Will Lake Powell's minimum elevation be at least 3,500 but below 3,510 ft?

- [2026-10-09] The USBR RISE resolution source (data.usbr.gov item 508) is active and updated daily; the record low in this series was reached earlier in the water year, and the series' end date is listed as Oct 9, 2026 with most recent update Oct 10, 2026, confirming the feed is live and current. Daily instantaneous lake/reservoir elevation in feet for Lake Powell, Glen Canyon Dam, and Powerplant are typically updated once a day. - [2026-10-09] Latest observed elevation (water-data.com, sourced from USBR) was 3,518.97 ft on Oct 9, 2026, up slightly from recent days. Last Reading: 3518.97 on Friday, October 9th, 2026. - [2026-09-15] The series' record low so far in this water year was 3,516.62 ft, set in mid-September 2026, before a modest rebound into October. That elevation is its lowest October reading since 1964, and 2.17 feet above its record low of 3,516.62 ft (September 15, 2026, the lowest since the reservoir first filled), in a daily record going back to December 28, 1963. - [2026-08-31] End-of-August elevation/storage per USBR's official Glen Canyon Dam status page: the end of August elevation and storage of Lake Powell were 3,517.87 feet (approx. 183 feet from full pool) and 5.14 million acre-feet (maf) (22 percent of live capacity), respectively. - [2026-09-15] USBR's official page (last updated Sept 15, 2026) states the operative near-term projection: The August 2026 24-Month Study projected the October 1, 2026 Lake Powell elevation to be less than 3,540 feet and Lake Powell's elevation is projected to decline below 3,510 feet during water year (WY) 2027. - [2026-09-01] Using the latest September inflow forecast, USBR's model projects: the September 24-Month Study projects Lake Powell elevation will end water year 2026 near 3,514.98 feet with approximately 4.99 maf in storage (21 percent of capacity). - [2026-08-21] DOI/Reclamation finalized the 2027-2028 Operating Guidelines and classified Lake Powell operations for the water year starting Oct 1, 2026: Lake Powell will begin the October 1 water year between elevations 3,540 and 3,510 feet, placing operations in the Lower Elevation Infrastructure Protection Range... Reclamation will begin the water year with lower releases between 6.0 and 7.0 million acre-feet in order to attempt to maintain an elevation of 3,510 feet or higher and will adjust releases through April to continue to maintain elevation 3,510 feet. - [2026-08-22] Analyst summary of the August 2026 24-Month Study: Lake Powell is projected to fall below 3,510 feet during water year 2027. Reclamation is modeling Lake Powell releases of 6 million to 7 million acre-feet for 2027. Lake Powell inflow for water year 2026 is forecast at only 37 percent of average. - [2026-09-17] Thehill.com reporting on a newer Reclamation study: A study released by the Bureau of Reclamation this week projects that at the end of March 2027, Lake Powell's elevation could be just less than 3,492 feet... close to the minimum power pool level of 3,490 feet. This is the "minimum probable" or low-end scenario, not the most-probable case. - [2026-09-17] Same article noted current conditions at time of writing: As of Thursday, Lake Powell was at about 3,524 feet. (Note: this predates the record-low dip to 3,516.62 ft on Sept 15, 2026, so figures from different trackers diverge slightly by source and date.) - [2026-09-18] Newsweek, citing the September 2026 "most probable" 24-Month Study under the 6 maf release scenario: Lake Powell, by contrast, could rise to 3,542 feet in June 2027. The same study also noted both reservoirs had just hit record lows: The latest Bureau of Reclamation projections show both reservoirs reaching record lows in August. The agency said the record-low elevations followed a record-low winter snowpack in the Colorado River Basin in 2025-2026. - [2026-09-09] Independent tracker analysis (lakepowellwaterlevel.com), based on historical analog years from an Oct 7 starting elevation, projected: Projected Drop to Spring Low... 5.8 ft to ~3513.3 ft by December 31, Range: 7.4 to 4.1 ft — implying a likely winter low in the 3,506–3,509 ft range if the pattern continues through the full low-point of the season (typically March/April). BOTTOM LINE: As of Oct 9-10, 2026, Lake Powell sits at ~3,519 ft, well above both the 3,510 ft and 3,500 ft thresholds, but USBR's own operating guidance and 24-Month Study explicitly project the lake declining below 3,510 ft at some point in water year 2027 (by March 31, 2027 window end), with most-probable scenarios landing in the high-3,490s to low-3,510s and a minimum-probable scenario near 3,492 ft; this puts the 3,500–3,510 ft band squarely inside the plausible range for the eventual minimum, though drier scenarios could push the low below 3,500 ft (near minimum power pool) and wetter outcomes could keep it at or above 3,510 ft. NOT FOUND: No October 2026 (post-August) 24-Month Study update with a specific numeric "most probable" end-of-water-year-2027 or spring-2027 minimum elevation figure was found beyond the August/September studies cited above; the next scheduled 24-Month Study (typically issued monthly/quarterly, next major one expected around January 2027) was not yet available as of this research.

- [2026-09-15] The Bureau of Reclamation's official 24-Month Study set WY2027 Lake Powell operations under the Low Elevation Infrastructure Protection Range, stating "The August 2026 24-Month Study projected the October 1, 2026 Lake Powell elevation to be less than 3,540 feet and Lake Powell's elevation is projected to decline below 3,510 feet during WY2027." (https://www.usbr.gov/lc/region/g4000/24mo_6.pdf) - [2026-09-15] The official September 2026 Most Probable 24-Month Study (6 maf release scenario) end-of-month elevation table shows Lake Powell declining to 3,513.51 ft (Dec 2026), 3,512.26 ft (Jan 2027), and bottoming at 3,511.43 ft in Feb 2027 before rising to 3,511.57 ft in Mar 2027 — i.e., the Most Probable scenario stays just above 3,510 ft through the market window. (https://www.usbr.gov/lc/region/g4000/24mo_6.pdf) - [2026-10-07] A secondary tracker summarizing the same official study confirms: "The lowest projected end-of-month elevation is 3,511.43 ft (February 28, 2027) in the Most Probable run and 3,475.21 ft (February 29, 2028) in the Probable Minimum run." (https://reservoirbench.com/projections/) - [2026-08-22] Summarizing the August 2026 24-Month Study, a trade outlet reported: "Lake Powell is projected to fall below elevation 3,510 feet during water year 2027. As a result, the reservoir will be operated within what Reclamation calls the Low Elevation Infrastructure Protection Range." (https://www.western-water.com/2026/08/22/lake-powell-faces-low-elevation-operations-in-2027/) - [2026-07-21] An earlier (drier-scenario) federal study reported by The Hill projected a much deeper decline: "the Bureau of Reclamation this week projects that at the end of March 2027, Lake Powell's elevation could be just less than 3,492 feet." That figure is below the 3,500 ft floor required for this market's "Yes" outcome. (https://thehill.com/policy/energy-environment/5974862-bureau-reclamation-projects-reservoir-decline/) - [2026-07-xx] Reclamation's July 24-Month study had already flagged hydropower risk, noting "Reclamation's dry conditions forecast says Lake Powell could fall below 3,490 feet by December 2026." This illustrates how widely the dry-scenario and most-probable-scenario projections diverge for the same window. (https://watereducationcolorado.org/fresh-water-news/lake-powell-forecasts-show-hydropower-generation-is-at-risk-next-year-as-water-levels-drop/) - [2026-10-09] As of the most recent daily reading, Lake Powell's actual elevation was 3,518.97 ft, already above the Most Probable study's own projected near-term path (which had the lake near 3,515 ft at end of October). (https://lakepowell.water-data.com/) - [2026-09-15] The lake's lowest elevation so far during the market window (since Aug 17, 2026) was 3,516.62 ft, reached in mid-September 2026 — a new all-time record low for the reservoir, but still well above both the 3,510 ft and 3,500 ft thresholds. (https://reservoirbench.com/lake-powell/) - [2026-10-10] A compiled tracker of official releases shows the Probable Minimum scenario (a companion, drier run to the Most Probable study) falls below the 3,490 ft minimum power pool by September 2027 and continues down to 3,475.21 ft by February 2028 — again implying that if hydrology trends toward the dry case, the lake likely blows through the 3,500–3,510 band entirely rather than settling within it. (https://reservoirbench.com/projections/) - [2026-10-10] Historically, Reclamation's monthly 24-Month Studies have repeatedly revised Lake Powell's near-term outlook downward through 2026 as dry conditions persisted (e.g., the WY2026 release was cut from 7.48 maf to 6.00 maf after conditions were "projected to decline below 3,500 feet"), indicating actual outcomes have tended to track toward or below the driest published scenarios rather than the Most Probable line. (https://www.usbr.gov/lc/region/g4000/24mo_6.pdf) BOTTOM LINE: The only base-rate anchor available is Reclamation's own modeling: the official "Most Probable" 24-Month Study has Lake Powell bottoming at ~3,511.4 ft (Feb 2027) — just above the 3,510 ft upper bound needed for "Yes" — while the companion "dry"/minimum scenarios used earlier in 2026 pointed to levels near or below 3,492 ft by March 2027, which would fall below the 3,500 ft floor required for "Yes." This makes the 10-foot target band a narrow, contested middle ground between the two officially published scenarios, with the pattern of repeated downward revisions through 2026 suggesting actual outcomes have tended to run drier than the Most Probable case. NOT FOUND: No sibling/other-venue prediction markets or published probabilistic (e.g., ensemble/Monte Carlo) forecasts specifically quantifying the odds of landing in the 3,500–3,510 ft band were found; Reclamation's 24-Month Study publishes only point scenarios (Most Probable, Probable Minimum, sometimes Probable Maximum), not a full probability distribution.

YES means: the lowest daily USBR elevation reading at Glen Canyon Dam between Aug 17, 2026 and Mar 31, 2027 lands somewhere in the 3,500.00–3,509.99 ft band (i.e., it dips below 3,510 ft but never reaches 3,500 ft). - [2026-08-21] Reclamation's binding operating framework for the window is already set: the August 2026 24-Month Study projected October 1, 2026 Lake Powell elevation to be less than 3,540 feet and Lake Powell's elevation is projected to decline below 3,510 feet during water year (WY) 2027. This is Reclamation's own operative determination, not a third-party estimate, and it specifically names WY2027 (which includes the Jan–Mar 2027 resolution window) as the period of the sub-3,510 ft decline. (usbr.gov/uc/water/crsp/studies/24Month_08_ucb.pdf) - [2026-09-15] The September 2026 Most Probable study's own end-of-month table (as compiled from the source PDF) shows the lake sitting at 3,513.51 ft (Dec 31, 2026) and bottoming at 3,511.43 ft (Feb 28, 2027) before a slight rise — i.e., the central-case trajectory sits barely above 3,510 ft, meaning only a modest additional shortfall (on the order of 1–2 ft) is needed to push the actual minimum into the 3,500–3,510 band rather than staying above it. (reservoirbench.com/projections/) - [2026-09-15] Reclamation explicitly quantifies the forecast uncertainty band for this same window: In addition to the September 2026 24-Month Study based on the Most Probable inflow scenario, Reclamation has conducted runs to determine a possible range of reservoir elevations. The 24-Month Study minimum, most, and maximum probable scenarios were used to determine the range of probable outcomes...The probable minimum inflow scenario reflects a dry hydrologic condition which statistically would be exceeded 90 percent of the time...There is approximately an 80 percent probability that a future elevation will fall inside the range of the minimum and maximum inflow scenarios. With the Most Probable path sitting just above 3,510 ft and the companion dry (Probable Minimum) path sitting notably lower, the 3,500–3,510 ft corridor is the natural middle ground between these two officially bracketed scenarios for this window. (usbr.gov/uc/water/crsp/cs/gcd.html) - [2026-09-15] The Probable Minimum run's own December 31, 2026 figure is 3,511.82 ft — still above 3,510 ft at that date — only drifting into deeper deficit later in calendar 2027 (3,477.17 ft by Dec 2027, outside this market's window). This means even the dry scenario does not obviously blow through 3,500 ft before March 31, 2027; a 3,500–3,510 ft trough in Jan–Mar 2027, roughly midway between the Most Probable and Probable Minimum tracks, is consistent with both published runs converging toward that band rather than diverging sharply by March. (reservoirbench.com/projections/) - [2026-02-13] Illustrating how fast these models can swing, the February 2026 Most Probable study — issued earlier in the same water year — had projected the lake to fall to 3,476 ft – in March 2027; the lowest elevation on record since filling , a figure well below the 3,500 ft floor. The fact that the subsequent August/September 2026 studies revised this upward to the 3,511–3,513 ft range by the same March 2027 horizon shows the model's March-2027 minimum has already swung roughly 35+ feet within one water year — underscoring that a further ~5–10 ft downward revision (enough to land in the 3,500–3,510 band) is well within the demonstrated volatility of Reclamation's own forecasts. (wrrc.arizona.edu; reservoirbench.com) - [2026-08-22] A mechanism that could push the actual trajectory below the Most Probable line toward the 3,500–3,510 band: Reclamation's WY2027 release under the Low Elevation Infrastructure Protection Range is set at a Lake Powell release of 6 million acre-feet... [or] a release of 7 million acre-feet ; if the higher 7 maf release is ultimately used (plausible if downstream shortage pressure mounts), outflow increases and the lake draws down faster than the 6 maf Most Probable case, pulling the minimum lower than the 3,511 ft central estimate. (western-water.com) - [2026-10-07] As a reality check on current trajectory, the live gauge on Oct 6, 2026 read 3,519.04 ft against the Most Probable study's implied near-term glide path toward ~3,513.5 ft by Dec 31 — meaning the lake has roughly 5.5 ft of further seasonal decline still priced into the official central forecast over the next ~12 weeks even before any further winter drawdown through March, consistent with a trajectory that continues past 3,510 ft into the 3,500s if conditions track the model. (reservoirbench.com/projections/) - [2026-09-01] USBR's own stated WY2027 inflow uncertainty band is wide: the September 24-Month Study projects Lake Powell elevation will end water year 2026 near 3,514.98 feet with approximately 4.99 maf in storage (21 percent of capacity) , and separately the September forecast for WY2027 unregulated inflow itself ranges from "a minimum probable of 3.50 maf (36 percent of average) to a maximum probable of 14.30 maf (149 percent of average)" with a most-probable of 7.32 maf — a roughly fourfold spread that, propagated through the elevation model, plausibly spans several feet on either side of the 3,510 ft line by spring 2027. (usbr.gov/uc/water/crsp/cs/gcd.html) BOTTOM LINE: Reclamation's own Most Probable study already has the winter 2026–27 trough sitting only 1–2 ft above the 3,510 ft threshold, its Probable Minimum companion run holds above 3,510 ft at year-end 2026 before diverging further into 2027, and the agency's track record this water year shows large (tens-of-feet) month-to-month revisions in the March-2027 minimum — all of which make a settle between 3,500 and 3,510 ft a highly plausible middle outcome if actual hydrology or releases come in just modestly drier than the current central case, without requiring the more extreme near-3,490-3,476 ft dry scenarios also on record. NOT FOUND: No October 2026 24-Month Study (the next scheduled update) has yet been published with a specific numeric Jan–Mar 2027 minimum; no official probability-weighted (as opposed to three-scenario) distribution exists to quantify the chance the minimum lands specifically inside the 3,500–3,510 ft band versus above or below it.

YES means: the lowest daily elevation recorded at Lake Powell (Glen Canyon Dam gauge) between Aug 17, 2026 and March 31, 2027 lands in the narrow 3,500.00–3,509.99 ft band — i.e., the reservoir must drop below 3,510 ft but not as far as 3,500 ft at any point in that window. - [2026-09-15] The USBR's own official "Most Probable" September 2026 24-Month Study (6 maf release scenario) gives month-end Lake Powell elevations of 3515.05 feet in October 2026, 3514.64 feet in November 2026, 3513.51 feet in December 2026, 3512.26 feet in January 2027, 3511.43 feet in February 2027, and 3511.57 feet in March 2027 — i.e. the federal government's central-case model never dips below 3,510 ft for the entire market window, which would resolve this market NO outright. (usbr.gov/lc/region/g4000/24mo_6.pdf) - [2026-10-10] A cross-check of the same study on an independent tracker confirms the lowest projected end-of-month elevation is 3,511.43 ft (February 28, 2027) in the Most Probable run , corroborating that the Reclamation base case keeps Powell just above the 3,510 ft threshold throughout the window, missing the 3,500–3,510 ft band entirely on the high side. (reservoirbench.com/projections) - [2026-10-09] Actual observed elevation (3,518.97–3,519.04 ft, Oct 9–10) is running roughly 4–5 feet above the Most Probable study's own October 2026 projection of 3,515.05 ft, per the same source's comparison table, implying real conditions are currently tracking wetter/better than the official median forecast and reinforcing the case that the lake may stay above 3,510 ft rather than sliding into the 3,500–3,510 band. (reservoirbench.com/projections) - [2026-10-10] A recent synthesis of basin operations history (Getches-Wilkinson Center) states explicitly that two measures were put in place to maintain the elevation of Lake Powell above 3500 ft: the 1.0 MAF of DROA releases and a reduction of the Water Year 2026 annual release from Glen Canyon Dam from 7.5 MAF to 6.0 MAF , showing active, ongoing federal intervention specifically engineered to keep the lake from falling into — or through — the sub-3,510 range. (coyotegulch.blog, Oct 10 2026) - [2026-09-15] The same September 2026 study explains the operational mechanism: because conditions were projected to decline below 3,500 ft, the Department of the Interior implemented an action under Section 6.E of the 2024 Interim Guidelines SEIS ROD by reducing Lake Powell's annual release from 7.48 maf to 6.00 maf in WY 2026 , paired with up to 1.0 maf of Flaming Gorge drought-response releases into Powell by April 2027 — both designed to prop up Powell's elevation and work against a dip into (or below) the 3,500–3,510 band. (usbr.gov/lc/region/g4000/24mo_6.pdf) - [2026-09-20] Reporting on current Grand Canyon ecosystem/operations choices confirms Reclamation is actively avoiding additional water releases this fall: the Bureau of Reclamation has decided against releasing cold water from deep in Lake Powell... these environmental releases would not change the total volume of water flowing out of Lake Powell over the year, just the timing... the Bureau of Reclamation will not be doing them because they would bypass turbines — another sign operations are tuned to protect, not draw down, Powell's elevation in the near term. (kunc.org) - [2026-10-07] A July 2026 Probable Minimum run (the "dry" companion scenario available before the September update) had shown Lake Powell's elevation is projected to be 3,503.65 feet on December 31, 2026 under the Probable Minimum scenario — but by September's update, the companion dry scenario had already been revised upward to 3,511.82 ft for the same date per the official study, i.e., the driest officially published scenario now also sits above 3,510 ft at that checkpoint, narrowing the path to the 3,500–3,510 band. (usbr.gov/lc/region/g4000/24mo_MIN.pdf; reservoirbench.com/projections) - [2026-10-10] Flood-control space tables in the same September study show Lake Powell's projected storage content rising from 18,170 kaf (Sept 2026) to a peak near 18,518 kaf by March 2027, consistent with elevation gradually recovering rather than falling further — reinforcing the Most-Probable narrative of a shallow winter dip that stays near/above 3,510–3,511 ft rather than cutting into the 3,500 ft floor. (usbr.gov/lc/region/g4000/24mo_6.pdf) BOTTOM LINE: Reclamation's own official "Most Probable" 24-Month Study — the government's central operational forecast, reinforced by active drought-response releases and a reduced WY2026/27 release schedule explicitly intended to protect Powell's elevation — projects the lake's monthly lows bottoming at 3,511.4–3,511.6 ft through March 2027, staying above the 3,510 ft threshold for the entire market window; combined with actual levels (~3,519 ft) currently running above even that optimistic path, the strongest NO case is that the lake simply never crosses below 3,510 ft at all during the window, rather than landing in the 3,500–3,510 ft band. NOT FOUND: No October 2026 24-Month Study (the next scheduled monthly update) has been published yet as of Oct 10, 2026, so there is no fresher official point-forecast superseding the September 15, 2026 study cited above; daily (rather than monthly) minimum elevation projections from USBR were also not found, so the true intra-month daily low could differ modestly from the end-of-month figures used here.