The Eadda Channels

From publisher blurb:

Water on the Restorae Steppes in northern Tres is a valuable resource to the generational farmers in the region. After decades of development and ambitious projects, they have created several channels that feed off the Thetter String Lakes, providing much-needed water to their essential farmland. Recently, a set of large mounds have appeared along the southern lake of Abugurd, spreading panic.

The Eadda Channels is a combat encounter, ranging from 'medium' to 'hard' in difficulty for four to six players and is scalable, starting at 1st level.