In the castle grounds were several fish ponds which were supplied by a mill race taken from the stream which rises up at Kilmashogue and flows down through Grange Golf Club and Saint Enda's Park. This served several mills before entering the fish ponds, whence it ran through the golf links while a smaller branch was conducted under the road to the flour mills which stood at the corner of Butterfield Lane, on the site later occupied by Borgward Hansa Motors Ltd.