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MASON RESERVOIR
Structure dossier · WDID 1203814 · 3 · BEAVER CREEK · DWR record
Where this page's figures come from
Generated 2026-08-28 00:01 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
Location as DWR records it. Faint dots are the neighbouring water; click any to open it.
Which of its rights are out of priority?
Not computable for this structure: this structure is not on the modelled flow network, so no reference gage can honestly stand in for it.
Where it sits in line
Priority 1903-08-26 — 331st most senior of the 1967 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: RUNYON DITCH (1895-05-01). Immediately behind: MCREYNOLDS RESERVOIR (1903-08-26).
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 |
|---|---|---|---|---|---|---|---|
| 19595.0 | 1903-08-26 | 1916-02-14 | 2653.3714 | 0.0 | A | MUNINDFIRDOMALL | R5 |
Legal record & documents
1 decreed actions on record across
1 court case:
CA2637.
Every case, dated
| Case | Actions | Latest adjudication | Types |
|---|---|---|---|
CA2637 | 1 | 1916-02-14 | O |
DWR's own records for this structure: net amounts · transactions & adjudication history · scanned decrees (search a case number there for the imaged document). On this site: the district's full legal picture →
Recorded use (last 12 years on record)
In a median year this structure has a recorded diversion of 378 AF. Its most recent year on record, 2025, came in at 1,082 AF — 286% of that, and 12th lowest of the 12 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) |
|---|---|---|---|---|---|
| 1991 | 587 | 9th lowest of 12 · 155% of median | — | 19 | 45.1 |
| 2015 | 313 | 6th lowest of 12 · 83% of median | 736 | 51 | 31.0 |
| 2016 | 222 | 4th lowest of 12 · 59% of median | 1,098 | 122 | 10.3 |
| 2017 | 112 | 2nd lowest of 12 · 30% of median | 973 | 61 | 3.1 |
| 2018 | 213 | 3rd lowest of 12 · 56% of median | 80 | 308 | 25.3 |
| 2019 | 536 | 8th lowest of 12 · 142% of median | 780 | 95 | 8.7 |
| 2020 | 285 | 5th lowest of 12 · 75% of median | 615 | 142 | 20.2 |
| 2021 | 444 | 7th lowest of 12 · 117% of median | 1,243 | 50 | 18.5 |
| 2022 | 92 | 1st lowest of 12 · 24% of median | 1,683 | 215 | 3.2 |
| 2023 | 588 | 10th lowest of 12 · 155% of median | 1,917 | 365 | 60.7 |
| 2024 | 695 | 11th lowest of 12 · 184% of median | 3,259 | 365 | 50.4 |
| 2025 | 1,082 | 12th lowest of 12 · 286% of median | 1,212 | 304 | 35.6 |
Trends for this structure
Recorded use shows no clear trend over its last 12 recorded years — which is itself worth knowing.
How good is our record of it?
Grade B (7/10 points) — the components below are the finding; the letter alone is not.
The rubric, component by component
| Check | State | Detail |
|---|---|---|
| identity | complete | name, type, and water source all on file |
| decreed rights | on file | 1 right(s), seniority decoded |
| diversion record | present | 2097 measured days; currency unknown (no data-coverage date to compare against) |
| record continuity | sparse | 28% of the irrigation seasons in 1991-2025 carry measured days |
| published-record stability | stable | no upstream revisions recorded against this structure |
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.