Are you in Purwakarta? Why not you visit Waduk Jatiluhur (Jatiluhur Dam). Its about 6.5 KM from down town.
There are some 3 star hotels, children play area, boat rental and others facility. You may stay and enjoy this quite place with your family.
Waduk Jatiluhur acts as water reservoir for farming, also as water power plan, PLTA Djuanda. Please read more info about Waduk Jatiluhur here.