It is 891 hectares (2,202 acres) in surface area, with a maximum depth of 14.3 metres (47 ft) and a shore length of 65.5 kilometres (41 mi) [1] Sand Lake is the southernmost of the original pre-Rideau Canal lakes in this area.
At the southern outlet of Sand Lake, the 1-mile (2 km) long Jones Falls Rapids flowed into the White Fish River, which then flowed through Morton Bay on its way to Lower Beverley Lake and from there via the Gananoque River to Gananoque, Ontario.
The name, Sand Lake, first appears on an 1816 map of the Rideau waterway drawn by Lieutenant Joshua Jebb, Royal Engineer.
The British military purchased Davis's sawmill and property in 1829 so that a lock for the new Rideau Canal could be built there.
The many islands, as if floating on a transparent mirror which mellowed and reflected by the tint of the morning, strikes the contemplative mind with a sensation of pleasure not easily forgotten”[3] In late 1831, the level of the lake was raised by 8 feet (2 m) with the completion of the Jones Falls Dam, part of the Rideau Canal.
The lake acidity is neutral, likely buffered by the underlying geology which mostly consists of crystalline limestone.
In 2001 the lake was invaded by zebra mussels, which had the initial impact of increasing the clarity of the water by 30%.