The Pinn was at one time also known as Ruislip Brook, once this was a good fishing stream. In 1804 there was a right of way three feet wide along the banks of the Pinn so that the lord of the manor and his lessees and servants could enjoy the fishing, in those days there was far more water in the Pinn.

As the various channels of the Colne approach the Thames they spread out across an ancient alluvial fan. This broad deposit of gravel and sand was formed during the ice age and is somewhat higher than the ground to its east. This has allowed radial distributaries to drain eastwards towards the Thames. Extending six miles from Staines to Sunbury, the River Ash is the easternmost of the natural channels of the Colne  providing a important wildlife corridor through the western fringes of London. The nearby Sweeps Ditch also preserves the radial pattern, both watercourses have been greatly modified by human activity but fortunately they have survived as valuable features of the ancient landscape.

In previous centuries, travellers on the highway from Kingston to Windsor would have been familiar with the ford across the Ash which gave the Saxon parish of Ashford its name.The ford is now gone but a century ago it was a still beauty spot for the Edwardian inhabitants of Ashford. The marshy meadows beside the river were liable to winter flooding and the parish church is wisely situated on higher ground over half a mile from the ford itself.

The Duke of Northumberland River was first constructed during the reign of Henry VIII to augment the flow supplying existing mills and to supply new mills. The Longford River was constructed in 1638/39 at the instigation of Charles I  to bring water from the River Colne to augment the water supply to the Royal Parks at Bushy Park and Hampton Court.

Explore your local river

There are many attractive walks along our rivers and other waterbodies in the Colne Catchment. Walks along the River Pinn can be found here.

Brunel University and Hillingdon Council collaborate on Natural Flood Management in Ruislip Woods.

Egham and Staines Conservation Volunteers continued their spring activities with a task at Fordbridge Field, Ashford on Sunday 19 March 2023.

Pollution can find its way into urban rivers via surface water outfalls (drains). The Zoological Society of London and Thames21 are recruiting volunteers to help conduct the Pinn Outfall Safari.

There has been extensive fish mortality along the twin rivers, this is part of a wider problem affecting various catchments across London. Heathrow Airport  is responding to this problem.

Design by LTD Design Consultants and build by Garganey Consulting. From an original concept by the Herts and Middlesex Wildlife Trust.