The Gwash then helps to fill the Rutland Water reservoir which was formed by damming its valley at Empingham.

The flow is enhanced by the Gwash's tributary, the North Brook, at SK956083 in Empingham, which significantly helps maintain riverlife.

[2] East of Stamford, its course is now fixed, but it lies in a small flood plain which shows clear signs of the river's former meandering.

The pasture fields include depressions that fill during wet seasons, forming oxbow lakes, though they are not of the classical shape.

[12] Local poet John Clare wrote a sonnet about the Gwash, published in Poems Descriptive of Rural Life and Scenery (London, 1820): Where winding gash wirls round its wildest scene On this romantic bend I sit me down On that side view the meads their smoothing green Edg'd with the peeping hamlets checkering brown Here the steep hill as dripping headlong down While glides the stream a silver streak between As glides the shaded clouds along the sky Brightning & deep'ning loosing as they're seen In light & shade—so when old willows lean Thus their broad shadow—runs the river bye With tree & bush repleat a wilderd scene & mossd & Ivyd sparkling on my eye— O thus wild musing am I doubly blest My woes unheeding—& my heart at rest.