Withlacoochee River
To determine the health of our local waters and trends in water quality, the Southwest Florida Water
Management District (District) monitors environmental conditions at a number of water bodies in its 16county area, including the Withlacoochee River. The District operates and maintains two (2) structures on
the Withlacoochee River, the Wysong-Coogler Water Conservation Structure and the Inglis Structure at
Lake Rousseau. The District collects and analyzes data from seven (7) separate stations on the River. These
include Trilby, Highway 50, Croom, Nobelton, County Road 48, Lake Panasoffkee Outlet River, and Highway
50. This update provides a snapshot of the most recent data collected and historic information about the
water quality of the Withlacoochee River.
Representative Stations on the Withlacoochee River
Trophic State Index: 34.2 TSI (Range 0-100) Trophic State Index (TSI) is calculated by using
nitrogen, phosphorus, Secchi depth and Chlorophyll a values. The TSI is designed to rate the amount
of biological productivity occurring in the water. The higher the value, the more productive the system
is. Extremely high values may indicate an over abundance of nutrients leading to a detrimental effect
on native plants and animals.
Below Historic Average
39.72
Historic Average
39.72
Exceeds Historic Average
39.72
Dissolved Oxygen: 4.24 mg/l. This number, represented in milligrams per liter, indicates the amount
of oxygen present in the water. This affects the lakes ability to support aquatic life.
Above Average
More than 5.95 mg/l
Average
5.95 mg/l
Below Average
Less than 5.95 mg/l
Water Clarity (Vertical Secchi Depth): 1.83 feet. This number represents the overall clarity of water
and more specifically, the ability of light to penetrate the water column.
Above Historic Average
Greater than 2.05 feet
Historic Average
2.05 feet
Below Historic Average
Less than 2.05 feet
Total Nitrogen: 1.07 mg/l. This number, measured in milligrams per liter, represents one of the
important nutrients available for plants and aquatic life and in excess is generally associated with
eutrophication. This value is also represented in calculating Trophic State Indicies (TSI).
Below Historic Average
Less than 0.96 mg/l
Historic Average
0.96 mg/l
Exceeds Historic Average
Greater than 0.96 mg/l
Total Phosphorus 0.132 mg/l. This number, measured in milligrams per liter, represents one of the
important nutrients available for plants and aquatic life and in excess is generally associated with
eutrophication. This value is also represented in calculating Trophic State Indicies (TSI).
Below Historic Average
Less than 0.063 mg/l
Historic Average
0.063 mg/l
Exceeds Historic Average
Greater than 0.063 mg/l
Chlorophyll a: 1.04 ug/l. Represented in micrograms per liter, is a green pigment found in almost all
plants, algae, and cyanobacteria. Higher values are generally indicative of eutrophication and are also
represented in calculating Trophic State Indicies (TSI).
Below Historic Average
Less than 5.55 ug/l
Historic Average
5.55 ug/l
Exceeds Historic Average
Greater than 5.55 ug/l