We went with our DD3 and DD1 last March (the younger child was 14 months) and went to both water parks. They both have nice children's areas, but with only a one year old you likely won't experience other parts of either park (unless one adult when on their own). With a three year old, she did the long tube slides in the kiddie area, we went to the wave beachers, etc - things a one year old can't so yet. So, while our one year old had fun splashin gin the kiddie area, if it were just her I don't think either park is worth it.
At what resort are you staying? Most of them have very nice pools that might be enough for a one year old (and some have kiddie splash areas)