Iowa DNR Interactive Mapping, Water Web Help Files

Turning On/Off and Viewing Symbology for Layers in the Map Legend:

You can turn on and off any layer that is visible in the Legend of the Water Web map. Notice that layers are currently categorized into 2 types: Reference Layers and Program Layers.

To view the layers underneath each type, click on the "+" icon to the left of the legend type name, which will reveal all of the layers available at the current map scale. Click on the "-" icon to the left of the legend type name to hide the layers. More layers will become visible as you zoom in on the map.

To turn a layer on or off simply check or uncheck the box to the left of the layer name, then select the Update Map link located at the bottom of the Legend. The interactive map will then be updated according to the changes you make. Keep in mind that you can turn on and off several layers before selecting the Update Map link to refresh the map with multiple changes with one click.

Below the Update Map link you will find a View Legend Key link. Selecting this link will reveal the entire legend for the Water Web map, and it will appear in a separate browser window. This feature was designed so that the user could view the entire map legend symbology in a separate window and could also print to a letter-size page, if desired.

In the Legend, also notice that a small legend image is available to the left of the checkbox next to each layer. This image corresponds to the symbology of this layer as represented on the map.

Some layers have more detailed symbology that is not revealed in the small legend image to the left of each layer name. For example, the Beach Lake Status layer is symbolized on the interactive map with 4 different colored point features. To view more detailed symbology for a layer, if available, you need to select the layer name with your mouse. After clicking on the layer name with your mouse, a new content area will appear on your web page directly above the Legend. Look at the image below, which shows the example of selecting the Beach Lake Status layer with the mouse:

This new information not only contains the full legend for the layer, if applicable, but also a link to metadata for the selected layer in the Iowa DNR NRGIS Library. Select the View Metadata link to go the NRGIS Library and open the metadata document. This document will tell you the time period, source, brief description, contact person of the layer. Within the NRGIS Library website you can also download a layer in shapefile format (if publicly available for download) for display in your own GIS software.

Finally, please note that not all layers have more detailed symbology. The Beach Lake Status layer has 4 different points, but many layers are represented on the map with only 1 unique symbol. When you select a layer with your mouse that does not have detailed symbology, you will be linked directly to the metadata page for that layer.