Hiss, then a river of water flowing below floor boards

That is never good !

I was working today in my little office in the V-berth and I heard a noise, not to loud, but a sort of Pffsstt sound.  I didn't recognize it, but I looked toward the back of the boat and could see both cats in the galley so figured they were batting something around on the floor to play with it.  As I watched them for a few minutes, I noticed that one was sniffing at one of the joints where the galley floor opens to expose the engine room.
The other was on three steps that lead down to the lower salon and also facing the stair sniffing at them.

Hmm, that doesn't seem right.     As I walked over to check it out I could hear a motor running and assuming it was the bilge, I wasn't sure what I was going to find.  The water was less than a foot deep in the lowest portion of the bilge where the standard bilge pump is and it was running.  The water was just getting up to the height of the second and third high output bilge pumps.

I noticed a stream of water shooting upward, but luckily it was not coming from a thru-hull location.
I realized one of the fresh water T connectors had broken and the water was shooting vertically up from that about 3 feet and just causing a river toward the lowest part of the bilge.

The good news is that I was able to just turn off the fresh water pressure pump and the water flow stopped.  I figure it was a good time to test out the high output Bilge pump so let it run for another few minutes to get the water in the bilge about 16" deep or so.  Sure enough the high output kicked on and emptied a LOT of water in about 30 seconds and then it was just the small pump to clean up the lower water level in the sunken portion of the bilge.

So I have a project to do, I will like do a quick patch on this for now as our intent is to replace all of the plumbing lines on this boat any way with PEX.  A few of the joints from Copper to Poly were dripping so we knew we needed to upgrade it.  When it was working it was a bit lower on the priority level. Now that this happened, it has moved to the top of the list.

Such is the way it goes with project prioritization.