We have just had a torrential downpour flooded the front garden and back as it runs down into the back. luckily it didn't go in the air vents, but next door had water in their garage went over their sandbags,
Plus one side of their house is in our front garden and back and it went in the vents to their house that are on our side.
couldn't flush the toilet as the drains were so backed up water was at the top.
Just ordered some vents to clip over the air bricks if it rains hard again to ensure it doesn't go under the bungalow.
£103 we weren't expecting to shell out for today.

My Lord thats scary. Hope you get the vent covers quickly and I suspect they will be worth having on all year round.

There is something you can get to go over the loo that stops water coming back out as well if overflowing

Will have to look into that Kazz. Thankfully it didn't overflow just got to the top and stayed there. Didn't dare flush though.
The vent covers clip over a frame so you can take the covers off which we will need to do if not threatening heavy downpours. They clip onto the frame easily though if needed.

The toilet thing was not expensive I think about £30-£40 from Amazon I think or screw fix can't recall. But the fireman said it had saved a lot of disaster of sewerage coming back up to say the least called a toilet seal

Yeah.. agree with kazz, it was a lock type thing that kind of covers the pan. Not any help for now, but maybe there's a charitable type place that does flooding stuff, not what anyone wants or needs!