Loch Valley

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

{{Infobox body of water

| name = Loch Valley

| image = Loch Valley from Buchan Hill.jpg

| caption = The loch viewed from Buchan Hill, looking east. Loch Narroch is visible at the far end.

| image_bathymetry =

|pushpin_map=Scotland Dumfries and Galloway

| caption_bathymetry =

| location = Galloway, Scotland

| coords = {{coord|55|06|15|N|4|26|20|W|region:GB_type:waterbody|display=inline,title}}

| type = freshwater loch

| inflow = Mid Burn, Loch Narroch

| outflow = Gairland Burn

| catchment =

| basin_countries = United Kingdom

| length =

| width =

| area = {{convert|37.2|ha|abbr=on}}

| depth =

| max-depth =

| volume =

| residence_time =

| shore =

| elevation = ~{{convert|320|m|abbr=on}}

| islands =

| cities =

| reference = {{cite web |url=http://www.jncc.gov.uk/PDF/jncc317.pdf |title=An estimate of the extent of dystrophic, oligotrophic, mesotrophic and eutrophic standing fresh water in Great Britain |accessdate=2008-06-28 |publisher=Joint Nature Conservation Committee |date=April 2001 |author1=MA Palmer |author2=DB Roy |name-list-style=amp }}

}}

Loch Valley is a loch in Galloway Forest Park to the east of Buchan Hill, north of the Rig of the Jarkness and southwest of Craignaw. It drains via Gairland Burn down to Loch Trool.

The loch has a catchment area entirely on the Loch Doon granite, is oligotrophic, and has suffered from gradual acidification since the mid-19th century{{cite journal |author=Richard W. Battarbee |date=November 1989 |title=The Acidification of Scottish Lochs |journal=The Geographical Journal |volume=155 |issue=3 |pages=353–360 |doi=10.2307/635210 |publisher=The Geographical Journal, Vol. 155, No. 3 |jstor=635210}} leading to the elimination of the original Brown Trout population.{{cite web |url=http://www.snh.org.uk/pdfs/publications/commissioned_reports/F01AC6.pdf |title=Evaluating the ecological and conservation status of freshwater fish communities in the United Kingdom |accessdate=2008-06-28 |author=P S Maitland |year=2004 |work=Scottish Natural Heritage Commissioned Report No. 001 |publisher=Scottish National Heritage |page=35 |archive-url=https://web.archive.org/web/20071024134010/http://www.snh.org.uk/pdfs/publications/commissioned_reports/F01AC6.pdf |archive-date=2007-10-24 |url-status=dead }} It has recovered to some extent, with the pH increasing slowly from around 4.4 in 1978 to 5.2 in 2003.{{cite web|last=|first=|date=16 August 2004|title=Recovery from Acid Rain Gives Hope to Scottish Upland Salmonid Populations|url=http://www.marlab.ac.uk/FRS.Web/Uploads/Documents/FW16Recovery.pdf|archive-url=|archive-date=|accessdate=2008-06-25|work=Fisheries Research Services}}{{dead link|date=January 2014}}

Between 1983 and 2003 the loch's dissolved organic carbon levels increased,{{cite web |url=http://www.scotland.gov.uk/Resource/Doc/1063/0055432.pdf |title=Freshwater Environment Group |accessdate=2008-06-28 |publisher=Fisheries Research Services}} and the loch had a sediment accumulation rate of around 0.01 g cm⁻² yr⁻¹ from 1850 to 1975.{{cite web |url=http://www.eurolimpacs.ucl.ac.uk/oldsite/docstore/Deliverable_089.pdf |title=Sediment accumulation rate changes in European lakes: A first report |accessdate=2008-06-28 |work=Integrated Project to evaluate the Impacts of Global Change on European Freshwater Ecosystems |publisher=Environmental Change Research Centre, University College London |date=February 2006 |author1=Neil Rose |author2=David Morley |name-list-style=amp |archive-url=https://web.archive.org/web/20091110044755/http://www.eurolimpacs.ucl.ac.uk/oldsite/docstore/Deliverable_089.pdf |archive-date=2009-11-10 |url-status=dead }}