PeakFQ Annual Flood Frequency Analysis Using Bulletin 17C and Bulletin 17B Guidelines Version 7.4.1 2023/07/24 ---> ---> NOTICE: Compiled for Windows. ---> ---> This release has been tested on Windows 10. ---> ---> It has not been tested under Vista, XP nor earlier versions ---> of Windows; no assistance or support will be provided for ---> using the program under these older versions of Windows. ---> For assistance, enhancement requests, or to report bugs, contact USGS by sending e-mail to h2osoft@usgs.gov. A. Quick Start 1. If you have previously installed version 5.0 or later of PEAKFQ or PKFQWin use the "Add/Remove Programs" under the "Settings-Control Panel" Window to uninstall the old PeakFQ before installing the new version. 2. From http://water.usgs.gov/software/PeakFQ/, download PeakFQ_7.4.1.exe 3. To launch the installation, double click on the downloaded PeakFQ_7.4.1.exe If you accept all defaults during the installation process, PeakFQ will be installed in C:\Program Files(x86)\PeakFQ, a PeakFQ icon will be placed on your desktop, and PeakFQ will be added to the start menu under USGS 4. PeakFQ is launched by a. clicking on the desktop PeakFQ icon or b. selecting USGS/PeakFQ from the Start menu 5. Bulletin 17C is a good reference for how to conduct flood frequency analyses. It can be downloaded from: https://doi.org/10.3133/tm4B5 B. Input Files *** NOTE: PeakFQ cannot recognize file paths (including directory names and filenames) that are too long. The program will fail to compute an output unless the input files are placed into a short file path. *** PeakFQ recognizes peak flow data in the PeakFQ (watstore) standard format. Annual peak flows are available in the PeakFQ standard format from NWIS-Web, see http://nwis.waterdata.usgs.gov/usa/nwis/peak. (Note: the PeakFQ program CANNOT read the Tab-separated format.) C. Changes in Version 7.4.1 (limited version history) 1) Addressed a memory leak that resulted in PeakFQ crashing when reading batch files with a large number of analyses 2) Increased the length of file paths PeakFQ can process 3) Corrected the web address in the help menu 4) Fixed bug in version 7.4 where output graphs had the incorrect version number 5) Corrected misnamed variable in lgpstx.for source file D. Known Bugs - On Input/View tab, if in the Perceptible Range Table a Start Year value is entered that differs from the Beginning Year field on the Stations Specification tab, the Beginning Year field on the Station Specification tab will not be automatically updated. The user must update this value. - On Input/View tab, if in the Perceptible Range Table an End Year value is entered that differs from the Ending Year field on the Stations Specification tab, the Ending Year field on the Station Specification tab will not be automatically updated. The user must update this value. - In PRT file, some Diagnostic Messages printed in Table 2 - Diagnostic Message and PILF Results are not applicable to EMA analysis.