Here comes a stupid question, what is with all the various size and shapes of man make lakes and ponds in the part of Florida?
Do landowners dig these holes to collect water (ground or rain water), farm, grow crocs, or what? These areas have to be breeding grounds for who-knows how many varieties of flying and crawling bugs ...
I think the reason is that the elevation is so low that basically any swale fills with water. It's not like property owners dig most of them.
It's also why there are no basements in Florida -- if you dig a hole in peninsular Florida, it will fill with water because the water table is so high.
Futhermore, developers build retainage ponds so water has somewhere to go. Because it's so very flat, when hurricanes come there is no where for water to run too. So these ponds act as a capacitor. Finally some are built for irrigation purposes. In many places public water is used for irrigation. But because of the heat & sun you have to irrigate more often in Florida and so homeowners used reclaimed water from these retainage ponds for water lawns -- which means it stinks. But it's better environmentally and cheaper than using potable water for irrigation.
And you're right about breeding ground for who-knows-what: When I moved here 3 years ago I learned that gators aren't the biggest thing to be afraid of swimming in Florida's lakes -- it's the one-celled organisms that can cause nasty infections if either swallowed or they get in open wounds.