Mountain Island Lake, by the measurements

Most questions about this lake are really questions about scale. It is the smallest of the three Catawba River reservoirs around Charlotte, and nearly everything distinctive about it — the quiet water, the thin housing inventory, the protected shoreline, the drinking-water rules — follows from that.

The reference numbers

Is it man-made?

Yes. Mountain Island Lake is an impoundment of the Catawba River, created when the dam closed in 1923. The riverbed, the farm roads, and a mill village are still down there — the history page covers what was lost when the water came up.

Where it sits

Between Lake Norman upstream and Lake Wylie downstream, on the boundary of Mecklenburg, Gaston, and Lincoln counties, roughly 12 to 18 miles northwest of uptown Charlotte. The map and location page shows the shape of the water and the road approaches from each side.

Why the level barely moves

Because it is a drinking-water reservoir serving roughly a million people, the pool is managed inside a tight range rather than drawn down seasonally the way a storage lake is. Day to day, generation at Cowans Ford above and Mountain Island below can move the water and put current in the channel. Over a year, the elevation stays remarkably stable — one of the practical advantages of owning here, and one reason dock design differs from Lake Norman.

Water temperature

Surface temperatures follow the piedmont seasons: cold in the 40s in midwinter, climbing through spring, and warm enough for comfortable swimming from late spring into early fall. Because water is pulled through from Lake Norman, the upper lake often runs a touch cooler than the lower coves. Check a current reading rather than an average before planning a paddle or a swim.