Hugel down instead of up?

I'm going full speed ahead making plans to expand my hugel operation at my place.  My ground is flat as a pancake.  I've been running a test hugel mound for a couple years now, and i'm sold on the concept.  Now it's time to scale up in a big way, but with one big modification.  I wanted to run that by this group for feedback.  

Instead of building a hugel mound, I am planning to make a hugel trench.  I've got access to heavy equipment and endless supplies of wood.  My experience with the above ground hoog was not good in the drought this past year.  I am water challenged at my site, so watering is out of the question.  Then it hit me.  Why don't I just go below ground instead of above ground?  

I plan to source some large logs from my woods and use them as raised bed borders.  From the outside looking in, they'll look like simple raised beds, maybe 8-10" above the soil surface.  But below it, I'd like to go 5' deep and backfill with as much wood/brush/stumps I can get my hands on.  I'm not rich in topsoil either, but I've got enough piled up I can give myself maybe 6-8" to begin with, and lots of wood chips to boot.  

So, I'm gonna bury my wood instead of mound it up, to outlast the drought.  What says the community?

I think your path can work.

Many people follow your basic idea, I did. I believe some people call it a hugel beet. I don't really know why, but that search term may help you as you look at other plots.

Going down also gives you a lot of soil material to put on top. That will help with your first year's crop, since it's essentially tilling the ground. After that you can do no-till and compost or mulch as the wood decomposes.

I think my first year of plants got a huge boost because of that effect. The second year wasn't so happy... I'm hoping the third will bounce back as the wood stops sucking nutrients from the soil.

my understanding is that ‘beet’ is just german for ‘bed’, so hugelbeet is an appropriate name for any hugel-type planting area, in-ground or on.

You might also try the term buried wood bed, or sunken hugel. Here is one thread about a terraced system.

Here, Tyler made her whole garden this way in Texas.

Here is a newer concept Mathew is calling a hugel path.

Darron explains 5 hugelkultur variations.

Good luck!

been there, done that in my terraces on heavy clay (not on your scale though!!), it was a great solution (especially to avoid having all my good stuff wash downhill).
Good luck and take pics-- tell us how it goes!