Siston Brook

Siston Brook
Clack Mill Brook
Siston Brook; Clack Mill Brook
	Londonderry Wharf Bridge crossing the Siston Brook as it joins the Bristol Avon
	Diagrammatic map of the Siston Brook and tributaries in South Gloucestershire, England
Location
Country	England
Region	South Gloucestershire
Physical characteristics
Source
• location	Siston, South Gloucestershire, England
• coordinates	51°28′48″N 2°26′55″W / 51.4799°N 2.4487°W
• elevation	338 ft (103 m)
2nd source
• location	Siston, South Gloucestershire, England
• coordinates	51°28′38″N 2°27′01″W / 51.4773°N 2.4503°W
• elevation	305 ft (93 m)
Source confluence
• location	Siston, South Gloucestershire, England
• coordinates	51°28′28″N 2°26′52″W / 51.4744°N 2.4478°W
• elevation	246 ft (75 m)
Mouth	River Avon
• location	Londonderry Wharf, South Gloucestershire, England
• coordinates	51°25′36″N 2°29′18″W / 51.4268°N 2.4883°W
• elevation	35 ft (11 m)
Length	6 mi (9.7 km)
Basin features
Tributaries
• right	Warmley Brook
River system	Bristol Avon

Siston Brook rises in two separate streams which issue from a ridge just north of the village of Siston, South Gloucestershire, England. The brook is approximately 6 miles (9.7 km) long and is a tributary of the Bristol Avon. Much of its course is through the eastern suburbs of Bristol, although it remains outside the city boundaries. Tributaries include the Warmley Brook and an unnamed tributary from Bridgeyate.

The stream has provided power for watermills and battery mills in the past and some mill buildings still survive. Wildlife is supported by nature reserves through which the Siston Brook runs. Flooding has caused problems in the past, but modern measures to alleviate this include an attenuation reservoir and proposals to reinstate historic weirs and sluices. The name Siston is believed to derive from Anglo-Saxon, meaning Sige's Farmstead.