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WILLIS DITCH
Structure dossier · WDID 3400583 · 1 · MANCOS RIVER · DWR record
Where this page's figures come from
Generated 2026-08-27 22:16 by Hydrohistorian. Sources: DWR HydroBase snapshot HydroBase_CO_20260707 (history) + CDSS REST (current), USGS NWIS cross-checks. Engine v0.5.0 (f6d7fdc) — 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 1876-05-15 — 175th most senior of the 495 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: TOWN OF MANCOS DITCH (1876-05-15). Immediately behind: NO 6 DITCH (1877-07-15).
Decreed rights (4)
| 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 |
|---|---|---|---|---|---|---|---|
| 9632.0 | 1876-05-15 | 1893-04-28 | 0.4 | 0.0 | C | IRR | M-3 |
| 11093.0 | 1880-05-15 | 1893-04-28 | 2.17 | 0.0 | C | IRR | M-8 |
| 12195.0 | 1883-05-22 | 1893-04-28 | 0.0 | 0.0 | C | IRR | M-18 |
| 30667.09609 | 1876-04-22 | 1963-03-22 | 2.5 | 0.0 | C | IRRDOMSTK | 62-2 |
Legal record & documents
5 decreed actions on record across
3 court cases:
CA0967, CA1993, 25CW3039.
Every case, dated
| Case | Actions | Latest adjudication | Types |
|---|---|---|---|
CA0967 | 2 | 1963-03-22 | O, S |
CA1993 | 2 | 1893-04-28 | O |
25CW3039 | 1 | 1893-04-28 | 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 15 years on record)
In a median year this structure has a recorded diversion of 626 AF. Its most recent year on record, 2025, came in at 585 AF — 94% of that, and 5th lowest of the 15 years with a recorded volume.
| 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 | Days recorded | Peak (cfs) |
|---|---|---|---|---|
| 2011 | 841 | 13th lowest of 15 · 134% of median | 365 | 3.8 |
| 2012 | 609 | 6th lowest of 15 · 97% of median | 366 | 2.6 |
| 2013 | 524 | 4th lowest of 15 · 84% of median | 365 | 3.1 |
| 2014 | 623 | 7th lowest of 15 · 100% of median | 365 | 3.8 |
| 2015 | 835 | 12th lowest of 15 · 133% of median | 365 | 2.8 |
| 2016 | 1,147 | 15th lowest of 15 · 183% of median | 366 | 3.5 |
| 2017 | 955 | 14th lowest of 15 · 153% of median | 365 | 3.3 |
| 2018 | 421 | 1st lowest of 15 · 67% of median | 327 | 2.5 |
| 2019 | 713 | 10th lowest of 15 · 114% of median | 365 | 3.6 |
| 2020 | 465 | 3rd lowest of 15 · 74% of median | 322 | 2.7 |
| 2021 | 421 | 1st lowest of 15 · 67% of median | 313 | 2.6 |
| 2022 | 726 | 11th lowest of 15 · 116% of median | 365 | 2.8 |
| 2023 | 626 | 8th lowest of 15 · 100% of median | 365 | 2.9 |
| 2024 | 710 | 9th lowest of 15 · 113% of median | 366 | 3.4 |
| 2025 | 585 | 5th lowest of 15 · 94% of median | 304 | 3.4 |
Trends for this structure
Recorded use shows no clear trend over its last 15 recorded years — which is itself worth knowing.
How good is our record of it?
Grade A (9/10 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 | 4 right(s), seniority decoded |
| diversion record | present | 20138 measured days; currency unknown (no data-coverage date to compare against) |
| record continuity | continuous | 100% of the irrigation seasons in 1949-2025 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.