Course

The headwaters of the Santa Lucía River are in the Lavalleja

Lavalleja Department

The Department of Lavalleja is a department of Uruguay. The capital is Minas. It is located in the southeast of the country, bordered to the north by the department of Treinta y Tres to the east with Rocha, to the south with Canelones and Maldonado, and to the west to Florida.The department is...

 department. For a large part of its course it forms the limit between the departments of Florida

Florida Department

Florida is a department of Uruguay. Its capital of is Florida.-Population and Demographics:As of the census of 2004, there were 68,181 people and 21,938 households in the department. The average household size was 3.1...

 and San José

San José Department

San José Department is a department of Uruguay. Its capital is San José de Mayo.-Population and Demographics:As of the census of 2004, there were 103,104 people and 33,063 households in the department. The average household size was 3.0...

 on one bank and Canelones

Canelones Department

The Canelones Department , with an area of and 485,240 inhabitants, is located to the south of Uruguay. Its capital is Canelones.-Geography and climate:...

 and Montevideo

Montevideo Department

Montevideo is a department of Uruguay.It is by far the smallest one in area, and the most populated as well. It contains the city of Montevideo, capital of Uruguay. While most of the department is covered by the capital city, there are still smaller towns within its limits, e.g...

 on the other. Its outlet is the Río de la Plata

Río de la Plata

The Río de la Plata —sometimes rendered River Plate in British English and the Commonwealth, and occasionally rendered [La] Plata River in other English-speaking countries—is the river and estuary formed by the confluence of the Uruguay River and the Paraná River on the border between Argentina and...

, forming a small delta, in which Tiger Island is located.

Significance as a watercourse

It is the principal watercourse of southern Uruguay

Uruguay

Uruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...

. It is the primary source of drinking water for Montevideo

Montevideo

Montevideo is the largest city, the capital, and the chief port of Uruguay. The settlement was established in 1726 by Bruno Mauricio de Zabala, as a strategic move amidst a Spanish-Portuguese dispute over the platine region, and as a counter to the Portuguese colony at Colonia del Sacramento...

and other localities in the south of the country.