On our way back from our NH vacation, we spent a hot and humid day at Whales Tales water park in Lincoln, NH.  It is about one hour south of Storyland and our 5 yr old and 2 1/2 yr old loved it.  It was just enough for the kids and they loved the mini water slides in the kiddie area.  Our 5 yr old was an inch too short to go on the bigger water slides, even with an adult with her.  There  is a lazy river, wave pool, a kiddie area and also a pool right in the middle of the lazy river so for young kids there is just enough without dealing with an overwhelming park.  The bigger water slides looked really fun too.  All the lounge chairs were taken but we just used our large towels and were fine since we were in the water most of the time anyway.  We had our own snacks and drinks packed in a cooler but had to buy lunch there which was not so great and was expensive even for just 3 sandwiches.  I recommend packing your own lunch and perhaps either some fold up chairs or a large blanket just incase.  After 4 hours there it tired out our girls and our drive home was nice and peaceful since they fell asleep!