Pat River

The rivière à Pat (in English: Pat River) is a tributary on the east bank of the Nicolet Southwest River. It crosses the municipalities of Sainte-Élizabeth-de-Warwick, Sainte-Séraphine and Sainte-Clotilde-de-Horton in the Arthabaska Regional County Municipality (MRC), in the administrative region of Estrie, in Quebec, in Canada.

Geography
The main neighboring hydrographic slopes of the Pat river are:
 * north side: Nicolet Southwest River, Nicolet River;
 * east side: Nicolet River, rivière des Rosiers;
 * south side: Léon-Gélinas stream, Dubuc stream, Nicolet Southwest River;
 * west side: Nicolet Southwest River.

The Rivière à Pat originates from various streams in the municipality of Sainte-Élizabeth-de-Warwick, very close to the limit of the municipality of Kingsey Falls.

From its source, Pat's River flows on 18.4 km in the following segments:
 * 3.7 km north-west, in the municipality of Sainte-Élizabeth-de-Warwick, to the intermunicipal limit of Sainte-Séraphine;
 * 4.8 km north, passing 2.2 km east of the village of Sainte-Séraphine, up to the road to seventh rank;
 * 4.8 km north-west, up to the municipal limit of Sainte-Clotilde-de-Horton;
 * 5.1 km westward to its confluence, of which 2.8 km in Sainte-Séraphine, 2.0 km in Sainte-Clotilde-de-Horton, 0.6 km in Sainte-Séraphine and 1.7 km in Sainte-Clotilde-de-Horton.

The Rivière à Pat drains on the east bank of the Nicolet Southwest River. Its confluence is located 1.6 km upstream from Île Lemire and upstream from the village of Sainte-Clotilde-de-Horton.

Toponymy
The toponym "Rivière à Pat" was formalized on September 5, 1985, at the Commission de toponymie du Québec.