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CBT GRANBY RESERVOIR
Structure dossier · WDID 5104055 · 3 · COLORADO RIVER · DWR record
Where this page's figures come from
Generated 2026-08-27 19:54 by Hydrohistorian. Sources: DWR HydroBase snapshot HydroBase_CO_20260707 (history) + CDSS REST (current), USGS NWIS cross-checks. Engine v0.5.0 (2deb1d7) — every figure regenerates from this named code version and data image.
Where it sits in line
Priority 1935-08-01 — 427th most senior of the 2208 structures with decreed rights in this water districtDWR's administrative subdivision of a river basin; the unit calls are usually stated in..
Under prior appropriationColorado's rule for sharing water: first in time, first in right. Age decides, not proximity or need., everything ahead of it in this line is satisfied in full before it receives any water. Immediately ahead: CBT WILLOW CREEK RESERVOIR (1935-08-01). Immediately behind: CBT ALVA B ADAMS TUNNEL (1935-08-01).
Decreed rights (1)
| Admin noDWR's numeric encoding of a water right's seniority. Smaller is more senior; the integer part counts days from 1849-12-31 to the date that ranks the right. | AppropriatedWhen water was first put to beneficial use. It sets seniority unless a prior adjudication date is later. | AdjudicatedWhen the water court confirmed the right. A use decreed in 1975 was not a decreed use in 1955, however old the appropriation is. | AbsoluteA right actually put to use, as opposed to conditional -- a placeholder for a use not yet made. | ConditionalA right reserving a place in line for a use not yet made; it must be diligently pursued or it lapses. | Units | UsesWhat the court said this water may be used for -- irrigation, municipal supply, augmentation and so on. | Case |
|---|---|---|---|---|---|---|---|
| 31258.0 | 1935-08-01 | 1955-10-12 | 543758.0 | 0.0 | A | IRRINDREC |
Recorded use (last 15 years on record)
In a median year this structure has a recorded diversion of 188,148 AF. Its most recent year on record, 2024, came in at 102,702 AF — 55% of that, and 2nd lowest of the 15 years with a recorded volume.
This structure records both diversions and reservoir releases — they are separate water movements and are accounted separately below.
| Year | Diverted (AFA volume: one acre covered a foot deep, about 326,000 gallons -- roughly a suburban household's outdoor use for a year.) | Compared with its own record | Released (AF) | Days recorded | Peak (cfs) |
|---|---|---|---|---|---|
| 2010 | 226,426 | 11th lowest of 15 · 120% of median | 162,714 | 365 | 4529.9 |
| 2011 | 200,857 | 10th lowest of 15 · 107% of median | 198,613 | 365 | 3373.8 |
| 2012 | 44,568 | 1st lowest of 15 · 24% of median | 207,880 | 365 | 858.1 |
| 2013 | 233,370 | 13th lowest of 15 · 124% of median | 126,027 | 365 | 3421.7 |
| 2014 | 278,537 | 15th lowest of 15 · 148% of median | 140,700 | 304 | 4465.1 |
| 2015 | 188,148 | 8th lowest of 15 · 100% of median | 303,309 | 216 | 2950.0 |
| 2016 | 192,757 | 9th lowest of 15 · 102% of median | 211,976 | 365 | 3250.6 |
| 2017 | 183,535 | 7th lowest of 15 · 98% of median | 122,582 | 365 | 2740.1 |
| 2018 | 138,152 | 3rd lowest of 15 · 73% of median | 198,667 | 364 | 1920.3 |
| 2019 | 227,904 | 12th lowest of 15 · 121% of median | 181,123 | 335 | 3293.0 |
| 2020 | 157,694 | 5th lowest of 15 · 84% of median | 161,902 | 306 | 2464.1 |
| 2021 | 143,227 | 4th lowest of 15 · 76% of median | 206,193 | 365 | 2440.8 |
| 2022 | 253,056 | 14th lowest of 15 · 134% of median | 131,933 | 365 | 3496.8 |
| 2023 | 177,291 | 6th lowest of 15 · 94% of median | 168,828 | 365 | 2239.4 |
| 2024 | 102,702 | 2nd lowest of 15 · 55% of median | 110,956 | 305 | 2344.0 |
Advisory reading aid on public data — not an administrative or legal conclusion, not a title opinion, and not a substitute for DWR administration or an engineer's analysis. Methodology review status is disclosed at hydrohistorian's basin pages.