What the HEC?


HEC vs. HEC


H&H trivia question: Does the “H” in HEC stand for hydrologic or hydraulic?


H&H trivia answer: Well, the answer depends whether you’re dealing with the U.S. Army Corps of Engineers or the U.S. Department of Transportation Federal Highway Administration. In relation to the Corps of Engineers’ Hydrologic Engineering Center, the “H” stands for Hydrologic, but to the Department of Transportation that publishes Hydraulic Engineering Circulars, it stands for Hydraulic. If you want to avoid confusing them, just remember that the FHA publications always use two digits and avoid dashes (HEC 05 is FHWA whereas HEC-5 is USACE).

For reference, here’s a list of the HEC programs and publications of which I’m aware. If I’ve missed some, please let me know.

Legacy U.S. Army Corps of Engineers Hydrologic Engineering Center Software along with the current software packages that followed from the original FORTRAN code:

  • HEC-1 Flood Hydrograph Package => HEC-HMS
  • HEC-2 Water Surface Profiles Program => HEC-RAS
  • HEC-3 Reservoir Analysis for Conservation => ?
  • HEC-4 Stochastic Streamflow Generation Program => ?
  • HEC-5 Simulation of Flood Control and Conservation Systems => HEC-ResSIM
  • HEC-6 Scour and Deposition in Rivers and Reservoirs => HEC-RAS

Current software supported by the Hydrologic Engineering Center:

  • CWMS Corps Water Management System
  • HEC-DSS Data Storage System
  • HEC-DSSVue Data Storage System Viewer
  • HEC-EFM Ecosystem Functions Model
  • HEC-EFM Plotter Ecosystem Functions Model Plotter
  • HEC-FDA Flood Damage Reduction Analysis
  • HEC-FIA Flood Impact Analysis
  • HEC-GeoDozer Terrain data editor for HEC-GeoHMS
  • HEC-GeoEFM ArcGIS extension for Ecosystem Functions Model
  • HEC-GeoHMS ArcGIS extension for HEC-HMS
  • HEC-GeoRAS ArcGIS extension for HEC-GeoRAS (no longer supported)
  • HEC-GridUtil HEC-DSS gridded data set utilities
  • HEC-HMS Hydrologic Modeling System
  • HEC-LifeSim Life loss and economic damage simulation system
  • HEC-RAS River Analysis System
  • HEC-ResPRM Prescriptive Reservoir Model
  • HEC-ResSim Reservoir System Simulation
  • HEC-RPT Regime Prescription Tool
  • HEC-RTS Real Time Simulation
  • HEC-SSP Statistical Software Package (Originated with FREQFLOW, includes former HEC-FFA flood frequency analysis and Bulletin 17B & 17C, formally called HEC-WRC Water Resources Council)
  • HEC-WAT Watershed Analysis Tool, including FRA Flood Risk Analysis
  • Water Quality Modules built into HEC-RAS, HEC-ResSIM, and HEC-HMS

Federal Highway Administration Hydraulic Engineering Circulars:

Another area of overlap between USACE and FHWA (not to be confused with FHA, the Federal Housing Administration) is that the Federal Highway Administration publishes the Hydraulic Design Series documents, one of which (HDS 5) serves as the basis for inlet-control culvert computations in HEC-RAS. Here are the HDS publication of which I’m aware:

Have a look inside HDS 5 in our Hydraulic Structures Webinar:

If anyone happens to know what became of the FHWA documents HEC 02 through 04 and HEC 06 through 08 along with HDS 1, please let me know so I can complete my list! I’m also curious what current USACE programs HEC-3 and HEC-4 morphed into if anyone has further information to offer around that.

Finally, for the real retro fans, here is a list of FORTRAN programs that the Corps of Engineers was using in 1973, most of which ended up incorporated into one or more of the subsequent HEC programs (from Bugliarello and Gunther, Computer Systems and Water Resources, 1974):

 


HEC Chronology 1964 – 2014 from a photo I took of a wall poster in the HEC offices. [Note: if anyone has the original pdf or a better quality version of this, please let me know so I can replace these images]

  • For nostalgia’s sake, here is a screen shot from HEC-RAS Version 1.0 from Chris Maeder’s “Road to HEC-RAS” article:


And just for fun, here is a bit of the background around HEC and the Corps of Engineers as addressed in the online polls during our recent HEC-HMS webinar:

The HEC offices are located on the second floor of a shop in Davis, California. Pop quiz Question #1:

Are the HEC offices located above:

a) Cookie Shop
b) Shavery
c) Kava bar
d) Wine bar

Other nearby choices include a smoke shop, sushi shop, Bizarro World, Ho Ho Market, and lots of pizza and coffee but the answer is all of the above. Here is a map for the key:


Pop Quiz Question #2:

Which is oldest?

a) Australia
b) United States
c) Corps of Engineers

Answer:

c) The “Corps” of Engineers comprised a chief engineer and two assistants who were appointed by George Washington when the Continental Congress organised an army on 16 June 1775, with the first task being the construction of the Bunker Hill fortifications. More from Wikipedia: U.S. Army Corps of Engineers


Pop Quiz Question #3:

What are these kayakers doing?

a) looking for the remains of Greased Lightning
b) bathymetric surveying
c) publicity stunt questioning the definition of “navigable waterways”

Read more about the controversial expedition here.


Please let us know if you are aware of any other resources we should highlight here!