[sub]Both are crappy.
Playback will be totally dominated by terran. Terran can do the most with only one exp, zerg and toss will be forced to expand to islands early to even have a chance. The whole middle should be opened up, and a natural for each base. And maybe a choke so its not so easy to run into either base and harass.
Waterback is also terran favoring. Raised jungle is not good for this map, any unit can camp right below and attack the base with ease, expecially tanks. Just think if terran floated a racks to the lower area agaist a toss player. Rines could easdily attack the workers at the minerals untill toss got goons or air. Tanks would be even worse, what if terran captured the lower area and planted tanks and turrets there. The whole base would be destroyed and there would be nothing they could do.
How to fix them? I think you might as well ditch them and start new maps. Few things you should know, 4 expos is hardly enough. Even for a two player map, 6 would be much better or maybe 8 if its a 128x128. Don't try to put starting locations in places that are easily get to, like wide in the open or on raised jungle. Most bases usally have two things, a choke to defend at, and a natural to expand. Zerg really needs a second gas node to tech properly. If you're not going to make your maps symmetrical, try to do a better job at making them even. On playback, reds entrace is much smaller then blues.
If you havent read
this yet I suggest starting there, it has alot of good information on balance.[/sub]