Jane
Yes, your moth is the Imperial.
The more yellow color tells me it is a male, the females have more brown markings. Here is a photo of both -http://bugguide.net/node/view/465919/bgimage
This is one of the giant silk moths in the family Saturniidae. Being so large they do fly rather awkwardly. It probably came in to lights and ended up in the pool.
The adults come to lights at night. They do not feed.
Larva come in a green or brown coloration. According to Bugguide, larvae feed on leaves of Bald Cypress, basswood, birch, cedar, elm, hickory, Honeylocust, maple, oak, pine, Sassafras, Sweetgum, sycamore, and walnut.
The larva pupate in burrows in the soil. The pupa stage is what overwinters, so the adult comes out in summer.
They are beautiful moths. Here are photos of caterpillars and moths - http://bugguide.net/node/view/4757/bgimage?from=0
