Excavation in Palm Beach County
Excavating is a common construction practice in South Florida for a number of reasons. Mines are excavated to extract materials from the earth such as fossilized shell used to make concrete. Lakes are excavated to acquire fill for construction and to store water.
Rapid development in South Florida during the 1970s and 1980s resulted in many excavated lakes and mines becoming hazardous to people and the surrounding environment. The excavations were too deep, poorly sloped, and had poor water quality.
In 1986 an ordinance was adopted to oversee certain excavations in unincorporated Palm Beach County to ensure the following:
- Reduce health and safety hazards
- Prevent soil erosion
- Contain stormwater runoff to reduce flooding
- Increase water quality through nutrient uptake
- Provide habitat for wildlife
To view the current County law governing excavation, Article 4.D of the Unified Land Development Code, click here
ERM's Role in Excavation
Palm Beach County Department of Environmental Resources Management (ERM) regulates several types of excavations in unincorporated Palm Beach County that occur as a result of many commercial, government, and planned unit development projects.
It is important to note that Palm Beach County Planning and Zoning, Palm Beach County Health Department and South Florida Water Management also govern certain types of excavations. For more information on their rules and regulations concerning excavations, contact the appropriate agency.
Why Do Some Lakes Have Littoral Zones?
Some of the excavations that ERM oversees are required to install native aquatic vegetation along the shoreline in an area called the "littoral zone". All lakes larger than 1 acre and deeper than 6 feet are required to have a littoral zone which is critical for erosion control, wildlife habitat and enhanced water quality.
Long term compliance of littoral zones is regulated by ERM to ensure the following:
- At least 80% of the littoral area is covered with native aquatic plants
- No more than 10% of the littoral area is covered with exotic vegetation
Important Littoral Zone Facts
- Littoral zone size is determined by the length of the lake's shoreline
- 16 square feet per linear foot for bulkheaded lakes (regardless of use)
- 8 square feet per linear foot for all other lakes
- Lakes excavated prior to 1987 are not required to have littoral zones
- Developers install and property owners/HOA's maintain littoral zones
- Multiple lake systems may include the required littoral zones in specific lakes
- A lake's slope should gradually drop down by 1 foot for every 10 feet out
- A 20 foot maintenance easement exists around entire lake
- Algae growth is cyclical and increases during hot weather
- Littoral plants should be diverse and include at least 5 different species
- Littoral plants that recruit or fill in the littoral zone indicate a healthy lake
- Native plants within the littoral zone cannot be removed or trimmed
- Some littoral plants go dormant, turn brown, or loose their leaves in the winter