From the article:
The Battlefield in a Box range of tabletop-ready scenery is a quick and easy way to create a wargaming table straight out of the box, suitable for any scale miniature troops to fight over.
Water features have played a major part in battles throughout history. Both streams and mighty rivers are natural obstacles that are sure to influence the strategy of any commander intent on victory. Battlefield in a Box provides everything you need to construct your battlefield, at all scales of gaming. Combine this set with the others from the list below to build more complex waterways.