I'd recommend finding some beaver ponds to look at. It doesn't really sound like you are looking to plant and maintain a garden, but something more natural. If you are looking for something more garden-like, pictures of Innisfree Garden might help.

I don't think it has as much water as your site, but the well published garden at Federal Twist in west NJ is a similar wet meadow habitat with several small ponds incorporated into the naturalistic design and drainage.

Federal Twist is high end, gardening elite inspiration.

Looks like you have a natural water meadow, but before you go moving dirt, I recommend you take a year to see what is already there. You could have some rare and beautiful plants that you can't see at winter's end. Here is ONE list, and here is ANOTHER. Only after you have an idea of what you have, should you consider changing it.

Does this area have water all year long? If so, you could dig some ponds, but make sure to leave naturally grassy areas between to control runoff. Every place can get a stalled system that rains for days.

Maintaining a meadow means limiting mowing. Late fall or winter is probably the safest time to mow as perennials and grasses will be dormant. Using a weed trimmer is probably a better idea. The tall, clumping grasses especially should be cut at least 6" above the ground. You can cut paths through the meadow this way.

Thanks all, these are great sources of inspiration. What a range of possibilities!

This is going to be a multi-year project to get started. We’re not yet living there, so there’s still going to be a lot of poking around and exploring to see what’s already there, while also trying to make a dent in the multiflora rose, phragmites, and various other invasives. (On a positive note, no sign of Japanese knotweed anywhere…yet)

This year, I’m more focused on learning where the water moves through the landscape, and how it reaches the roadside ditches and drains away.

I took the drone out this morning to get a better shot of the area. Not many signs of life yet, so the photos really flatten out. The central area that I'm talking about is around 150' from left to right. I've highlighted it slightly in the second image. You can see that there's a lot of clumps of grass. I'm thinking that eventually I could selectively remove some of the clumps, and fill in between others, could help to create some areas of open water and channels between them. The water flows towards to drainage culvert in the upper right corner of the first photo, so part of it would be working out the proper levels to make sure things continue to flow in the proper direction.

I have been trying to figure that out. Here’s a shot of the the full property, just under 5 acres. I have been thinking about how I want to move through it, roughly half wooded, half open field. I started a few entry points south of the wet are in the fall, but there have been a few tree falls during the winter that I need to deal with. Paths have definitely been on my mind.

Does the drainage culvert pass beneath the main road, or beneath your driveway and continuing across the front of the property?

Directly north of the west end of the house is one culvert, passing under the road

North east corner is the low point of the lot, but there also appears to be a buried culvert along the same side of the road. The access to both of these is limited and needs to be improved. Likely buried because this property has been vacant for many many years.