I'm an American living in the Netherlands who is learning Dutch. There's an idiom in Dutch that describes performing a needless/futile activity, "water naar de zee dragen," which literally translates to "carrying water to the sea." My Dutch parents-in-law asked me if there was an English equivalent, but I couldn't think of one.
In doing somesearchesonline, I found that the English translation given for the this idiom is always "carrying coals to Newcastle." This was the first time I'd ever come across the phrase, and subsequent searches revealed that it was indeed of Britishorigin, though one site I found did claim that it was an American phrase. However, neither I nor any of my culturally American friends have ever heard of this phrase.
Is there an American English idiom or phrase that carries the same connotations for carrying out a futile activity?
A Chinese fire drill (a large, ineffective, and chaotic activity carried out by a group of people that accomplishes nothing—but note that, as the Wikipedia article points out, this phrase is uncommon today due to the politically incorrect ethnic reference.)
I've heard "Watering the garden (or lawn) in the rain". The meaning would probably be very clear to most people but I strongly suspect it's not in common usage (except to the few people I know that use it often).
"Tilting at Windmills" has a connotation of needless/futile. Although admittedly also with a connotation towards fighting unwinnable battles.
Sisyphean comes to mind as an adjective. This could be extrapolated as "pushing a stone uphill" but it tends to only be properly understood among more academic types, due to its roots being in Greek Mythology.
"Pushing rope" or "pushing a rope uphill" would be the closest thing I can think of that I've actually heard in conversation.
Swimming upstream. I agree with Frustrated. Wrong connotation.
I once attended a technical presentation near Tektronix headquarters in Beaverton, Oregon. The presenter was from the UK, and for some odd turn of events, his company had actually moved some coal towards Newcastle once.
The best part was that after having made the reference, later in his presentation he talked about designing some high-speed oscilloscopes. One of the first clients? Tektronix. (The irony here being that Tek was the world leader in scopes for many decades.)
So the US equivalent could be "selling scopes to Tektronix". :)
Programmers tend to use the expressions "yak shaving" and "bikeshedding". These expressions tend to be used in reference to losing view of the big picture and spending inordinate amounts of time on incredibly trivial things.
Another option is "gilding the lily", although it carries a connotation of an activity which occurs after a task should already have been completed, or has already been satisfactorily addressed by other means.
Many of the answers given here have involved futile tasks, that are either impossible to complete, or will be immediately undone. They're missing the point of the original question. I wouldn't call carrying coals to Newcastle exactly a futile task. It's certainly easily possible to do, but the point is that it's completely unnecessary and pointless, and therefore a waste of effort.
Phrases such as teaching your grandmother to suck eggs (unnecessary, she already knew how to do that) and rearranging the deck chairs on the Titanic (a pointless task, as they'll be in the drink soon enough) are my favorites among all those mentioned, but may not be of American origin.
I've heard of the phrase "bringing sand to the desert". I'm from the west coast of the United States. I'm not sure how common it is, but I feel like a native speaker would understand the intended meaning (as with many of the other examples provided on this thread).
"Go find you a white crayon and color a fucking zebra" - This lyric from Eminem's song "My Mom" (off of his Rehab album), represents the ultimate in futile efforts: coloring a black and white coloring book white.
How about "an exercise in futility?" It's not as picturesque of an idiom but it's certainly spot on in expressing "pointlessness" as opposed to "unimportance", "difficulty", or "tediousness" like some of the other answers.
"Carrying coals to Newcastle" is futile and unnecessary because it is completely the wrong way around. It refers to doing something in the opposite way that it should be done, or in a manner contrary to logic.
It depends on the context you are using; if you are talking spare time, it might be “watching the tube,” and referring to finances, it might be “robbing Peter to pay Paul”. In the United States, we have so many idioms used each day, that we have new ones we hear all the time. I like to call it writer's or speaker's license. I think that is why people from other countries have problems at times understanding us, because they take us literally, instead of figuratively. An example would be to “kick the bucket”.