When I started racing, I didn’t take water for anything less than 1 hour. I didn’t want the aero drag of a bottle and cage. I too got that urge to drink for the first 10-15minutes, but then it subsided after that point of the race. I still get an urge for water early in a race, but just don’t give it any attention. So I continue not taking a bottle for races less than 60-70minutes. Seems to be working fine for me, although I have recently taken a sweat test and counter to my belief that I was a big sweater, I am not 
The speculation was I am a head sweater, which makes me think I am a big sweater.