Upper Colne Marshes

{{Use dmy dates|date=April 2022}}

{{Infobox SSSI

|image=Roman River at Rowhedge - geograph.org.uk - 999812.jpg

|image_caption=

|name= Upper Colne Marshes

|aos= Essex

|interest= Biological

|gridref={{gbmappingsmall|TM 022232}}
{{gbmappingsmall|TM 050209}}

|area= 114.1 hectares

|notifydate=1992

|map=[http://magic.defra.gov.uk/MagicMap.aspx?startTopic=Designations&activelayer=sssiIndex&query=HYPERLINK%3D%271006373%27 Magic Map]

}}

Upper Colne Marshes is a {{convert|114.1|hectare|acre|adj=on}} biological Site of Special Scientific Interest south and west of Wivenhoe in Essex. It lies along stretches of the River Colne and Roman River.{{cite web|url= http://www.sssi.naturalengland.org.uk/citation/citation_photo/1006373.pdf|title=Upper Colne Marshes citation|series= Sites of Special Scientific Interest|publisher=Natural England|access-date= 8 August 2016}}{{cite web|url=http://magic.defra.gov.uk/MagicMap.aspx?startTopic=Designations&activelayer=sssiIndex&query=HYPERLINK%3D%271006373%27 |title=Map of Upper Colne Marshes|series= Sites of Special Scientific Interest|publisher=Natural England|access-date= 8 August 2016}}

The site has grazing marshes, salt tidal marshes, beaches, sea walls and intertidal mud. It has an important assemblage of nationally scarce plants and diverse ditch types. The grassland is species rich, with rare types such as sea barley, and salt marsh has the nationally uncommon lax-flowered sea-lavender. Insects include the nationally scarce Roesel's bush-cricket.

The site is in five areas, some of which are crossed by roads and footpaths.