Here are some sirens I have taken pictures/video of that are on or near water towers.
One of Jones' Thunderbolts is next to a water tower. The tower is not shown in the picture. No video.
The T-128 in Okarche, Oklahoma is near both of their water towers. The 2T22 shown is not there anymore.
http://www.youtube.com/watch?v=k8EgiOGpzq4
The Sterling M (16/16) in Calumet is mounted on their water tower. This town is the only one I know of so far in Oklahoma with a noon whistle.
http://www.youtube.com/watch?v=5tcgR-79L1I
This Allertor (one of three) in Piedmont is near their water tanks.
Not the greatest pic, and you can't see it, but this 2001-130 in Edmond is right next to an Edmond water tower.
http://www.youtube.com/watch?v=jLVYmTnhgNs
Allen, OK has a Model 5 on their water tower. No video.
Hinton, OK has a Sentry 40V2T on their water tower. Video belongs to Cory Watkins. I will be filming this siren in January.
http://www.youtube.com/watch?v=MqemGLVapq4
This REALLY low Thunderbolt in Amber, OK is near a water tower.
http://www.youtube.com/watch?v=PQ0Gt3e9lb0
I got to set it off!
http://www.youtube.com/watch?v=Xrb2Pct62QA
(Didn't know what he said at first, I had hearing protection. So I kinda stood there retardedly.

)
Bucklin, Kansas has a Thunderbeam on the water tower near (I think) a Federal B. No video.
A Thunderbeam in downtown Kingfisher, OK used to be near a water tower. The water tower was removed. This siren also replaced a Thunderbolt. In street view you can see a blower and controls, but no pipe or head. The mount is still on the tower in the image though.
That's all I have for now.