The following provides instructions for downloading shapefiles from the National FFMP Basin Repository.

If you need access to the repository or have any problems with the map viewer or download functionality, please contact Ami Arthur ( or 405-325-6457).

FFMPA Shapefile Download Instructions

Please download the rectangular domain that includes your CWA and the CWAs for which you have flash-flood backup responsibility, plus a buffer (25 km or so).

It is recommended that you download the shapefiles using the most powerful CPU machine possible.

For some of the larger domains, you may need to do two separate downloads--one for the streams and one for the basins.

1) To specify the download extent, there are two options:

a) Zoom to the approximate area of interest in the map viewer and then click the Download button. A download window will appear.


b) Click the Download button and then enter lat/lon bounding coordinates in the Extent section of the download window that appears.

2) Layer selection:

The CONUS FFMP basins are represented in three shapefiles for the eastern, central, and western regions of the country. The CONUS DEM-derived streams are represented in one seamless shapefile. Select the layer(s) you would like to download, using the SHIFT key to select multiple layers. To determine which shapefiles cover your area of interest, you can either return to the map viewer and display the FFMP basins (be sure to zoom in before displaying these layers--large areas can take a while to draw) or simply select all of the layers in the list (extra layers outside your area of interest will be ignored).

3) Download format and coordinate selection:

FFMP users should use the default ESRI Shape download format and Lat/Long NAD83 coordinate system.

4) Data extraction:

When all parameters have been specified, click the Download Data button to submit the request. After a few minutes, a new window will open with a link to a zip file containing the data. Save and unzip the file in the directory where you plan to continue with the basin integration instructions. The unzipped shapefiles will be named:

Note: You can download up to approximately 100 square-degrees of a single layer during one request. When requesting multiple layers, the allowable download area will be smaller. For large-area or multi-layer requests, data extraction make take several minutes.

New!!! KMZ Downloads Now Available (03/13/08)

Thanks to Tim Brice, WFO El Paso, for assembling and sharing the basin and stream KMZ files.

To download these files, make the KMZ Downloads layer both visible and active, and then click the Refresh Map button. Click the Hyperlink (lightning bolt) button, and then click any of the "+" symbols to download the KMZ file for that state (some states have multiple files).

NOTE: Only CONUS KMZ files are currently available--OCONUS files are coming soon.

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