When I started my aquaponics setup, I dug a smallish (4 foot x 8 foot x 3 foot) pond. Ended up using a different tank so I decided to use that for hugelkultur. I filled it with wet logs and decomposed matter, mostly oak limbs and bamboo. Next, a friend and I built a retaining wall out of 2" hickory lumber from a local mill. Filled that with a dead oak that was razed a year ago. Next I put a bunch of hedge trimmings on top until they were mounded slightly above the bed. I'm adding compost and manure, though I only have one bag of each so it won't go far. Anyway, it is off to a start.
I dig it. 😀 I'm not ballsy enough to add bamboo but I do hope it works for you. I built one similar last year as drought protection. Well then we have the wettest summer on record! Everyone else gardens failed but not mine. All the excess water stayed far enough down to prevent wet feet. I planted beets, broccoli, zucchini, sweet potatoes, and black eyed peas and it all did wonderful. Just be careful to have all the wood completely covered by dirt and other organics. Any wood sticking out will wick moisture away from the plants. Thanks for posting.