It appears that you are using Internet Explorer Version 6, 7 or 8
Internet Explorer Versions 8 (IE8) and older are not supported by this application and many features will be broken or work incorrectly.

In the case of IE 8, most features should work, however none of the map highlighting features work. This includes outlining the reach currently identified with the Identify Reach tool and outlining sets of reaches on the Adjustments Tab using the Show on Map tool.

Why are these older browsers not supported?
The World Wide Web Consortium (W3C) creates standards so that web pages work consistently for everyone. Newer browsers generally support these standards while older browsers generally don't. In particular, IE7 does not support or incorrectly implements many of the W3C standards. Your choice of browser may be out of your hands, however, if you are able to, you should consider upgrading your browser to the latest version of Internet Explorer or installing one of the browsers below. Doing so will improve your web experience, enabling you to use and view sites as their creators intended.

A partial list of browsers supporting current W3C standards includes:
* Chrome
* Firefox
* Safari (available by default on Apple computers)
* The latest Internet Explorer version
Map out of sync Map out of sync warning

Alert: Older saved sessions may not work

Saved sessions created for NHD models before June, 2013 will likely not work. Prior to June 2013, reaches were identified by the NHD GridCode. In June this was changed to ComIds, which are more commonly used as identifiers for reaches within the NHD network.

NHD models include the MRB 1 North Atlantic models and the Chesapeake Bay Models. Other models will continue to work. Sorry for any inconvenience.

Upload a previously saved session

Please note that no endorsement, expressed or implied, is made by the USGS or the U.S. Government of any interpretations or decisions that result from the use of these models, nor shall the fact of distribution constitute any such endorsement, and no responsibility is assumed by the USGS in connection therewith.

Looking for Downstream Tracking / Delivered Load Information?

If you are mapping a delivery-based data series, a Delivery Report is available that summarizes where load is delivered to and where it originates from. For more details, a complete tutorial video is available.

Export Format

Included Rows

Some reaches slightly outside the current region may be included in the export.

This option will result in a very large download which may be sensitive to network interruptions. Please verify that all   data rows are received in the downloaded file.

Included Content

The export always includes the following columns:
Reach id, Total Contributing Area, Total Upstream Area and the Mapped Value (see notes in the export file for definitions)
Additional columns of data can be added below:

Data series that reflect source input changes on the Change Inputs tab

These options are enabled if there are active changes on the Change Inputs tab and will include model data reflecting those changes. If you have created a scenario using the Change Inputs tab, you will likely want to select these options.

These are the predicted values generated by the model after changes to the input values have been applied from the Change Inputs tab.

These source values will reflect the changed input values from the Change Inputs tab.

Data series that do NOT reflect source input changes on the Change Inputs tab

These options will include original, as-calibrated model data, unaffected by changes made on the Change Inputs tab. This data is useful for comparison, or if there are no source input changes.

This option will also include the original mapped value, which is the currently mapped data series unaffected by source input changes.

Other non-prediction related data series
Please wait while we process your request.
Map the model results by reach or catchment.
Map the effect of management scenarios on stream water quality, based on hypothetical changes in source inputs. For more information, click here.
Map the amount of load in upstream catchments that is delivered to a downstream reach. For more information, click here.