Sauer

{{short description|River in Belgium, Luxembourg and Germany}}

{{other uses}}

{{infobox river

| name = Sauer

| map = Sûre.png

| map_size =

| map_caption = Path of the Sauer [http://u.osmfr.org/m/383739/]

| image = Fluss_Sauer.jpg

| image_size =

| image_caption = The Sauer in Echternach

| mapframe = yes

| mapframe-zoom = 8

| subdivision_type1 = Countries

| subdivision_name1 = {{ubl|Belgium|Germany|Luxembourg}}

| subdivision_type2 = Location

| subdivision_name2 =

| subdivision_type3 = Reference no.

| subdivision_name3 = DE: 262

| length = {{convert|173|km|abbr=on}}

| width_avg =

| depth_avg =

| source1_location = Source region: In the Ardennes on the soil of Libramont-Chevigny near the Planchipont farm (Belgium)

| source1_coordinates =

| source1_elevation = ca. {{convert|510|m|abbr=on}}

| mouth_location = Between Wasserbilligerbrück (Germany) and Wasserbillig (Luxembourg) into the Moselle

| mouth_coordinates = {{Coord|49.7135889|6.5066861|type:river_region:DE-RP|format=dms|display=inline,title}}

| mouth_elevation = ca. {{Höhe|133|DE-NHN|link=false}}

| basin_population =

| basin_landmarks =

| river_system = Moselle

| progression = {{RMoselle}}

| basin_size = {{convert|4,259|km2|abbr=on}}

| discharge1_location = at its mouthAdded gauge data from Bollendorf (Sauer), [http://213.139.159.46/prj-wwvauskunft/projects/messstellen/wasserstand/register2.jsp?msn=2628050400&pegelname=Pr%FCmzurlay&gewaesser=Pruem&dfue=1 Prümzurlay] (Prüm) und [http://213.139.159.46/prj-wwvauskunft/projects/messstellen/wasserstand/register2.jsp?msn=2628085400&pegelname=Alsdorf-Oberecken&gewaesser=Nims&dfue=1 Alsdorf-Oberecken] (Nims), increased by the remaining catchment area (199 km²) with a conservatively estimated mq of 10

| discharge1_min =

| discharge1_avg = {{convert|53.8|m3/s|abbr=on}}

| discharge1_max =

| tributaries_right =

| tributaries_left =

| waterbodies =

| ports =

| bridges =

| extra =

}}

The Sauer (German and Luxembourgish, {{IPA|de|ˈzaʊ̯ɐ|-|De-Sauer2.ogg}}, {{IPA|lb|ˈzɑʊɐ|lang|Lb-Sauer.ogg}}) or Sûre (French, {{IPA|fr|syʁ|-|LL-Q150 (fra)-Lyokoï-sûre.wav}}) is a river in Belgium, Luxembourg and Germany. A left tributary of the Moselle, its total length is {{convert|173|km|mi}}.

Rising near Vaux-sur-Sûre in the Ardennes in southeastern Belgium, the Sauer flows eastwards and becomes the border with Luxembourg near Martelange. It forms the border between Belgium and Luxembourg for {{convert|13|km|mi|0}} north of Martelange. West of Esch-sur-Sûre it flows into an artificial lake, the Upper Sûre Lake created by the Esch-sur-Sûre Dam, which gives its (French) name to the Luxembourgish commune of Lac de la Haute-Sûre. After flowing through Ettelbruck and Diekirch, the Sauer forms the border between Luxembourg and Germany for the last {{convert|50|km|mi}} of its course, passing Echternach before emptying into the Moselle in Wasserbillig. The rivers Wiltz, Alzette, White Ernz, Black Ernz, Our, and Prüm are tributaries.