Montana · Bureau of Reclamation (Tiber Dam)

Tiber Reservoir water level

Today's reading against full pool and Tiber Reservoir's own seasonal history.

FULL POOL 2985 2990
Elevation, feet (project datum)

as of August 20, 2026

2989.37 ft project datum

level 3.6 ft below full pool — typical for mid-August

Reading comes straight from U.S. Army Corps of Engineers Access to Water data (USACE series TIBR.Elev.Inst.1Hour.0.Best-NWO) and updates live when you load this page.


Tiber Reservoir through the year

The band is the lake's own normal: where the level has run on each calendar day, 1990–2026. The summer drawdown — and how this year sits in it — shows up without reading a single number.

full pool 2920 2940 2960 2980 3000 JFMAMJJASOND
Median and normal range by day of year, 1990–2026 · elevation, feet (project datum)

This year vs the years that matter

This year's trace against last year and the driest and wettest years on record — the drought-context question every lake regular asks.

full pool 2900 2950 3000 JFMAMJJASOND
  • 2026 (this year)
  • 2025 (last year)
  • 2011 (wettest on record)
  • 1991 (driest on record)

Full pool, datum, and the gauge

"Full pool" here means the conservation pool — the level the lake is designed to hold for water supply and recreation, not the flood-control space above it. The full explainer covers flood pool and dead pool too.

Full pool 2993.00 ft project datum · per Bureau of Reclamation (Tiber Dam) full-pool reference
Conservation capacity 925,648 acre-feet · per Bureau of Reclamation (Tiber Dam) capacity reference
Gauge USACE series TIBR.Elev.Inst.1Hour.0.Best-NWO · U.S. Army Corps of Engineers Access to Water data
Datum project datum — The district publishes the gauge and the top of conservation pool figure in the project's own datum, so the two compare like for like.
Last verified August 20, 2026

LakeDates reports lake level, not ramp status. Whether a given ramp or marina is usable at this level varies ramp by ramp — call the marina before you tow.

Quick answers

How full is Tiber Reservoir right now?

Tiber Reservoir is at 2989.37 ft (project datum) as of August 20, 2026 — 3.6 ft below full pool — typical for mid-August

Is Tiber Reservoir full?

Not quite — at 2989.37 ft, Tiber Reservoir is 3.6 ft below its full pool of 2993.00 ft (project datum).

What is full pool for Tiber Reservoir?

Full pool (the conservation pool) for Tiber Reservoir is 2993.00 ft project datum, per Bureau of Reclamation (Tiber Dam) full-pool reference. Levels above it use flood storage; levels below it are drawdown.