I've searched the forums and come across a couple of threads but not been able to identify if I actually need to do anything with regards to this problem.

I hit a semi-deep puddle on the way to work this morning at about 15 or 20mph, and about 10 seconds through the experience, water was pouring in from somewhere around the passenger footwell area.

I've identified that it could be through the pollen filter...

a) Is there anything else it might be?

Do I need to get anything repaired, or just dry out the interior of the car and not drive through deep puddles?

I did the same thing to the extent that the heaters were blowing steam into the cabin and you could hear the fan blades paddling in the water.

I would suggest that you pull out the pollen filter (remove the cover and pull the cassette with the filter downwards) and dry it out and run with the aircon on as this will help dry out the air in the cabin.

I did this in the summer so the car interior dried out quite fast but the air system took a LOT longer - about 4 months I think.

Don't think that there's been any lasting damage.

Oh yes, I found out doing something else later on that if you remove the pollen filter, you can actually reach up quite a long way inside the vent pipes and touch the fan so it might be an idea to get up there with a rag and soak up any puddles - I think that the fan's in a bit of a dip which seems to hold water.

Thank you! Now I have to find out how to remove the pollen filter (one assumes it's very simple and done from inside the cabin) - the car's in the car park 1/2 a mile away so I can't run outside and look, haha...

I was concerned about damage to electrical items such as fan motors mainly!