Lake Roland is a 100-acre (0.40 km²) defunct reservoir in Baltimore County, Maryland named for Roland Run, a nearby stream-bed that feeds the lake and eventually flows into the Jones Falls which runs southeast through the city center to the Northwest Branch of the Patapsco River and the Baltimore Harbor. It initially served as the first municipal water supply for the city of Baltimore by in 1861, with the dam and Greek Revival style pumping building on the eastern shore constructed around 1860, but was abandoned in 1915 because of silting problems.