On the Loweswater side Gavel Fell is neatly contained by Highnook Beck to the north west and Whiteoak Beck to the east. These merge beneath the nose of the ridge at High Nook Farm, before joining Dub Beck, the outflow of Loweswater. One of the feeders of Highnook Beck is High Nook Tarn, a small pool with a low earth dam. Tarns are unusual in this part of the District, although Gavel Fell has a share in a second on its southern boundary. This is Floutern Tarn, lying beneath Floutern Cop. A long brooding pool with a depth of about 12 ft, Floutern Tarn drains east and then north into the morass of Mosedale. A walker's pass, Floutern Tarn Pass, crosses beside Floutern, providing access from Buttermere to Ennerdale. The western side follows Gill Beck, the southern boundary of Gavel Fell. The western face of the fell is drained by Croasdale Beck, a tributary of the Ehen.