Almost all the boating water here sits behind a dam. Navajo Reservoir runs long up a canyon on the San Juan. Elephant Butte opens out wide enough that a chop builds across it by early afternoon, and Caballo sits below it on the same river. Ute Reservoir and Conchas Lake are open water with plains around them and very little to break a wind. Eagle Nest Lake is up in the mountains and fishes like it. Cochiti, El Vado, Heron and Abiquiu are smaller, and each one behaves like the canyon it was put in.
The pack for this water carries 4,335 charted water bodies. Of those, 791 carry a name, and 53 named lakes measure more than a square kilometer. The largest the pack carries is Navajo Reservoir at 61.9 square kilometers, which is 15,296 acres measured from the chart polygon itself. Inside those outlines there is depth. Contours and a reading under the boat, built from state elevation surveys, because no nautical chart was ever made for a lake behind a dam.
The pack draws 4,335 charted water bodies, which puts it twentieth of the 48 state packs by count. That count is made mostly of small water: stock tanks and playa basins that hold whatever runs into them. Only 791 of the 4,335 carry a name at all.
The gap between those two numbers is the character of the water out here. Most of what holds water has no name on any map, and the water people run boats on is a short enough list to recite at the ramp. Both kinds are drawn. The unnamed ones are mostly useful for knowing where you are once the pavement gives out. The named ones are where the depth work matters, and 53 of them come in over a square kilometer, which is roughly the point at which a lake is worth backing a trailer down for.
| Lake | Charted surface area |
|---|---|
| Navajo Reservoir | 62 km² (15,296 acres) |
| Red Bluff Reservoir | 44 km² (10,971 acres) |
| Elephant Butte Reservoir | 44 km² (10,873 acres) |
| Ute Reservoir | 22 km² (5,412 acres) |
| Caballo Reservoir | 19 km² (4,596 acres) |
| Heron Reservoir | 18 km² (4,473 acres) |
| Laguna del Perro | 18 km² (4,448 acres) |
| Salt Lake | 17 km² (4,176 acres) |
| Lake Lucero | 13 km² (3,311 acres) |
| Abiquiu Reservoir | 13 km² (3,237 acres) |
| El Vado Reservoir | 12 km² (3,089 acres) |
| Playas Lake | 9 km² (2,273 acres) |
The twelve largest named lakes the New Mexico pack carries, by charted surface area, measured from the chart polygon itself. The pack carries 4,335 charted water bodies in all, 791 of them named, and 53 named lakes larger than one square kilometer.
There is no NOAA chart for a reservoir. NOAA surveys salt water and the navigable rivers that reach it, and a pool held behind a dam was never part of that program. So inland depth in Helm is built from a different pair of sources. The outline of the water body, the shape you see on the chart, comes from the National Hydrography Dataset. The depth inside that outline is built from state elevation surveys, which measured the ground the reservoir was filled over.
Put the two together and the blue shape stops being a shape. It becomes water with a bottom under it, and once there is a bottom, the draft you entered has something to be measured against. That is the difference between a lake drawn as scenery and a lake you can plan a route across before you leave the house. Readings carry the date of the survey behind them, so you can see how old the measurement under you is.
A lake is not the sea. The sea comes back to the same place twice a day and you can plan against that. A reservoir sits wherever the people running the dam are holding it, and that level moves with the irrigation season and with whatever the snowpack sent down that spring.
So read a contour on a reservoir for what it is, which is a line at a fixed elevation on the ground beneath the water. The line does not move. What moves is where the surface crosses it. When the pool is down, every contour is still in the same place on the chart and the water has simply retreated up the slope toward the deeper ones. A cove that carried you in June has the same bottom in September. You just meet that bottom sooner.
The shoulders of the old creek channel are the thing to watch. On a drawn down reservoir that channel is still the deepest path across the basin, and the flats on either side of it come up fast. With a draft on the chart, those flats shade while the channel stays open, which is what you want on the screen before you commit the boat to an arm you have not run this year. Check the level being held, then read the chart knowing which way it has moved.
These areas are measured from the chart polygon, so they are comparable with one another rather than with whatever figure is painted on a sign at the ramp.
Navajo Reservoir is the largest lake the pack carries at 61.9 square kilometers, and nothing else is close. Red Bluff Reservoir at 44.4 and Elephant Butte at 44.0 are near enough the same size that the difference is inside the noise of where you draw a shoreline. The gap between Navajo and Elephant Butte is about the area of Heron Reservoir all by itself. Caballo at 18.6 and Heron at 18.1 are a matched pair, as are Abiquiu at 13.1 and El Vado at 12.5. Conchas Lake and Eagle Nest Lake come out identical at 7.3 square kilometers, or 1,804 acres each, which is worth knowing if you have only ever launched on one of them. Cochiti Lake at 5.2, then Lake Sumner and Morgan Lake at 5.1 apiece, close out the water over a thousand acres.
Not every large polygon on that list is water you launch on. Laguna del Perro at 18.0 square kilometers, Lake Lucero at 13.4 and Playas Lake at 9.2 are basin floors that the National Hydrography Dataset carries as water bodies, and what stands in them depends on the season. They are drawn because they are real features of the ground, and they are useful on a chart for the same reason a dry arroyo is useful on a map.
One more thing about a list like this. The packs are cut to a box rather than to a state line, so water near a boundary can sit in two packs at once. If you run a lake down in a corner, the pack on the other side of that corner carries it too.
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.
With depth. The outline comes from the National Hydrography Dataset and the depth inside it is built from state elevation surveys, so you get contours and a reading on the water rather than a flat blue shape, with your own draft shading the water you cannot cross. Elephant Butte measures 44.0 square kilometers, or 10,873 acres, off the chart polygon. Caballo Reservoir, on the same river below it, is 18.6 square kilometers, or 4,596 acres.
Red Bluff Reservoir at 44.4 square kilometers is the second largest the pack carries. After Elephant Butte come Ute Reservoir at 21.9, Caballo at 18.6, Heron at 18.1, Abiquiu at 13.1 and El Vado at 12.5. Conchas Lake and Eagle Nest Lake are 7.3 each, Cochiti Lake is 5.2, and Lake Sumner and Morgan Lake are 5.1 apiece. In all the pack draws 4,335 water bodies, 791 of them named, with 53 named lakes over a square kilometer.
Yes, as long as you read it as elevation. A contour is a line at a fixed height on the ground the reservoir was filled over, and that line does not move when the pool does. What moves is where the surface crosses it. On a low Navajo the old creek channel is still the deepest path across the basin, and the flats beside it come up sooner than they did at full pool. Check the level being held before you tow, then read the chart from there. With your draft entered, the water too thin for the boat shades on its own.
Helm Boating