Impaired Lakes in New Mexico
39 of 58 graded New Mexico lakes (67%) are officially listed as impaired under Clean Water Act §303(d) in the most recent EPA ATTAINS reporting cycle. 5 have an approved TMDL restoration plan.
Top Causes of Impairment in New Mexico
Reading the New Mexico impairment landscape
67% of New Mexico's tracked lakes — 39 of 58 — appear on the EPA Clean Water Act §303(d) impaired-waters list. At that share, impairment is the default state rather than an exception: the majority of lakes are flagged for at least one pollutant exceeding water-quality standards. Trip-planning for clean water in New Mexico typically requires checking impairment status as a first filter, not as an edge case.
The leading impairment category in New Mexico is Nutrients (phosphorus, nitrogen) — nutrient enrichment, typically from agricultural fertilizer runoff, septic discharge, or stormwater carrying lawn-care residue. Nutrient-impaired lakes can still be safe for contact recreation in many conditions, but they're prone to algal blooms (including potentially toxic cyanobacteria) during warm-water periods. Check the state's beach-monitoring or harmful-algal-bloom dashboard before swimming on nutrient-impaired waters in summer.
Impaired-waters listings come from the state environmental agency's §303(d) submission to EPA, refreshed on a roughly 2-year cycle. A listed lake stays on the list until either a TMDL is established and the cleanup completes, or subsequent monitoring shows the pollutant concentrations no longer exceed water-quality standards. The list below reflects the most recent available New Mexico submission to the EPA Assessment, Total Maximum Daily Load Tracking and Implementation System (ATTAINS) dataset.
All 39 EPA-Listed Impaired Lakes in New Mexico
| Lake | County | Grade | Causes | TMDL |
|---|---|---|---|---|
| Conchas Reservoir | San Miguel | A | Mercury, PCBs | — |
| Santa Rosa L Dp Sta Midchannel Buoy Lake | Guadalupe | A | Mercury, Nutrients (phosphorus, nitrogen) | — |
| Heron Lake Deep Dam | Rio Arriba | C | Temperature | — |
| Grindstone Canyon Reservoir Deep | Lincoln | C | Temperature | — |
| Heron Lake Shallow | Rio Arriba | C | Temperature | — |
| Mescalero Lake Deep | Otero | C | Temperature | — |
| Mescalero Lake Shallow | Otero | C | Temperature | — |
| Grindstone Caynon Reservoir Inlet | Lincoln | D | Temperature | — |
| Hopewell Lake | Rio Arriba | F | Nutrients (phosphorus, nitrogen) | — |
| Burns Lake Deep | Rio Arriba | NR | Nutrients (phosphorus, nitrogen) | — |
| Six Mile Dam Lake | Eddy | NR | Nutrients (phosphorus, nitrogen) | — |
| San Gregorio Deep Lake | Rio Arriba | NR | Nutrients (phosphorus, nitrogen) | — |
| Fenton Lake | Sandoval | NR | Nutrients (phosphorus, nitrogen) | — |
| Lake Carlsbad Deep Station | Eddy | NR | Fish consumption advisory, PCBs | — |
| Figure Eight Lake | Chaves | NR | Nutrients (phosphorus, nitrogen) | — |
| Lake Van | Chaves | NR | Temperature | — |
| Brantley Reservoir Deep | Eddy | NR | Fish consumption advisory, Mercury | — |
| Clayton Lake Deep Dam | Union | NR | Mercury, Nutrients (phosphorus, nitrogen) | — |
| Snow Lake | Catron | NR | Nutrients (phosphorus, nitrogen), pH / acidity, Temperature | — |
| Quemado Dam Lake | Catron | NR | Mercury, Nutrients (phosphorus, nitrogen) | — |
| Bluewater Lake | Cibola | NR | Mercury, Nutrients (phosphorus, nitrogen) | ✓ |
| Lake Maloya | Colfax | NR | Nutrients (phosphorus, nitrogen) | ✓ |
| North Shuree Pond | Colfax | NR | Nutrients (phosphorus, nitrogen) | ✓ |
| Lower Charette Lake | Mora | NR | Mercury, Temperature | — |
| Eagle Nest Lake | Colfax | NR | Nutrients (phosphorus, nitrogen) | ✓ |
| Springer Lake | Colfax | NR | Mercury | — |
| Goose Lake | Taos | NR | Oxygen depletion (low DO), pH / acidity | — |
| Lake Farmington Deep | San Juan | NR | Mercury | — |
| Santa Cruz Lake | Santa Fe | NR | Metals (other than mercury), Nutrients (phosphorus, nitrogen), Temperature | ✓ |
| Cabresto Lake Deep | Taos | NR | pH / acidity | — |
| Lake Roberts | Grant | NR | Mercury, Nutrients (phosphorus, nitrogen), Temperature | — |
| Sumner Lake Dam | De Baca | NR | Mercury | — |
| Bear Canyon Reservoir Deep | Grant | NR | Mercury, Nutrients (phosphorus, nitrogen), Temperature | — |
| Bill Evans Lake Deep | Grant | NR | Mercury, PCBs | — |
| Elephant Butte Reservoir | Sierra | NR | Mercury, PCBs | — |
| Brantley Reservoir Shallow | Eddy | NR | Fish consumption advisory, Mercury | — |
| Jal Lake | Lea | NR | Nutrients (phosphorus, nitrogen) | — |
| Ramah Reservoir Deep | McKinley | NR | Nutrients (phosphorus, nitrogen) | — |
| Lea Lake Overflow | Chaves | NR | Nutrients (phosphorus, nitrogen) | — |
Frequently Asked Questions
How many lakes are impaired in New Mexico?
39 of 58 graded New Mexico lakes (67%) are listed as impaired in the most recent EPA ATTAINS reporting cycle. Of those, 39 are on the federal Clean Water Act §303(d) list and 5 have an approved Total Maximum Daily Load (TMDL) restoration plan.
What does Clean Water Act §303(d) mean?
Section 303(d) of the federal Clean Water Act requires every state to identify waters that don't meet water quality standards even after pollution control measures. Each listed water must then have a Total Maximum Daily Load (TMDL) developed — a plan that caps how much of each pollutant can enter the waterbody. The "303(d) list" is the impaired-waters list. The EPA reviews each state's list every two years.
What are the top causes of impairment in New Mexico?
The most common causes flagged across New Mexico's impaired lakes are: Nutrients (phosphorus, nitrogen) (20 lakes); Mercury (15 lakes); Temperature (12 lakes); PCBs (4 lakes); Fish consumption advisory (3 lakes); pH / acidity (3 lakes). Mercury is widespread in fish tissue across the upper Midwest from atmospheric deposition. Nutrient impairment (phosphorus, nitrogen) typically reflects agricultural runoff and urban stormwater.
Can I swim in an impaired lake?
It depends on the cause of impairment. A lake impaired for "mercury in fish tissue" is generally safe to swim in — the warning is about long-term consumption of fish. A lake impaired for "pathogens" (E. coli) or "algal growth" may pose a swimming risk and often has a separate beach advisory. Check the cause categories listed for each lake below, and consult your state health department's beach monitoring program for current advisories.
Where does this impairment data come from?
Every impairment record on this page comes from the EPA's ATTAINS (Assessment and TMDL Tracking and Implementation System) public dataset, the federal repository of state-reported water quality assessments. EPA ATTAINS is published as GeoParquet files on the EPA Office of Water S3 bucket and refreshed several times per year. Causes and use-support codes follow EPA's standard taxonomy.
More on impaired waters
What it means when a lake is listed as impaired, why mercury is the most common reason, and why a listed lake can still be clear water with a good grade.
Why states issue fish-consumption advisories, which contaminants — mercury, PCBs, PFAS — drive them, and how to eat the fish you catch more safely.
How phosphorus and nutrient runoff drive algae growth and turn lakes green, where the nutrients come from, and what it means for a lake's grade.
Which lakes are actually improving: multi-year EPA monitoring trends, the named recoveries still in progress, and what it takes to move a letter grade.
Data source
Impairment data from the EPA ATTAINS (Assessment and TMDL Tracking and Implementation System) public dataset. Assessment unit IDs are matched to LakeQuality lakes by name and proximity; some lakes may not appear here if their ATTAINS name doesn't match our naming convention. For an official query, consult .