With special thanks to links provided by new poster, OliveLeaf ... now a person can see how much Lake JB Thomas has dried up in the past four years.
I believe SA took Hailey's body out to Lake JB Thomas with the intention of dumping it in the water. That doesn't mean he tried to throw her out in the middle of the lake. All he needed was enough water to help hide and decompose her body. He may have even buried her in part of a semi-wet mud flat at the edge of the lake.
If you look at the two maps below, you'll see where water fingers of the southeast end of Lake JB Thomas have dried up between October 2008 and November 2012. Any one of those little inlets/mud flats could have been where SA dumped and/or shallow-buried Hailey. SA didn't count on our extended drought to reveal his handwork.
SA's previous residence was near (ironically named) Dunn, TX, which is only 17 miles due east of Lake JB Thomas on Farm-to-Market-Road 1606. SA knew the lake and that area well.
And while we're on the subject; most children are killed by their mother's boyfriends. SA made Hailey uncomfortable, and he was into violence and *advertiser censored*. IMHO, SA tried to rape or molest Hailey while he was alone in the house with her, and she fought back. She may have screamed out, and SA suffocated her to stop her screams. SA walked out on two polygraphs and failed a third. He is the last one to see her alive, and we know he lied about where he was the following morning.
Oh, and before someone goes off on possible sex offenders in the area who left after Hailey went missing, that was thoroughly checked out by LE long ago, and there were none. Don't you think if one of them did leave, it would have been a red flag to LE? You have no idea how small Colorado City is, or how sparse the population is in this area of the country between Midland/Odessa and Abilene. There have been no other girls who have gone missing, except for known runaways, in the past several years.
Hailey has been the focus in this part of Texas for the past 2 1/2 years, and I don't know of one person who believes it was some transient or a sex predator or psychopath. Most people are killed by someone they knew. Hailey knew her killer, and her killer knew just where to hide the body because he was familiar with the lake and the area. A transient would not have thought to take Hailey north to Lake JB Thomas, but would have left her on a nearby oil lease or ranch road. Means, motive and opportunity. SA had them all.