I went to a carwash recently with a friend, somewhere in Enugu Nigeria. On arrival, I noticed to my surprise that the surrounding that was previously dry and serene the last time we visited, was completely flooded, though it rained heavily the night before but it was only for a short period of time.
Curious, I inquired on how short duration of rainfall could make such a big mess. One of the guys that work there was quick to tell me that, the carwash is located in a valley, and as a result, most of the rain run-off from the different part of the city converge at this point.

As I was about to take a seat, my attention was drawn to the boys fetching from the stagnant water (flood) to wash the cars and tricycle (Keke) drivers at the other end washing their tricycle with the same water. I approached one of them to know if they are aware of health implication of their act. He told me that he knows it's unhealthy to drink the water but sees nothing wrong with washing with it.

That brings us back to our topic, is this man right? Or are there really any diseases contracted from making contact with such water sources (stagnant water, fresh water, slow flowing water, and irrigation)?

Yes, there are lots of diseases one could get by just making contact with such water sources, they are called water impounding diseases (Diseases that are transmitted by contact/wading through the water). In fact, such water could be a source of an epidemic outbreak of these diseases, all it takes is for one infected person to defecate or urinate close to the water or even far from it, and the rain floods the infected faeces into the water, then whoever makes contact becomes infected. The organisms responsible for these infection penetrates the skin to enter the bloodstream from where they are carried to other parts of the body where they cause different types of disease.
read more at http://intimemedics.com/stagnant-water-health-hazards-why-you-shouldnt-make-contact/