The following data are summarized as seasonal average values for lake and river sampling locations located within the watershed. While these data are useful to serve as a general picture of watershed health, these data must be viewed with caution because these samples have been taken from ecologically different water resources.

Rivers:

Samples from most rivers located in this watershed are averaged as part of these data summaries.

Season	Total Nitrogen	Nitrate (NO3)	Total Phosphorus	Orthophosphate	Number of Sample Stations	Number of Samples
JAN-MAR 2025	1,874 ug/l	24.0 ug/l	276 ug/l		4	4
OCT-DEC 2024	1,590 ug/l	41.3 ug/l	121 ug/l		5	6
JUL-SEP 2024	1,819 ug/l	15.0 ug/l	300 ug/l		5	6
APR-JUN 2024	790 ug/l		75 ug/l		3	3
JAN-MAR 2024	1,386 ug/l		165 ug/l		4	4
OCT-DEC 2023	1,037 ug/l		45 ug/l		4	4
JUL-SEP 2023	1,517 ug/l		167 ug/l		5	5
APR-JUN 2023	1,213 ug/l		240 ug/l		5	6
JAN-MAR 2023	1,537 ug/l		177 ug/l		4	4
Five Year Seasonal Graph	Graph	Graph	Graph	Graph
Five Year Graph of All Samples	Graph	Graph	Graph	Graph

Source(s): Polk County Parks & Natural Resources Division, FDEP Central Regional Operations Center, FDEP Watershed Monitoring Section, SWFWMD Water Quality Sampling Data, FDEP Southwest Regional Operations Center, USGS National Water Information System, FDEP - Central Regional Operations Center, FDEP Watershed Monitoring Section, Polk County Natural Resources Division, Southwest Florida Water Management District, FDEP - Southwest Regional Operations Center

Lakes:

Samples from most lakes located in this watershed are averaged as part of these data summaries.

Season	Total Nitrogen	Nitrate (NO3)	Total Phosphorus	Orthophosphate	Number of Sample Stations	Number of Samples
JAN-MAR 2025	890 ug/l	11.5 ug/l	34 ug/l		6	6
OCT-DEC 2024	1,040 ug/l	10.0 ug/l	52 ug/l		7	8
JUL-SEP 2024	1,207 ug/l	10.0 ug/l	41 ug/l		7	10
APR-JUN 2024	1,429 ug/l		44 ug/l		8	11
JAN-MAR 2024	878 ug/l		47 ug/l		7	7
OCT-DEC 2023	796 ug/l		35 ug/l		6	6
JUL-SEP 2023	867 ug/l		40 ug/l		6	6
APR-JUN 2023	942 ug/l		64 ug/l		7	7
JAN-MAR 2023	976 ug/l		49 ug/l		8	8
Five Year Seasonal Graph	Graph	Graph	Graph	Graph
Five Year Graph of All Samples	Graph	Graph	Graph	Graph

Source(s): LAKEWATCH Volunteer Water Quality Monitoring, Polk County Parks & Natural Resources Division, FDEP Central Regional Operations Center, Florida Fish and Wildlife Conservation Commission Water Quality Data, FDEP Watershed Monitoring Section, Polk County Natural Resources Division, SWFWMD Water Quality Sampling Data, FDEP Southwest Regional Operations Center, FDEP, Water Quality Standards and Special Projects (Florida), SWFWMD Water Quality Monitoring Program Data, USGS National Water Information System, FDEP - Central Regional Operations Center, FDEP Watershed Monitoring Section, Polk County Natural Resources Division, FDEP - Southwest Regional Operations Center

Southwest Florida Water Management District calculates the Aquifer Resource Indicator (ARI) for their three groundwater regions each month. The ARI was created to provide the public with a gauge of groundwater levels in their area, so they can develop an understanding of the severity and cycles of drought and recovery. The three regions include: North (Citrus, Hernando, Lake, Levy, Marion, and Sumter counties), Central (Hillsborough, Pasco, Pinellas, and Polk counties), and South (Charlotte, DeSoto, Hardee, Highlands, Manatee, and Sarasota counties). Learn More about the Aquifer Resource Indicator >>

To determine the ARI for a region, each well is compared weekly to its respective low-normal value and the difference is calculated. The weekly differences are reduced to a monthly value for all monitoring wells within a region, and the resulting ARI value represents how far water levels in the aquifer must rise or fall to reach their respective low-normal values.

Source: SWFWMD Hydrologic Data Section Data

River	Flows Whole River Range	Flows Data by Segment	Levels Whole River Range	Levels Data By Segment
Hillsborough River	In the past 30 days Average river flow is slower than it has been historically.	Flows Data Table and Graph	In the past 30 days Average water levels are higher than they have been historically.	Levels Data Table and Graph
Withlacoochee River	In the past 30 days Average river flow is slower than it has been historically.	Flows Data Table and Graph	In the past 30 days Average water levels are higher than they have been historically.	Levels Data Table and Graph

Source(s): Not Available

Source(s): Not Available