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)
Shellfish Environmental Assessment Data January 1979 — June 2003 30,440 88,200
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 210 1,000
Briarwood Stormwater Treatment Facility July 2020 — June 2023 580 600
Sarasota County Coastal Creeks February 1998 — January 2024 195,230 312,000
Sarasota County Environmental Services Department Sampling Data March 2004 — April 2007 410 220,200
Sarasota County Environmental Services Department Sampling Data February 1998 — January 2024 268,490 526,700
USGS National Water Information System October 1939 — March 2024 19,950 134,100
FDEP Charlotte Harbor Aquatic/Buffer Preserves Sampling Data November 1996 — January 2024 17,930 61,400
Flatwoods Consulting Group January 2018 — December 2022 500 600
FDEP South District Sampling Data September 2003 — January 2024 8,300 14,900
FDEP Watershed Monitoring Section October 1998 — December 2023 7,180 13,900
Florida LAKEWATCH December 2018 — September 2023 4,640 5,600
Manatee County Environmental Management Sampling Data January 1995 — September 2023 22,820 55,700
City of North Port September 2004 — December 2022 9,790 12,100
Sanibel-Captiva Conservation Foundation October 2022 — March 2023 40 0
Enviro-Audit January 2022 — January 2024 70 100
SWFWMD Water Quality Sampling Data August 1997 — December 2023 28,470 75,000
FDEP Southwest Regional Operations Center April 2013 — November 2023 1,990 4,700
FDEP Watershed Assessment Section December 2012 — August 2019 150 200
Peace River Manasota Regional Water Supply Authority (FL) August 1996 — December 2022 24,510 223,100