SMB, HSB, YP, HBG are the fish I will be stocking. I want to add some structure but still be safe for swimmers. I know I will have some rock areas and gravel/pebbles around some of the pond for easier entry (no muck )...or less muck. Reviewing and think some of the flexible tubing ideas could work as well.

Any suggestions?

Keep it away from the swimming area.

I am having a hard time thinking of anything that would be "safe" structure in or near a swimming area. Anything that gives a fish a place to get into and hide or hangout potentially lends itself to trapping a foot which could hold someone under = Bad. Rock piles of any sort could lead to head injuries and /or cuts.

The least dangerous ideas might be tires or flexible hose like assemblies that have NO loops, BUT I would not swim in the areas nor let anybody else. esshup is absolutely right - keep the structure out of the swimming areas.

Yeah, that is somewhat the problem...you tell kids don't swim there...what do they want to do? Probably just keep it safe by using some rocks towards the bottom, pea gravel , and then maybe some flexible material that would not trap...everyone will be required to have a life jacket on and we are adding a swimming pool so really shouldn't be a big need to swim in the pond but I know it will happen some....

Not a huge fan of them, but how about building some out of old tires.

Don't ponds in summer heat have a high chance of having the brain eating amoeba present? Especially when the bottom is stirred up by swimming? Nose plugs and life jackets should be mandatory to help prevent intake of pond water.

I have swam in ponds and lakes my whole life, and so have most of my friends, and never heard of the brain eating amoeba till a few years ago. It is so rare, not sure it is worth worrying about. You are 1000s times more likely to drown than be killed by the amoeba.

It (amoeba) seems to be more common lately, or maybe more diagnosed?

You only need some structure and not everywhere. None in swimming area. Is there a pier/dock. If so that is a big structure. See the structure archive for ideas. Small variations in bottom hight can work well (1-2 foot hump or mound for example).

Maybe?

But I look at it this way: today there is instant media, and flesh eating, brain eating gets a headline because it is flashy and garners clicks (advertising, cash). 30 years back there wasn't a program MONSTERS INSIDE OF ME. Now there is.

I think the Internet has made information, real or false, much more readily available. It also pushes information to people who never sought it in the first place. Further, it has forced many old school channels, television news, to change their format and content to keep pace.

Flesh eating, brain eating, etc. would s**k for sure. But yer so much more likely to get injured, maimed, or killed by someone texting while driving than you are a parasite in your pond.

That said, I won't be surprised to learn that somewhere out there someone has built a pond that is at least 12 feet deep at the edge and with a concrete bottom with a lip around the edge to keep runoff dirt/soil/silt out ...

Certainly the incident of infection by any water borne pathogen is basically small. Especially in a remote natural pond. But as Nature would have it, the incident of infection is in direct proportion to the level of human use (immersion). The more people that utilize a body of water for recreational swimming coupled with the level of use (cumulative person/hours)the higher the chances of infection. E coli is a prime example of this relationship. the occurrence of intestinal parasites such as Giardia and Cryptosporidium also relates directly to the frequency (and hygiene) of human use.

Here's a thought, don't know how good or bad it is. BUT first, I agree with ewest, keep the cover away from the swimming area.

What about taking swimming pool noodles, sticking a piece of pencil rod thru one end, and sticking a number of them in a 5 gal bucket of concrete? Enough to sink them, but they'd be the "Nerf Ball" of pond structure.....

I like that idea, will have to try it out and try to post some pics. Not sure how snag resistant they'd be but would be safe.

They will be hook magnets.....

You might be able to rip the hooks out of them with stronger line.

We swim in our pond all the time. I bought a dock building kit from Menards, and put a ladder on it. There just isn't a easy bank to get in and out. I kept the sides steep, to keep weed growth down.
I built structure from plastic pipe and tubing, plus I've submerged three big cedar trees. I just marked it with four different duck decoys. They aren't too bad to look at, and it tells everyone where to stay away from. So far, so good. I don't mind swimming near the cedars, I've even moved stuff around while swimming.
One other thing to consider. I have SMB, YP, HSB, RES myself, but added HBG. The HBG really attack floaters. They draw blood, if given a chance. I run a feeder too. Great for the grandkids to catch, which is why they are there, but I now swim with a shirt on.

Our kids got bit by BG occasionally. They really did not give it much thought - Farm kids.

Ha! I've swam in a million farm ponds. This is 100% different. My HBG are crossed with piranha!

Edit, maybe it's because I'm floating now, with an adult beverage. Kids swim, I just float.

We teased my son that he needed to where a girls bathing suit when he was attacked (and bleeding). It did not phase him anymore than when he got bit catching snakes (non-poisonous).