Technical Release 55 (TR-55) presents simplified procedures to calculate storm runoff volume, peak rate of discharge, hydrographs, and storage volumes required for floodwater reservoirs. These procedures are applicable in small watersheds, especially urbanizing watersheds, in the United States. Limits: NRCS type distributions, 24-hour duration rainfall, 10 subwatersheds, minimum 0.1 hour and maximum 10-hour time of concentration.

Download TR-55 StormNET Software
File Size: 106068037 bytes
File Date: Wed Apr 23 05:41:02 2008

Download TR-55 Software from NRCS (EXE File)
File Size: 320699 bytes
File Date: Fri Mar 23 11:53:55 2007

To download the following FEMA technical documents, check the box of the desired documents below and then click the "Download Selected" button. An e-mail will be sent to you with the download links. These documents are available in Adobe Acrobat 4.0 PDF format.

Download FEMA Flood Insurance Study Guidelines and Specifications (PDF File)

Download FEMA Flood Insurance Study Guidelines and Specifications (PDF File)

File Size: 513134 bytes
File Date: Tue Mar 14 05:40:59 2006

The Federal Emergency Management Agency (FEMA) has compiled the Flood Insurance Study Guidelines and Specifications for Study Contractors to define technical policy and procedures to be followed in the preparation of FISs, restudies, and LMMP projects. Adherence to these guidelines is required in the Contract Statement of Work. Performance in accordance with these guidelines is required of any contractor preparing a FIS, restudy, or revision unless otherwise specified in the contract.

Download TR-55 Documentation (PDF File)

Download TR-55 Documentation (PDF File)

File Size: 2583423 bytes
File Date: Fri Mar 23 11:53:50 2007

Technical Release 55 (TR-55) presents simplified procedures to calculate storm runoff volume, peak rate of discharge, hydrographs, and storage volumes required for floodwater reservoirs. These procedures are applicable in small watersheds, especially urbanizing watersheds, in the United States. Limits: NRCS type distributions, 24-hour duration rainfall, 10 subwatersheds, minimum 0.1 hour and maximum 10-hour time of concentration.

The Natural Resources Conservation Service used government funds to develop the Technical Release 55 (TR55) computer program. It may be downloaded for use and copying at no additional expense or license requirements.