Lower 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
Five Year Seasonal Graph
Five Year Graph of All Samples

Source(s): Not Available

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
Five Year Seasonal Graph	Graph		Graph
Five Year Graph of All Samples	Graph		Graph

Source(s): Not Available

River	Flows Whole River Range	Flows Data by Segment	Levels Whole River Range	Levels Data By Segment

Source(s): LAKEWATCH, Southwest Florida Water Management District, Southwest Florida Water Management District, USGS National Water Information System

Source(s): Not Available