Sarratt is a village and civil parish in Three Rivers District, Hertfordshire. It is situated north of Rickmansworth on high ground near the county boundary with Buckinghamshire. The chalk stream, the River Chess, rising just north of Chesham in the Chiltern Hills, passes through Sarratt Bottom in the valley to the west of the village to join the River Colne in Rickmansworth. The conditions offered by the river are perfect for the cultivation of watercress. Sarratt has the only commercially operating watercress farm in Hertfordshire. The valley to the east of Sarratt is dry.