Here's a peeve of mine: baby-talk conjunctions in professional writing.

"The cause might be heavy rainfall or impervious surfaces or poorly-designed revetments."

instead of

"The cause might be heavy rainfall, impervious surfaces or poorly-designed revetments."

To me, the first way is how children talk. They start a sentence, then they add elements with "or" or "and" as they think of them. A professional should think ahead.