to flood mitigation specialists we’ve consulted, properties within 1,000 feet of large lake shorelines with elevations less than 15 feet above normal water levels face the highest risk. In the Great Lakes region alone, thousands of structures fall within this vulnerability zone, yet many lack specific seiche protection measures.

Structural Protection Measures

Elevated foundations: Consider pier foundations that allow water to flow beneath structures in high-risk areas
Flood barriers: Deployable flood barriers can be stored and quickly installed when warnings are issued
Reinforced doors and windows: Water-resistant doors with reinforced frames and impact-resistant windows help prevent water intrusion
Backflow prevention: Install check valves in plumbing to prevent sewage backup during flooding events
Landscaping considerations: Use terraced designs and native vegetation to create natural buffers against wave action
Seawalls and riprap: For direct shoreline properties, properly engineered shoreline protection can dissipate wave energy

Many of the lakefront homeowners we work with have found that relatively simple measures like keeping plywood sheets pre-cut to window dimensions can make a significant difference during rapid-onset events when there’s limited preparation time.

Explore Batten’s emergency preparation products to protect your home from unexpected water events

Creating a Seiche-Specific Emergency Plan

The unique characteristics of seiche events—their sudden onset, potentially destructive wave action, and relatively short duration—require specialized emergency planning. Unlike hurricanes that might prompt evacuation days in advance, seiches often require immediate vertical evacuation (moving to higher floors) rather than horizontal evacuation (leaving the area). Based on after-action reports from past seiche events, families with clear, practiced emergency plans have consistently fared better than those making decisions during the crisis. The most effective plans account for both the immediate response to rapidly rising water and the potential aftermath, including power outages and property damage.

Key Components of a Seiche Emergency Plan

Evacuation routes: Identify multiple paths to higher ground or upper floors, including routes that avoid potentially flooded areas
Meeting locations: Designate primary and secondary meeting points for family members who might be separated
Emergency contacts: Maintain a list of important contacts including neighbors, relatives, and emergency services
Go-bags: Prepare waterproof emergency kits containing essential documents, medications, first aid supplies, and communication tools
Communication plan: Establish how family members will contact each other if separated during an event
Pet considerations: Include pet carriers, food, and evacuation plans for animals

Practice your emergency plan at least twice yearly, particularly at the beginning of seasons when seiches are most common in your region. For Great Lakes residents, this typically means spring and fall when weather patterns are most conducive to seiche formation.

Essential Supplies for Seiche Preparedness

The rapid onset and potentially destructive nature of seiche events make having appropriate emergency supplies readily accessible particularly important. Unlike gradual flooding where supplies might be moved to higher ground as waters rise, seiche events can strike with little warning, potentially cutting off access to preparation materials. Based on our experience working with lakefront property owners, we recommend maintaining supplies in waterproof containers at elevations above potential flood levels. For multi-story homes, this means keeping emergency kits on upper floors; for single-story structures, consider wall-mounted cabinets positioned high on walls.

Seiche-Specific Emergency Supplies

Water removal equipment: Battery-operated sump pumps, wet/dry vacuums, and manual water extraction tools
Waterproof document storage: Sealed containers for important papers, including insurance policies and property deeds
Emergency lighting: Waterproof flashlights, headlamps, and battery-powered lanterns
Communication tools: Hand-crank or battery-powered weather radios, fully charged power banks for mobile devices
Personal flotation devices: Life jackets for each family member, particularly important for households with children
Water purification: Tablets or portable filters in case water systems become contaminated
Cleanup supplies: Mold prevention products, disinfectants, and protective equipment for post-flood cleanup

For properties in areas with frequent seiche activity, consider investing in rapidly deployable flood barriers that can be installed in minutes when warnings are issued. These systems have become more affordable and user-friendly in recent years, with some designs requiring no tools for installation.

Check out Batten’s water and food supply solutions for emergency preparedness

Financial Preparedness for Seiche Damage

The financial implications of seiche events are often overlooked in standard disaster planning, yet they present unique insurance and recovery challenges. Many standard homeowners insurance policies exclude flood damage, regardless of whether the flooding comes from rivers, storm surge, or seiches. According to insurance specialists we’ve consulted, approximately 80% of lakefront property owners lack adequate coverage for seiche-related damages. This coverage gap exists partly because seiches fall into a gray area between traditional flood events and storm damage, sometimes creating confusion about which insurance products apply.

Insurance Considerations for Seiche Protection

Flood insurance evaluation: Determine if your property is in a designated flood zone and whether National Flood Insurance Program (NFIP) coverage is appropriate
Coverage verification: Explicitly confirm with your insurance provider whether seiche damage is covered under your current policy
Documentation: Maintain detailed inventory of belongings with photos and value estimates stored in cloud-based services
Elevation certificates: Consider obtaining an elevation certificate that documents your property’s height relative to base flood elevations
Rider options: Explore additional coverage riders specifically for water damage from weather events
Emergency funds: Maintain accessible emergency savings to cover immediate post-event expenses before insurance claims are processed

Beyond insurance, creating a detailed home inventory with photographs and documentation of valuables can significantly streamline the claims process following a seiche event. Store this information in cloud-based services that remain accessible even if local devices are damaged.

What to Do During an Active Seiche Event

When a seiche is imminent or actively occurring, quick decision-making can mean the difference between safety and tragedy. The rapid water level changes characteristic of seiches—sometimes several feet within minutes—leave little time for deliberation once the event begins. According to emergency management officials who have responded to seiche events in the Great Lakes region, the most dangerous aspect is often the false sense of security that occurs between oscillations. Water may recede temporarily before returning with even greater force, trapping people who ventured into previously flooded areas. Understanding the rhythmic nature of these events is crucial for making appropriate safety decisions.

Immediate Actions During a Seiche

Move to higher ground: Immediately relocate to upper floors or elevated areas away from the shoreline
Stay informed: Monitor emergency broadcasts via weather radio or mobile alerts
Avoid flooded areas: Never attempt to walk, swim, or drive through seiche waters, which may contain debris or dangerous currents
Beware the recession: Don’t return to lower elevations when water appears to recede, as seiches typically involve multiple oscillations
Check on neighbors: If safe to do so, verify that elderly or disabled neighbors are aware of the situation
Turn off utilities: If time permits and it’s safe, shut off electricity at the main breaker to prevent electrical hazards
Avoid shorelines and piers: Stay away from shoreline structures that may be undermined by rapid water movement

If you’re caught outdoors when a seiche begins, move perpendicular to the shoreline rather than trying to outrun the water along the shore. Seeking vertical refuge—climbing trees, sturdy structures, or hillsides—provides better protection than attempting to outpace the advancing water horizontally.

Recovery After a Seiche Event

The aftermath of a seiche presents unique recovery challenges compared to other flooding events. While seiches typically last hours rather than days, they can leave behind significant damage from both the initial water intrusion and the forceful wave action that may have undermined foundations or structural elements. The water involved in Great Lakes seiches often carries less sediment than riverine floods but may contain higher levels of contaminants from disturbed lake-bottom materials or sewage system overflows. According to environmental health specialists, this contamination risk necessitates thorough cleaning and disinfection of affected areas, even after relatively minor water intrusion.

Post-Seiche Recovery Steps

Safety assessment: Before re-entering structures, check for structural damage, electrical hazards, and gas leaks
Documentation: Photograph all damage thoroughly before beginning cleanup for insurance purposes
Water extraction: Remove standing water as quickly as possible using pumps, wet vacuums, or professional services
Dehumidification: Use dehumidifiers and fans to dry affected areas within 24-48 hours to prevent mold growth
Contamination control: Disinfect all surfaces that contacted flood waters using appropriate cleaning solutions
Electrical systems: Have a licensed electrician inspect electrical systems before restoring power
Structural evaluation: Consider professional assessment of foundations and load-bearing elements if significant water force was involved
Insurance claims: File claims promptly, providing thorough documentation of all damages

Many of the homeowners we’ve assisted following seiche events report that moisture detection tools, including infrared cameras and moisture meters, were invaluable for identifying hidden water damage in walls and under flooring that wasn’t immediately apparent during initial inspections.

Discover Batten’s power generation solutions for post-emergency recovery

Community-Level Seiche Preparedness

While individual preparation is essential, seiche resilience significantly improves when communities develop coordinated response systems. In regions with recurring seiche activity, such as communities along Lake Erie’s eastern basin, collaborative approaches have demonstrated measurable improvements in both property protection and public safety outcomes. According to emergency management professionals, communities with established warning systems and educated populations typically experience 30-40% less property damage and significantly fewer injuries during seiche events compared to unprepared communities of similar size and exposure. This community-level preparation becomes particularly important given the rapid onset of seiches, where neighbors often serve as the first alert system.

Community Preparedness Strategies

Warning systems: Advocate for community sirens, alert systems, or automated notification networks specific to water level changes
Education initiatives: Support public awareness campaigns about seiche risks in vulnerable areas
Neighborhood networks: Establish phone trees or messaging groups for rapid communication during emerging events
Vulnerable population registries: Create systems to identify and assist elderly, disabled, or transportation-limited residents
Equipment sharing: Organize community-level resource sharing for water pumps, generators, and cleanup equipment
Infrastructure advocacy: Support municipal investments in shoreline protection, stormwater management, and early warning systems

Consider organizing community-wide seiche drills, particularly in high-risk areas. These exercises not only improve individual preparedness but also help identify gaps in community response capabilities before an actual emergency occurs.

Long-Term Mitigation Strategies for Seiche-Prone Areas

For those living in areas with recurring seiche activity, implementing long-term mitigation strategies can substantially reduce vulnerability over time. Unlike temporary measures deployed during warnings, these permanent modifications address fundamental vulnerabilities through structural, landscape, and property management approaches. According to coastal engineers specializing in Great Lakes shoreline protection, properties implementing comprehensive mitigation strategies typically experience 50-70% less damage during major seiche events compared to similar unprotected properties. While some measures require significant investment, many homeowners find that phased implementation over several years provides cost-effective protection that often pays for itself during the first major event.

Long-Term Protection Measures

Structural elevation: Consider raising existing structures or building new ones with elevated first floors
Shoreline stabilization: Install professionally designed seawalls, riprap, or living shorelines appropriate for your location
Landscape modification: Create tiered landscapes that channel water away from structures and reduce erosion
Foundation reinforcement: Upgrade foundations to withstand hydrostatic pressure and wave action
Permanent flood barriers: Install permanent flood shields for doors, windows, and other vulnerable openings
Utility relocation: Move electrical panels, HVAC equipment, and other utilities to higher elevations
Water-resistant materials: During renovations, choose flooring, wall materials, and insulation that resist water damage

When planning long-term mitigation, consider consulting with professionals familiar with local seiche patterns and behavior. Regional differences in seiche characteristics may influence which strategies provide optimal protection for your specific location.

Conclusion: Building Resilience Against the Inland Tsunami

Seiche events represent a unique hazard that combines the destructive potential of tsunamis with the geographical reach of inland waters, affecting communities far from coastal regions typically associated with tsunami risk. Despite their potential for causing significant damage and endangering lives, seiches remain underrepresented in many emergency preparedness discussions and community planning efforts. By understanding the science behind these standing waves, implementing appropriate warning systems, and developing comprehensive preparation strategies, residents of vulnerable areas can significantly reduce their risk exposure.

The most effective seiche preparedness combines physical protection measures with knowledge-based preparation—knowing when conditions are conducive to seiche formation, recognizing warning signs, and understanding appropriate response actions. For communities along the Great Lakes, large reservoirs, and other susceptible water bodies, integrating seiche awareness into broader emergency management frameworks represents an essential step toward comprehensive disaster resilience.

Remember that preparation for seiche events largely overlaps with preparation for other flooding scenarios, meaning investments in seiche readiness typically provide protection against multiple hazards. By taking the steps outlined in this guide, you’ll not only be better prepared for these unique standing wave events but also enhance your overall emergency resilience.

Explore Batten’s complete emergency preparation solutions to protect your family and property from unexpected disasters

Sources used for this article:

Great Lakes Environmental Research Laboratory, https://www.glerl.noaa.gov/education/seiche/

National Weather Service, https://www.weather.gov/safety/flood-states-il

NOAA, https://oceanservice.noaa.gov/facts/seiche.html

U.S. Geological Survey, https://www.usgs.gov/special-topics/water-science-school/science/seiches-and-sloshing-water