I need to see wet soils remain moist and open.
Soil wetness is an important diversity factor. Natural wetland or moist soil qualities are hard to duplicate. Luckily, you may not need to try. On one hand, if you have moist areas, wildlife are already busy there. On the other, if you have no wet soils, local box turtles have learned to get enough water from food, dew, and rainfall. Turtles can adapt to drier conditions if that is the nature of their birthplace. They may suffer if accustomed water sources disappear.
If an area resembles a wetland, leave the soil alone. It is hard at work. Watch the area through the seasons, and you will love it just as the turtles do. If moist areas have been filled recently (who would do that?) it will be hard to correct that unfortunate loss. Once you alter soil profiles near wetland, turtles may abandon the area for a more stable site.
If you must work in a wetland, focus on vegetation. Ask a native plant expert to view the site with you. (What's good for native plant communities usually helps box turtles, too.) The best guide has more ties to land trusts and universities, and fewer to government or sporting groups. Avoid 'conservation' or 'wildlife' specialists, who promote non-native plantings to benefit game species. Rabbits and deer are easy: set higher standards.
You may hear surprising ideas. Certain brushy plants must be cut or pulled (or even poisoned by painting herbicide on fresh stumps). Other flora may be rare, and at risk from weedy intruders. Those extremes intermingle more in wetland than in meadow or woods. A qualified ecologist may suggest controlled burning, especially of grassy areas, to keep them from being overgrown with woody plants. Diversity requires sunlight.
Many species use standing water, but you must not destroy existing wetland to create it. Wetland functions are worth far more than a little blue-green circle. Box turtles are terrestrial. They use standing water only to cool when they have an infection, fever, or other irritating condition. For them, typical steep-sided dug ponds are more a trap than a treasure.
For more box turtle stewardship guidelines, see Habitat from Humanity.