Stormwater History

Press Enter to show all options, press Tab go to next option

Sarasota County has had a stormwater management division since 1981 when the Aquatic Plant Control Department became part of the Department of Transportation. The department completed a master plan for the county in 1987 that identified the county’s drainage basins and recommended the enactment of a stormwater utility fee as a dedicated funding source. The Stormwater Environmental Utility was established in 1989.

An inter-local agreement between the city of Sarasota and the county was drawn up in 1991 and revised in 1997 giving the utility responsibility for portions of the drainage system in the city of Sarasota, in addition to the parts in the unincorporated county. Legal authority to establish a stormwater utility in Sarasota County was provided by Chapter 403 and Section 197.3632 of the Florida Statutes that allow communities to create stormwater benefit areas and charge special assessments.

Since the establishment of the stormwater utility, the county has been working on master plans for each of its 27 drainage basins. After severe flooding in 1995, the work schedule was accelerated to complete all the master plans by the end of year 2001.

Sarasota County’s stormwater utility started its first capital improvement projects in 1994 and began assessing drainage basins for Stormwater Improvement Assessments in 1995. The same year, Sarasota County and its joint applicants North Port, Venice, Sarasota, Longboat Key, and the Florida Department of Transportation received the first NPDES permit issued in the state.

In 1999, the county reorganized its administrative divisions and the Stormwater Management Division became part of the Public Works Business Center, the department that was historically responsible for maintaining the county’s drainage system. 


Utility Objectives
  • The Sarasota County Stormwater Environmental Utility’s objectives include reducing the threat of flooding, improving surface water quality and encouraging appropriate development practices in the region.
  • Reduce the threat of flooding by ensuring that the stormwater drainage system is properly operated and maintained.
  • Reduce the threat of flooding by developing Basin Master Plans which will identify level of service deficiencies and cost effective solutions. 
  • Protect and improve area surface water quality by ensuring county compliance with federal and state regulations under the National Pollutant Discharge Elimination System (NPDES) Permit and other local, state and federal regulations. 
  • Mitigate the impacts of flooding and save money for the county residents by implementing activities in the Community Rating System (CRS) program to prevent and reduce flood losses and flood insurance cost.
  • Protect existing property while encouraging appropriate community development by formulating and enforcing stormwater regulations for development. 
  • Maintain a customer service database to assure accuracy of parcel records and assessments.
Utility Responsibilities 
The Stormwater Environmental Utility administers the Sarasota County NPDES permit requirements including master planning, the capital improvement program, inspection and maintenance of the stormwater management system, and the proper use, storage, and disposal of sediments, herbicides and other materials. The utility is also responsible for public relations, customer service, flood control, development review, and the administration of the stormwater utility’s funding and other activities. Water quality monitoring and enforcement duties are the responsibilities of the Environmental Services/Pollution Control Department.
Utility Organization
The goal of the Utility is to create and maintain a comprehensive, planned stormwater infrastructure within Sarasota County. Each section is tasked with a specific goal. The utility is divided into four main sections: 
  1. Master planning
  2. Capital improvements
  3. Maintenance
  4. Development review


Master Planning

The Master Planning Division is responsible for the completion of each drainage basin’s master plan. For each of the 27 drainage basins, the master planning crew inspects the existing stormwater system, identifies maintenance, repair, and replacement needs, develops a schedule for needed improvements, and estimates the costs of the needed improvements.

  • During the assessment process, the team also identifies methods to reduce the pollutant load that enters the county’s water supply and analyze current land use patterns to determine future stormwater management needs in the area.
  •  Basin Master Planning involves field survey work, inventorying the existing drainage system and researching historical drainage and flooding problems. Features, such as topography, soil type, and land uses, are considered during planning. Lakes, ponds, and wetlands are evaluated for possible storage areas for stormwater.
  • The Master Planning Division engineers use a computerized modeling program based on the physical characteristics of each basin to determine the impacts of storms of varying intensity and the effects of different types of improvements on the level of stormwater service provided to the basins.


Capital Improvements

The Capital Improvements division works with the Master Planning Division to identify and design improvement projects and consults the Drainage Operations staff regularly to learn more about the current conditions of the project sites and ensure that the operations staff will be able to repair and maintain the new projects after their completion.

  • The capital improvements staff consults with the Public Works Business Center’s Real Property Officer on projects involving easements and property acquisitions and with the County Attorney’s Office and the Environmental Services Natural Resources Section to ensure that the construction projects comply with county regulations.
  • The Road Program Construction Division of the Department of Public Works also cooperates with the Stormwater Management staff to administer the bidding, inspection, and accounting aspects of the capital improvement projects.



Maintenance of canals, lakes and drainage systems form a large part of the Stormwater Environmental Utility’s activities. There are approximately 600 miles of canals in Sarasota County. The Utility maintains those canals where appropriate easements or rights of way exist.

  • There are currently 375 miles of maintained canals.
  • Canal cleaning is done on schedules ranging from annually to once every three years.
  • In addition, canal banks are mowed and periodic herbicide application keeps canals draining properly.
  • Pipes are maintained by jetting high pressure water hoses through them and vacuuming the debris.
  • Inlets are cleared of leaves, pine needles and debris on a regular basis throughout the city and the county.

Designed to remove pollutants, all county-owned and operated retention ponds are mowed monthly by county contractors. Herbicide applications control the vegetation. Construction projects that cost less than $85,000 are the responsibility of the maintenance division.

  • The maintenance division also conducts regular inspections of the county’s stormwater system, performs routine maintenance duties and responds to emergency maintenance requests.
  • Maintenance requests are handled using a rating system to ensure the uniform handling of all of the county’s maintenance requests.
  • The maintenance needs of the county stormwater system are prioritized by land use category, the type of flooding experienced, and the type of facility in need of repair.
  • High-density residential developments, structure flooding problems, and main stormwater facilities are given the highest priority.
  • The maintenance staff also works closely with the Capital Improvements and Master Planning Divisions to ensure that the computerized modeling system is up-to-date and that the maintenance efforts undertaken are consistent with the overall goals for the drainage basin.


Development Review

The Development Review section is responsible for reviewing proposed development plans to ensure that the plans meet the county’s infrastructure construction standards that are outlined in the county land development ordinance.

  • The county currently requires all new developments to meet the 100-year storm event criteria and ensure that the runoff rate from new developments is less than or equal to the pre-development rate.
  • Some areas of the county are known to be problematic during storms and the Development Review section applies more stringent standards to those areas until capital improvement and maintenance projects are completed to rectify those situations.


Initial Rate Structure

The assessment methodology has gone through several challenges and changes since its inception in 1989. As one of the first stormwater utilities created, Sarasota County has been a leader among local governments in developing such a program. Sarasota County’s stormwater utility initially assessed its customers using Equivalent Residential Units (ERU’s) that were based on the average amount of impervious area on a single-family parcel. The ERU rate structure that was implemented with the establishment of the utility in 1989 had two property classes – residential and non-residential. Residential customers were charged a flat fee that was based on the average amount of impervious area on a single-family lot (one ERU). Non-residential customers were charged individually based on the amount of impervious area on their parcels. The initial rate structure didn’t charge owners of undeveloped parcels and didn’t include credits for onsite stormwater controls.
Current Rate Structure

The rate structure was changed in 1994 to a more equitable system that takes into account the pervious and impervious areas of each parcel and includes several new property classes. The Sarasota County Stormwater Environmental Utility assesses its customers based on Equivalent Stormwater Units (ESU’s) that are based on the effective impervious area of the average single-family parcel. Based on statistically valid sampling of Single Family Developed Parcels, an “ESU Value” of 3,153 square feet was derived from a medium Net Impervious Area and Net Pervious Area of the sampled parcels.

  • The ESU Value is used to establish a basis for comparison of the relative runoff from the base ESU Value and from all parcels within the Stormwater Utility Area, including residential parcels, industrial/commercial parcels and condominiums. Effective Impervious Area as defined by the Sarasota County utility is calculated as:

“The sum of (I) the hard surfaced areas which either prevent or severely restrict the entry of water into the soil or cause increased water runoff (the “Impervious Area”) minus any exempt areas (collectively, the “Net Impervious Area”), and (II) the amounts computed by multiplying for each pervious area category (A) the surface are which, under standard conditions, is permeable to Stormwater runoff and other surface water (the “Pervious Area”) minus any exempt areas (collectively, the “Net Pervious Area”) by (B) a factor based upon the Pervious Area Category.” The pervious area categories and factors are listed in Table 1. The multiplication factors are based on the intensity of development on the parcel with land in its natural state receiving a factor of zero and urban pervious land receiving a factor of 0.148.

Table 1: Pervious Area Factors by Category

 Pervious Area Category         Pervious Area Factor
 Natural State  0.000
 Pasture/Meadow  0.002
 Groves and Orchards  0.017
 Tilled Agriculture  0.030
 Open Space  0.037
 Urban Pervious  0.148


Types of Assessments

Customer Service
The user fee has three components – the customer service assessment, the planning assessment and the maintenance assessment. The customer service assessment is a uniform charge that everyone in the service area pays to cover the costs of the administration of the stormwater utility fee system.

  • The customer service assessment currently is $3.10 per parcel, per year.

Planning Assessment
Planning and maintenance assessments are based on the number of ESUs in each parcel.

  • The planning charge, currently $23.10 per ESU, (.5 minimum), per year, covers master planning, engineering and inspection services, development review, system design and management costs.

The maintenance charge covers ditch and canal cleaning and mowing, the application of herbicides, the cleaning and repair of the stormwater system components, and low-cost construction projects.

  • The maintenance charge is currently $64.45 per ESU per year.
  •  The charges for each of the three user-fee components are determined when the stormwater utility’s staff determines the amount of revenue that must be generated to cover its operating expenses, debt service requirements, and capital improvement plans for the next fiscal year.
  • The anticipated stormwater service charges are published in a local newspaper then presented at a Sarasota County Commission meeting and mailed to each Sarasota County property holder who is subject to the assessments before they can be adopted.
  • The current base charge for a medium sized single-family parcel (one ESU) is $90.65 annually, or about $7.56 per month.

Capital Improvement Assessments
Stormwater utility customers may also be charged a capital improvement assessment if their parcel is located in a drainage basin scheduled for capital improvements during that billing cycle.

  • The capital improvements assessment is based on the number of ESUs per parcel and is determined by dividing the capital improvement costs of the basin by the total of ESUs in the basin.
  • Capital improvement costs that are currently being charged range from $1.89 to $108.26, depending on the capital improvement needs of the basin.
  • Sarasota County’s stormwater utility was the first in Florida to charge its customers based on the drainage basin the property is located in rather than charge everyone uniformly for countywide capital improvement expenses. 


Property Classifications

The Sarasota County Stormwater Environmental Utility currently has seven major parcel classifications that it uses to assign property owners the appropriate number of ESU’s. Each property in the stormwater service area is assigned to one of the following categories:

  1. single family residential.
  2. single family vacant lot.
  3. mobile home parcel.
  4. duplex parcel.
  5. condominium residential.
  6. condominium nonresidential.
  7. general parcels.

The single-family residential and vacant parcels are subdivided into small, medium, and large categories and given rate factors according to their size. The ESU calculations for each type of parcel are shown in Table 2.


Table 2: Equivalent Stormwater Units (ESU) Calculations

 Equivalent Stormwater Units (ESU) Calculations
 Parcel Type                                         ESUs
 Small Single Family Residential
 (< 8,100 square feet)
 Medium Single Family Residential
 (8100 - 14,600 square feet)
 Large Single Family Residential
 (> 14,600 square feet)
 Small Single Family Vacant Lot
 (< 8.100 square feet)
 Medium Single Family Vacant Lot
 (8,100 – 14,600 square feet)
 Large Single Family Vacant Lot
 (>14,600 square feet)
 Mobile Home  0.7
 Duplex Calculated the same as a single family parcel of equal size
 Condominium, Residential Effective Impervious Area of Parcel + Pro Rata Share of Common Areas (cannot exceed 1.7)
 Condominium Nonresidential  Effective Impervious Area of Nonresidential Areas (excluding streets) is divided pro-rata among condominium owners
 General Parcels Effective Impervious Area divided by 3,153