Storm Sewer - HEC 22 Service Pack Changes

[fcernst]

Can you please clarify to us what has been done?  For example, has the junction loss method been updated to the latest version of HEC 22 (HEC 22 3rd Edition, September 2009)? 

By what the old help is says, Hydraflow Storm Sewers is using the HEC 22 Approximate Method for junction loss, which is not to be used for final design.

I didn't see any changes in the Help.

[Matt.Anderson]

Storm Sewers follows the methods outlined in the second edition of HEC-22.

The changes occured in both 2012 SP2 and 2013 SP1 are specific clarifications to methodologies outlined in the 2nd edition of the manual.

[fcernst]

Ok, yes that manual is from 2001 and was superseded three years ago. The latest is the 3rd Edition from 2009.

Major Changes in 3rd Edition 2009:

"Page 7-16 – Section 7.1.6.7 has been totally revised to reflect a new methodology for calculating energy losses in access holes."

Page 7-34 – Section 7.5, the energy gradeline computational procedure has been completely changed to reflect the new energy loss methodology.

• So for junction losses, are they using correction factors for diameter, flow depth, relative flow, plunging flow and benching from the Second Edition 2001? Or the Approximate Method which was only meant to be used for preliminary design,  not to be used for final design?