Tools and Results
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You must determine a watershed before data can be displayed.
Run a model to see data tables.
Run a model to see data graphs.

This Online Watershed Delineation (OWL) tool will delineate the area that flows to a pour point and allow you to send that outline, and the soil and landuse data within the outline to our online models.

Process: four separate ways to locate your point:

A) Search / Zoom and click "Delineate"
B) Type in your location coordinates
C) Select a HUC area for analysis
D) Manually select an area to analyze

Press F11 for full screen in Windows

MSDSS LTHIA tutorials and help

Search for or Zoom-in to your area using your ZIP code.

Select "Delineate" button and click on the stream whose watershed you plan to analyze. Your location is sent to our L-THIA engine and the watershed of that point is calculated; then you can run our L-THIA model on it to predict runoff.

Enter a specific latitude-longitude, longitude with minus sign must be within -85.00 to -82.50000 and latitude within 40.50000 to 42.00

Finally click Done


We are using a 8 - digit HUC watershed as the largest possible size!

(What is a 10 Digit HUC versus a 12 digit HUC?)

To run analysis on a specific HUC Region, click one of the buttons and click within the desired watershed.

You can display the HUC 10 and HUC 12 regions from the "L-Thia Layers" frame.

This function allows you to manually create an area of interest, rather than relying on actual watersheds. NOTE: You will not be able to create areas that cover large areas; your areas will be limited to a single HUC8 area

After clicking start, click on the map to create corners for your desired area. Hover your mouse over a point, and when a hand appears, press and drag the point for better fit, or click to remove the point.

Click to begin digization.

Click to zoom to your polygon. Click to clear all placed markers on the map.
Your current area is 0 acres (0 km squared).
Click when you are finished creating your polygon.
Resize Button