The River Misbourne is a tributory of the River Colne and disappears underground for part of its course. The source of the Misbourne is at Mobwell Pond in Great Missenden. It is a chalk river and feeds the lake at Chalfont Park. Salmon were introduced into the Thames in 1973 resulting in salmon spawning further down the River Misbourne. The River supports abundant vegetation and wildlife including herons, snipe, green sandpiper, kingfisher and teal.
Some further information regarding the River Misbourne can be found at the Chiltern Society's web site.
There is now a Misbourne River Action Group which are a group of volunteers who regularly carry out improvement work. Information on this group can be found on http://www.misbourneriveraction.org/