Erin. When you water, how much water do you apply each time? I'm not seeing just one brown spot, it looks to be patchy over the whole area. Does your lawn service do the mowing? Pictures can be a bit deceiving but it looks mown a little short, do you know the mowing height? There are many possible causes of browning on grasses and it can be hard to differentiate. The pattern does look like it could be dry, though. If I'm missing the one brown spot you mean, could you post a close-up picture of it? BTW "brown patch" is the name for a specific fungal disease of turf but it doesn't sound like that's what you mean in your title.