Adda (river)

{{Redirect|Addua|the moth genus formerly known as Addua|Dysschema}}

{{Infobox river

| name = Adda

| image = Adda7.JPG

| image_caption = The Adda in Imbersago

| image_alt = The Adda in Imbersago

| source1 = Val Alpisella{{cite web |url=https://www.openstreetmap.org/note/1882593 |title=Cartello sorgente dell'adda 2122 m |language=it |accessdate=2023-10-27}}

| source1_location = east of Livigno, Italy

| source1_coordinates = {{coord|46|32|50.64|N|10|14|21.12|E|region:IT_type:river|display=inline}}

| source1_elevation = {{convert|2122|m|ft|abbr=on}}

| mouth = Po

| mouth_location = near Castelnuovo Bocca d'Adda{{cite encyclopedia |language=it |encyclopedia=Enciclopedia Italiana |title=Adda |url=https://www.treccani.it/enciclopedia/adda |accessdate=2023-10-27}}

| mouth_coordinates = {{coord|45|06|38|N|9|53|12|E|region:IT-CR_type:river_source:dewiki|display=title,inline}}

| progression = {{RPo}}

| subdivision_type1 = Countries

| subdivision_name1 = Italy, Switzerland

| length = {{convert|313|km|mi|abbr=on}}

| discharge1_avg = {{convert|187|m3/s|cuft/s|abbr=on}}

| basin_size = {{convert|7979|km2|mi2|abbr=on}}

| map = Adda, rivière.png

| map_size =

| map_alt = Location of the Adda River

| map_caption = Location of the Adda

| tributaries_left = Brembo, Serio

| tributaries_right = Mallero, Mera

}}

The Adda (Latin: *Abdua*, or *Addua*; Lombard: *Ada*, or *Adda*) is a river in North Italy, a tributary of the Po. It rises in the Alps near the border with Switzerland and flows through Lake Como. The Adda joins the Po near Castelnuovo Bocca d'Adda, a few kilometers upstream of Cremona. The river's length is {{convert|313|km|mi}}. The highest point of the drainage basin is the summit of La Spedla (a subpeak of Piz Bernina), at {{convert|4020|m|ft}}.

Towns along the river include Bormio, Tirano, Sondrio, Bellagio and Lecco (both on Lake Como), Brivio and Lodi. The Poschiavino, a tributary, originates in Switzerland and flows through the town of Poschiavo.

Course

The Adda's source is in the Alpisella valley near the head of the Fraele glen, within the Rhaetian Alps. Its flow is augmented by several smaller streams near Bormio. From there, it flows southwest, then west, through the Valtellina, passing Tirano, where the Poschiavino joins from the right, and Sondrio, where the Mallero joins, also from the right. This section of the Adda's course is unusual in Northern Italy, as it flows from east to west. The river flows into the northern end of Lake Como, contributing significantly to the lake's volume. Exiting the lake's southeastern (Lecco) arm, it crosses the Lombardy Plain. It receives water from the Brembo and Serio from the left, and ultimately joins the Po.{{EB1911|inline=1|wstitle=Adda|volume=1|last= Coolidge |first= William Augustus Brevoort |author-link= W. A. B. Coolidge|page=183}}

The Trezzo sull'Adda Bridge, constructed in 1377, had a single arch of {{convert|72|m|ft}}, the longest bridge arch built before the introduction of metal in bridge construction.{{cite book |last=Whitney |first=Charles S. |title=Bridges of the World: Their Design and Construction |publisher=Courier Dover Publications |year=2003 |orig-year=1929 |isbn=9780486429953 |page=137}}

The lower course of the Adda historically marked the border between the Republic of Venice and the Duchy of Milan, as established by the Treaty of Lodi in 1454. Several significant battles have been fought along its banks, including the Battle of Lodi in 1796, where Napoleon defeated Austrian forces. The bridgehead at Cassano d'Adda and its surrounding area have also been the site of multiple battles, including one in 1705 involving Prince Eugene of Savoy and the French, and another in 1799 where Alexander Suvorov led his forces across the river.