Updated August 2026 · Top 25 of 41 lakes with a Secchi reading
Clearest Lake in New Mexico: Top 25 by Secchi Depth
Perch Lake in Guadalupe County is the clearest lake in New Mexico by Secchi depth, at 14.8 ft. Mapped and ranked below: the 25 clearest of 41 New Mexico lakes with a Secchi reading. Secchi depth is shown, not scored: the letter grades nutrients and algae, so a clear lake can be unrated or carry a lower grade than a murkier one.
How clear are New Mexico's clearest lakes?
From 14.8 ft at Perch Lake to 3.9 ft at #25, Jal Lake; the median of the 25 is 6.9 ft.
| # | Lake | County | Secchi depth | Grade | Area |
|---|---|---|---|---|---|
| 1 | Perch Lake | Guadalupe | 14.8 ft | NR | — |
| 2 | Navajo Reservoir la Jara Confluence | Rio Arriba | 13.5 ft | NR | — |
| 3 | Cabresto Lake Deep | Taos | 13.1 ft | NR | 29 acres |
| 4 | Bill Evans Lake Deep | Grant | 11.5 ft | NR | 63 acres |
| 5 | Lake Farmington Deep | San Juan | 9.8 ft | NR | 198 acres |
| 6 | Grindstone Canyon Reservoir Deep | Lincoln | 9 ft | C | 39 acres |
| 7 | Alto Lake | Lincoln | 8.9 ft | D | 15 acres |
| 8 | Conchas Reservoir | San Miguel | 8.9 ft | A | 2,694 acres |
| 9 | North Shuree Pond | Colfax | 8.9 ft | NR | 0 acres |
| 10 | Eagle Nest Lake | Colfax | 8.9 ft | NR | 2,496 acres |
| 11 | Lake Maloya | Colfax | 8.2 ft | NR | 147 acres |
| 12 | Fenton Lake | Sandoval | 7.9 ft | NR | 32 acres |
| 13 | Figure Eight Lake | Chaves | 6.9 ft | NR | — |
| 14 | Lower Charette Lake | Mora | 6.9 ft | NR | — |
| 15 | Santa Cruz Lake | Santa Fe | 6.3 ft | NR | 100 acres |
| 16 | Goose Lake | Taos | 5.7 ft | NR | — |
| 17 | Lake Roberts | Grant | 5.7 ft | NR | 61 acres |
| 18 | Canjilon Lake | Rio Arriba | 5.2 ft | NR | 3 acres |
| 19 | Sumner Lake Dam | De Baca | 4.9 ft | NR | 7,615 acres |
| 20 | San Gregorio Deep Lake | Rio Arriba | 4.3 ft | NR | 33 acres |
| 21 | Monastery Lake Deep | San Miguel | 4.1 ft | NR | — |
| 22 | Hopewell Lake | Rio Arriba | 3.9 ft | F | 13 acres |
| 23 | Brantley Reservoir Deep | Eddy | 3.9 ft | NR | 39,301 acres |
| 24 | Clayton Lake Deep Dam | Union | 3.9 ft | NR | 175 acres |
| 25 | Jal Lake | Lea | 3.9 ft | NR | — |
Sources and method
- Secchi depth: Median of each lake's EPA Water Quality Portal readings, sampled May 2012 to October 2024, in feet. For 24 of these 25 lakes the submitting agency is NM Environmental Dept./SWQB. Portal: EPA Water Quality Portal.
- Grade: A–F water-quality grade from nutrient and algae sampling (total phosphorus and chlorophyll-a) against the lake's EPA ecoregion classes, where enough recent samples exist to support one; the dashed NR mark otherwise. Clarity is not part of the grade, which is why a clear lake here can be unrated or carry a lower letter than a murkier one.
- Area: state agency lake surveys and, for reservoirs, US Army Corps of Engineers National Inventory of Dams records, in acres at normal pool. A dash means no record carries one.
- Map pins: all 25 table rows, colored by grade. No other lakes are plotted.
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Frequently Asked Questions
What is the clearest lake in New Mexico?
Perch Lake in Guadalupe County is the clearest lake in New Mexico by Secchi depth, at 14.8 ft. Secchi depth is measured by lowering a black-and-white disk until it disappears from view; a deeper reading means clearer water. Perch Lake is not rated: no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years).
How clear are New Mexico's 25 clearest lakes?
They span 3.9 ft to 14.8 ft of Secchi depth, with a median of 6.9 ft. Perch Lake leads by 1.3 ft. Rio Arriba County has 4 of the 25; the rest are spread across 15 other counties. 4 of the 25 carry an A–F grade; the other 21 are not rated because their recent sampling does not support a letter.
How is water clarity measured?
Water clarity is measured by Secchi depth, named after the 19th-century Italian astronomer Pietro Angelo Secchi who developed the method. A standardized black-and-white disk is lowered into the water on a rope; the depth (in feet or meters) at which the disk disappears from view is recorded. Greater Secchi depth means clearer water, usually a sign of low sediment, low phosphorus, and limited algae growth. The figure for each lake here is the median of its readings.
What makes a lake clear?
Lake clarity is driven by three factors: low suspended sediment (clay, silt), low nutrient load (especially phosphorus, which fuels algae), and low chlorophyll-a (active algae biomass). Deep lakes with rocky basins and forested watersheds tend to be clearest because they take in little soil runoff and few nutrients. Shallow lakes in farmed watersheds are typically less clear because they receive more sediment and fertilizer runoff.
Is the clearest lake the cleanest?
Not always. Clarity (Secchi depth) is measured and shown; the letter grades nutrients and algae (total phosphorus and chlorophyll-a) against that lake’s EPA ecoregion classes. A lake can be very clear but still have elevated phosphorus that just hasn't bloomed yet. Too few New Mexico lakes carry a letter to rank the state on nutrients and algae, so there is no cleanest-lakes list for New Mexico. The grade on each lake page is the honest unit there.
Where to stay near New Mexico's clearest lakes
Planning a trip? Jump to live cabin, resort, and hotel availability near New Mexico's clearest lakes.
- Perch Lake · Guadalupe CountyCabins & hotels near Perch Lake →
- Navajo Reservoir la Jara Confluence · Rio Arriba CountyCabins & hotels near Navajo Reservoir la Jara Confluence →
- Cabresto Lake Deep · Taos CountyCabins & hotels near Cabresto Lake Deep →
- Bill Evans Lake Deep · Grant CountyCabins & hotels near Bill Evans Lake Deep →
- Lake Farmington Deep · San Juan CountyCabins & hotels near Lake Farmington Deep →
More on water clarity
The clearest lakes in America, ranked by measured Secchi depth in feet from EPA monitoring data — and why the famously clear lakes are missing.
What a Secchi depth reading measures, how many feet counts as good clarity, and why clear water is not always clean — with readings from graded lakes.
County-by-county Secchi champions: the clearest measured lake in each county, the murkiest county winners, and why a county title is not a national one.
Surveyed maximum depth against A–F nutrient-and-algae grades: the pattern, the shallow lakes that still grade an A, and why land use beats bathymetry.