Lake Farmington Deep
San Juan County, New Mexico198 acresView mapDirections
NMED publishes the water-quality measurements for Lake Farmington Deep. Here is what has been measured.
- Impaired · Mercury
- Limited data
Lake Farmington Deep in San Juan County, New Mexico has water-quality measurements published by NMED, shown here as reported. Water clarity: 9.8 ft visibility. Chlorophyll-a (algae): 2.4 µg/L. Surface area: 198 acres.
Lake Farmington Deep is a 198-acre lake in San Juan County, New Mexico. Overall water quality is improving over recent sampling years.
Source: EPA Water Quality Portal sampling records, NMED, last sampled 2018-10-17. Methodology: how these readings are compared.
Lake Farmington Deep covers about 200 acres in San Juan County. If you are planning to stay, you can search lake houses and cabins around Lake Farmington Deep on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Lake Farmington Deep is good for
From access and monitoring records, not editorial picks.
- Clear water9.8 ft of visibility
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Lake Farmington Deep is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Whether Lake Farmington Deep is safe to swim in today is a call for the New Mexico Environment Department and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Lake Farmington Deep
These are the measurements NMED publishes for Lake Farmington Deep, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 9.8 ft. Chlorophyll-a 2.4 µg/L. TSI 42.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 9.8ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | 2.4µg/L | Measured, not scored The green pigment in algae — a direct measure of how much algae is in the water. |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 42 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Lake Farmington Deep
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
198 acres
No bathymetric survey has been published for Lake Farmington Deep, so its depth is not documented here.
Stays via Stay22
Stays near Lake Farmington Deep
Compare lakeside cabins, hotels, and vacation rentals near Lake Farmington Deep in San Juan County, New Mexico — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Lake Farmington Deep
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Fishing Lake Farmington Deep
Water quality readings over time
2 seasons of samples on record (2012–2017). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Stable2 years
Chlorophyll-a
Improving-0.24 µg/L/yr2 years
Reservoir Info (USACE NID)
Lake Farmington Deep is a man-made reservoir impounded by the Farmington Lake Dam (completed 1964), built primarily for water supply on the Animas River-Os; earth-type dam, 117 ft tall and 1,075 ft long.
- Surface area
- 198 ac
- Normal storage
- 6,703 ac-ft
- Max storage
- 8,470 ac-ft
- Drainage area
- 3.11 sq mi
- Hazard class
- High
- Owner
- CITY OF FARMINGTON
Source: USACE National Inventory of Dams, NID ID NM00302 · Operator website · Matched by proximity (0.05 km)
EPA Impairment Status
Lake Farmington Deep is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Aquatic life.
Source: EPA ATTAINS assessment unit NM-9000.B_006 · Official waterbody report
Nearby Lakes in San Juan County
Frequently asked questions about Lake Farmington Deep
Where is Lake Farmington Deep?
- Lake Farmington Deep is a lake in San Juan County, New Mexico. Its water-quality measurements are published by NMED and shown on this page as reported.
What is the water quality of Lake Farmington Deep?
- Lake Farmington Deep in San Juan County, New Mexico has water-quality measurements published by NMED, shown here as reported. Water clarity: 9.8 ft visibility. Chlorophyll-a (algae): 2.4 µg/L. Surface area: 198 acres.
Is Lake Farmington Deep safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Lake Farmington Deep is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Explore Lake Farmington Deep across LakeQuality
Planning a trip around Mesa Verde?
Lake Farmington Deep is about 37 miles from Mesa Verde National Park. Crowds there swing hard by season, so the month you pick changes both how busy the park is and what lodging costs.
Best time to visit Mesa Verde →More lakes in New Mexico
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Where this data comes from
6 measurements from 1 monitoring station, 2017–2018. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- NM Environmental Dept./SWQB
21NMEX_WQX6 samples · 2017–2018
Analytical methods
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database