A hardy welcome to the PB forum.
The pond design is close enough to the house for aeration that will produce better overall water quality so I would consider a minimum of 8ft depth and better if it was 10ft that allows for droughts and low water conditions and leaks. Many pond's water level is 2-3ft below top bank thus 8ft leaves you with 5-6ft of water. A leaky pond is a distinct possibility if less than optimum soils and poor building methods are used. Proper soil/clay is utmost importance in your case. A leaky pond usually costs as much or more to fix as to originally build the pond. Study this thread on pond building and proper soil compaction:
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=92487#Post92487Many pond construction guys get is a hurry to finish and create too thick of soil lifts that are not properly compacted - thus leaks commonly occur. All soil bottom ponds leak, the degree of leakage is the big variable. There are also soil additives to reduce soil permeability pre and post pond building/filling.
A pond will accumulate sediments over the years to annually cause shallower depths, so plan for this to occur. Rate of fill in is dependent on water shed and fertility. Normal fill-in rate is 1" per year.
A smaller pond with a high fish biomass should have aeration to optimize water quality. Adding depth in poor deep soil structure can be done by using up-ground embankment design. Be aware without very good compaction, not a wide enough embankment, and poor building methods many of these ponds leak. Up-ground ponds have no runoff to help keep them full.
IMO not a lot needs to be done to create "shelves, trenches and varying depths". These structure features IMO are designed for larger ponds to concentrate fish and not necessarily increase productivity. The small golf course ponds lacked structure where you caught large fish. So structure in small ponds is not really needed to grow big fish.
However in a 0.3-0.5 ac pond where can the fish go that you cannot reach them by angling? If you are not catching them, something is remiss. Many, many reasons for lack of angling success. Increasing productivity and producing big fish in small ponds can be achieved with feeding the fish &/or fertilizing together with proper fish management. Lower fish numbers usually results in bigger fish because they have more food available. Crowding decreases available food and stessors due to crowding and water quality.
For a small pond with great angling excitement consider the suggested HSB with hyb bluegill (HBG) and pellet feeding. This stocking method allows for a years later relatively easy shift to LMB-BG combination. Since you are from AK and have close access, you should research the relatively new HBG called the SSS southern specklebelly sunfish. These with HSB and pellet feeding, would create a exciting fishery. By all means keep us updated on your pond progress using this thread which could be the history and notes of your pond.
