Australian Pine removal

That’s A Good Question

What are LWDD’s contingency plans for canal maintenance projects that are underway during hurricane season?

The Lake Worth Drainage District is always mindful of the potential effects of severe storms on project sites. Staff regularly monitor weather conditions for potential impacts. Each storm is unique, and the required preparation will be determined depending on the specific weather prediction and status of the project site.

hurricane image

El Niño and La Niña Explained

El Niño and La Niña are climate phenomena that originate in the equatorial Pacific Ocean. These phenomena can have wide-ranging effects on weather around the world.

Never occurring simultaneously and sometimes not at all, El Niño and La Niña are the opposite phases of the El Niño-Southern Oscillation, or ENSO. ENSO describes the fluctuation of two elements, temperature and pressure.

The temperature component of ENSO refers to ocean water temperature. When sea-surface temperatures are above average by about 1 degree Fahrenheit or more, El Niño can develop. When temperatures are below average, La Niña can form. When temperatures are at or near average neither develops. This is called ENSO-neutral.

The air pressure component refers to the difference in air pressure between the western and eastern parts of the equatorial Pacific. Scientists use readings from Darwin, on the north-central coast of Australia, and from Tahiti, more than 5,000 miles to the east. When the pressure is lower than normal in Tahiti and higher than normal in Darwin, conditions favor the development of El Niño. When the opposite occurs, La Niña may develop.

The two components, temperature and pressure, are strongly related, and conditions of both must be right for either El Niño or La Niña to form. For example, if sea-surface temperatures favor El Niño but air pressure conditions do not, El Niño will not develop.

Scientists are not sure exactly what starts the process. But from time to time, air pressure conditions change over the equatorial Pacific, affecting the trade winds, which normally blow from east to west. The winds act on the surface of the water pushing it along. If the trade winds strengthen, as occurs during La Niña, more warm water is pushed westward. And in the eastern Pacific cold, deep water rises-up to replace it. If the trade winds weaken, as happens during El Niño, less water moves westward and less cold water rises, and the central and eastern Pacific warm up more than usual.

A huge mass of warm water in the ocean transfers a lot of heat high into the atmosphere through convection. Convection is when warm, moist air rises from the sea surface and forms storms. The heat in turn affects atmospheric circulation, both in the north-south direction and east-west.

The location of the convection is important. In El Niño, because the warm water stays in the eastern Pacific, the convection occurs there. In La Niña, the eastern Pacific stays colder, and the convection occurs much farther to the west.

The changes in atmospheric circulation can result in changes in weather in various parts of the world, what meteorologists call teleconnections. Much of this is related to the position of the jet stream, the high-altitude winds that sweep across the planet from west to east.

In El Niño, the jet stream tends to shift to the south. That can bring rain and cooler conditions to much of the Southern United States, and warmer conditions to parts of the North. Elsewhere, El Niño can create warm, dry conditions in Asia, Australia and the Indian subcontinent. Parts of Africa and South America can be affected as well.

In La Niña, the jet stream shifts northward. That can lead to warm and dry conditions in the Southern United States, and cooler, wetter weather in parts of the North, especially the Pacific Northwest. Parts of Australia and Asia can be wetter than normal.

In the U.S., the National Oceanic and Atmospheric Administration (NOAA) declares when an El Niño or La Niña event begins. Weather forecasters will talk about how a developing El Niño, for example, may bring a wetter, or perhaps a drier, winter. Or they may describe how an established La Niña is making for a more active hurricane season. It’s important to note that these are just typical effects. El Niño and La Niña sometimes don’t follow the expected patterns. Also, strength matters and a strong El Niño, as measured by how high sea-surface temperatures are above normal, will have greater effect.

How do El Niño and La Niña effect the Atlantic Hurricane season? The chances for the continental U.S. and the Caribbean Islands to experience a hurricane substantially increase during La Niña and decrease during El Niño.

El Niño produces stronger westerly winds at upper levels of the atmosphere across the tropical Atlantic. This increases the vertical wind shear, basically shearing the tops from developing storms before a healthy circulation can form. El Niño events generally suppress Atlantic hurricane activity so fewer hurricanes than normal form in the Atlantic during August to October, the peak of Atlantic hurricane season.

During La Niña, westerly winds high in the atmosphere weaken. This results in an expanded area of low vertical wind shear, allowing more Atlantic hurricanes to develop. La Niña not only increases the number of hurricanes that develop but may allow stronger hurricanes to form.

El Niño and La Niña also influence where Atlantic hurricanes develop. During La Niña, more hurricanes form in the deep Tropics from weather disturbances that originate over North Africa. These systems have a much greater likelihood of becoming major hurricanes, and of eventually reaching the U.S. and the Caribbean Islands.

 Although hurricanes occur more often during La Niña episodes, significant tropical weather events have occurred during the neutral phase. For example, the record shattering 2005 hurricane season that included Katrina and Rita occurred during the neutral phase. And in 1992, Hurricane Andrew, the most destructive United States hurricane of record, made landfall along the Gulf coast during a neutral phase of the El Niño-Southern Oscillation.

Broom cleaning up vegetation

LWDD – Post-Storm Clean-up

Following a severe storm event, the Lake Worth Drainage District (LWDD) conducts immediate post-storm assessments, inspecting water control structures, canal channels and the canal rights-of-way for vegetative and other debris with the potential to negatively impact drainage.

The public can assist by reporting storm damage via our Citizen’s Reporting System located on our website at https://lwddnet.wpengine.com/storm-response.  The user will be asked a few questions and a map will be provided to help identify the location of the incident in real-time. These public reports as well as LWDD staff assessments are reviewed and prioritized for vegetation removal. Priority is based on the following criteria:

  • High Priority – vegetation is in the water and threatening drainage
  • Medium Priority – vegetation is blocking the right-of-way and encumbering access or vegetation is significantly leaning over the waterway and could be a potential future threat to drainage
  • Low Priority – vegetation located on the LWDD right-of-way that may partially reduce access

Depending on the severity of the storm damage it may take several weeks before crews can address low priority incidents. Private property owners that wish to trim vegetation that has fallen or is leaning on their property from the LWDD right-of-way may do so at their discretion and expense. If access to the LWDD right-of-way is necessary to trim or remove vegetation, the property owner should receive prior approval from the LWDD for temporary access.

Any material from trimming or tree removal by the property owner must be properly disposed of by the resident or if applicable the contractor performing the work. Keep in mind that it is unlawful to place any debris in the canal or on the right-of-way in anticipation that LWDD will remove the material. Unlawful dumping will be reported to the authorities.

If fallen debris has damaged personal property, the individual property owner should contact their insurance company to submit a claim. The LWDD will not directly reimburse property owners for damage caused by acts of mother nature.

After a major storm event, debris clean-up is paramount to getting back to normal and the LWDD is committed to quick removal of hazardous flood prone debris for the safety of our residents.

Man looking a damaged landscaping

Storm Readiness Includes Landscaping

Many residents work hard creating beautiful yards but living in Florida means we live with hurricanes. There is no way to completely protect your landscape from the effects of a severe storm, but there are some things you can do to minimize potential damage.

When a storm is approaching take time to mow your yard. This may seem unimportant at the time, but it will make debris clean-up easier, and you have one less thing to think about post-storm. Also, once the rain starts it may be days or even weeks before you can safely operate a lawn mower through the soggy soil and grass.

Do not prune trees and leave debris on site if a storm is imminent. It is better to take a chance and leave the tree intact if you cannot get the debris off site before the storm. Remove coconuts from coconut palm trees and harvest fruits from other trees that are mature enough to be picked. These items can become dangerous projectiles during high winds. If you have waited until the last minute, store debris in your garage or another safe place away from the wind.

Support small trees and tall plants with sturdy stakes driven at least 8-inches into the ground. You can also lay arches and trellises on the ground and anchor them with a rope. Masses of heavy vines growing on fences can pull fencing over in high winds. If the vines are extensive you may want to trim or remove them altogether.

In addition to wind damage, you may be faced with flooded areas of your yard for several days or weeks. Flooded conditions can seriously impact water-intolerant plants leading to fruit drop, wilting and root rot. Saturated soil coupled with high winds lead to uprooted trees, especially trees with shallow root systems. Do not add to the flooding. Turn your sprinkler system off. This includes irrigation systems with a rain shut-off device. You can reset your system to automatic when the soil dries out.

Clear house gutters of debris to ensure water from heavy rains has free flow. Make sure gutters are firmly attached and directing water away from the home. If there are no gutters and the water pours off the roof in a concentrated area, consider placing pavers or rocks in the runoff area to reduce soil erosion.  Residents adjacent to a drainage canal should also be sure that gutters are directing water away from canals to avoid washouts and bank failure.

Before the storm arrives, check surrounding areas to ensure there are no blockages that may prevent drainage. Clear debris from areas where water will flow toward, like storm drains and swale areas. After the storm, check these areas again for possible blockages.

Making landscaping a part of your hurricane readiness plan is a great way to help protect your property and landscaping investment.

FEMA Guide: How To Prepare For A Hurricane

House in Storm