Perfect World
Hydrology Metering

New Melones Dam · Stanislaus River · CA

New Melones Lake

The last big dam the Bureau finished, over a decade of protest — and the CVP's second-largest pool.

Water surface elevation

1,009.6 ft

Bureau of Reclamation, daily · daily value, Sep 1

Water in storage

1.56 million acre-feet

Bureau of Reclamation, daily · daily value, Sep 1

Share of capacity

65.0% full

against the project figure capacity figure (USBR Central Valley Project data)

Below full pool

78.4 ft

full pool at 1,088.0 ft

This month in the record

lower than 22% of the 82 Septembers on record

monthly mean storage; record low 906 acre-feet (1949), record high 2.15 million acre-feet (1998)

30-day trend

-1,778 af/day

storage, 2026-07-312026-08-30; over the year -244 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 1,088 ftcolumn continues below1,010

65.0% full

of capacity, by storage (project figure figure, USBR Central Valley Project data). 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.

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).

1006.21025.21044.2May 2Jul 2Aug 301009.8
See the numbers as a table
DateElevation (ft)
Aug 301009.84
Aug 291009.99
Aug 281010.16
Aug 271010.31
Aug 261010.42
Aug 251010.49
Aug 241010.57
Aug 231010.70
Aug 221010.74
Aug 211010.85
Aug 201010.98
Aug 191011.18
Aug 181011.37
Aug 171011.51
Aug 161011.62
Aug 151011.80
Aug 141012.02
Aug 131012.29
Aug 121012.50
Aug 111012.71
Aug 101012.93
Aug 91013.14
Aug 81013.32
Aug 71013.55
Aug 61013.78
Aug 51014.03
Aug 41014.30
Aug 31014.64
Aug 21014.84
Aug 11015.07

Most recent 30 days shown.

The whole record

Monthly mean elevation, Nov 1978 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
6668891,112Nov 1978Oct 2002Aug 2026full pool1,012
See the numbers as a table
MonthMean elevation (ft)Days gaged
Aug 20261012.130
Jul 20261019.131
Jun 20261028.729
May 20261038.731
Apr 20261040.030
Mar 20261040.331
Feb 20261033.327
Jan 20261029.331
Dec 20251019.831
Nov 20251016.530
Oct 20251015.731
Sep 20251017.030
Aug 20251022.131
Jul 20251030.631
Jun 20251039.630
May 20251049.231
Apr 20251052.130
Mar 20251048.531
Feb 20251043.528
Jan 20251039.631
Dec 20241036.831
Nov 20241034.030
Oct 20241034.731
Sep 20241037.530

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 project figure capacity figure (USBR Central Valley Project data) — sedimentation slowly shrinks real capacity. Storage can legitimately rise past a conservation-pool line when the flood pool is in use.

monthly mean storagecapacity
01.3M2.5MOct 1943Mar 1985Aug 2026capacity1.6M
See the numbers as a table
MonthMean storage (acre-feet)Days gaged
Aug 20261,584,49230
Jul 20261,652,92831
Jun 20261,750,01929
May 20261,853,59031
Apr 20261,867,28730
Mar 20261,870,72731
Feb 20261,796,86227
Jan 20261,755,86631
Dec 20251,660,22431
Nov 20251,627,32530
Oct 20251,620,03631
Sep 20251,632,49630
Aug 20251,683,20131
Jul 20251,768,75631
Jun 20251,862,68930
May 20251,966,37631
Apr 20251,997,80230
Mar 20251,958,78931
Feb 20251,904,93828
Jan 20251,863,02031
Dec 20241,833,72331
Nov 20241,804,42530
Oct 20241,810,72931
Sep 20241,840,06730

Most recent 24 months shown.

Where these numbers come from

Readings at New Melones Lake 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 project figure USBR Central Valley Project data number; sedimentation slowly shrinks real capacity, so the vintage travels with the percent.