Brantley Reservoir Deep
Eddy County, New Mexico39,301 acresView mapDirections
NMED publishes the water-quality measurements for Brantley Reservoir Deep. Here is what has been measured.
- Impaired · Fish consumption advisory
- Limited data
Brantley Reservoir Deep in Eddy County, New Mexico has water-quality measurements published by NMED, shown here as reported. Water clarity: 3.9 ft visibility. Chlorophyll-a (algae): 21 µg/L. Surface area: 39301 acres.
Brantley Reservoir Deep is a 39,301-acre lake in Eddy County, New Mexico.
Source: EPA Water Quality Portal sampling records, NMED, last sampled 2022-04-13. Methodology: how these readings are compared.
What Brantley Reservoir Deep is good for
From access and monitoring records, not editorial picks.
- Big water39,301 acres
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Brantley Reservoir Deep is listed impaired under Clean Water Act §303(d) (IR 5) for fish consumption advisory, mercury. Check local advisories before you swim.
Whether Brantley Reservoir 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 Brantley Reservoir Deep
These are the measurements NMED publishes for Brantley Reservoir Deep, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 3.9 ft. Chlorophyll-a 21 µg/L. TSI 59.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3.9ft | 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) | 21µg/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. | 59 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Brantley Reservoir Deep
Answers come straight from the public measurements and survey records on this page.
→ Brantley Reservoir Deep water level: the live USGS gauge reading
Lake Details
Surface area
39,301 acres
No bathymetric survey has been published for Brantley Reservoir Deep, so its depth is not documented here.
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Fishing Brantley Reservoir Deep
Reservoir Info (USACE NID)
Brantley Reservoir Deep is a man-made reservoir impounded by the Brantley Dam (completed 1989), built primarily for flood risk reduction on the Pecos River; concrete-type dam, 144 ft tall and 20,850 ft long.
- Surface area
- 39,301 ac
- Normal storage
- 41,054 ac-ft
- Max storage
- 966,300 ac-ft
- Drainage area
- 17,650 sq mi
- Hazard class
- High
- Owner
- BUREAU OF RECLAMATION
All listed purposes: Flood Risk Reduction;Irrigation;Recreation.
Source: USACE National Inventory of Dams, NID ID NM00500 · Operator website · Matched by proximity (0.6 km)
EPA Impairment Status
Brantley Reservoir 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-2205_00 · Official waterbody report
Nearby Lakes in Eddy County
Frequently asked questions about Brantley Reservoir Deep
Where is Brantley Reservoir Deep?
- Brantley Reservoir Deep is a lake in Eddy County, New Mexico. Its water-quality measurements are published by NMED and shown on this page as reported.
What is the water quality of Brantley Reservoir Deep?
- Brantley Reservoir Deep in Eddy County, New Mexico has water-quality measurements published by NMED, shown here as reported. Water clarity: 3.9 ft visibility. Chlorophyll-a (algae): 21 µg/L. Surface area: 39301 acres.
Is Brantley Reservoir Deep safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Brantley Reservoir Deep is listed impaired under Clean Water Act §303(d) (IR 5) for fish consumption advisory, mercury. Check local advisories before you swim.
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Brantley Reservoir Deep is about 30 miles from Carlsbad Caverns National Park. Crowds there swing hard by season, so the month you pick changes both how busy the park is and what lodging costs.
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Where this data comes from
12 measurements from 1 monitoring station, 2013–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- NM Environmental Dept./SWQB
21NMEX_WQX12 samples · 2013–2022
Analytical methods
- Phosphorus by Colorimetry
- 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