... If you hear this

http://gfretwell.com/wildlife/Mom%20and%20baby%20gator.mp3

That is a Mom and baby alligators.

No Video??

They never saw the gators, they were down the pipe a ways. Animal control came out and verified what the sound was and said they are just part of nature, then drove away.
It was originally reported as a "puppy in the storm drain".
Because they were connected, the sound was coming out of several storm drains so they got multiple reports.

Gators in the manhole?

Well ....

That's one way to solve the puppy problem

These storm drains usually just go to the retention ponds on the property and any body of water here is likely to hold a gator or two.