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CHATFIELD RESERVOIR

Structure dossier · WDID 0803514 · RESERVOIR · SOUTH PLATTE RIVER · DWR record

Chatfield Reservoir is a reservoir on South Platte River in Colorado. This page is its public record: the water it has a right to, whether it may take it today, and its history, compiled from the Colorado Division of Water Resources.

Source DWR administrative record · verify at DWR structure ↗ Source DWR administrative record · verify at DWR diversion records ↗ Source Our computation, scored against a reference · scored against DWR's call analysis, see /methods

Where this page's figures come from

Generated 2026-10-14 06:44 by Hydrohistorian. Sources: DWR HydroBase snapshot HydroBase_CO_20260928 (history) + CDSS REST (current), USGS NWIS cross-checks. Engine v0.5.0 (dd58e60) — every figure regenerates from this named code version and data image.

Who owns it

DWR’s own records name no owner for a ditch, reservoir or well, so this comes from the source shown and can be out of date. Organisations only: a private landowner’s name is never listed.

The record and the river

In short

CHATFIELD RESERVOIR holds 55 decreed rights on SOUTH PLATTE RIVER. As of 2026-10-02, 49 of them are out of priority under a call at admin 5112.00000 placed by SOUTH PLATTE RIVER AT WATERTON. Its 6 most senior rights, back to 1861-06-15, keep diverting. 6 further calls state no district and sit outside this one, so they are counted here rather than assumed either way. In a median year over its last 15 recorded years it diverts 27,289 acre-feet. It was a party to 22 court cases that also touched 85 other structures.

Assembled from the figures on this page — every number above is checked against them before it is shown (11 checked). The detail, with its method, is in the cards below.

Download this structure

Everything on this page as data you can work with — and a README that makes it citable: the HydroBase snapshot it was built from, the build commit, what every column means, the method behind each derived figure, and that method's stated limits.

⇩ Full record (.zip) Print / save as PDF

Or one table at a time: rights.csv · annual_use.csv · curtailment_now.csv · court_cases.csv · co_parties.csv · call_climatology.csv

What is in the bundle
  • rights.csv — every decreed right, most senior first, with admin numbers, dates, amounts, uses and case numbers.
  • annual_use.csv — recorded diversion by year, with releases accounted separately.
  • curtailment_now.csv — each right's current priority status and how often it was out across analog years.
  • court_cases.csv — the cases attached to its rights.
  • co_parties.csv — the other structures that were parties to those cases. Not available anywhere else.
  • call_climatology.csv — how often each right has been out of priority by week of season, with confidence intervals and the seasons the record could actually judge.
  • README.txt — provenance, methods, limits, disclaimer, and links back to DWR's own records for verification.

Where it sits

Location as DWR records it (storage). Faint dots are the neighbouring water; click any to open it.

Dam safety

Dam CHATFIELD (completed 1973)
Hazard class High
Condition at last inspection Satisfactory (2013-09-11)
Storage restriction None on file
Normal storage 26,600 AF
Physical status Active
Emergency action plan Yes

Source: DWR Dam Safety’s jurisdictional-dam inventory (damsafety/damsafetydaminfojd), refreshed weekly. Joined on this structure’s own WDID as DWR records it on the dam. Hazard class describes the consequence of failure, not the likelihood of it. DWR’s dam record.

Current administration

● Junior rights called out — call at LITTLETON BOAT CHUTE NO 10 (SOUTH PLATTE RIVER, priority 1994-12-02).

● Junior rights called out — call at SOUTH PLATTE RIVER AT WATERTON (SOUTH PLATTE RIVER, priority 1863-12-30).

● Junior rights called out — call at CHATFIELD RESERVOIR (SOUTH PLATTE RIVER, priority 1865-12-30).

Which of its rights are out of priority?

Under today's controlling call (SOUTH PLATTE RIVER AT WATERTON, priority 1863-12-30): 49 of this structure's 55 rights are out of priority now. (6 call(s) state no district and sit outside this one — not judged, not assumed.) In the 5 past years most like this one (2015, 2025, 2023, 2017, 2024), 3 of the rights shown below were out at least one week in at least one analog year.

Right (priority)NowAnalog years outMajority out by
1861-06-15 4184 ● in priority 0 of 5 —
1861-07-30 4229 ● in priority 0 of 5 —
1861-08-30 4260 ● in priority 0 of 5 —
… 1 more right between these …
1863-05-01 4869 ● in priority 0 of 5 —
1863-12-30 5112 ● in priority 0 of 5 —
1864-12-30 5478 ● out 0 of 5 —
1865-12-30 5843 ● out 0 of 5 —
… 44 more rights between these …
2016-04-27 60748 ● out 4 of 5 2026-10-02
2018-02-28 61420 ● out 4 of 5 2026-10-02
2019-12-31 62091 ● out 4 of 5 2026-10-02
How this table is built, and what it is not

“Now” compares each right's admin number with today's most senior applicable active call. The outlook uses flows at COLORADO PARKS AND WILDLIFE CHATFIELD FISH HATCHERY around 2026-10-02 (the newest reading on file) — currently 179% of that gage's own median for this window — to pick the 5 most similar past years with complete administration records (2011–2026). Only calls that verifiably apply count: DWR's own district statements in the call's set comments, a caller located in this district, or — on the same stream, where DWR records both stream miles (measured from the mouth) — a caller DOWNSTREAM of this structure. An upstream senior cannot demand water this diversion never deprives it of. Calls that state nothing and sit elsewhere are counted as unjudged rather than assumed, which also means the verified record is shorter than the raw one: early calls rarely state districts. For each week it finds the most senior call then in force; a right is out in that week exactly when that call is senior to it, which is why one line prices every right and juniors can be out while seniors keep diverting. “Majority out by” is the first week out in more than half the analog years. A frequency among named historical years, not a probability from a model, and not a forecast of what the division engineer will do. It says how often years whose flow resembled this one were under a call senior to this right in a given week. Snowpack, storage, and the actual administrative decisions of a given season are not modelled. Check the analog years listed: if they do not resemble this year to you, the outlook does not either.

Where it sits in line

Priority 1861-06-15 — 32nd most senior of the 21886 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: PLATTE CANON DITCH (1861-06-15). Immediately behind: STRONTIA SPRINGS DIVERSION DAM (1861-06-15).

On MAINSTEM at river mile 89.9, it is 638th of 890 down the reach. Immediately upstream: GURTNOR HOWARTH W SYS. Immediately downstream: NEVADA DITCH.

Position on the modelled network, not a claim about whose water this is — a stream carries water from many rights at once, and diverted water returns to it.

Decreed rights (61)

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. Alt-pointAn absolute amount decreed at another structure that may be diverted here instead -- an alternate point of diversion or an exchange. DWR calls this the APEX amount; a right showing 0.0 absolute but an alt-point amount is exercised here under another structure's decree. Decreed forWhat the court said this water may be used for -- irrigation, municipal supply, augmentation and so on.Case
4184.00000 1861-06-151889-10-18 0.0 cfs 0.0 13.0 cfs Municipal 80CW0039
4229.00000 1861-07-301883-12-10 0.0 cfs 0.0 4.7 cfs Municipal 80CW0039
4260.00000 1861-08-301883-12-10 0.0 cfs 0.0 19.086 cfs Irrigation, Municipal +8 80CW0035, 88CW0202 +2
4352.00000 1861-11-301883-10-18 0.0 cfs 0.0 7.0 cfs Irrigation, Municipal +5 80CW0035
4869.00000 1863-05-011913-05-22 0.0 AF 0.0 18.7 AF Irrigation, Municipal +8 18CW3188
4869.00000 1863-05-011913-05-22 0.0 cfs 0.0 0.23 cfs Irrigation, Municipal +8 18CW3188
5112.00000 1863-12-301883-10-18 0.0 cfs 0.0 27.66 cfs Irrigation, Municipal +8 80CW0035, 80CW0039 +2
5478.00000 1864-12-301883-12-10 0.0 cfs 0.0 17.3 cfs Municipal 80CW0039
5843.00000 1865-12-301883-12-10 0.0 cfs 0.0 2.25 cfs Irrigation, Municipal +8 90CW0172, 88CW0202 +1
5965.00000 1866-05-011889-10-18 0.0 cfs 0.0 8.7 cfs Municipal 18CW3038, 80CW0039
6637.00000 1868-03-031883-12-10 0.0 cfs 0.0 3.644 cfs Irrigation, Municipal +6 91CW0117
7659.00000 1870-12-201930-06-16 0.0 cfs 0.0 3.0 cfs Municipal 80CW0039
8645.00000 1873-09-011889-10-18 0.0 cfs 0.0 1.48 cfs Irrigation, Municipal +4 79CW0274
8659.00000 1873-09-151883-04-28 0.0 cfs 0.0 1.4071 cfs Municipal 18CW3038
8765.00000 1873-12-301883-10-18 0.0 cfs 0.0 5.286 cfs Irrigation, Municipal +5 80CW0035
8918.00000 1874-06-011889-10-18 0.0 cfs 0.0 7.94 cfs Irrigation, Municipal +8 W7931, W9234 +1
9131.00000 1874-12-311930-06-16 0.0 cfs 0.0 3.78 cfs Municipal 80CW0039
9252.00000 1875-05-011889-10-18 0.0 cfs 0.0 2.31 cfs Irrigation, Municipal +8 84CW0057, 80CW0039 +1
10348.00000 1878-05-011889-10-18 0.0 cfs 0.0 11.75 cfs Irrigation, Municipal +8 05CW0111
10348.00000 1878-05-011889-10-18 0.0 AF 0.0 1724.0 AF Irrigation, Municipal +8 05CW0111
10449.00000 1878-08-101889-10-18 0.0 cfs 0.0 0.21 cfs Irrigation, Municipal +8 84CW0010, 79CW0274
10480.00000 1878-09-101930-06-16 0.0 cfs 0.0 13.22 cfs Municipal 80CW0039
10744.00000 1879-06-011889-10-18 0.0 cfs 0.0 3.65 cfs Municipal 80CW0039
11139.00000 1880-06-301930-06-16 0.0 cfs 0.0 10.0 cfs Municipal 80CW0039
11170.00000 1880-07-311889-10-18 0.0 cfs 0.0 1.15 cfs Irrigation, Municipal +8 05CW0111
11170.00000 1880-07-311889-10-18 0.0 AF 0.0 185.0 AF Irrigation, Municipal +8 05CW0111
11414.00000 1881-04-011889-10-18 0.0 AF 0.0 2134.0 AF Irrigation, Municipal +8 05CW0111
11414.00000 1881-04-011889-10-18 0.0 cfs 0.0 11.75 cfs Irrigation, Municipal +8 05CW0111
11451.00000 1881-05-081889-10-18 0.0 cfs 0.0 1.71 cfs Municipal 80CW0039
11809.00000 1882-05-011889-10-18 0.0 cfs 0.0 0.48 cfs Irrigation, Municipal +8 88CW0262, 80CW0039 +1
12924.00000 1885-05-201889-10-18 0.0 cfs 0.0 2.04 cfs Municipal, All beneficial uses 80CW0039, 88CW0263
13707.00000 1887-07-121889-10-18 0.0 cfs 0.0 0.09 cfs Irrigation, Municipal +4 79CW0274
14041.00000 1888-06-101889-10-18 0.0 cfs 0.0 0.19 cfs Irrigation, Municipal +4 79CW0274
14519.00000 1889-10-011930-06-16 0.0 cfs 0.0 12.38 cfs Municipal 80CW0039
14536.12936 1885-06-011913-05-22 0.0 cfs 0.0 0.13 cfs Irrigation, Municipal +4 88CW0263, 79CW0274
15585.00000 1892-09-011930-06-16 0.0 cfs 0.0 25.33 cfs Municipal 80CW0039
18018.00000 1899-05-011930-06-16 0.0 cfs 0.0 38.08 cfs Municipal 80CW0039
22254.00000 1910-12-061930-06-16 0.0 cfs 0.0 42.72 cfs Municipal 80CW0039
45804.00000 1975-05-291975-12-31 24000.0 AF 0.0 211200.0 AF Irrigation, Municipal +5 W8783, W7997 +1
46020.41714 1964-03-171976-12-31 0.0 cfs 0.0 190.0 cfs Municipal W8456
46748.00000 1977-12-281977-12-31 12523.0 AF 198677.0 AF 211200.0 AF Irrigation, Municipal +8 W8783, 88CW0143 +1
49179.00000 1984-08-241983-12-31 0.0 AF 26400.0 AF — Irrigation, Municipal +8 83CW0184
49193.00000 1984-09-071984-12-31 0.0 AF 6000.0 AF — Irrigation, Municipal +8 84CW0411
49437.00000 1985-05-091985-12-31 0.0 AF 2500.0 AF — Irrigation, Municipal +4 85CW0314
49582.00000 1985-10-011985-12-31 0.0 AF 800.0 AF — Irrigation, Municipal +8 85CW0463
49598.00000 1985-10-171985-12-31 0.0 cfs 0.0 75.1 cfs Irrigation, Municipal +8 85CW0415
51079.00000 1989-11-061989-12-31 2000.0 AF 0.0 — Municipal 89CW0169, 23CW3002
51312.00000 1990-06-271990-12-31 0.0 AF 75.0 AF — Fishery, Augmentation +1 90CW0123
52623.00000 1994-01-281994-12-31 0.0 AF 2000.0 AF — Fishery, Augmentation +1 94CW0012
56490.00000 2004-08-302004-12-31 0.0 AF 0.0 5000.0 AF Municipal, All beneficial uses 15CW3092, 04CW0218
56490.00000 2004-08-302004-12-31 0.0 cfs 0.0 225.0 cfs Municipal, All beneficial uses 15CW3092, 04CW0218
56561.00000 2004-11-092004-12-31 0.0 AF 1000.0 AF — Municipal 04CW0308
56977.00000 2005-12-302005-12-31 0.0 cfs 0.0 3251.0 cfs Augmentation, CUR +1 05CW0331
58074.56639 2005-01-262009-12-31 0.0 AF 2000.0 AF — Commercial, Recreation +3 09CW0265
58438.00000 2009-12-302009-12-31 0.0 cfs 0.0 428.941 cfs Municipal 09CW0279
59664.00000 2013-05-092013-12-31 45.29 AF 85.71 AF — Irrigation, Municipal +8 13CW3148, 23CW3092
60586.00000 2015-11-172015-12-31 0.0 AF 9641.0 AF — Irrigation, Industrial +4 15CW3148
60748.00000 2016-04-272016-12-31 0.0 AF 2000.0 AF — Municipal, Industrial +1 16CW3178
61420.00000 2018-02-282018-12-31 0.0 AF 500.0 AF — Municipal 18CW3039
61420.00000 2018-02-282018-12-31 0.0 cfs 0.0 3.5 cfs Municipal 18CW3039
62091.00000 2019-12-312019-12-31 0.0 cfs 0.0 13.1 cfs Municipal 19CW3257

Amounts marked cfs are flow rates; AF are stored volumes (storage rights are decreed in acre-feet). An absolute amount of 0.0 beside an alt-point amount is not a dead right: the water is decreed at another structure, and that row records permission to divert it here instead (an alternate point or exchange). A case listing several numbers reflects the original decree plus later change cases.

How often is it out of priority?

Across the 11 seasons whose call record is complete enough to judge this structure (2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025, 2026), week by week from April.

most senior right · admin 4184.00000 · never out of priority in these seasons
AprMayJunJulAugSep
middle right · admin 13707.00000 · peaks at 10 of 11 seasons
AprMayJunJulAugSep
most junior right · admin 62091.00000 · peaks at 10 of 11 seasons
AprMayJunJulAugSep
Why only 11 seasons, and what the bars mean

Each bar is one week: how many of those seasons that right was out of priority under a call this site can lawfully attribute to this structure. Green is never, red is every season on record.

The short record is a property of DWR's data, not of the river. A call only counts against a structure when we can establish it applies — by the districts named in its set comments, or by stream mile on the same source. DWR did not begin stating affected districts routinely until about 2015: fewer than one call in ten can be judged before then, against roughly two in three since. A season we cannot judge is not a season without calls, so it is dropped rather than counted as quiet — 12 seasons dropped here.

This is a frequency over past seasons, not a forecast. It says nothing about what the division engineer will do this year.

Recorded use (last 15 years on record)

Years far under the decreed amount? That gap has a name — paper water vs. wet water, explained on this structure.

In a median year this structure has a recorded diversion of 27,289 AF. Its most recent year on record, 2026, came in at 5,398 AF — 20% of that, and 1st lowest of the 15 years with a recorded volume.

This structure records both diversions and reservoir releases — they are separate water movements and are accounted separately below.

YearDiverted (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 recordReleased (AF)Days recordedPeak (cfs)
2012 37,212 11th lowest of 15 · 136% of median 11,695 366 240.9
2013 42,176 13th lowest of 15 · 155% of median 12,704 361 446.6
2014 21,320 5th lowest of 15 · 78% of median 6,768 286 463.6
2015 29,805 9th lowest of 15 · 109% of median 5,185 316 497.3
2016 20,709 4th lowest of 15 · 76% of median 1,428 300 231.2
2017 27,289 8th lowest of 15 · 100% of median 98 298 433.1
2018 25,014 7th lowest of 15 · 92% of median 174 355 151.8
2019 21,623 6th lowest of 15 · 79% of median 214 335 585.0
2020 29,844 10th lowest of 15 · 109% of median 8,114 350 207.3
2021 37,348 12th lowest of 15 · 137% of median 10,225 365 500.4
2022 18,873 2nd lowest of 15 · 69% of median 4,906 365 151.1
2023 105,689 15th lowest of 15 · 387% of median 8,670 365 1950.1
2024 53,398 14th lowest of 15 · 196% of median 17,827 366 764.9
2025 19,600 3rd lowest of 15 · 72% of median 9,111 365 67.5
2026 5,398 1st lowest of 15 · 20% of median 5,807 287 39.5

How good is our record of it?

Grade A (10/10 points) — the components below are the finding; the letter alone is not.

The rubric, component by component
CheckStateDetail
identity complete name, type, and water source all on file
decreed rights on file 61 right(s), seniority decoded
diversion record current 12734 measured days, newest -12 day(s) before the data's end (DWR publishes ~1 year in arrears)
record continuity continuous 100% of the irrigation seasons in 1975-2026 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.

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