Boating here means several different kinds of water behind the same trailer. Lake Pontchartrain is open enough that the far shore goes out of sight, and a south wind has all afternoon to build across it. Toledo Bend Reservoir is a long impoundment with creek arms, sitting at whatever level it is being held at that month. Closer to the coast, White Lake, Grand Lake, Calcasieu Lake and Lake Salvador lie in marsh that runs together through bayous and cuts, so the shape on the screen matters as much as the number under it. The north end is a different run again, with Caddo Lake, Lake Bistineau and Bayou D'Arbonne Lake.
The pack carries 10,425 charted water bodies, which is the sixth largest count of the 48 state lake packs. Of those, 1,366 carry a name. 291 of the named ones are larger than a square kilometer, and that figure ranks eighth among the 48. The water bodies come from the National Hydrography Dataset and the depth on them is built from state elevation surveys.
Only five of the 48 state lake packs carry more separate pieces of water than this one. The count here is 10,425. That number is high for a reason you can see from a boat: south of the Intracoastal the water breaks into thousands of ponds and openings, and each one that the National Hydrography Dataset carries is charted water in the pack.
Names run the other way. Of the 10,425 bodies, 1,366 have a name, which puts this pack twenty first for named water while it sits sixth for water bodies overall. The gap is the marsh. A pond off a bayou has a shape and a depth and no name at all, and there are thousands of them.
The figure worth knowing before a weekend is the third one. The pack carries 291 named lakes larger than a square kilometer, eighth among the 48 packs. That is a lot of water big enough to spend a full day on, and it is spread from the Texas line to the Mississippi side.
| Lake | Charted surface area |
|---|---|
| Lake Pontchartrain | 1,645 km² (406,389 acres) |
| Toledo Bend Reservoir | 668 km² (164,992 acres) |
| Lake Maurepas | 235 km² (58,119 acres) |
| Sabine Lake | 229 km² (56,686 acres) |
| White Lake | 226 km² (55,722 acres) |
| Lake Salvador | 202 km² (49,816 acres) |
| Calcasieu Lake | 183 km² (45,196 acres) |
| Grand Lake | 166 km² (40,945 acres) |
| Lac des Allemands | 67 km² (16,531 acres) |
| Catahoula Lake | 67 km² (16,457 acres) |
| Lake Fausse Pointe | 66 km² (16,432 acres) |
| Lake Verret | 61 km² (15,024 acres) |
The twelve largest named lakes the Louisiana pack carries, by charted surface area, measured from the chart polygon itself. The pack carries 10,425 charted water bodies in all, 1,366 of them named, and 291 named lakes larger than one square kilometer.
There is no NOAA chart for a reservoir. NOAA charts the coast, the Intracoastal and the navigable rivers, and a lake held behind a dam falls outside all of that. Inland depth in Helm is built from state elevation surveys instead, with the water bodies themselves taken from the National Hydrography Dataset. That is the whole difference between a lake being a blue shape and being water you can draw a line across and read a depth off against your own draft.
A reservoir also sits at whatever level it is being held at. Toledo Bend is managed water, and the surface in a wet spring is not the surface in a drawn down September. A contour on a lake like that is measured from a datum, so it is a fixed line under a moving top. When the level is down, the first thing to go is the shoulder of a creek channel or the flat at the mouth of a cove, and the contour is telling you where those shoulders are rather than how much water is over them today. Read the contour, then read the bank.
Lake Pontchartrain behaves differently again, because tide reaches it and the live NOAA water level does too. Toledo Bend, Lake Bistineau and Bayou D'Arbonne answer to a dam and to the season. The same chart carries both kinds of water, and the survey date sits with the reading either way. What Helm does with that depth once it is on the screen, the shading against your draft and the routing that follows from it, belongs to the depth and route pages.
Lake Pontchartrain is the largest named lake in the pack at 1,644.6 square kilometers, or 406,389 acres, and nothing else in the pack is near it. Toledo Bend Reservoir is second at 667.7 square kilometers, 164,992 acres, so Pontchartrain is close to two and a half times its size and about seven times the size of Lake Maurepas next door.
The eight largest named lakes the pack carries, measured from the chart polygon itself:
Four of those land close together. Lake Maurepas, Sabine Lake, White Lake and Lake Salvador all fall between 201.6 and 235.2 square kilometers, a spread of under 34 square kilometers across the four, which means a day on any one of them is a day on roughly the same amount of water. Sabine Lake and Toledo Bend Reservoir both sit along the Texas boundary. The packs are cut to a box rather than traced along a state line, so both of those lakes appear in the Texas pack as well as this one.
Below the big eight the sizes bunch up hard. Lac des Allemands is 66.9 square kilometers, Catahoula Lake is 66.6 and Lake Fausse Pointe is 66.5, which is a spread of under half a square kilometer across all three. Lake Verret at 60.8 and Caddo Lake at 60.6 are the same story. If you have fished all five you know how little that tells you, which is the point of having contours on the screen rather than acreage.
Up north, Lake Bistineau is 52.6 square kilometers, 12,998 acres, and Bayou D'Arbonne Lake is 52.4 square kilometers, 12,948 acres. Fifty acres separates them. Black Lake is 41.6 square kilometers, 10,280 acres, and Haggerty Camp Lake, at 57.6 square kilometers and 14,233 acres, is larger than any of the three.
Down in the marsh the numbers run Lake Mechant at 45.1 square kilometers, Lake Palourde at 43.6 and Caillou Lake at 41.5, which by acreage is 11,144, 10,774 and 10,255. On water like that the lake outline is often less useful than the cuts and bayous that join it to the next one, and those are in the pack too, named or not. The whole pack is one download, and once it is on the phone it does not need a signal at the ramp.
Inland lake depth comes from state elevation surveys rather than from nautical charts, and a reservoir sits at whatever level it is being held at that week. Treat the shape and the depth as a guide, keep a lookout, and verify locally.
Depth. The pack carries Toledo Bend Reservoir at 667.7 square kilometers, about 164,992 acres, and the depth on it is built from state elevation surveys, because no NOAA nautical chart is produced for a reservoir. The outline comes from the National Hydrography Dataset. Keep in mind the lake is managed water, so the level you launch at is whatever it is being held at that month, and a contour is a fixed line measured from a datum. Because the packs are cut to a box rather than to the state line, Toledo Bend also sits in the Texas pack.
Both. The packs are cut to a rectangle instead of being traced along the state line, so a lake on a border falls into two of them and you get the same water either way. In this pack Caddo Lake measures 60.6 square kilometers, about 14,975 acres, taken from the chart polygon itself. That puts it within a fifth of a square kilometer of Lake Verret, which is 60.8.
Because the count includes every pond and marsh opening the National Hydrography Dataset carries. The pack has 10,425 charted water bodies and 1,366 of them are named, so most of what fills the screen once you are south of the Intracoastal never got a name. The charting does not depend on the name. An unnamed pond off a bayou is drawn from the same data as Lake Verret or Lac des Allemands.
Helm Boating