I have a peculiar situation that I am pulling my hair out.

We have had some really heavy rain storms this past year. Back in April 2023 we had 26" or rain in six hours. The entire neighborhood got flooded. I don't mean flooded as in a few inches of water on the road, I mean flooded as in I have 22" of water inside my garage. They said it was a 1000 year event.

Since then we had some additional rain storms, not as bad, but definitely worse then years past.

When that happens, the streets get flooded, my driveway would be under 8 to 10" of water. The street outside would be also 8" to 10" under water.

I have noticed a pattern inside the house, when I flush the toilet, the shower gurgles. This is typically a sign of a blockage, but what's blocking is not a "clog", but pipe full of water!

I have a 4" CO "A" right outside where the main drain exits the house, another CO "B" where the line changes direction, and finally a CO "C" where the drain crosses my property line and head out to the city sewer.

So when I flush the toilet (a few times) and the shower gurgles, I went outside, the ground is wet with a puddle of water, I opened CO "A" and as soon as the plug is loose, water inside the pipe rises and spill over to the ground. I then walked over to CO "B", opened it up and the same. I then went to CO "C", and it too, is full of water. If I close up the CO plugs, wait a few hours, the water will recede and if I open up CO "A", "B" and "C" again, they will be clear and free throwing.

Question 1: If the entire street is flooded, can the stormwater enter the city sewer through the man hole covers, I don't think these covers are waterproof right? Can enough water enter the city sewer to cause it to fill up and back into my pipes?

Question 2: My three COs are only about 3-4 inches above grade, I know when it rains really hard and the streets get flooded, these CO plugs are also below water, and I know they are not waterproof. I tighten them up as much as I can but still they are not 100%. Can the flood water enter through my slightly leaky CO covers and fill the pipes?

Question 3: If the water is not coming in through my CO covers, or the city's man hole covers, then where is this water coming from? Could the city have a break somewhere in their sewer line, and when you have lots of stormwater infiltrating the ground, that water enters the pipe through the break and fill their pipes then my pipes?

What is the best way to diagnose this? Should I do a camera inspection of my pipes? I did one in 2021 from CO "A" to CO "C" and beyond and it was all clear, I can do it again.

yes

not likely

yes

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

city must do a smoke test.

When I opened the CO covers water pushed out of the riser and spilled into the ground. This has to be due to the water filled the pipes, then I flushed the toilet 4-5 times after I heard the shower gurgled.

Should I cut the three risers and raise them say 10" above grade? That won't help the water filling the pipes but will prevent sewer water from spilling into the ground when I unscrew the cover to inspect?

What would a smoke test reveal? Wouldn't smoke just come out of manholes and house vents? If there is a break in the city main pipe the smoke will not show through the pavement right?

one thought just occurred to me. If my pipes are full, then my neighbors pipes should also be fulled right?

I may try to talk to my neighbors. Problem is this is a short duration, like 2 hours later the pipes are clear, so they kind of have to flush their toilets a few times when it was flooding out to notice, and I don't think my neighbors are curious like me to go exploring, and if 2 hours later the problem disappears they don't worry about it.

May be I ask permission from them to go open their CO outside when it floods? Would it look really strange if I go open my neighbor's CO cover when it's pouring outside?

Sum, there are two types of municipal sewers, storm sewers and sanitary sewers. Manholes allow access to the storm sewers that are there to manage storm water runoff. Sanitary sewers manage sewage waste exiting homes and businesses from sinks and toilets. Your neighborhood wouldn't smell very good if there were manholes that provided access to the sanitary sewer.

Sounds like there is a condition present that allows storm water to enter the sanitary system and temporarily fill attached sewage pipes until it drains off. In addition to being an inconvenience for the reasons you mention, it could be creating a serious health hazard due to sewage entering the storm water system when the sewage system drains off the excess water.

Storm sewers usually drain into ditches and other areas where the clean water can be absorbed into the ground, while sewage is routed specifically to treatment facilities where health hazards are mitigated before water is discharged into public spaces.

I would notify the municipality about this and task them to find where these two sewer systems are cross connecting.

why raise all three?
cut and raise the lowest one. if it is clear so will the other two be clear.

the lowest one is the toughest, because it's 6" instead of 4".

I wonder if I can raise it by just connecting to the threaded hub with a 6" male adapter, applying primer and cement to the male & female threads will that make a waterproof joint? I don't have any tools like a giant plier or plumber's wrench to turn & tighten a 6" fitting.

yes, the storm drains and the sanitary drains are supposed to be separated. Actually the two storm drains outside my house do not connect to the city's storm drain system but empties out to the river a block away.

but I noticed when it rains hard and floods outside the city sewer backs up, so I think there must be something happening that allows storm water to enter the sanitary sewers.

I don't think I can ask the city to look into it as it involves something at a certain level to look at the situation at a different level. When I call the city to talk about this it is a public works clerk who takes the call and then relay that to a sewer crew who comes by to look at my particular case.

I did call the city and someone came out and agreed that since the CO at the property line is full of water, then the issue is on the city's end. They opened the man hole cover at the street and said it's OK there (he didn't open it long enough for me to look, he just lifted it and close it within 2 seconds). So the line is blocked between the property line and the main pipe. They will send another crew to snake the line.

I asked why this always happen when there is a heavy rain storm is the storm water entering the sanitary sewers he said "who knows"? He said he was at a job this morning to put man hole covers back into their holes, they said somehow the covers were raised off and flipped over, so he just went to set the covers back. I said those are very heavy covers, may be sewage rose high enough to push the covers off? He just shrugged.

May be the city of Fort Lauderdale is different form other cities?

The crew they sent to me to find out what is happening with the drain, I showed them the CO at the property line that is full of water.

The guy said "oh I need to open the man hole at the street to take a look if it's full there, but I don't have the tool for it, so I will call someone to come out with that tool". So the two of them went back to their truck and sat inside listening to the radio and looked at their phones for an hour, another truck came by, the driver came out and had a crow bar, and used it to pull open the man hole lid half way up for him to look, he said it's OK in the city main. So the line from that CO to the city needs to be snaked, and they don't have a snake and another crew will come to do the snaking, may be tonight, may be tomorrow.

Is that typical? The crew sent to investigate a blocked sewer does not have the tool to open a man hole cover, and the truck that has a crow bar to open the man hole cover does not have a snake to clear the drain.

Sounds like your tax dollars at work....maybe if you call and tell them your sewer is "woke" instead of "broke" they will send out a better crew....