Manatee River 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		445.8 ug/l	399 ug/l	0.31 mg/l	18	47
JUL-SEP 2012		305.8 ug/l	395 ug/l	0.34 mg/l	18	48
APR-JUN 2012		221.5 ug/l	501 ug/l	0.43 mg/l	18	44
JAN-MAR 2012		382.5 ug/l	377 ug/l	0.33 mg/l	18	46
OCT-DEC 2011	756 ug/l	310.4 ug/l	346 ug/l	0.3 mg/l	18	49
JUL-SEP 2011	1,077 ug/l	241.4 ug/l	473 ug/l	0.4 mg/l	18	48
APR-JUN 2011	824 ug/l	351.2 ug/l	512 ug/l	0.45 mg/l	19	50
JAN-MAR 2011	875 ug/l	390.0 ug/l	419 ug/l	0.38 mg/l	21	51
Five Year Seasonal Graph	Graph	Graph	Graph	Graph
Five Year Graph of All Samples	Graph	Graph	Graph	Graph

Source(s): FDEP Historic Data from Legacy STORET, Lower watershed program (LWP), FDEP Ambient Monitoring Sampling Data, South West Florida Water Management District Sampling Data, FDEP Southwest District Sampling Data, 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
OCT-DEC 2012		268.3 ug/l	307 ug/l	0.25 mg/l	2	6
JUL-SEP 2012		176.3 ug/l	390 ug/l	0.35 mg/l	2	6
APR-JUN 2012		76.8 ug/l	284 ug/l	0.23 mg/l	2	6
JAN-MAR 2012		266.8 ug/l	310 ug/l	0.27 mg/l	4	10
OCT-DEC 2011		281.7 ug/l	358 ug/l	0.31 mg/l	4	12
JUL-SEP 2011		169.3 ug/l	366 ug/l	0.31 mg/l	4	12
APR-JUN 2011		279.0 ug/l	349 ug/l	0.3 mg/l	4	12
JAN-MAR 2011		176.2 ug/l	320 ug/l	0.28 mg/l	4	11
Five Year Seasonal Graph		Graph	Graph	Graph
Five Year Graph of All Samples		Graph	Graph	Graph

Source(s): Lower watershed program (LWP), FDEP Ambient Monitoring Sampling Data, Manatee County Environmental Management Sampling Data, USGS National Water Information System

River	Flows Whole River Range	Flows Data by Segment	Levels Whole River Range	Levels Data By Segment
Cypress Strand	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 lower than they have been historically.	Levels Data Table and Graph
Gamble Creek	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 the same as they have been historically.	Levels Data Table and Graph
Wares Creek	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 lower than they have been historically.	Levels Data Table and Graph
Lower 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
Upper 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
Braden 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 lower than 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