National Bulletin:	210-23-4	Date:	January 20, 2023
Subject:	ENG – Review of Draft 210-NEH Part 631, Chapter 23

Action Required By: March 10, 2023

Purpose. The purpose of this national bulletin is to request State (or equivalent) and Center review of draft Title 210, National Engineering Handbook (NEH), Part 631, Chapter 23, “Sediment Transport.”

Expiration Date. March 10, 2023

Background. 210-NEH-631, Chapter 23 is the preferred NRCS reference for sediment transport in sedimentation investigations and rehabilitation and design of structures and conservation practices. This version of 210-NEH-631, Chapter 23 replaces 210-NEH, Section 3, “Sedimentation,” Chapter 4, “Transmission of Sediment by Water.”

Attached to this national bulletin are:

1. A draft copy of 210-NEH-631, Chapter 23 for review

2. A revision summary sheet for 210-NEH-631, Chapter 23, which includes notes regarding NEH chapter formatting

3. A spreadsheet for compiling State review comments for Chapter 23.

Explanation. State Conservation Engineers (or equivalent) and Center staffs are to review the attached 210-NEH-631, Chapter 23 and submit one set of compiled comments per State (or equivalent) or Center by March 10, 2023. The attached spreadsheet contains further instructions.

More than one submittal per State or Center will not be accepted. State Conservation Engineer or Center Director, or their designee, must send submittal with an explanatory note. States are asked to respond by the due date whether they submit comments or not.

Email comments and responses to Kevin Farmer, Director of Conservation Engineering Division (CED), at kevin.farmer@usda.gov.

States are urged not to delay starting reviews until right before the due date.

Contact. Contact Kevin Farmer, Director of CED, by email at kevin.farmer@usda.gov with any questions or concerns about the contents of this national bulletin.

/s/

Noller Herbert
Deputy Chief for Science and Technology

Attachment 1 Draft of 210-NEH-631, Chapter 23
Attachment 2 Revision Summary to 210-NEH-631, Chapter 23
Attachment 3 Spreadsheet for Compiling State Review Comments for Chapter 23