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SYLVAN RESERVOIR
Structure dossier · WDID 5103701 · 3 · LITTLE MUDDY CREEK · DWR record
Where this page's figures come from
Generated 2026-08-28 02:41 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 1907-11-03 — 242nd 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: SYLVAN DITCH (1907-11-03). Immediately behind: CAIRNS PIPELINE NO 1 (1907-11-26).
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 |
|---|---|---|---|---|---|---|---|
| 21125.0 | 1907-11-03 | 1911-08-03 | 1133.74 | 1133.74 | A | IRRAUG | 250 |
Legal record & documents
6 decreed actions on record across
4 court cases:
98CW0292, 17CW3129, W0676, CA0183.
Every case, dated
| Case | Actions | Latest adjudication | Types |
|---|---|---|---|
98CW0292 | 3 | 1998-12-31 | O, S |
17CW3129 | 1 | 1998-12-31 | O |
W0676 | 1 | 1911-08-03 | S |
CA0183 | 1 | 1911-08-03 | S |
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 14 years on record)
In a median year this structure has a recorded diversion of 1,004 AF. Its most recent year on record, 2024, came in at 1,499 AF — 149% of that, and 10th lowest of the 11 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) |
|---|---|---|---|---|---|
| 1976 | — | no recorded volume | 2,281 | 0 | — |
| 1987 | 1,956 | 11th lowest of 11 · 195% of median | — | 127 | 20.0 |
| 1988 | 916 | 4th lowest of 11 · 91% of median | 901 | 57 | 16.0 |
| 1989 | 912 | 3rd lowest of 11 · 91% of median | — | 79 | 10.0 |
| 1990 | 983 | 5th lowest of 11 · 98% of median | — | 22 | 23.6 |
| 1991 | 1,055 | 7th lowest of 11 · 105% of median | — | 29 | 19.0 |
| 1992 | 1,004 | 6th lowest of 11 · 100% of median | — | 57 | 20.0 |
| 2016 | 589 | 1st lowest of 11 · 59% of median | 491 | 28 | 11.0 |
| 2018 | 779 | 2nd lowest of 11 · 78% of median | — | 73 | 15.0 |
| 2020 | — | no recorded volume | 555 | 0 | — |
| 2021 | — | no recorded volume | 897 | 0 | — |
| 2022 | 1,450 | 9th lowest of 11 · 144% of median | 1,209 | 59 | 40.0 |
| 2023 | 1,297 | 8th lowest of 11 · 129% of median | 1,126 | 77 | 20.3 |
| 2024 | 1,499 | 10th lowest of 11 · 149% of median | 1,755 | 72 | 30.0 |
Trends for this structure
Recorded use shows no clear trend over its last 11 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 | 680 measured days; currency unknown (no data-coverage date to compare against) |
| record continuity | sparse | 7% of the irrigation seasons in 1976-2024 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.