Middle Tampa Bay Watershed

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
Click here to view a period of record graph for the central, north, and south groundwater regions

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
OCT-DEC 2012	1,116 ug/l		260 ug/l	0.2 mg/l	18	33
JUL-SEP 2012	1,358 ug/l		396 ug/l	0.32 mg/l	20	38
APR-JUN 2012	1,213 ug/l		371 ug/l	0.31 mg/l	32	45
JAN-MAR 2012	1,133 ug/l		452 ug/l	0.41 mg/l	21	35
OCT-DEC 2011	1,214 ug/l		266 ug/l	0.25 mg/l	33	51
JUL-SEP 2011	1,416 ug/l		389 ug/l	0.32 mg/l	35	55
APR-JUN 2011	987 ug/l		327 ug/l	0.29 mg/l	25	44
JAN-MAR 2011	1,750 ug/l		364 ug/l	0.32 mg/l	34	54
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, EPC Water Quality Data, EPC Water Quality data gathered from reports, LAKEWATCH Volunteer Water Quality Monitoring, Legacy Pinellas Water Quality Data, FDEP Historic Data from Legacy STORET, PINELLAS Water Quality Data, FDEP Ambient Monitoring Sampling Data, IMC Agrico (Florida), South West Florida Water Management District Sampling Data, FDEP Southwest District Sampling Data, FDEP, Water Quality Standards and Special Projects (Florida), Stream Waterwatch Water Quality Data, Volunteer , USGS National Water Information System

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
JUL-SEP 2012	1,365 ug/l		113 ug/l		2	2
APR-JUN 2012	913 ug/l		59 ug/l		1	2
JAN-MAR 2012	1,838 ug/l		290 ug/l		2	2
OCT-DEC 2011	3,087 ug/l		365 ug/l		1	1
JUL-SEP 2011	643 ug/l		69 ug/l		2	2
APR-JUN 2011	1,590 ug/l		72 ug/l		1	2
JAN-MAR 2011	1,957 ug/l		246 ug/l		3	3
Five Year Seasonal Graph	Graph		Graph
Five Year Graph of All Samples	Graph		Graph

Source(s): EPC Water Quality data gathered from reports, LAKEWATCH Supplemental Water Quality Sampling, LAKEWATCH Volunteer Water Quality Monitoring, FDEP Historic Data from Legacy STORET, PINELLAS Water Quality Data, FDEP Ambient Monitoring Sampling Data, South West Florida Water Management District Sampling Data, FDEP, Water Quality Standards and Special Projects (Florida), Southwest Florida Water Management District Hydrologic Data, SWFWMD Water Quality Monitoring Program Data, USGS National Water Information System

River	Flows Whole River Range	Flows Data by Segment	Levels Whole River Range	Levels Data By Segment
Little Manatee River - South Fork	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
Little Manatee 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
Sawgrass Lake East Outfall Canal	In the past 30 days Recent river flow data is unavailable.	No data table or graph available	In the past 30 days Average water levels are the same as they have been historically.	Levels Data Table and Graph

Source(s): Hillsborough County Environmental Protection Commission, LAKEWATCH, Manatee County Department of Environmental Management, Orange County, City of Orlando, Sarasota County, St. Johns River Water Management District, Southwest Florida Water Management District, Southwest Florida Water Management District, USGS National Water Information System

Source(s): Not Available