PeakFQ
U.S. Geological Survey (USGS)
USGS PeakFQ performs flood-frequency analysis on annual peak-flow series using the US Bulletin 17C procedures. It fits a log-Pearson Type III distribution and returns the frequency curve, discharges for a range of return periods and confidence limits. It is available as a browser application and as an R package, with older desktop versions kept in the USGS legacy-software archive. Suited to drainage, bridge and culvert engineers who need a design flood from gauge records. Limitations: the method follows US guidance rather than local standards; automatic data retrieval reads from the USGS NWIS database of US gauges, so other data must be prepared in the expected format.
Ratings & Reviews
| Licence type | Completely Free, Open Source |
|---|---|
| Licence terms | US government (USGS) tool in the public domain: free to use with no charge, including commercial work. The R package is available from the USGS code repository. |
| Platforms | Runs in the Browser |
| Engineering field | Civil Engineering, Environmental & Water |
| Tool type | Hydrology & Drainage, Engineering Calculators |
| Vendor site | www.usgs.gov |
This link goes to the vendor site. EngiFree hosts no installers and distributes no cracked versions.
Last verified: 2026-10-06
