Wyoming · US Bureau of Reclamation (Boysen Dam)

Boysen Reservoir water level

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

FULL POOL 4710 4715 4720 4725
Elevation, feet (USBR project datum)

as of August 15, 2026

4711.74 ft USBR project datum

level 13.3 ft below full pool — on the low side for mid-August

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


Boysen 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 4710 4720 JFMAMJJASOND
Median and normal range by day of year, 1990–2026 · elevation, feet (USBR 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 4690 4700 4710 4720 4730 JFMAMJJASOND
  • 2015 (wettest on record)
  • 2002 (driest on record)
  • 2025 (last year)
  • 2026 (this year)

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 4725.00 ft USBR project datum · per US Bureau of Reclamation (Boysen Dam) full-pool reference
Conservation capacity 741,594 acre-feet · per US Bureau of Reclamation (Boysen Dam) capacity reference
Gauge USACE series BOYN.Elev.Inst.1Hour.0.Best-NWO · U.S. Army Corps of Engineers Access to Water data
Datum USBR project datum — 4725.0 = top of conservation/joint use per USACE CDA; USBR project page (id=26) lists 4717.0 as top of active conservation below joint use.
Last verified August 15, 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 Boysen Reservoir right now?

Boysen Reservoir is at 4711.74 ft (USBR project datum) as of August 15, 2026 — 13.3 ft below full pool — on the low side for mid-August

Is Boysen Reservoir full?

Not quite — at 4711.74 ft, Boysen Reservoir is 13.3 ft below its full pool of 4725.00 ft (USBR project datum).

What is full pool for Boysen Reservoir?

Full pool (the conservation pool) for Boysen Reservoir is 4725.00 ft USBR project datum, per US Bureau of Reclamation (Boysen Dam) full-pool reference. Levels above it use flood storage; levels below it are drawdown.