The variable water levels are a factor
I used to live in Bangor (North Wales) and there was a handy country road that led around the main part of the town - but went through a ford half way round
In summer it was only a few inches deep and was great fun on bikes and cars could go through with no problem
In winter locals knew to have a think about recent rain before going that way - it could get a few feet deep quite quickly
although it was kinda obvious - especially as there was a very clear depth gauge on a bridge (for pedestrians)
I used to take my daughter and her friends there on little bike rides - they loved it - my partner at the time thought I was being childish and always insisted the kids walk across the bridge with their bikes!!!!
