Note:
The trophic state index (TSI) value is a calculated index of lake condition based on nutrient and chlorophyll a concentrations. The TSI range that relates to a specific descriptor is that range, if obtained by the waterbody, which would provide the condition described by the term. The lakes on the map are given a color code for the condition descriptors of "good" (TSI 0-59), "fair" (TSI 60-69) and "poor" (TSI 70-100). Lakes without appropriate data are not coded. These verbal descriptors are based on an early determination by stakeholders of the generally acceptable and understood terms for describing the state of lakes. The source for the TSI to concentration relationships is the Florida Water Quality Assessment, 1996, 305(b) (Table 2-8, p 87). To download data, visit the Data Download Tool. To read about TSI and eutrophic states in general visit our Learn More about TSI page.
When reading any chart or graph, please keep in mind that space and software limitations may create misleading spatial relationships. The Y-Axis may not necessarily start at zero, further distorting spatial relationships among the data. Furthermore, if multiple samples were taken on the same date at different locations on the water body, multiple values are plotted for that date. This presentation of the data explains the appearance of vertical lines on some of the graphs. If you need to see accurate spatial relationships, we highly recommend that you use the Data Download section, download the available data, and graph according to your needs.
To download data, visit the Data Download tool within the Analysis area of the Hillsborough County Water Atlas.