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GREAT WESTERN RESERVOIR
Structure dossier · WDID 0203861 · RESERVOIR · WALNUT CREEK · DWR record
Where this page's figures come from
Generated 2026-08-27 19:49 by Hydrohistorian. Sources: DWR HydroBase snapshot HydroBase_CO_20260707 (history) + CDSS REST (current), USGS NWIS cross-checks. Engine v0.5.0 (e70d0b5) — every figure regenerates from this named code version and data image.
Current administration
● In priority — no active call senior to this structure's rights affects its district (23 active call(s) checked).
Where it sits in line
Priority 1878-12-31 — 863rd most senior of the 21881 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: 8000826 (1895-07-01). Immediately behind: POITZ RES (1884-10-01).
Decreed rights (8)
| 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 |
|---|---|---|---|---|---|---|---|
| 16718.10592 | 1878-12-31 | 1936-05-13 | 98.0 | 0.0 | A | IRR | |
| 16718.13468 | 1886-11-15 | 1936-05-13 | 198.0 | 0.0 | A | MUN | |
| 16718.14124 | 1888-09-01 | 1936-05-13 | 21.25 | 0.0 | A | MUN | |
| 16718.14595 | 1889-12-16 | 1936-05-13 | 154.0 | 0.0 | A | MUN | |
| 19468.0 | 1903-04-21 | 1918-08-02 | 1595.74 | 1595.74 | A | IRR | |
| 20188.19468 | 1903-04-21 | 1907-03-13 | 296.0 | 0.0 | A | IRRMUNCOMINDFIRDOM | |
| 27930.19468 | 1903-04-21 | 1943-02-09 | 1757.0 | 0.0 | A | IRRMUNCOMINDFIRDOM | |
| 47931.0 | 1981-03-25 | 1981-12-31 | 736.0 | 25264.0 | A | IRRMUNCOMINDRECFISDOMAUG |
Recorded use (last 11 years on record)
In a median year this structure has a recorded diversion of 2,292 AF. Its most recent year on record, 2024, came in at 1,284 AF — 56% of that, and 3rd lowest of the 10 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) |
|---|---|---|---|---|---|
| 1997 | — | no recorded volume | 318 | 0 | — |
| 1999 | 187 | 1st lowest of 10 · 8% of median | — | 21 | 6.8 |
| 2016 | 2,207 | 5th lowest of 10 · 96% of median | — | 258 | 32.1 |
| 2017 | 1,516 | 4th lowest of 10 · 66% of median | — | 130 | 11.5 |
| 2018 | 970 | 2nd lowest of 10 · 42% of median | 509 | 97 | 10.0 |
| 2019 | 3,266 | 7th lowest of 10 · 142% of median | 1,942 | 230 | 33.2 |
| 2020 | 2,376 | 6th lowest of 10 · 104% of median | 602 | 300 | 19.2 |
| 2021 | 3,825 | 9th lowest of 10 · 167% of median | 1,537 | 298 | 57.0 |
| 2022 | 3,571 | 8th lowest of 10 · 156% of median | 634 | 263 | 45.1 |
| 2023 | 3,866 | 10th lowest of 10 · 169% of median | 2,452 | 304 | 99.2 |
| 2024 | 1,284 | 3rd lowest of 10 · 56% of median | 518 | 305 | 13.0 |
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.