TheRiver Gade is achalk stream running almost entirely throughHertfordshire. It rises from aspring in thechalk of theChiltern Hills atDagnall,Buckinghamshire[1] and flows throughHemel Hempstead,Kings Langley, then along the west side ofWatford throughCassiobury Park. After passingCroxley Green it reachesRickmansworth, where it joins theRiver Colne.[2] For its whole course the Gade is unnavigable, with the exception of a short section inApsley, Hertfordshire over which tour boats travel to reach Frogmore Wharf.
Its principal tributary is theRiver Bulbourne which joins it at Two Waters, just below Hemel Hempstead.
The river was once used to powerwater mills, such as those at Water End,Cassiobury Park and Two Waters as well as powering theJohn Dickinsonpaper mills atApsley andCroxley. The river was diverted to provide this power, but in 2025 the Gade was restored to its natural course.[3]
It supported the farming ofwatercress atCassiobury Park, Water End, the Grade 2 listedJellicoe Water Gardens and Two Waters until water was diverted from the river in 1947 to supply the growingnew town ofHemel Hempstead.
Below Hemel Hempstead it runs alongside and sometimes forms part of theGrand Union Canal.
The remains of aRoman villa were found at Gadebridge Park in Hemel Hempstead.
The Gade is one of the rivers referred to in the name of theThree Rivers district.
It is home to a wide range of biodiversity, including ducks and a range of insect life.
The river bed from the source at Dagnall to Great Gaddesden, about 3 miles downstream is usually dry. After prolonged rain, it will fill and often flood.
