South Carolina lake charts, and what the pack carries

Most of the big water in this pack is impounded river. Lake Marion and Lake Moultrie sit joined behind the Santee Cooper dams, Lake Murray backs up the Saluda, and Hartwell Lake, Richard B Russell Lake and J. Strom Thurmond Reservoir come one below the next going down the Savannah. Running water like that is a different job from running the coast. The old creek channel is still down there under the flat you are crossing, the coves shallow out at the head faster than they look like they will, and a shoreline of pine and clay bank reads about the same for a long way in either direction.

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The pack carries 2,251 charted water bodies. 975 of them are named, and 40 named lakes run over a square kilometer. The water bodies themselves come from the USGS National Hydrography Dataset, so a reservoir in Helm has its shoreline and its name.

What is in the pack

2,251 charted water bodies is mostly small water. Only 975 of them carry a name, so the bulk of what the pack holds is the unnamed stuff: mill ponds, farm ponds, the wide places in a creek, the backwater behind a causeway. The 40 named lakes over a square kilometer are the ones people trailer to.

Surface area is concentrated hard at the top of the list. Four of them are over 40,000 acres apiece, and the first two are over 56,000. These are the largest named lakes the pack carries, measured off the chart polygon itself rather than off a published figure:

Lake Keowee and Lake Jocassee are on the list at 68.0 and 31.0 square kilometers, and the pack also carries Monticello Reservoir at 26.8, Lake Tillery at 19.5 and Parr Shoals Reservoir at 12.5.

LakeCharted surface area
Lake Marion322 km² (79,691 acres)
Lake Moultrie229 km² (56,587 acres)
Lake Murray196 km² (48,556 acres)
J. Strom Thurmond Reservoir164 km² (40,649 acres)
Richard B Russell Lake99 km² (24,488 acres)
Hartwell Lake73 km² (17,965 acres)
Lake Keowee68 km² (16,803 acres)
Wateree Lake47 km² (11,713 acres)
Lake Greenwood42 km² (10,329 acres)
Lake Wylie38 km² (9,514 acres)
Lake Waccamaw36 km² (8,797 acres)
Lake Jocassee31 km² (7,660 acres)

The twelve largest named lakes the South Carolina pack carries, by charted surface area, measured from the chart polygon itself. The pack carries 2,251 charted water bodies in all, 975 of them named, and 40 named lakes larger than one square kilometer.

The bottom of a reservoir, and the level it is being held at

There is no NOAA chart for a reservoir. The federal nautical charts cover the coast and the navigable rivers, and Lake Greenwood or Wateree Lake was never part of that work. Helm's pack takes the water bodies from the USGS National Hydrography Dataset instead.

The bottom of a reservoir is the part that stays put. The surface sits wherever it is being held, full through the spring and pulled down through a dry stretch of summer, and on working water like Monticello Reservoir and Parr Shoals Reservoir it moves on a much shorter clock than a season. The shape of the creek channel and the shoulders on either side of it is the part you can rely on, and the level tells you how much water is standing on top of it that day. That shape is local knowledge worth bringing with you.

One lake against the next

Lake Marion at 322.5 square kilometers is larger than Lake Murray and Hartwell Lake put together. Lake Moultrie is the next one down at 229.0, and it still covers more water than J. Strom Thurmond Reservoir does at 164.5. The two of them are joined, which is why a long day on the Santee Cooper water can be two lakes without the boat leaving the piece of chart you started on.

Going up the Savannah the steps get smaller. Richard B Russell Lake at 99.1 square kilometers is about three fifths of Thurmond. Hartwell Lake at 72.7 and Lake Keowee at 68.0 land within five square kilometers of each other. Lake Jocassee at 31.0 is a little under half of Keowee, which surprises people who have run both.

The middle of the list is crowded. Wateree Lake at 47.4, Lake Greenwood at 41.8, Lake Wylie at 38.5 and Lake Waccamaw at 35.6 all sit inside twelve square kilometers of each other. If you know the scale of one of them, you know roughly what you are looking at on the other three before you pull up to the ramp.

The pack is cut to a box, not to the state line

Chart packs are rectangles, so the edge of this one does not follow the border, and near the line that works in your favor. Lake Wylie at 38.5 square kilometers is in the box, and so are Mountain Island Lake at 7.9, Lake Tillery at 19.5, Lake Waccamaw at 35.6 and Lake Burton at 10.2. None of that makes any of them a South Carolina lake, and the pack makes no such claim. It means border water is generally carried in more than one pack, and the North Carolina and Georgia packs hold the same lakes from their own side.

Once the pack is on the phone, the charts and the measure tool keep working without a signal. Pull it down at home on wifi, before the tow rather than in the ramp parking lot.

The state lake packs draw lake shorelines from the USGS National Hydrography Dataset, and a reservoir sits at whatever level it is being held at that week. Treat the shape as a guide, keep a lookout, and verify locally.

Common questions

Is there a depth map for Lake Marion and Lake Moultrie?

Helm shows them by name and outline. Both are charted water bodies in the South Carolina pack, Lake Marion at 322.5 square kilometers or 79,691 acres and Lake Moultrie at 229.0 square kilometers or 56,587 acres. The outline comes from the USGS National Hydrography Dataset. Of the state lake packs, Minnesota is the one that also adds depth contours.

What happens to the chart when Lake Murray is drawn down?

The pack draws Lake Murray as an outline, and that outline stays put while the level moves. Lake Murray is 196.5 square kilometers, 48,556 acres, at the chart polygon, so on a low lake the water you see ends inside the line on the chart. The creek channels and the shoulders beside them stay where they are, so check the level the lake is being held at and bring your own knowledge of where they run.

Does the South Carolina pack include Hartwell, Russell and Thurmond?

Yes. The packs are cut to a box rather than to the state line, so Hartwell Lake at 72.7 square kilometers, Richard B Russell Lake at 99.1 and J. Strom Thurmond Reservoir at 164.5 are all carried here. The Georgia pack carries that same Savannah water from its own side, so either one puts the whole chain on your screen.

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