Water Quality
Florida Department of Environmental Protection Water Quality Guidelines
The Florida Department of Environmental Protection provides standards (PDF) for the amounts of some substances that can be discharged into Florida waters. They further reinforce a “designated use” approach by adopting surface water quality standards as follows:
- Class I waters are for potable water supplies.
- Class II waters are for shellfish propagation or harvesting and generally apply to coastal waters where shellfish harvesting occurs.
- Class III waters are based on recreation, propagation and maintenance of a healthy, well-balanced population of fish and wildlife. Note: The surface waters of the state are Class III unless described in rule 62-302.400 F.A.C. (PDF)
- Class IV waters for agricultural water supplies and are generally located in agriculture areas around Lake Okeechobee.
- Class V waters are evaluated for Navigation, Utility and Industrial Use. Currently, there are not any designated Class V bodies of water.
Water quality is a term used to describe the condition of a waterbody. It’s often preceded by the words “good” or “bad.” However, such evaluations vary widely depending on who is making the assessment, their needs and values, and the intended use of the waterbody or freshwater habitat. For example, citizens tend to judge water quality using physical properties they can see such as water clarity, the color of the water, or maybe the type or quantity of plants in the water. The health department determines water quality largely by counting bacteria and/or toxic algae. Lake managers are likely to evaluate water quality using some or all of the following parameters:
- The nutrients nitrogen and phosphorus are the main chemical properties measured and analyzed.
- Dissolved oxygen, temperature, water clarity and turbidity are commonly measured physical properties
- Chlorophyll (algae) concentrations, bacteria counts and plant communities are biological properties commonly surveyed.
The bottom line is that even if we have measurements for all of these parameters, there is no simple formula for determining good or bad water quality. It is a subjective process closely tied to the need or intended use. For example, a particular gray water source may be considered “good” for watering one’s lawn but “very poor” for drinking purposes.
Another example: Judging water quality based on aquatic plant communities can vary greatly depending on the values and needs of the people and/or wildlife involved. One lakefront homeowner may say a lake has "poor” water quality because an abundance of aquatic plants hamper swimming or boating, while another person says the lake has "good” water quality because those same plants provide habitat for fish or birds. (For more on this see Shared Uses and Functions.)
Plant managers are constantly challenged to consider differing opinions from various user groups while protecting Florida’s unique aquatic habitats for both citizens and wildlife. They must recognize how plant management can affect water quality and water chemistry and, conversely, how water quality parameters influence selections from the various management strategies available.