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Watershed Assessment Section

The core function of the Watershed Assessment Section is to use the best available information to identify waterbodies and water segments (WBIDs) that are not meeting the applicable water quality standards and designated uses based on the Impaired Waters Rule Chapters 62-303 and 62-302, Florida Administrative Code (F.A.C.).

How often are WBIDs assessed?

DEP’s watershed management approach is an established five-year cycle that rotates through 29 basins throughout the state over a five-year period (all WBIDs will be assessed once every five years).

What are the designated uses addressed during the assessment?

The designated uses that are addressed during the assessment process can be classified in one of the categories below. The classification of a waterbody according to a particular designated use or uses does not preclude use of the water for other purposes. Water quality standards classifications are arranged in order of the degree of protection required, with Class I having generally the most stringent water quality criteria and Class V the least.

Waterbody Class

Designated Use


Class I
Potable Water Supplies
Includes 14 areas throughout the state that are used as a source of potable water.
Class II
Shellfish Propagation or Harvesting
Generally coastal waters where shellfish harvesting propagation occurs.
Class III
Fish Consumption; Recreation, Propagation and Maintenance of a Healthy, Well-Balanced Population of Fish and Wildlife
The surface waters of the state are Class III unless described in Rule 62-302.400, F.A.C.
Class III Limited
Fish Consumption; Recreation or Limited Recreation; and/or Propagation and Maintenance of a Limited Population of Fish and Wildlife
This classification is restricted to waters with human-induced physical conditions that, because of those conditions, have limited aquatic life support and habitat that prevent attainment of Class III status.
Class IV
Agricultural Water Supplies
Generally located in agricultural areas around Lake Okeechobee.
Class V
Navigation, Utility and Industrial Use
Currently, there are no waterbodies designated as Class V waters. The Fenholloway River was reclassified as Class III in 1998

*For a more detailed description of classes and specific waterbody designations, see 62-302.400, F.A.C.

What are the assessment categories and what do they mean?

Assessment Category

Assessment Category Definitions

1 Attains all designated uses
2 Attains some designated uses and insufficient or no information or data are present to determine if remaining uses are attained
3a No data and information are present to determine if any designated use is attained
3b Some data and information are present but not enough to determine if any designated use is attained
3c Enough data and information are present to determine that one or more designated uses may not be attained according to the Planning List methodology
Impaired for one or more designated uses but does not require TMDL development because a TMDL has already been completed
4b Impaired for one or more designated uses but does not require TMDL development because the water will attain water quality standards due to existing or proposed measures
4c Impaired for one or more criteria or designated uses but does not require TMDL development because impairment is not caused by a pollutant
4d Waterbody indicates non-attainment of water quality standards, but the Department does not have enough information to determine a causative pollutant; or current data show a potentially adverse trend in nutrients or nutrient response variables; or there are exceedances of stream nutrient thresholds, but the Department does not have enough information to fully assess non-attainment of the stream nutrient standard.
4e Waterbody indicates non-attainment of water quality standards and pollution control mechanisms or restoration activities are in progress or planned to address non-attainment of water quality standards, but the Department does not have enough information to fully evaluate whether proposed pollution mechanisms will result in attainment of water quality standards.
5 Water quality standards are not attained and a TMDL is required

What are the requirements for DEP to place a WBID-parameter listing into category 4e?

A waterbody can be placed in category 4e if it is impaired but recently completed or ongoing restoration activities are underway to restore the designated uses of the waterbody. Because DEP recognizes the ongoing implementation of restoration activities with the goal of restoring water quality, a TMDL is not scheduled at the time of assessment. The need for a TMDL is re-evaluated after the activities have been completed and the waterbody has been reassessed. Waterbody impairments identified in this category will be submitted to EPA for inclusion on the section 303(d) list.

What is the Impaired Waters assessment/303(d) listing process?

This process occurs every five years and is currently in Cycle 4.

  1. Evaluate Previous Cycle's Planning and Study Lists
  2. Implement Strategic Monitoring Plans
  3. IWR Evaluation
  4. Draft Master List (includes Verified, Delist, Study List, and Study List Removals)
  5. Public Meeting & Comments
  6. Final Master List (includes Final Verified, Delist, Study List, and Study List Removals)
  7. Secretarial Adoption of Verified and Delist lists
    • 21-day challenge period
  8. Submit 303(d) List updates to EPA

What is the TMDL Tracker?

The TMDL Tracker is a web-based application that is designed to share important information regarding assessments, TMDL documents and permit/facility locations.

How can I download the Impaired Waters Database?

The Impaired Waters Rule (IWR) Database is available from this website. 

Revision to 303(d) Assessment Schedule

Implementation of numeric nutrient criteria requires two to three years of data to assess a waterbody for attainment rather than a single year of data under previous rules. As a result of this data sufficiency requirement, in most years, DEP will be monitoring in multiple basins. This shift in monitoring does not require any changes in schedules for uploading data to the Watershed Information Network (WIN).

What is the Watershed Assessment Section's Annual Schedule?

Get a copy of the WAS Annual Schedule and Timeline to see the schedule.

The department requests that external data providers who would like to submit applicable bioassessment data in support of the Impaired Waters assessment to please download and complete the Biology Template available as a Microsoft Excel worksheet (.xlsx) on our website (Biology Template). Once the template has been completed, please submit the worksheet and supporting documentation (all field sheets, the program’s Quality Assurance Plan, photos, associated water quality results for the date of sampling, and the general sampling routine, etc.) by email to Kevin O'Donnell.​​​​​​

How can I provide feedback?

The Florida DEP is always interested in hearing feedback from its stakeholders. Comments and questions can be submitted to the Watershed Assessment Section by contacting Kevin O'Donnell at 850-245-8469 or via email.

Cycle 4 Assessment Periods

Group Planning Period Verified Period


1/1/2006 – 12/31/2015

1/1/2011 - 6/30/2018 

2 1/1/2007 – 12/31/2016 1/1/2012 - 6/30/2019
3 1/1/2008 – 12/31/2017 1/1/2013 - 6/30/2020
4 1/1/2009 – 12/31/2018 1/1/2014 - 6/30/2021


1/1/2010 - 12/31/2019

1/1/2015 - 6/30/2022


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