Question: In order to construct, operate, and maintain a "floodwater retarding structure," the Lincoln County Conservation District purchased a written easement from Eddie Fowler and others. The easement permitted storing "any waters impounded, stored, or detained by such structure" (a lake). Fowler used the lake to water his cattle. A dozen years later he noticed a greenish substance on the lake. When the District did nothing about it and 46 head of cattle died, Fowler sued for breach of contract.

He alleged the floodwater retaining structure included the lake. There was evidence at trial that the lake could be a floodwater-retarding structure, but the District argued that in this case, it was just the dam. Fowler testified that in return for the easement the District had orally promised to make a nice lake and "take care of it." Should this oral testimony be admitted?