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Hydrology Metering

Elephant Butte Dam · Rio Grande · NM

Elephant Butte Reservoir

The reservoir the Mesilla Valley's irrigation water actually sits in — when this desk says the Rio Grande project is short, this is the number it means.

Water surface elevation

4,275.5 ft

Bureau of Reclamation, daily · daily value, Aug 31

Water in storage

27,506 acre-feet

Bureau of Reclamation, daily · daily value, Aug 31

Share of capacity

1.4% full

against the 2019 survey capacity figure (USBR 2017-19 sedimentation survey (at el. 4,407 ft))

Below full pool

131.5 ft

full pool at 4,407.0 ft

This month in the record

lower than 98% of the 111 Septembers on record

monthly mean storage; record low 20,193 acre-feet (1951), record high 2.07 million acre-feet (1986)

30-day trend

+24.3 af/day

storage, 2026-07-312026-08-30; over the year -130 af/day. Measured change, not a forecast.

Drought at the dam

D2 — Severe drought

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

full pool 4,407 ftcolumn continues below4,275

1.4% full

of capacity, by storage (2019 survey figure, USBR 2017-19 sedimentation survey (at el. 4,407 ft)). Sedimentation slowly shrinks real capacity.

The water line is elevation (USBR project 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.

Snowpack in the feeding basin

Measured across the Rio Grande headwaters in Colorado and northern New Mexico.

Snow season

typically Oct 26 – May 27

0.1 in on the ground, 2026-09-01; median peak 17.3 in around Apr 17

Last winter's verdict

50% of median peak

water year 2026 — the snow that fed this year's pool

5 highest active SNOTEL stations in the basin (Elwood Pass, Rat Creek, Grayback, …), NRCS AWDB REST (SNOTEL), station set pinned 2026-08-31. Daily snow-water equivalent against the stations' own 30-year medians; off season the percent is withheld rather than divided by zero.

The last 120 days

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

4269.94296.74323.5May 2Jul 1Aug 304275.5
See the numbers as a table
DateElevation (ft)
Aug 304275.46
Aug 294275.46
Aug 284275.45
Aug 274275.44
Aug 264275.47
Aug 254275.44
Aug 244275.46
Aug 234275.44
Aug 224275.43
Aug 214275.39
Aug 204275.37
Aug 194275.37
Aug 184275.39
Aug 174275.34
Aug 164275.34
Aug 154275.35
Aug 144275.32
Aug 134275.31
Aug 124275.31
Aug 114275.29
Aug 104275.35
Aug 94275.30
Aug 84275.25
Aug 74275.24
Aug 54275.24
Aug 44275.30
Aug 34275.22
Aug 24275.20
Aug 14275.16
Jul 314275.14

Most recent 30 days shown.

The whole record

Monthly mean elevation, Apr 1915 to Aug 2026. The axis spans the pools, not zero; elevations in USBR project datum. Months with fewer than 15 gaged days are dropped, and gaps in the record break the line. Source: USBR RISE, retrieved 2026-08-31.

monthly mean elevationpool reference lines
4,2544,3364,417Apr 1915Dec 1970Aug 2026full pool4,275
See the numbers as a table
MonthMean elevation (ft)Days gaged
Aug 20264275.429
Jul 20264281.831
Jun 20264302.730
May 20264316.431
Apr 20264319.230
Mar 20264318.731
Feb 20264316.128
Jan 20264312.431
Dec 20254306.031
Nov 20254297.330
Oct 20254292.131
Sep 20254289.130
Aug 20254291.431
Jul 20254296.131
Jun 20254310.830
May 20254320.931
Apr 20254322.430
Mar 20254321.331
Feb 20254318.528
Jan 20254314.631
Dec 20244308.331
Nov 20244302.430
Oct 20244299.831
Sep 20244302.930

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 2019 survey capacity figure (USBR 2017-19 sedimentation survey (at el. 4,407 ft)) — sedimentation slowly shrinks real capacity. Storage can legitimately rise past a conservation-pool line when the flood pool is in use.

monthly mean storagecapacity
01.2M2.4MApr 1915Dec 1970Aug 2026capacity27,218
See the numbers as a table
MonthMean storage (acre-feet)Days gaged
Aug 202627,21830
Jul 202644,31231
Jun 2026133,63730
May 2026227,11431
Apr 2026250,92930
Mar 2026246,44031
Feb 2026224,83028
Jan 2026195,64531
Dec 2025151,49331
Nov 2025101,33430
Oct 202577,77831
Sep 202566,02830
Aug 202574,56831
Jul 202596,24731
Jun 2025185,23130
May 2025266,28131
Apr 2025280,57430
Mar 2025269,79831
Feb 2025244,82228
Jan 2025212,60831
Dec 2024166,14831
Nov 2024128,76330
Oct 2024113,93931
Sep 2024132,07630

Most recent 24 months shown.

Where these numbers come from

Readings at Elephant Butte 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 capacity figure is the 2019 survey USBR 2017-19 sedimentation survey (at el. 4,407 ft) number; sedimentation slowly shrinks real capacity, so the vintage travels with the percent.