Algae Blooms

Most algae in District canals is not harmful to human health and provides a food source for aquatic life 

Algae are simple organisms that grow through photosynthesis, a process by which sunlight is used to metabolize nutrients. Algae are a basic component of the food chain and can be found in marine, estuarine, fresh water lakes, canal systems and even swimming pools. Algae appear as green, red or yellowish-brown particles that float on the water surface.

Most algae found in District’s canals, while visually unappealing, are not harmful to human health. However, some types, like “Blue-green” algae, which is a cyanobacteria, secrete toxins that may be harmful. The algae toxins can be inhaled by people living around the waterbody. It will aggravate respiratory illnesses like asthma. Symptoms of exposure to toxic algae include difficulty breathing, wheezing, skin rashes, headaches, and possibly tingling in the fingers and toes if the water was consumed.

Although algae are a normal component of an aquatic ecosystem, nutrient-rich waters warmed by the summer sun, provide a favorable medium for the overgrowth. This overgrowth is called an ‘algae bloom’. Herbicide or chemical treatments for the removal of algae uses a heavy metal compound that may adversely impact the waterbody. Since algae is a food source for aquatic animals and does not impact flood control operations, the District does not regularly treat its canal system for algae blooms. Most algae growth in our canals is harmless and will dissipate on its own or will be flushed out after a heavy rainfall.

Additional information on algae toxins can be found at the US Environmental Protection Agency and the Center for Disease Control website at www.epa.gov/nutrientpollution/harmful-algal-blooms.

Controlling Aquatic Plants

Two different methods are used for more efficient control of aquatic vegetation growth 
Lake Worth Drainage District regularly treats and removes aquatic vegetation in canals to maintain the flow of water and facilitate effective flood control for communities in Southeastern Palm Beach County. To accomplish this task, the District utilizes both mechanical and herbicide treatment to remove unwanted vegetation.

Containment Boom

Recently, the District has expanded its mechanical removal of aquatic growth with the use of containment booms. Containment booms are floating ribbon-like structures that span the canal cross-section and extend approximately one foot both above and below the water surface. As water flows through a canal or as winds move across the water’s surface, floating debris will move through the canal network. The booms serve as a physical barrier, “corralling” the debris while allowing water to continue to flow unimpeded. Installed at critical locations in order to concentrate floating vegetation and other debris, the booms allow District staff to more effectively collect, treat and dispose of the material.

Herbicide Application

Given the proliferation of aquatic vegetation in Florida’s subtropical climate, it remains necessary to continue the use herbicide treatment to control vegetation growth. When applying herbicides, the District strictly adheres to the rules and regulations established by the U.S. Environmental Protection Agency (EPA) and the Florida Department of Environmental Protection (FDEP). Staff applying chemical treatments are trained and certified annually on the proper application and handling of all herbicides used. Periodically, the District receives calls from residents regarding an odor detected after the application of herbicides. Although this concern by residents is understandable, it is important to know that the odor is an expected occurrence the oil emulsion that is mixed with the herbicide. Emulsion herbicides are a thicker consistency, allowing the herbicide to adhere to the vegetation so that it stays in place long enough to be effective.

With more than 500 miles of canals, the District is continually conducting maintenance of its canal system. Effective flood control and your safety is dependent on well-maintained canals.

Storm-Related Debris Removal

What you should know about storm debris removal 

Following a storm event, the District conducts immediate post-storm assessments, inspecting water control structures and clearing debris from canals and rights-of-way. Debris reports submitted by staff or property owners are individually reviewed and prioritized for vegetation removal as follows:

  • 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 waterway and could be a potential future threat to drainage.
  • Low Priority – Vegetation originating on the District right-of-way and significantly occupying or fallen onto private property. (Please note, the District will not dispatch crews for removal of individual branches or to trim trees that are not leaning more than 50% on private property).

Vegetation that has fallen or leaning from the District right-of-way into private property but does not threaten flood control will be scheduled for removal after the District has completed removal of high and medium priority vegetation. The District estimates that removal of medium priority vegetation will be completed by the end of the 2017.

Private property owners that wish to trim vegetation that has fallen or is leaning on their property from the District’s right-of-way may do so at their discretion and expense. Any debris from trimming or tree removal by property owners must be disposed of by the property owner or, if applicable, the contractor performing the work.It is unlawful to place any debris on canal rights-of-way and illegal dumping will be reported to authorities.

If access to the District’s right-of-way is necessary to trim or remove vegetation, the property owner should receive prior approval from the District for right-of-way access and provide an executed hold harmless agreement.  Likewise, if the District must access private property to remove vegetation, the property owner must provide an executed hold harmless agreement prior to start of work.If fallen debris has damaged personal property, the individual property owner should contact their insurance company to submit a claim. The District will not directly reimburse property owners for damage. Email your debris removal questions to info@lwdd.net.

Hurricane Highlights Importance of Maintenance

Canal Rehabilitation Program reduced recovery efforts

During recovery efforts from the aftermath of Hurricane Irma, it was evident that the District’s Canal Rehabilitation Program is working. Post-storm assessments reflected no structural flooding, minimal damage to the canal system and a reduced need for vegetative clean-up. The District’s recovery efforts after Hurricane Irma required far less resources than that of past storms in bringing the flood control system back to fully operational.

Many people in Palm Beach County live along a District canal. In order to enhance their properties, they sometimes plant vegetation or place other encroachments such as fences and sheds on the District’s rights-of-way. Encroachments are a public safety issue because they can cause canal blockages, obscure sightlines for visual inspections, slow the progression of drainage and impede access for maintenance and emergency response. Free flowing canals and unencumbered access along the rights-of-way are critical components to overall public safety and flood control.

As part of the District’s Canal Rehabilitation Program, staff vigorously enforces a policy of unencumbered canal rights-of-way within the District’s boundaries. Depending on the condition of the site,
rehabilitation projects may include the removal of vegetative and both structural and non-structural encroachments. Additionally, the dredging of the canal channel and reshaping of the canal bank may be required. More information on canal maintenance can be found on our website at www.lwdd.net/canal-maintenance.

E-3 Canal north of Linton Blvd. - blocked right-of-way

LWDD Cleans Up After Irma

Following Hurricane Irma, the Lake Worth Drainage District identified more than 350 sites along its 500-mile canal network which require debris removal. Nearly half of the sites identified included debris in the canal channels which could potentially threaten drainage by restricting water flow or creating blockages at water control structures.

District field crews were immediately mobilized after the storm passed to begin the clean-up process, focusing first on the most problematic areas that might affect drainage. To date, approximately half of these priority projects have been completed. Once canal channels are cleared of debris, District crews will begin removing downed trees and vegetation located on canal rights-of-way. All hurricane debris removal projects are expected to be complete within six weeks.

The impacts of Hurricane Irma highlight the importance of keeping canal rights-of-way free of trees, vegetation and other encumbrances. Last year, the Lake Worth Drainage District doubled its efforts to remove trees and encumbrances from canal rights-of-way to ensure effective drainage for its 750,000 customers in Palm Beach County. Prior to Hurricane Irma, crews completed the clearing of more than 25 miles of rights-of-way, removing exotic vegetation and structural encroachments such as fences and sheds.

“As a result of our accelerated efforts, we are in a much better position today than we would have been if this storm happened five years ago. It only takes one tree to obstruct water flow and create potential drainage issues for thousands of residents,” said Robert Brown, LWDD Executive Director.

Maintaining canal rights-of-way free of vegetation and encumbrances is a continual challenge for many water control districts. Florida’s tropical climate is ideal for the proliferation of exotic vegetation which must be continually treated or removed. Also, many residents that live adjacent to drainage canals identify the public rights-of-way as part of their backyards and often plant trees or construct fences that could ultimately end up in the canal channel during a storm event.

Following hurricane recovery efforts, the District will continue its program to clear an additional 100+ miles of encumbered canal rights-of-way with expected completion by 2021.

Click here for photos and videos of Hurricane Irma’s impacts and recovery efforts.