Brantley Lake
Brantley Lake held 43,825 acre-feet on Nov 2, 2026, 102.3% of its conservation pool: much above normal for the date (the middle of past years is 46.2%).
A flood-control dam with a conservation or recreation pool beneath a much larger flood pool. On Pecos River. Pecos basin.
These lakes hold a normal "conservation" or recreation pool and keep a much larger space empty to catch floods. Percent is measured against the conservation pool, so a reading above 100% means flood water is being held back.
Last 365 days
Percent of the conservation pool, against the middle and spread of the same date in other years (the shaded bands: the middle half and the 10th to 90th percentile of past years).
- Median of past years
- Percent of conservation pool
- 10th–90th percentile of past years
- Middle half of past years
Show the data as a table
Year by year
The highest, average and lowest percent of the conservation pool in each calendar year. The latest year is partial. Years whose capacity is less certain are marked in the table below.
- Highest
- Average
- Lowest
Show the data as a table
The comparison uses 21 years of 1991-2020 whose capacity figure is published, current-table, high- or medium-confidence, 1991–2020, pooling 3 days either side of each date.
Readings are what the operating agencies report; we have not audited the latest values. Reclamation labels its data "provisional and subject to revision unless otherwise noted."
Year-by-year table, with how well capacity is known
| Year | Days | Most (acre-feet) | Average | Least | Highest % | Average % | Lowest % | Capacity figure |
|---|---|---|---|---|---|---|---|---|
| 2026 | 306 | 43,825 | 20,367 | 8,885 | 102.3% | 47.5% | 20.7% | Capacity published by the operator for that year |
| 2025 | 365 | 42,998 | 29,316 | 14,908 | 100.4% | 68.4% | 34.8% | Capacity published by the operator for that year |
| 2024 | 366 | 42,265 | 23,704 | 12,240 | 98.7% | 55.3% | 28.6% | Capacity published by the operator for that year |
| 2023 | 365 | 39,764 | 26,002 | 12,200 | 93.3% | 61.0% | 28.6% | Capacity published by the operator for that year |
| 2022 | 365 | 36,090 | 24,729 | 7,877 | 84.7% | 58.0% | 18.5% | Capacity published by the operator for that year |
| 2021 | 365 | 48,786 | 24,513 | 9,352 | 114.5% | 57.5% | 22.0% | Capacity published by the operator for that year |
| 2020 | 366 | 44,439 | 23,292 | 4,177 | 104.3% | 54.7% | 9.8% | Capacity published by the operator for that year |
| 2019 | 365 | 42,110 | 29,244 | 12,595 | 99.1% | 68.8% | 29.6% | Capacity published by the operator for that year |
| 2018 | 365 | 45,391 | 27,624 | 9,008 | 106.9% | 65.1% | 21.2% | Capacity published by the operator for that year |
| 2017 | 365 | 40,447 | 30,082 | 11,813 | 95.5% | 71.0% | 27.9% | Capacity published by the operator for that year |
| 2016 | 366 | 44,543 | 30,440 | 14,373 | 105.3% | 72.0% | 34.0% | Capacity published by the operator for that year |
| 2015 | 365 | 85,302 | 63,033 | 19,620 | 202.2% | 149.4% | 46.5% | Capacity published by the operator for that year |
| 2014 | 365 | 81,366 | 45,536 | 16,699 | 193.5% | 108.3% | 39.7% | Capacity published by the operator for that year |
| 2013 | 365 | 38,392 | 13,524 | 4,155 | 87.5% | 30.8% | 9.5% | Capacity published by the operator for that year |
| 2012 | 366 | 22,201 | 9,616 | 1,773 | 51.7% | 22.4% | 4.1% | The operator's current table fits the record |
| 2011 | 365 | 29,834 | 12,140 | 5,166 | 69.5% | 28.3% | 12.0% | The operator's current table fits the record |
| 2010 | 365 | 33,441 | 19,921 | 6,434 | 77.9% | 46.4% | 15.0% | The operator's current table fits the record |
| 2009 | 365 | 29,834 | 18,326 | 10,262 | 69.5% | 42.7% | 23.9% | The operator's current table fits the record |
| 2008 | 366 | 39,834 | 22,088 | 8,930 | 92.8% | 51.4% | 20.8% | The operator's current table fits the record |
| 2007 | 365 | 42,259 | 24,733 | 4,299 | 98.4% | 57.6% | 10.0% | The operator's current table fits the record |
| 2006 | 365 | 35,331 | 21,477 | 11,778 | 82.3% | 50.0% | 27.4% | The operator's current table fits the record |
| 2005 | 365 | 43,839 | 25,949 | 9,588 | 102.1% | 60.4% | 22.3% | The operator's current table fits the record |
| 2004 | 366 | 42,466 | 21,871 | 5,616 | 98.9% | 50.9% | 13.1% | The operator's current table fits the record |
| 2003 | 365 | 20,845 | 9,937 | 2,534 | 48.6% | 23.1% | 5.9% | The operator's current table fits the record |
| 2002 | 365 | 30,080 | 14,673 | 6,241 | 70.1% | 34.2% | 14.5% | The operator's current table fits the record |
| 2001 | 365 | 39,401 | 23,511 | 6,900 | 86.4% | 51.6% | 15.1% | Capacity recovered from the record, weakly supportednot used for "this date in other years" |
| 2000 | 366 | 44,672 | 29,571 | 15,672 | 98.0% | 64.9% | 34.4% | Capacity recovered from the record, weakly supportednot used for "this date in other years" |
| 1999 | 365 | 41,300 | 31,709 | 18,083 | 90.6% | 69.6% | 39.7% | Capacity recovered from the record, weakly supportednot used for "this date in other years" |
| 1998 | 365 | 47,990 | 29,166 | 16,900 | 105.3% | 64.0% | 37.1% | Capacity recovered from the record, weakly supportednot used for "this date in other years" |
| 1997 | 365 | 43,620 | 28,131 | 15,290 | 95.7% | 61.7% | 33.5% | Capacity recovered from the record, weakly supportednot used for "this date in other years" |
| 1996 | 366 | 39,260 | 25,923 | 13,530 | 86.1% | 56.9% | 29.7% | Capacity recovered from the record, weakly supportednot used for "this date in other years" |
| 1995 | 365 | 43,830 | 27,914 | 11,230 | 96.2% | 61.2% | 24.6% | Capacity recovered from the record, weakly supportednot used for "this date in other years" |
| 1994 | 365 | 42,500 | 26,091 | 11,590 | 93.2% | 57.2% | 25.4% | Capacity recovered from the record, weakly supportednot used for "this date in other years" |
| 1993 | 365 | 33,330 | 24,081 | 15,360 | 73.1% | 52.8% | 33.7% | Capacity recovered from the record, weakly supportednot used for "this date in other years" |
| 1992 | 366 | 50,130 | 29,523 | 8,910 | 110.0% | 64.8% | 19.5% | Capacity recovered from the record, well supported |
| 1991 | 365 | 49,270 | 22,772 | 5,940 | 108.1% | 50.0% | 13.0% | Capacity recovered from the record, well supported |
| 1990 | 365 | 14,270 | 8,490 | 2,040 | 31.3% | 18.6% | 4.5% | Capacity recovered from the record, weakly supportednot used for "this date in other years" |
| 1989 | 365 | 42,300 | 19,496 | 5,230 | 92.8% | 42.8% | 11.5% | Capacity recovered from the record, weakly supportednot used for "this date in other years" |
| 1988 | 366 | 19,400 | 4,725 | 0 | 42.6% | 10.4% | 0.0% | Capacity recovered from the record, weakly supportednot used for "this date in other years" |
About this reservoir
Reclamation's dam above Carlsbad, completed in 1989 to replace McMillan Reservoir. It holds the Carlsbad Project's irrigation supply in a conservation pool of about 42,000 acre-feet, under a pool far larger reserved for Pecos floods.
How to use these numbers
- Carlsbad irrigation supply. Percent of the conservation pool is the meaningful fill measure.
- Lower Pecos floods. Storage above the conservation pool is flood water; 2014 and 2015 show it clearly.
Read before quoting a number
- An earlier version of this report measured Brantley against its spillway, making it look far emptier than it is. It is now measured against its conservation pool.
- The conservation pool is redefined almost every year by an entitlement; the current value is used for every year.
The dam
| Dam | Brantley Dam |
|---|---|
| Owner | Bureau of Reclamation (Federal) |
| Operated with | Bureau of Reclamation |
| Type | Concrete, Gravity |
| Purposes, per the dam registry | Flood Risk Reduction, Irrigation, Recreation |
| Completed | 1989 |
| Height | 144 feet |
| Hazard class | High |
| Registry capacity | 966,300 acre-feet at most, 41,054 normal. Owner-reported and not corrected for sediment. |
National Inventory of Dams, U.S. Army Corps of Engineers.
How capacity is known
Capacity comes from the operator's elevation-to-storage table (USBR, effective 2020-01-01), checked against the storage the operator reports. Since the table took effect, it reproduces reported storage from reported elevation to within 0 acre-feet in the median (0.00% of storage), across 2,495 days. Where an older table was in force, we recover its capacity from the record and say how well supported it is.
| Pool | Elevation (ft) | Capacity now (acre-feet) | Where it comes from |
|---|---|---|---|
| Top of conservation poolused as 100% | 3,256.4 | 42,934 | CWMS level Brantley.Elev.Inst.0.Top of Conservation dated 2025-01-01Top of Conservation; Entitlement 2025 |
| Top of flood pool | 3,284.6 | 384,035 | CWMS level Brantley.Elev.Inst.0.Top of Flood dated 1900-01-01 |
| Top of dam | 3,309.6 | 1,194,318 | CWMS level Brantley.Elev.Inst.0.Top of Dam dated 1900-01-01 |
| Top of inactive pool | 3,229.2 | 2,514 | CWMS level Brantley.Elev.Inst.0.Top of Inactive dated 2019-01-01 |
Capacity over time (5 tables in force)
| Period | Capacity (acre-feet) | How well supported |
|---|---|---|
| 1988-01-01 to 1988-01-011988-1988 table | 45,577 | Capacity recovered from the record, weakly supported |
| 1990-10-01 to 1992-12-311990-1992 table | 45,577 | Capacity recovered from the record, well supported |
| 1993-01-01 to 1999-12-311993-1999 table | 45,577 | Capacity recovered from the record, weakly supported |
| 2000-01-01 to 2001-12-312000-2001 table | 45,577 | Capacity recovered from the record, weakly supported |
| 2002-01-01 to 2026-11-02current table | 42,934 | The operator's current table fits the record |
Rivers
Data and sources
Record from 1988 (39 years with readings), through Nov 2, 2026. Where several agencies report the same reservoir, we take each day's value from the first in this list that has one:
- Bureau of Reclamation HydroData: 14,124 days
- U.S. Army Corps of Engineers CWMS: 62 days
Year by year (CSV) · Last 365 days (CSV)
Credit: Bureau of Reclamation HydroData; U.S. Army Corps of Engineers CWMS; National Inventory of Dams (U.S. Army Corps of Engineers). Capacity analysis by New Mexico Water. Data accessed November 4, 2026.