This is a level trail made of gravel fill that connects two lake loop trails. There is a lookout tower on the west end of the trail and a small dam in the middle that keeps the water on the north side deeper than on the south side (hence the name spillway). If it's been dry, there may be no water flowing over the dam, in which case you could also hike along it rather than taking the bridge. Look for alligators and birds on both sides of the trail.
Parking is available from either loop, so access is easy from either direction