I recently visited the Splash Water Park. It is situated on the Grand Trunk Road, Delhi.
Park is not that big and has only got maximum of 15 rides including both for adults and children. Few rides are only dedicated for the childeren, however I could not find anything exiciting for the adults. Few instruments in the park need an immediate maintenence.
Entry of the park is of Rs 1000 for the adults and Rs 600 for children. There are quite a few food joints inside the park which are of average quality.
We have quite a few other options available in Delhi for this price and would not recommend.