Stormwater Management

Stormwater Management 

Leon County's Stormwater Maintenance Division provides the following services  to citizens living in the unincorporated areas of Leon County to improve water quality and minimize flooding:

• Respond to all stormwater service requests;
• Inspect county stormwater systems for maintenance problems and ensure systems are functioning properly;
• Mow or cut vegetation in stormwater systems including ditches, swales, treatment ponds, etc.;
• Remove silt (sand, mud and clay), trash or other debris from stormwater systems;
• Repair or replace filter systems that do not function properly;
• Repair other structures such as spillways, overflow pipes, concrete swales, etc;
• Perform erosion control by replanting vegetation or other stabilization methods;
• Remove non-native plants and maintain beneficial plants; and
• Provide educational services.

How Leon County Manages Stormwater to Protect Surface Waters

Proper stormwater management is essential to controlling the water cycle impacted by changes in land use and urbanization. In Leon County, we accomplish this through regulatory programs, regular monitoring of our lakes and streams and retrofitting areas that had no prior stormwater controls.

Regulatory Programs and Stormwater Standards

• Water quantity (rate control)
• Operating Permit Program
• Protection of natural features

Leon County protects the water quality of its surface waters by enforcing stormwater standards for both water quality and rate control, implementing an operating permit program for permitted stormwater management facilities and delineating and protecting environmentally sensitive features during the development review process.

Stormwater design and treatment standards are intended to manage water volumes to minimize flooding and to provide treatment by filtration and/or settling of sediments. Detention standards hold the stormwater temporarily in the stormwater treatment facility and the facility recovers its volume by releasing the stormwater by either a control structure or a sand filter thereby allowing a discharge to downstream surface waters. Retention standards hold the stormwater in the stormwater facility and the stormwater is not released downstream. Retention of stormwater is much more efficient in removing nitrogen and phosphorous because these pollutants do not leave the site. 

Leon County has adopted Minimum Countywide Environmental Regulations for stormwater treatment facility design and construction. There are four options for treatment, but the most commonly used standard captures the first 1.125 inches (1 1/8”) of runoff.  This standard is more than twice the volume of the State standard; however, the standard allows recovery of the treatment volume by filtration.

 Water Quantity (rate control)

The County’s minimum stormwater rate control standard requires peak post-development stormwater discharge rates not to exceed the pre-development rates for all duration storms with return period frequency of up to and including the 25-year storm period. A second requirement is that the stormwater discharge shall not cause flooding or other adverse impacts for downstream areas. This is accomplished by performing either a conveyance analysis or by meeting a restricted discharge. 

Operating Permit Program

Every permitted and constructed stormwater facility must have an operating permit, which must be renewed every three years. During the renewal review process, an inspector will check the facility to ensure that it is operating as originally designed. In some cases, maintenance is required such as removing sediment, re-bedding sand filters, removing vegetation, etc., to ensure the facility is operating as originally permitted.

Protection of Natural Features

Natural waterbodies, watercourses, cultural resources, wetlands and floodplains as well as other features are protected during the development review process by requiring setback buffers and in some cases conservation easements. 

Water Quality Monitoring

Leon County's Water Quality Monitoring program collects quarterly data on approximately 39 water quality parameters from each monitoring station. Visit the Water Quality Monitoring page to learn more.

Retrofitting Areas Without Prior Stormwater Controls

• Stormwater improvements
• Water quality improvement projects
• Advanced septic pilot project
• Transportation pilot projects

Stormwater Improvements

Capital improvement projects for flood mitigation and relief and drainage improvements are proposed and approved by the Board of County Commissioners through the budget process. By increasing stormwater retention or detention capacities, the water quality can be improved through particle settlement. While the drainage systems are improved, the enhanced conveyance capacities can minimize flooding. The improved conveyance systems also stop or reduce erosion resulting in less sediment in stormwater management facilities. Example projects include: the construction of Lake Henrietta and the stabilization of Munson Slough between Lake Henrietta and Lake Munson; the Timber Lake stormwater facility expansion and the Harbinwood Estates stormwater facilities construction and conveyance improvements.

Water Quality Improvement Projects

Leon County has implemented several projects to improve water quality, including the Comprehensive Wastewater Treatment Facilities Plan, adopting the Basin Management Action Plan for Wakulla Springs and reducing nitrogen impacts in the Primary Springs Protection Zone through septic to sewer conversion projects.

Transportation Projects

All intersection improvements are required to meet the current stormwater treatment and volume control requirements in the County codes as well as State and Federal permitting requirements for stormwater and wetland impacts. The requirements for stormwater treatment, retention, and level of services are always incorporated into design and construction of all road improvement projects.  Dependent upon the project site location (stormwater drainage basin), the stormwater treatment may be required for new impervious areas.

Drainage Maintenance 

Drainage maintenance is performed by the Leon County Public Works Operations Division. Work can be scheduled following routine inspections which identify obstructions to flow or in response to citizen requests for service. Work is performed to ensure that runoff remains within the limits of the dedicated right-of-way or easement. The work can also occur at treatment facilities to restore capacity of the ponds for water quality improvement prior to discharge to a stream or easement. Treatment facilities and major drainage facilities are inspected on an annual basis to identify any issues to be addressed. For questions or issues with stormwater management, contact Leon County Public Works at (850) 606-1500.