Shimna River

Shimna River
Shimna River in Tollymore Forest Park, September 2010
Location of mouth within Northern Ireland
Location
Country	Northern Ireland
Region	County Down
Physical characteristics
Source
• location	Mourne Mountains on the slopes of Ott Mountain
• elevation	430 m (1,410 ft)
Mouth
• location	Dundrum Bay, Irish Sea
• elevation	5 m (16 ft)
Length	11.77 km (7.31 mi)[1]
Basin features
Tributaries
• left	Trassey River Spinkwee River Tullybrannigan River
• right	Burren River

The Shimna River (Irish: Simhné, meaning river of bulrushes^[2]) is a river in County Down, Northern Ireland. It rises on the slopes of Ott Mountain, in the Mourne Mountains, and enters the Irish Sea at Newcastle, on Dundrum Bay. It is acidic and nutrient-poor, as a result of which its most common flora are mosses and liverworts, including the rare Portuguese feather-moss and Holt's mouse-tail moss. Its principal fish are salmon and sea trout, and it is managed by the Shimna Angling Club. The river is an Area of Special Scientific Interest (ASSI).

The Shimna has a history of flooding; the most serious recent flooding was in 2008. There have also been incidents of pollution, and there were serious fish kills in 2004, 2006 and 2009.