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HSPF BMP Web Toolkit

The HSPF BMP Web Toolkit builds hydraulic function tables(FTABLES) for the HSPF model. FTABLES are depth-area-volume-discharge relationships of engineered systems(e.g., sewer networks and best management practices--BMPs) and natural systems such as river reach networks. Accurate representation of channel and sewer networks is important for modeling flow, and fate and transport of water quality constituents. Therefore, the accuracy with which channel hydraulics are represented in HSPF has important implications for TMDL load estimation. The toolkit consists of three tools: GRAY Tool, GREEN Tool, and FTABLE Builder.


The GRAY Tool builds FTABLES for natural and engineered channels and is used when stream or river cross-section data is available. At times when surveyed cross-section(x,y) data is not available tool users can use the trapezoidal shape as a proxy for a natural channel shape. The tool can also be used when the geometric dimensions of an engineered channel is known.

Stage-Storage-Discharge Relationships
Pond graphic linked to Storage BMP Tool
There are hydrologic models other than HSPF that use stage-area-storage-outflow relationships to represent ponds, wetlands, and reservoirs. These models include SWMM, HEC-HMS, and TR-20. The tool offers users of these models ease of calculating these relationships from channel shape and channel dimensions or, in the case of a natural channel, from surveyed cross-section (x, y) data. The tool allows users to export the calculated relationships as an EXCEL spreadsheet.

Storm Sewers
Modeling graphic linked to Storage BMP Tool

The GRAY tool allows HSPF users to calculate FTABLES for free flowing open channels (channels with no flow control devices). When developing FTABLES for storm sewer networks with storage facilities, users should use flow control devices for the storage BMP facility.

Storage BMPs (Photo: Storage Basin)
Storage basin image linked to Storage BMP Tool
The GRAY tool allows users to calculate FTABLES for the HSPF model. The tool represents Storage BMPs as open channels with flow control devices (orifices and weirs). Note that this option assumes no infiltration. If a user desires a BMP with infiltration, we recommend that they use the GREEN Infrastructure Tool.

The GREEN Tool has many of the GRAY Tool functionalities, but it was developed for the representation and simulation of stormwater management measures that are used for low impact development(LID). Unlike the GRAY Tool, the GREEN Tool has infiltration process representation and was developed for small urban watersheds with sewer networks and best management practices(BMPs).

Infiltration BMPs (Photo: Grassy Swale)
Grassy swale image linked to Infiltration BMP Tool

This tool allows HSPF users to represent infiltration BMPs as channels that infiltrate. There are two types of infiltration BMPs. One stores water on the surface and the other stores water on both the surface and subsurface (backfilled reservoir). BMPs that store runoff on the surface include infiltration basins, and BMPs that use underground reservoirs to store runoff include infiltration trenches.


The FTABLE Builder offers HSPF users the flexibility to format FTABLEs by joining FTABLE columns from the GRAY and GREEN Tools. The Builder ensures that formatted FTABLEs can be pasted onto the HSPF User Control Interface(UCI) text file. FTABLEs formatted with the Builder do not create formatting problems when pasted in a UCI file.

Known Issues

To resolve issues with copy and paste functionality not working with certain versions of Java follow the instructions for Workaround from external forum.

Tutorials and Documentation

For a step by step walkthrough of the GRAY Tool, read the Tutorial (PDF). (13 pp., 143 KB, about PDF)
A walkthrough for the GRAY Tool's FTABLE creation of Natural Channels with Floodplains can be found here
For a step by step walkthrough of the GREEN Tool, read the Tutorial (PDF). (17 pp., 274 KB, about PDF)
For a step by step walkthrough of the FTABLE Builder Tool, read the Tutorial (PDF). (14 pp., 1299 KB, about PDF)

Tutorial Project Files

Users can download GRAY Infrastructure Tool example project files (Self-extracting zip file, 676 KB)
Users can also download example files for the GRAY Tool's FTABLE creation of Natural Channels with Floodplains here

Related Web Sites CEAM HSPF Model Page
BASINS Modeling System Download Page
WinHSPF Fact Sheet
Contact Page Link Contact Toolkit Support Staff

Contact the Athens, GA Ecosystems Research Web editor to ask a question, provide feedback, or report a problem.

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