Here is how to repair a broken head on your irrigation system. It could be broken by different things. I have seen kids kick them off, mowers run over them, and sometimes they just wear out. The best thing to do is take a shovel and dig around the head carefully so you don’t dig too deep and break the line supplying water to the head. Exposed the head and unscrew it making sure you don’t get dirt in the line. If you are going to replace the head with exactly the same type and they are still available, depending on the age of the head you can just unscrew the top and replace the guts unless the body has been damaged. Replace the nozzle and adjust the stream as needed.