That's not goosegrass, it's nutsedge. Nutsedge is a royal PITA! It makes sense that it's growing where it's getting plenty of moisture, because it does like moist areas. Although it will survive and thrive in areas that are not necessarily moist, and is an excellent reproducer, so get rid of it now! It's very easy to pull up - HOWEVER, it has little root tubers which stay in the soil even though roots come up when you pull it. Then next year, you'll have a dozen to replace each one you pulled. I learned this the hard way. The only herbicide that will kill nutsedge is Sedgehammer. You probably won't see it at Lowe's or someplace like that, but nurseries and garden centers usually carry it. Deanna Here is a link that might be useful: Nutsedge

here are few more photos these are in my backyard. seem like the same plant. 1st one is 7 inches tall and the other 2 photos seems like the same plant but fully matured.

I was about to say raise your mower height. It looks like a rotary mower scalp. Then I seen where you wrote you have it on the highest setting, hmm Have any pets that would be peeing in those areas? Also you could also do a screwdriver test and see whats underneath. Maybe some big rocks, roots from the big tree??

I have an established Bermuda grass that looks fantastic, other than a 10x10 patch of this grass. I thought it was centipede, but someone else said it wasn’t. Please help me identify it and kill it! Thanks!