Perfect World
Hydrology Metering

Falcon Dam · Rio Grande · TX

Falcon Reservoir

The last big pool on the Rio Grande before the Gulf — the storage story that starts above Las Cruces ends here, shared with Mexico.

Water surface elevation

262.3 ft

Texas Water Development Board, daily · daily value, Sep 2

Water in storage

353,750 acre-feet

Texas Water Development Board, daily · daily value, Sep 2

Share of conservation capacity

22.6% full

against the live feed conservation capacity figure (TWDB Water Data for Texas, statewide conditions feed)

Below full pool

38.9 ft

full pool at 301.2 ft

This month in the record

lower than 79% of the 73 Septembers on record

monthly mean storage; record low 108,097 acre-feet (1956), record high 1.55 million acre-feet (1981)

30-day trend

-1,985 af/day

storage, 2026-08-012026-08-31; over the year +317 af/day. Measured change, not a forecast.

Drought at the dam

D0 — Abnormally dry

US Drought Monitor at the dam's coordinates, released 2026-08-27; the feeding basin can differ.

full pool 301 ftcolumn continues below262

22.6% full

of conservation capacity, by storage (live feed figure, TWDB Water Data for Texas, statewide conditions feed). Sedimentation slowly shrinks real capacity.

The water line is elevation (TWDB feed datum); the percentage is storage ÷ capacity. They are different measures — a reservoir's volume is not linear in its depth, so the line's height in this column is not the percentage.

The last 120 days

Daily water-surface elevation in feet. The axis hugs the data — it does not start at zero. Source: committed snapshot (TWDB, retrieved 2026-08-31).

257.6261.8266.0May 4Jul 3Aug 31262.5
See the numbers as a table
DateElevation (ft)
Aug 31262.49
Aug 30262.57
Aug 29262.66
Aug 28262.73
Aug 27262.80
Aug 26262.88
Aug 25262.98
Aug 24263.07
Aug 23263.16
Aug 22263.25
Aug 21263.32
Aug 20263.39
Aug 19263.47
Aug 18263.57
Aug 17263.65
Aug 16263.72
Aug 15263.79
Aug 14263.87
Aug 13263.95
Aug 12264.02
Aug 11264.10
Aug 10264.21
Aug 9264.31
Aug 8264.41
Aug 7264.47
Aug 6264.54
Aug 5264.58
Aug 4264.60
Aug 3264.67
Aug 2264.75

Most recent 30 days shown.

The whole record

Monthly mean elevation, Sep 1953 to Aug 2026. The axis spans the pools, not zero; elevations in TWDB feed datum. Months with fewer than 15 gaged days are dropped, and gaps in the record break the line. Source: TWDB, retrieved 2026-08-31.

monthly mean elevationpool reference lines
232271310Sep 1953Mar 1990Aug 2026full pool264
See the numbers as a table
MonthMean elevation (ft)Days gaged
Aug 2026263.731
Jul 2026263.631
Jun 2026261.930
May 2026258.931
Apr 2026257.530
Mar 2026257.131
Feb 2026256.828
Jan 2026256.131
Dec 2025254.331
Nov 2025252.930
Oct 2025254.331
Sep 2025254.330
Aug 2025254.731
Jul 2025255.431
Jun 2025254.730
May 2025254.731
Apr 2025256.430
Mar 2025255.631
Feb 2025256.128
Jan 2025257.031
Dec 2024256.131
Nov 2024255.930
Oct 2024255.931
Sep 2024254.830

Most recent 24 months shown; the full monthly series is in the page's API response.

Storage against capacity

Monthly mean storage in acre-feet, zero baseline. The dashed line is the live feed conservation capacity figure (TWDB Water Data for Texas, statewide conditions feed) — sedimentation slowly shrinks real capacity. Storage can legitimately rise past a conservation-pool line when the flood pool is in use.

monthly mean storageconservation capacity
0820,2431.6MSep 1953Mar 1990Aug 2026capacity386,270
See the numbers as a table
MonthMean storage (acre-feet)Days gaged
Aug 2026386,27031
Jul 2026399,84431
Jun 2026381,83030
May 2026339,63031
Apr 2026312,22730
Mar 2026313,69231
Feb 2026320,63728
Jan 2026293,54231
Dec 2025254,26731
Nov 2025237,94130
Oct 2025255,57731
Sep 2025247,70030
Aug 2025243,75531
Jul 2025248,82531
Jun 2025236,46530
May 2025236,30031
Apr 2025245,35130
Mar 2025242,60531
Feb 2025242,42728
Jan 2025229,70231
Dec 2024204,25631
Nov 2024207,55030
Oct 2024212,24131
Sep 2024203,42230

Most recent 24 months shown.

Where these numbers come from

Readings at Falcon Reservoir are the measuring agencies' own: each value above names its source (USGS gage, Bureau of Reclamation daily record, Army Corps project data, or this desk's committed copy) and its observation time in the reservoir's own time zone. The conservation capacity figure is the live feed TWDB Water Data for Texas, statewide conditions feed number — its basis: conservation capacity (TWDB); sedimentation slowly shrinks real capacity, so the vintage travels with the percent.