USGS Bulletin 17C: The Document Behind Flood-Frequency Method

U.S. Geological Survey “Techniques and Methods 4–B5” — commonly cited by its short title, Bulletin 17C — is the federal report that sets out guidelines for determining flood-flow frequency (source). Its title page also records the document’s release and revision history, summarized below.

This article identifies the document and restates the version history printed on its own title page; it does not address a flood elevation for any specific property or location (see “What this article does not answer” below).

This original record-reading guide is a general reading aid, not cited evidence. It does not depict a source record; the article text and source links provide the facts.

Key points

• The technical document is designated “Techniques and Methods 4–B5” (source).
• Its title page states a first release of “2018, online and in print” (source).
• It was subsequently marked “Revised: May 2019 (ver. 1.1), online” (source).
• Its current stated version is “Version 1.1, May 2019” (source).
• This document does not itself contain or produce a base flood elevation for any specific place; that figure lives only on a dated FIRM/FIS report.

Title page version history

The document’s own front matter records two dated milestones: a “First release: 2018, online and in print” and a “Revised: May 2019 (ver. 1.1), online” (source). Consistent with that history, the title page identifies the document’s current version as “Version 1.1, May 2019”. Readers who need to confirm they are citing the same edition referenced elsewhere can check for this exact label — “ver. 1.1, May 2019” — on the copy they are using.

How the document cites itself

For anyone who needs to cite this document precisely — for example in a report, permit application, or engineering study — the document supplies its own preferred citation:

“England, J.F., Jr., Cohn, T.A., Faber, B.A., Stedinger, J.R., Thomas, W.O., Jr., Veilleux, A.G., Kiang, J.E., and Mason, R.R., Jr., 2018, Guidelines for determining flood flow frequency—Bulletin 17C (ver. 1.1, May 2019): U.S. Geological Survey Techniques and Methods, book 4, chap. B5, 148 p., https://doi.org/10.3133/tm4B5.” (source)

What this article does not answer

This article identifies one federal technical document and states only the version history printed on its own title page. It does not:

• State or compute a base flood elevation for any specific property, parcel, or location — those elevation numbers, where they exist, are published only on a dated FIRM or FIS report for that location, not in this methods document.
• Walk through or apply the statistical method the document describes, or make any claim about how to derive a flood-flow-frequency estimate from streamflow data.
• Claim that this document determines, updates, or supersedes any FIRM or FIS report — those are separate, place-specific products with their own publication and revision history.

Readers who need a flood elevation, flood zone designation, or insurance determination for a specific address should consult the current FIRM/FIS report for that location rather than this methods document.

Source links

• https://pubs.usgs.gov/tm/04/b05/tm4b5.pdf