Ok, if the HOA
won't voluntarily remove the head or take action to prevent any flooding of your property, then you will have to take legal action to force them to do so under the doctrine of "private nuisance
". A private nuisance is an interference with a person's enjoyment and use of his land. The law recognizes that landowners, or those in rightful possession of land, have the right to the unimpaired condition of the property and to reasonable comfort and convenience in its occupation.
So if their actions in operating the sprinkler are damaging or preventing you from using your property, this is a private nuisance and you can sue them in court to get an injunction forcing them to abate the nuisance.
If you didn't want to jump right to litigation, you can have a local attorney send a "cease and desist" letter to them basically threatening to sue for damages
, court costs and attorney fees for private nuisance and property damage if they don't relocate the sprinkler or otherwise take action to prevent any overflow onto your property. You would probably be looking at $150-200 for the letter, but in many cases, this would be enough to "encourage" them to abate the nuisance rather than be dragged into court, have to hire an attorney to defend, and lose and be responsible for all your costs.