No! That hole with the cable running through it is where the scuttle panel area drains down through (via the back of the wheel arch liner). Blocking these drainage holes would create a flood and drown your ECU. You need to check that the black grommet to the right of the pollen filter housing is secure though. That cable is the wire to the side repeater on the wing.

It has been ages since I looked at the underside of the drivers door for drainage holes, but there appear to be at least three at the far end of the door.

Woops!!

So, I had to removed my little diy bung that I'd already put in place before you replied.

The grommet looks okay, but I attempted to seal around it just to be sure.

I also looked at the door again. The holes are not visible in that photo; they are on the other side of the door seal to the right. There's a narrow gap between the seal and the edge of the door, and the holes are along there.

They're not blocked, though, so that's not it.

What do you mean by 'door membrane cut in the door panel'?

Inside the door, there is a membrane, which is quite often cut when people fit after market speakers, replace window glass, fix window motors, etc. If cut and not sealed properly it can cause the water to drain into the car rather than out of the holes in the bottom of the door.

You're a legend!

As I was working at this, it started to rain and I noticed water dripping into the pollen filter.

Is it possible that water could get in around, or drop inside the pollen filter unit and cause ingress issues? Or is that unheard of?

Some people have found that poorly fitted filters can cause a problem, and in the odd instance, the filter housing isn't sealed well. However with the scuttle panel on, not much (if any water) should actually end up on the filter or housing. The grommet to the right is in the direct water flow line on the passenger side for water draining off the windscreen.

have the same problem rear and front drivers footwell flooded on my 2003 tdi octavia estate will have a look at what you guys have said above hope i can get it sorted.

I have had problems with a wet drivers seatbelt for year on my octy 1 hatch.

 

I have checked drainage at front - no problem

had roof rails off to seal and repaint - no problem

waxoyled around door hinges etc - no problem

checked the rubber wiring loom boots - not problem

had door card off - no leaks

 

but still I get a v small amount of water pooling on the door seal after v heavy rain, and in any type of wet weather the drivers seatbelt feels damp.

Coming to the end of my tether on this, it is time to try a new door rubber?

calling rbaldwin? can you help me? I can't have been the only octavia owner to have this problem.

If you mean rwbaldwin, he has not been active on here since mid March this year I'm afraid - shame, very knowledgeable fella.

I have had problems with a wet drivers seatbelt for year on my octy 1 hatch.

 

I have checked drainage at front - no problem

had roof rails off to seal and repaint - no problem

waxoyled around door hinges etc - no problem

checked the rubber wiring loom boots - not problem

had door card off - no leaks

 

but still I get a v small amount of water pooling on the door seal after v heavy rain, and in any type of wet weather the drivers seatbelt feels damp.

Coming to the end of my tether on this, it is time to try a new door rubber?

Not too far away in that I had a 2003 Passat on a B5.5 platform. No leaks at all but drivers belt always felt slightly damp when pulled from spool. Have you felt the passenger belt .........

all other belts feel fine - this one definitely get damp from somewhere but I've ran out of ideas to fix...

As Tomah showed, periodically you need to get behind the plastic mud guard to remove the leaves etc that have fallen down the windscreen trough and are now merrily composting at the bottom of the wing panel, blocking up the drainage grommet and allowing the water level rise so that it can drain into the passenger compartment.

I have done this too, to no effect

 

also should add that it is the drivers belt that gets wet, passenger one is bone dry

Edited 12 October, 201510 yr by STSKODA

You haven't got a sunroof have you? Took me weeks to track down my leak. Had that amount of mud behind the wheek arch also.

If your foot well is wet it is likely to be the drain hole being blocked to check pour water over screen if it does drain out of mud flaps area then leaves are blocking the hole .

https://imgur.com/a/tEFGT with this gap you can clear out the mess . You will have saved taking off wipers and surround plastic which can lead to you breaking the windscreen.

 

Next tip is the mud clearing from behind the flaps , there are 2 screws to remove , you do not need to take the wheels off you can prise out the nylon flap and use a screw driver to clean the mud out . These tips will save you about 1.5 hours. 

 

https://imgur.com/a/6YiVk