maintaining canal

What Is Meant by a “Well-Maintained” Canal?

The Lake Worth Drainage District’s canals exist for the purposes of flood control and water supply. Through its network of over 500 miles of drainage canals, the District provides stormwater management making the area suitable for residents, businesses and agriculture. Effective flood control is dependent on well-maintained canals and rights-of-way. But what defines “well-maintained”? A canal or right-of-way that some property owners may consider an eyesore is often considered well-maintained for effective flood control operations of the District.

Some of the necessary components for effective flood control include the free flow of water in the canal channel to divert excess stormwater from properties, and unencumbered canal rights-of-way to provide access for regular maintenance and emergency response. Through the process of aquatic vegetation removal and canal bank mowing, effective flood control is achieved.

There are numerous species of aquatic plants found within the District’s canal system. Some aquatic vegetation has the potential to slow the flow of water within the canal channel or large flood control structures. The Lake Worth Drainage District staff controls aquatic vegetation growth with the application of herbicides and mechanical removal. Although not esthetically pleasing to some property owners, algae in canals is not a threat to flood control. Because algae are very small plants that break apart easily, they can pass through drainage pipes and control structures. This is good news since the herbicide used to treat algae can be harmful to the water body.

Canal rights-of-way and banks are mowed approximately four (4) times a year. Flat-mowers mow the rights-of-way, and arm-mowers maintain the side slopes of the canals. High grass does not prevent access to canals and control structures or threaten flood control operations. Grasses and other vegetation can grow several inches in height before mowing crews return to an area. Since these areas are not fertilized or irrigated, a quarterly mowing schedule allows for the seeding and regrowth of grasses.

Although most property lines do not extend to the water’s edge, some property owners adjacent to the right-of-way may choose to maintain the grass to a higher degree through irrigation and more frequent mowing. However, this higher degree of maintenance is at their cost and no encroachments such as trees or shrubs are allowed.

Flood control and the maintenance it requires comes at a cost. All property owners within the Lake Worth Drainage District boundary, whether adjacent to a canal or miles away, are assessed at the same tax rate base on the amount of land owned. In 2019, the non-ad valorem assessment rate is $49.50 for a parcel equal to or less than an acre in size and is established by the Board of Supervisors. By providing well-maintained canal rights-of-way necessary for flood control operations, the Lake Worth Drainage District can achieve its mission of effective flood control at an affordable cost for all residents.

L-50 Canal east Boca Raton After Hurricane Irma

LWDD’s Canal Rehabilitation In The City of Boca Raton

At the request of Mayor Scott Singer on behalf of the City of Boca Raton, the Lake Worth Drainage District Board of Supervisors agreed at its July 11th Board Meeting to postpone vegetation removal along the L-48, L-49 and L-50 Canal rights-of-way within the City of Boca Raton. This postponement will allow the District and City the opportunity to work together and consider options for necessary canal rehabilitation on these canals prior to final action by the District’s Board of Supervisors on October 17, 2018.  The District will be moving forward with the following necessary canal work.

L-48 Canal:

  • Removal of stacked vegetation that was previously cut from right-of-way
  • Stump grinding vegetation previously cut along the south bank
  • Dredging silt from a portion of the channel adjacent to I-95
  • Excavation of shoaling east of Southwest 9th Avenue as may be necessary

L-49 Canal:

  • Placement of erosion control mats (jute fiber) along the top of canal banks west of 12th Avenue
  • Stump grinding of rubber tree previously removed west of Southwest 9th Avenue

L-50 Canal:

  • Inspection of outfall pipe located west of Southwest 8th Avenue, and remedial work of such as may be necessary
  • Removal of shoaling between 9th and 12th Avenues

Residents are reminded to take proactive measures for hurricane preparedness and sustainable tree maintenance by pruning trees away from drainage canals and refraining from planting trees or vegetation on drainage or utility easements and public rights-of-way.

Additional information and video on the District’s Canal Rehabilitation Program can be found on our website at http://www.lwdd.net/canal-maintenance/canal-rehabilitation. The City of Boca Raton’s website provides civic alerts at https://www.myboca.us/.

House Blueprints

Policy Revisions That May Affect You

Policy changes to Docks, Davits and Boat Lifts provides improved flood control

As the agency responsible for local flood control, the District utilizes a Right-of-Way (ROW) Permitting program to manage its water resources and ensure proper stormwater drainage and unencumbered access to canal rights-of-way.

The ROW Permit is a revocable license granted to a permittee to occupy or utilize the District’s right-of-way. Boat docks are one example of a ROW Permit. The District may revoke a ROW Permit at any time, if determined to be in the best interest of the District’s flood control efforts. It is important for applicants to understand that any investment made in the right-of-way may be lost if the ROW Permit is revoked.

The personal use of the District’s right-of-way is a privilege and granted on a temporary basis to the permittee. The permittee is the person or entity to whom the right is granted. Only the person(s) or entities named on the face of the permit are authorized to use the right-of-way or make improvements that were constructed or installed in the right-of-way. For example, if you purchase a home with a dock in the canal, you are not authorized to use the dock until you transfer the permit into your own name. The rights of the permit are personal and are not automatically granted when a property is sold or transferred.

The District has a public duty to ensure that the canals perform in an optimal manner and ensure that uses within the canal and rights-of-way do not block the flow of water or create opportunities for storm debris to collect, causing the creation of a dam in the canal. For public safety reasons the District has modified its Operating Policy 3.6 regarding permits for docks, davits and boat lifts within its canal system. The modifications will mitigate risks to the District and the public as they pertain to flood control and emergency management, inefficiencies in the maintenance of the canal rights-of-way, and litigation/liability.

Highlights of the policy changes are:

  • Removal of the authorization for roofs on docks
  • Removal of the authorization for use of interlocking block revetment for erosion control
  • Revision to the allowable size of docks, davits, boat lifts
  • Limitations to location in canals and removal of non-compliant docks, davits, boat lifts
  • Requirement of proof of $300,000 general liability insurance

It is important for residents to understand these revisions are in place for their safety and those neighbors around them. Residents with a dock located adjacent to their property and with a non-compliant permit may have their permit revoked and be required to remove the structure. For more information or questions on the District’s Docks, Davits and Boat Lifts Policy, contact Shaughn Webb or Brian Tilles, P.E., at 561-498-5363 or email info@lwdd.net.

Herbicide Application

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.