We had a similar situation on a former property we owned. We sculpted our wet area (which in mid-summer was nothing but dead weedy sod in a sea of lawn) into a naturally shaped shallow pond. The soil from the pond excavation was used to form mounds around the edges of the pond which we planted with trees, shrubs and perennials. We lined the pond with gravel and rocks of various sizes so that when the pond dried out, it would be more decorative than just mud. The pond attracted a large population of volunteer frogs and toads which kept the mosquitoes at bay. The pond was definitely a focal point of the yard, it looked great when viewed from the house and it gave us a reason to wander about the landscape. Having said all this, if I were to do it all again, I would skip the excavation, gravel and rocks and just plant rain garden type native plants that could tolerate periods of drought and flood. The gravel bed became a chore trying to keep the weeds at bay. Seems to me that a native planting would be more carefree after the first few years of establishment.