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Illinois Field Handbook - Notice 68

United States Department of Agriculture
Natural Resources Conservation Service
2118 W. Park Court, Champaign, IL 61821
Phone: 217/353-6600 Fax: 217/353-6676


September 11, 2013

210 – ENG
Notice IL68

SUBJECT: ENG – National Engineering Handbook (NEH), Part 650, Engineering Field Handbook (EFH)

Purpose. To distribute new IL supplements to EFH Chapter 6 on grade stabilization structures.

Effective Date. Upon receipt.

Explanation of Changes. Written guidance on specific design criteria for certain types of grade stabilization structures has been lacking. This new supplement contains guidance on the following:

  • Rock lined chute allowable flow velocities with standard Illinois Department of Transportation riprap gradations
  • Minimum riprap thickness for rock lined chutes
  • Maximum flow velocities in concrete block lined chutes
  • Tail water requirements for open flow structures
  • Method of estimating downstream channel flow depth for side inlet structures

The Illinois NRCS engineering website will be updated with these changes: nrcs/main/il/technical/engineering/.

Filing Instructions. Holders of hardcopy Illinois Engineering Drawing binders should:

1. Print out the attached supplement on green paper and file in the EFH Chapter 6 after existing supplement IL6-7(1):
      a. IL EFH supplement IL650.06, pages IL 6-7(2) through IL 6-7(3).
2. Print out the attached table of contents and file at the beginning of the EFH, replacing the existing table of contents for Illinois Supplements.

Questions regarding this submittal should be directed to the Area Engineer.

State Conservation Engineer
Dist: All IL NRCS Employees
All IL SWCD Employees

This attachment requires Adobe Acrobat Reader to view:

EFHNotice68.pdf [PDF, 102kb]

EFH Supplemental Illinois Index
9-11-13 EFH Supplemental Index.pdf [PDF, 16kb]

Grade Stabilzation Structure Guidance
IL68 Structures.pdf [PDF, 27kb]


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