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
APR-JUN 2026	839 ug/l	176.5 ug/l	983 ug/l	0.9 mg/l	15	15
JAN-MAR 2026	1,542 ug/l	649.5 ug/l	1,394 ug/l	0.73 mg/l	42	77
OCT-DEC 2025	1,800 ug/l	677.2 ug/l	842 ug/l	0.7 mg/l	44	83
JUL-SEP 2025	1,336 ug/l	372.2 ug/l	1,088 ug/l	1.05 mg/l	32	83
APR-JUN 2025	1,217 ug/l	393.4 ug/l	901 ug/l	0.93 mg/l	32	79
JAN-MAR 2025	1,569 ug/l	607.0 ug/l	665 ug/l	0.53 mg/l	54	123
OCT-DEC 2024	2,029 ug/l	508.8 ug/l	892 ug/l	0.67 mg/l	55	120
JUL-SEP 2024	1,296 ug/l	210.1 ug/l	1,175 ug/l	0.94 mg/l	56	127
APR-JUN 2024	1,203 ug/l	368.6 ug/l	740 ug/l	0.66 mg/l	47	109
JAN-MAR 2024	1,315 ug/l	435.5 ug/l	740 ug/l	0.55 mg/l	54	116
Five Year Seasonal Graph	Graph	Graph	Graph	Graph
Five Year Graph of All Samples	Graph	Graph	Graph	Graph

Source(s): Quarterly Routine Water Monitoring, EPC Monthly Routine Water Monitoring, Hillsborough County Lake Assessments, EPC Water Quality Data, EPC Water Quality data gathered from reports, LAKEWATCH Volunteer Water Quality Monitoring, FDEP Historic Data from Legacy STORET, Polk County Parks & Natural Resources Division, FDEP Watershed Monitoring Section, IMC Agrico (Florida), SWFWMD Water Quality Sampling Data, Tampa Bay Water, FDEP Southwest Regional Operations Center, FDEP, Water Quality Standards and Special Projects (Florida), Stream Waterwatch Water Quality Data, Volunteer , USGS National Water Information System, FDEP Watershed Monitoring Section, Environmental Protection Commission of Hillsborough County, Polk County Natural Resources Division, Southwest Florida Water Management District, Tampa Bay Water, 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
APR-JUN 2026	1,193 ug/l	10.0 ug/l	447 ug/l		2	2
JAN-MAR 2026	1,245 ug/l	10.0 ug/l	333 ug/l		2	2
OCT-DEC 2025	1,225 ug/l	24.5 ug/l	378 ug/l		2	2
JUL-SEP 2025	1,285 ug/l	15.0 ug/l	522 ug/l		2	2
APR-JUN 2025	1,325 ug/l	10.0 ug/l	378 ug/l		2	2
JAN-MAR 2025	1,248 ug/l	10.0 ug/l	335 ug/l		2	2
OCT-DEC 2024	1,175 ug/l	10.0 ug/l	377 ug/l		2	2
JUL-SEP 2024	1,494 ug/l	13.5 ug/l	488 ug/l		3	3
APR-JUN 2024	1,580 ug/l		207 ug/l		3	6
JAN-MAR 2024	956 ug/l		151 ug/l		6	12
Five Year Seasonal Graph	Graph	Graph	Graph
Five Year Graph of All Samples	Graph	Graph	Graph

Source(s): Hillsborough County Lake Assessments, EPC Water Quality data gathered from reports, Hillsborough County Environmental Management Division, LAKEWATCH Supplemental Water Quality Sampling, LAKEWATCH Volunteer Water Quality Monitoring, Polk County Parks & Natural Resources Division, Florida Fish and Wildlife Conservation Commission Water Quality Data, FDEP Watershed Monitoring Section, SWFWMD Water Quality Sampling Data, FDEP Southwest Regional Operations Center, SWFWMD Water Quality Monitoring Program Data, FDEP Watershed Monitoring Section, Hillsborough County Environmental Services Division, Florida LAKEWATCH, Polk County Natural Resources Division, FDEP - Southwest Regional Operations Center, FDEP - Watershed Assessment Section

• Water Quality Sampling Locations - View a map showing the point locations of water quality monitoring stations which collect data being presented on the Water Atlas.

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
Alafia River	In the past 30 days Average river flow is faster 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
Alafia River - North Prong	In the past 30 days Average river flow is faster 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
Alafia River - South Prong	In the past 30 days Average river flow is faster 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
Little Alafia River	In the past 30 days NO DATA Recent river flow data is unavailable.	No data table or graph available	In the past 30 days Average water levels are lower than they have been historically.	Levels Data Table and Graph
Thirtymile Creek	In the past 30 days NO DATA Recent river flow data is unavailable.	No data table or graph available	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