Water Quality Contour Mapping

Water Quality Changes Over Space and Time

In an open body of water such as a bay, water quality may vary considerably in its different regions, and its water quality will also change continually from month to month, season to season, year to year. Tidal influence, land use in the watershed, inflow from tributaries, seasonal temperature changes, and rainfall are the most important factors driving these differences. A Water Quality Contour Map (WQCM) shows the spatial distribution of water quality for a defined period in time. By creating contour maps for multiple different periods, it is possible to detect both spatial and temporal patterns in water quality, and to see trends over time. Learn more »

Click on a parameter name and select a year from the dropdown below to discover spatial and temporal variations in water quality. Clicking on a PDF thumbnail will open the full report for viewing and download. Alternatively, click the "View Image Slideshow" button to view an interactive slideshow of the generated raster images.

Available Parameters (Select One)

Contours of

Select a report to open and view/download the corresponding PDF file. Alternatively, you can open an image slideshow of the contour rasters used in these reports.

Agency Summary

Data collected by the following agencies were used in preparation of these reports.

Agency Period of Record
(Month, Year)
Station Count
(Approximate)
Sample Count
(Approximate)
Charlotte Harbor Estuaries Volunteer Water Quality Monitoring Network November 1996 — December 2022 29,590 59,200
Shellfish Environmental Assessment Data January 1979 — June 2003 52,760 152,600
FLORIDA DEPARTMENT OF HEALTH IN SARASOTA COUNTY BEACH RESULTS November 2017 — July 2020 1,020 8,300
LAKEWATCH Volunteer Water Quality Monitoring August 2001 — December 2018 300 1,400
Briarwood Stormwater Treatment Facility July 2020 — June 2023 580 600
Sarasota County Coastal Creeks February 1998 — January 2024 216,430 347,800
Sarasota County Environmental Services Department Sampling Data March 2004 — April 2007 540 293,900
Sarasota County Environmental Services Department Sampling Data February 1998 — January 2024 265,510 521,700
USGS National Water Information System October 1939 — March 2024 21,570 138,700
FDEP Charlotte Harbor Aquatic/Buffer Preserves Sampling Data November 1996 — January 2024 24,670 88,300
Florida Healthy Beaches Program and Data (Bacterial Counts) July 2000 — August 2011 3,210 19,700
Flatwoods Consulting Group January 2018 — December 2022 500 600
FDEP South District Sampling Data September 2003 — January 2024 9,420 17,100
FDEP Watershed Monitoring Section October 1998 — December 2023 7,860 15,100
Florida LAKEWATCH December 2018 — September 2023 5,600 6,900
Manatee County Environmental Management Sampling Data January 1995 — September 2023 21,170 56,200
City of North Port September 2004 — December 2022 10,870 13,800
Sanibel-Captiva Conservation Foundation October 2022 — March 2023 40 0
Enviro-Audit January 2022 — January 2024 80 100
SWFWMD Water Quality Sampling Data August 1997 — December 2023 32,000 87,300
FDEP Southwest Regional Operations Center November 2013 — November 2023 2,230 5,400
FDEP Watershed Assessment Section December 2012 — August 2019 170 200
Peace River Manasota Regional Water Supply Authority (FL) August 1996 — December 2022 30,070 270,900