▁species , ▁including ▁gray ling ▁and ▁tr out . ▁Ch ub ▁and ▁d ace ▁inhab it ▁the ▁lower ▁length ▁below ▁New st ead ▁bridge ▁in ▁St am ford . ▁ ▁There ▁are ▁attempts ▁to ▁re - int rodu ce ▁water ▁vol es ▁in ▁the ▁area . ▁ ▁There ▁are ▁concerns ▁about ▁non - native ▁signal ▁c ray fish ▁becoming ▁dominant ▁in ▁the ▁river , ▁and ▁reports ▁of ▁a ▁deliber ate ▁introduction . ▁The ▁river ▁has ▁formed ▁part ▁of ▁pilot ▁control ▁tri als . ▁ ▁Et ym ology ▁ ▁The ▁name ▁appears ▁to ▁be ▁derived ▁from ▁the ▁Old ▁English ▁( ge ) wa esc ▁' a ▁ ▁was hing , ▁a ▁flo od '. ▁The ▁earliest ▁form ▁was ▁" le ▁Wh asse " ▁( c 1 2 3 0 ); ▁the ▁use ▁of ▁an ▁initial ▁G - ▁is ▁first ▁recorded ▁in ▁ 1 5 8 6 ▁and ▁the ▁sp elling ▁' G w ash ' ▁appears ▁to ▁be ▁a ▁quasi - Wel sh ▁sp elling . ▁ ▁In ▁literature ▁ ▁Local ▁poet ▁John ▁Cla re ▁wrote ▁a ▁son net ▁about ▁the ▁G w ash , ▁published ▁in ▁Po ems ▁Des cript ive ▁of ▁R ural ▁Life ▁and ▁Sc en ery ▁( Lond on , ▁ 1 8 2 0 ): ▁ ▁Where ▁w inding ▁g ash ▁w irls ▁round ▁its ▁wild est ▁scene ▁On ▁this ▁rom antic ▁b end ▁I ▁sit ▁me ▁down ▁On ▁that ▁side ▁view ▁the ▁me ads ▁their ▁sm o othing ▁green ▁Ed g ' d ▁with ▁the ▁pe eping ▁ham