| Tetbury Avon | |
| Name Other: | Little Avon |
| Name Etymology: | Welsh afon - river |
| Subdivision Type1: | Country |
| Subdivision Name1: | England |
| Subdivision Type3: | Region |
| Subdivision Name3: | West of England |
| Subdivision Type4: | District |
| Subdivision Name4: | Gloucestershire, Wiltshire |
| Subdivision Type5: | City |
| Subdivision Name5: | Tetbury, Malmesbury |
| Length: | 7miles, south easterly |
| Discharge1 Min: | 1cuft/s |
| Discharge1 Avg: | 24.4cuft/s |
| Discharge1 Max: | 141cuft/s |
| Source1: | Wor Well |
| Source1 Location: | Tetbury, Gloucestershire, England |
| Source1 Coordinates: | 51.6432°N -2.1424°W |
| Source1 Elevation: | 375feet |
| Mouth: | Bristol Avon |
| Mouth Location: | Malmesbury, Wiltshire, England |
| Mouth Coordinates: | 51.5821°N -2.0929°W |
| Mouth Elevation: | 230feet |
| Basin Size: | 28.5sqmi |
| Tributaries Right: | Cutwell Brook, Wormwell Brook |
| Custom Label: | River system |
| Custom Data: | Bristol Avon |
The Tetbury Avon, also known as the River Avon (Tetbury Branch), Little Avon or Ingleburn (Anglo-Saxon – English river), is a tributary of the Bristol Avon in south-west England. It rises at Tetbury in Gloucestershire and flows in a generally south-easterly direction, joining the Sherston Avon at Malmesbury in Wiltshire.[1] The water flow has been reduced by public water extraction from its source aquifer in the Cotswold Hills. In the past watermills were used for fulling wool and grinding corn; one working mill survives.
The Tetbury Avon rises at Wor Well to the north east of Tetbury in the Cotswold Hills. It flows first in a southerly direction, joined on the right bank by the Cutwell Brook at the southeast of the town. The river now turns in the southeasterly direction into a steep valley through Estcourt Park, where it is joined on the right by the Wormwell Brook, which has its origin at Westonbirt. Passing through Shipton Wood the river forms a lake, created as part of the Estcourt Estate in the late 18th century.[2] It then enters Wiltshire near the village of Brokenborough, flowing to the north of Malmesbury where it joins the Sherston Avon at the eastern edge of the town.
As is common amongst Cotswold streams, many watermills were established from early times for fulling wool and grinding corn. Shipton Mill in the wood of the same name still produces organic wheat and rye flours.[3] A mill at this site was recorded in the Domesday Book in 1086.[4]
A population of white-clawed crayfish in the Tetbury Avon has been eradicated by fungi hosted by the invasive North American signal crayfish.[5]
The Environment Agency has a gauging station at Brokenborough and reports a mean flow of 24.4cuft/s with a maximum of 141cuft/s and a minimum of 1cuft/s.[6] It is believed that abstraction of public water supplies from the Great Oolite aquifer of the Cotswolds has reduced flows in the Tetbury Avon, making it difficult to maintain high water quality and having a negative effect on the ecology.[7]