River Ash, Middlesex
The River Ash is a small river in south-western Middlesex with a course of some 6 miles to the River Thames, of which it is a tributary.
The course of the river has been much influenced by the hand of man. It flows from the River Colne, just south of Staines Moor, eastwards, running through the towns of Staines-upon-Thames, Ashford and Shepperton before joining the River Thames in the creek behind Sunbury Lock at Sunbury-on-Thames. It goes through many back gardens in Old Charlton Road, Shepperton.
There are maps dating back to the Middle Ages documenting the changes made to the course of the river by man. The earliest one shows the history of the Shepperton Studios site, more particularly Shepperton Manor. This refers to the monks of Westminster, who, it is suggested, may have done some widening still visible today.
In 1910 the Metropolitan Water Board built the Staines Aqueduct to supply water from the River Thames at Hythe End to its works at Sunbury.
Shortly after this, the River Ash was diverted to make way for the Queen Mary Reservoir in Laleham. Parts of the original course can still be seen near the Laleham Intake and Pumping Station.
In the early 1960s, the outflow from the River Colne, where the River Ash starts, was moved some yards south and some 100 yards of its length was diverted to make way for the Staines Bypass (the A30) . Here it flows underground for 300 yards beneath the Crooked Billet roundabout.
Flooding and alleviation
The most recent serious flood on the River Ash was in 1947, when homes and roads were severely affected by flood waters. This was not due to the flood prevention methods on the River Ash but to those on the River Colne, as well as high water levels on the River Thames.
More work has been carried out recently under the River Ash Flood Alleviation Scheme. A major upgrade of the water treatment works at Ashford Common was started by Thames Water Utilities during 1994 and 1995, resulting in increased flow and flood risk at properties along Old Charlton Road, Shepperton and Heriden Way, as the works discharges to the lower River Ash near the M3 motorway. Consequently, a flood relief channel was suggested. This was built during the first five months in 1995 and cost a total of £450,000.