Hydrohistorian
← My Water · Print / save as PDF
LAKE ANN RESERVOIR
Structure dossier · WDID 3803736 · 3 · SOPRIS 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 1912-06-13 — 393rd most senior of the 4788 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: DAVIS DITCH-TRIPLE M ENLARGEMENT (1904-04-01). Immediately behind: CERISE WELL 1 (1918-08-31).
Decreed rights (2)
| 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 |
|---|---|---|---|---|---|---|---|
| 24928.22809 | 1912-06-13 | 1918-05-15 | 212.0 | 0.0 | A | IRR | RES13 |
| 37552.36774 | 1950-09-07 | 1958-06-20 | 250.827 | 0.0 | A | IRROTH | 681 |
Legal record & documents
2 decreed actions on record across
2 court cases:
CA4613, CA1985.
Every case, dated
| Case | Actions | Latest adjudication | Types |
|---|---|---|---|
CA4613 | 1 | 1958-06-20 | S |
CA1985 | 1 | 1918-05-15 | 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 15 years on record)
In a median year this structure has a recorded diversion of 429 AF. Its most recent year on record, 2015, came in at 434 AF — 101% of that, and 6th 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) |
|---|---|---|---|---|---|
| 1994 | 1,354 | 10th lowest of 10 · 316% of median | — | 156 | 12.8 |
| 1997 | 508 | 8th lowest of 10 · 118% of median | 386 | 91 | 5.2 |
| 2008 | 424 | 5th lowest of 10 · 99% of median | 689 | 85 | 12.8 |
| 2009 | 1,294 | 9th lowest of 10 · 302% of median | 173 | 100 | 14.2 |
| 2010 | 27 | 1st lowest of 10 · 6% of median | 0 | 41 | 1.0 |
| 2011 | 463 | 7th lowest of 10 · 108% of median | 418 | 64 | 8.2 |
| 2012 | 99 | 3rd lowest of 10 · 23% of median | 101 | 31 | 2.5 |
| 2013 | 406 | 4th lowest of 10 · 95% of median | 165 | 63 | 5.1 |
| 2014 | 44 | 2nd lowest of 10 · 10% of median | 336 | 31 | 1.0 |
| 2015 | 434 | 6th lowest of 10 · 101% of median | 270 | 86 | 5.4 |
| 2016 | — | no recorded volume | 256 | 0 | — |
| 2018 | — | no recorded volume | 239 | 0 | — |
| 2019 | — | no recorded volume | 165 | 0 | — |
| 2023 | — | no recorded volume | 456 | 0 | — |
| 2024 | — | no recorded volume | 621 | 0 | — |
Trends for this structure
Recorded use shows no clear trend over its last 10 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 | 2 right(s), seniority decoded |
| diversion record | present | 822 measured days; currency unknown (no data-coverage date to compare against) |
| record continuity | sparse | 6% of the irrigation seasons in 1963-2024 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.