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Iowa Water Quality Index - All Years Average
includes sampling results through December 2010

For background information on the Iowa Water Quality Index (IWQI or WQI), click here to visit the monthly score version of the IWQI.

Below is a Interactive Map using Google Maps API technology. For general help using the map interface, click here to visit Google Maps Help.

Each colored marker on the map below represents one of the 98 ambient sites used to compute the Iowa WQI. Most sites have been sampled every month for the last 10 years. Use the legend in the lower right corner of the map to determine each site's water quality category: Excellent (blue), Good (blue-green), Fair (yellow), Poor (orange), or Very Poor (red).

When a marker is clicked, a small window appears revealing detailed information about the sampling location, including the overall site water quality trend: Improving, No Significant Trend, or Not Available. There were no "Declining" water quality trends found at any site in this statistical analysis. However, only 66 out of 98 sites had enough stream flow data to run the analysis (i.e. 24 sites are reported as "Not Available").

Move your mouse over a marker on the map. Click to retrieve detailed Iowa WQI site information. Use the Zoom and Pan buttons in the upper left corner of the map (or your mouse wheel) to view a site more closely. Use the View buttons (Map, Satellite, Hybrid, Terrain) in the upper right corner of the map to change your background data layers.