Archive for category: Hurricanes

In some places, homes and businesses constructed in areas known as the 1-in-100-year flood plain have been hit by multiple floods in the same year. The assumption that if their area has experienced a 1-in-100-year flood, then for the next 99 years they do not have to worry about flooding is not correct.  While it’s unlikely that two large storms will happen in close succession, history has demonstrated that it is not impossible.

Confused by the term 1-in-100-year flood, many people begin to wonder what their flood risk really is. The definition of a 1-in-100-year flood is a flood that has a 1% chance of occurring in any given year. Understanding the probability of your flood risk can be a complex process, but the hydrologists at the U.S. Geological Survey (USGS) are striving to communicate risk more effectively, in part by transitioning away from the term 1-in-100-year flood and instead referencing multiple year flooding probabilities. For example, a home in the 1-in-100-year flood plain can be better understood as a home with a 26% chance it will flood over the course of a 30-year mortgage.

Providing residents and community leaders with a clearer understanding of the probability of flood risk for a location is important. It allows decisions to be made that will better protect themselves and the community. For more information on flood risk probability, visit the USGS website at https://www.usgs.gov/special-topic/water-science-school/science/floods-and-recurrence-intervals.

Florida’s hurricane season begins on June 1 and ends November 30. Based on historical weather records dating back to the 1950s, a typical season will average 12 tropical storms with sustained winds of at least 39 miles per hour, of which six may turn into hurricanes with winds of 74 miles per hour or more. In addition to high winds, hurricanes and tropical storms can bring torrential rainfall. These severe weather events can produce localized flooding that can be exacerbated by improperly maintained drainage systems.

Residential communities and businesses can help mitigate the impacts of severe storms with a few simple steps. One of the most important steps is the regular inspection and maintenance of drainage infrastructure. Drainage infrastructure can include inlets, discharge control structures, connecting pipes, and lakes. Proper maintenance of these facilities will ensure the unobstructed flow of stormwater and fully operational equipment. Secondly, residential communities and businesses with operable discharge control structures can request authorization from the Lake Worth Drainage District to open these structures prior to the storm. Lowering lake levels provides additional storage for excess stormwater. The Lake Worth Drainage District recommends the establishment of a Drainage Committee whose role is to provide for the maintenance and operation of the community or business’ drainage system. Drainage Committees may consist of board members, residents and/or property managers. All members of the Drainage Committee should register with the Lake Worth Drainage District on its website at www.lwdd.net. This registration process ensures the Lake Worth Drainage District knows who to contact and where to send important weather alerts and instructions.

During the storm event, follow emergency management instructions via the television or radio and take appropriate actions to keep yourself, family and property safe. In most circumstances, emergency personnel will not be deployed during the weather event. Depending on the volume and duration of rainfall, expect streets, sidewalks, driveways, and lawns to flood. These areas are designed to act as secondary detention areas and help to keep water away from homes and businesses. This flooding is temporary and will begin to recede after an event has passed. District personnel will be monitoring canal elevations and making operational adjustments to major flood control structures. This work can be conducted during the storm via wireless mobile devices and provide instantaneous response to changes in water elevations.

It may be tempting to explore outside but stay indoors after the storm. For your safety and to keep roadways clear for emergency response vehicles, stay inside until told otherwise by authorities. Do not attempt to walk in flooded areas. Flood water may be unsanitary and there may be downed power lines or other hazards that are not visible. Do not attempt to drive through flooded areas. Vehicles can become unstable and float in as little as a few inches of water. Additionally, canal banks may fail, and roadways may be affected by sinkholes. The location of roads and sidewalks may not be discernible from canals and lakes and life-threatening accidents can occur.

While weather predictions are becoming more sophisticated, forecasters are still unable to predict exactly where a storm will make landfall. The likelihood of flooding depends on several variables such as rainfall volume, ground moisture, and local terrain. No system, no matter how well designed, is 100% flood proof but working closely with communities, businesses and other water management agencies, LWDD can help keep you and your property safe from potential flooding.