Lake Powell water level chart
By Mike, independent developer behind zovo.one. Data checked Sep 21, 2026.
Lake Powell stood at 3,517.21 ft on September 20, 2026, ranking 2 lowest of the 63 years Reclamation has recorded for that calendar date.
Is that normal for the date?
At 3,517.20 ft, Lake Powell is lower than 98% of Septembers in 64 years of daily record.
The median for this date across 64 years is 3,629.26 ft, so this is -112.06 ft against the lake’s own history. Placed on a quantile ladder built from 22,868 daily readings published by USBR for site 919, 1963-12-28 to 2026-08-06. This reservoir typically peaks in July and bottoms out in December.
Where today sits in 63 years of readings
Reclamation's latest daily reading is 3,517.21 ft on September 20, 2026. The lowest reading since the reservoir first filled is 3,516.62 ft on September 15, 2026, so today sits 122.7 ft above the whole-record minimum.
That phrase, since the reservoir first filled, needs a boundary, and the boundary is ours rather than Reclamation's. This page uses 1981-01-01. Lake Powell reached full pool in 1980, so readings before that describe a reservoir filling for the first time, not one being operated. It matters because the whole-record minimum is much lower, 3,394.50 ft on May 11, 1964, and today is 122.7 ft above that. Nobody should read today's figure as the lowest the lake has ever been.
For 09-20 specifically, the file carries 63 years of readings and today's ranks 2 lowest among them. The lowest ever recorded on this date is 3,490.24 ft, in 1964, and today sits 27.0 ft above it.
Where the line sits against the operating landmarks
The three dashed lines on the chart are published elevations, not chosen ones. Full pool at 3,700 ft is the top of the operating range. Minimum power pool at 3,490 ft is the line below which Glen Canyon Dam stops generating hydropower. Dead pool at 3,370 ft is the elevation down to which water can still be released through the river outlet works.
Reading a chart against those lines is the part most level pages skip. A reservoir sitting 27.2 ft above minimum power pool is in a different operational state from one merely below average, and the chart shows how rarely the line has been down here.
Two federal series, and only one of them publishes its datum
The chart is Reclamation's daily pool elevation. The live reading on the rest of this site comes from USGS gage 09379900, a separate instrument read every fifteen minutes. They will not match exactly on any given day, and that is expected rather than an error, because a daily pool elevation and a fifteen-minute instantaneous reading are different measurements.
There is a second difference worth knowing about before comparing numbers across sites. The USGS monitoring-location page states the gage datum as NGVD 1929. Reclamation's catalog entry for this series has a field for the vertical datum, and this page makes no claim about what belongs in it, because the value is not published there. So this page does not assert that the two series share a datum. It plots the Reclamation series, labels it as the Reclamation series, and links the source so you can check it.
The seasonal shape of an ordinary Powell year
A chart of the last twelve months will mislead you, because Powell runs a strong annual rhythm underneath whatever the long trend is doing. Snowmelt fills it through spring and early summer, then releases and evaporation draw it down through autumn.
Counting the 45 complete calendar years from 1981-01-01 onward in the same file, and asking only which month carried each year's highest and lowest reading, July takes the annual high most often, in 21 of those 45 years, and December takes the annual low most often, in 19, with April the runner-up trough in 14.
These are counts of which month won, not average levels, because a month that wins twenty times out of forty-five is a fact a row can carry and an average is not. The practical consequence: a falling level in September tells you very little on its own. Measure it against where the same year peaked, or against the same calendar date in earlier years, which is what the rank above does.
Check any elevation against the record
Pick a date and get the pool elevation Reclamation recorded that day, plus where it ranks among every reading in the file. Or enter an elevation and get how often the lake has been that low and when. Both answers are computed in your browser from the same series the chart draws. Nothing is sent anywhere.
Questions about the Lake Powell record
How far back does this chart go? To December 28, 1963, the first row in Reclamation's daily file for Lake Powell. The dam gates closed in 1963. The file carries 22,913 daily readings through September 20, 2026.
Is this the lowest Lake Powell has ever been? No. The lowest reading in the whole file is 3,394.50 ft on May 11, 1964, during the years the reservoir was filling for the first time. Today sits 122.7 ft above that mark.
What was the highest? 3,708.34 ft on July 14, 1983, which is 8.34 ft above the 3,700 ft full-pool line.
Why does this chart differ from the live reading elsewhere on the site? Because they are different series. This chart plots Reclamation's daily pool elevation for site 919. The live reading comes from USGS gage 09379900, sampled every fifteen minutes. Both are federal, neither is wrong, and they are not the same measurement.
How often does it update? The file is refetched and every figure on this page recomputed on each build, which runs daily.
Where these numbers come from
Every figure on this page is computed in code from one file, Reclamation's complete daily pool-elevation record for Lake Powell, site 919. The build fetches it, parses 22,913 daily readings, drops the sentinel values Reclamation uses for a missing day, and computes the extrema, the counts and the rankings from what is left. None of the numbers is typed by hand, and none is carried as a constant that could go stale, which is exactly what went wrong with the previous record-low figure this site published.
The rankings are computed over the whole file rather than over a window. That distinction matters. A minimum found inside a date range only tells you the minimum of that range, so this page establishes the record by measuring the entire population, which is the only honest way to use the word lowest.
The published landmark elevations, full pool, minimum power pool and dead pool, come from Reclamation and are constants because they describe the dam, not the water.
Want today's reading rather than the record? The Lake Powell water level page carries the live gage figure and the 30 day trend. Downstream, the same chart for Lake Mead covers the reservoir this one feeds, and both are at their lowest since they first filled. In Texas, the Lake Travis water level chart does the same job from the Texas Water Development Board's daily file, checked against LCRA's record book. For the depth at the dam, see how deep Lake Powell is right now. If you are launching a boat, every ramp minimum against today's level is the page you want.
Levels are point-in-time readings and can lag real conditions, confirm ramp and hazard status with the lake operator before heading out. Not affiliated with any government agency, data is republished from public USGS, CDEC, and USBR feeds.