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GILCREST RESERVOIR

Structure dossier · WDID 0203388 · RESERVOIR · SOUTH PLATTE RIVER · DWR record · probably AURORA CITY OF, GILCREST TOWN OF’s (matched on DWR’s contact or an EPA intake name; verify below)

Gilcrest 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 12:43 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.

The record and the river

In short

GILCREST RESERVOIR holds 11 decreed rights on SOUTH PLATTE RIVER. No active call senior to its rights reaches its district today (19 active calls checked), so it is in priority now. 7 further calls state no district and sit outside this one, so they are counted here rather than assumed either way. That is today's position; the weeks ahead cannot be projected for it: no gage record for this year at this date, so there is nothing to find analogs for. In a median year over its last 13 recorded years it diverts 487 acre-feet. That use is rising by about 69.2 acre-feet a year over 13 years (p=0.03273560958832089). It was a party to 11 court cases that also touched 25 other structures.

Assembled from the figures on this page — every number above is checked against them before it is shown (10 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.

Current administration

● In priority — no active call senior to this structure's rights affects its district (19 active call(s) checked).

7 further calls state no district and sit outside this one, so they are counted here rather than assumed either way.

Which of its rights are out of priority?

The outlook for the weeks ahead is not computable for this structure: no gage record for this year at this date, so there is nothing to find analogs for. Today’s position is a separate question, and it is answered in Current administration above — that screen reads the district’s active calls and needs no reference gage.

Where it sits in line

Priority 1870-10-25 — 344th 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: UNITED GRAVEL PIT STORAGE RES (1870-10-25). Immediately behind: BARR LAKE (1870-10-25).

On MAINSTEM at river mile 156.7, it is 861st of 890 down the reach. Immediately upstream: ULRICH FARMS AUG LRF-B RELEASE. Immediately downstream: GILCREST RESERVOIR NORTH DIVERSION.

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 (12)

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
7603.00000 1870-10-251882-04-11 0.0 cfs 0.0 4.92 cfs Municipal, Augmentation +2 16CW3195, 13CW3026
7928.00000 1871-09-151882-04-11 0.0 cfs 0.0 7.62 cfs Municipal, Augmentation +2 16CW3195, 13CW3026
9080.00000 1874-11-101882-04-11 0.0 cfs 0.0 8.25 cfs Municipal, Augmentation +2 16CW3195, 13CW3026
10120.00000 1877-09-151882-04-11 0.0 cfs 0.0 5.42 cfs Municipal, Augmentation +2 16CW3195, 13CW3026
45655.45437 1974-05-271975-12-31 0.0 cfs 0.0 2.92 cfs Municipal, Augmentation +2 16CW3195, 13CW3026
58585.00000 2010-05-262010-12-31 0.0 AF 100.0 AF — Irrigation, Augmentation +1 10CW0141
58585.00000 2010-05-262010-12-31 0.0 cfs 260.0 cfs — Irrigation, Augmentation +1 10CW0141
59167.00000 2011-12-292011-12-31 548.33 AF 2451.67 AF — Municipal, Augmentation +2 11CW0280, 20CW3161 +1
59791.00000 2013-09-132013-12-31 234.7 AF 765.3 AF — Municipal, Augmentation +2 22CW3039, 16CW3195 +1
60264.00000 2014-12-302014-12-31 0.0 AF 3000.0 AF — Municipal, Augmentation +2 14CW3164, 16CW3196
60750.00000 2016-04-292016-12-31 0.0 AF 33400.0 AF — Irrigation, Municipal +8 16CW3058, 16CW3059
60980.00000 2016-12-152016-12-31 0.0 AF 0.0 1360.0 AF Municipal, Augmentation +2 16CW3195, 16CW3196

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 7603.00000 · peaks at 1 of 11 seasons
AprMayJunJulAugSep
middle right · admin 58585.00000 · peaks at 10 of 11 seasons
AprMayJunJulAugSep
most junior right · admin 60980.00000 · 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 13 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 487 AF. Its most recent year on record, 2025, came in at 1,893 AF — 389% of that, and 13th lowest of the 13 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)
2013 173 3rd lowest of 13 · 36% of median — 24 5.9
2014 975 12th lowest of 13 · 200% of median 8 64 14.1
2015 231 4th lowest of 13 · 47% of median 9 29 6.6
2016 101 2nd lowest of 13 · 21% of median 51 23 4.8
2017 298 5th lowest of 13 · 61% of median 143 55 4.3
2018 59 1st lowest of 13 · 12% of median 249 22 3.1
2019 707 9th lowest of 13 · 145% of median 65 122 9.4
2020 306 6th lowest of 13 · 63% of median 258 79 4.7
2021 638 8th lowest of 13 · 131% of median 347 93 10.6
2022 487 7th lowest of 13 · 100% of median 744 126 8.5
2023 894 11th lowest of 13 · 184% of median 707 365 21.3
2024 792 10th lowest of 13 · 163% of median 70 366 20.8
2025 1,893 13th lowest of 13 · 389% of median 100 304 49.2

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
CheckStateDetail
identity complete name, type, and water source all on file
decreed rights on file 12 right(s), seniority decoded
diversion record current 1672 measured days, newest 336 day(s) before the data's end (DWR publishes ~1 year in arrears)
record continuity patchy 65% of the irrigation seasons in 2013-2025 carry measured days
published-record stability stable no upstream revisions recorded against this structure

Recent watch events

  • 2026-09-05 — legal document update (case 16CW3196)

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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