I've been seeing this water bird all spring and summer, but usually it was because I startled it and caused it to fly away. In flight, it looks very blue. I got lucky at dusk tonight, and captured it catching fish. I wish I could have gotten closer. This was taken from about 15' away. I've identified it as a Green Heron.
Here's how it is described in Birds of North America, " Common, locally abundant, in both fresh and salt water. Found more than other herons in small ponds and along wooded streams. Looks more blue than green. Told by its small size, dark underparts, and bright orange or yellow legs. Flight is rapid, with deep wingbeats. Appears all dark at a distance. The crest is not always visible. Neck is comparatively shorter than that of other herons. Call, a sharp, descending kew." According to the book, the average length is 14" with a wing span of 25".