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PETERSON LAKE RES

Structure dossier · WDID 0303677 · RESERVOIR · CACHE LA POUDRE RIVER · DWR record

Peterson Lake Res is a reservoir on Cache La Poudre 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 2026-10-15 11:30 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DWR’s own records name no owner for a ditch, reservoir or well, so this comes from the source shown and can be out of date.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

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 PETERSON LAKE (completed 1973)
Hazard class High
Condition at last inspection Satisfactory (2026-08-04)
Storage restriction None on file
Normal storage 1,183 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 CANAL 3 DITCH (CACHE LA POUDRE RIVER, priority 1870-04-01).

● Junior rights called out — call at OGILVY DITCH (CACHE LA POUDRE RIVER, priority 1884-04-10).

● Junior rights called out — call at B H EATON DITCH (CACHE LA POUDRE RIVER, priority 1866-03-01).

Which of its rights are out of priority?

The outlook for the weeks ahead is not computable for this structure: no administrative call record for this basin. 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 1862-03-01 — 58th most senior of the 2964 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: LONG DRAW RESERVOIR (1862-03-01). Immediately behind: CHAMBERS LAKE RES (1862-03-01).

On MAINSTEM at river mile 50.8, it is 5th of 818 down the reach. Immediately upstream: ZIMMERMAN LAKE RES. Immediately downstream: OWL SPRING #2 STOCKWATER DVLPMNT.

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 (9)

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
4443.00000 1862-03-011882-04-11 0.0 cfs 0.0 0.404 cfs Municipal 07CW0190
5372.00000 1864-09-151882-04-11 0.0 cfs 0.0 0.521 cfs Municipal 07CW0190
6649.00000 1868-03-151882-04-11 0.0 cfs 0.0 0.175 cfs Municipal 07CW0190
8480.00000 1873-03-201882-04-11 0.0 cfs 0.0 0.15 cfs Municipal 07CW0190
10318.00000 1878-04-011882-04-11 0.0 cfs 0.0 0.271 cfs Municipal 07CW0190
11438.00000 1881-04-251882-04-11 0.0 cfs 0.0 17.36 cfs Municipal 07CW0190
26409.23646 1914-09-281945-12-18 0.0 cfs 0.0 9.24 cfs Municipal 07CW0190
26409.26135 1921-07-221945-12-18 915.0 AF 0.0 — Irrigation, Augmentation 81CW0136, CA5362
45655.43337 1968-08-261975-12-31 336.9 AF 0.0 — Irrigation, Municipal +1 W7985

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.

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 1,247 AF. Its most recent year on record, 2025, came in at 0 AF — 0% 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)
2011 1,183 6th lowest of 15 · 95% of median — 27 49.9
2012 603 2nd lowest of 15 · 48% of median 465 101 12.1
2013 650 3rd lowest of 15 · 52% of median 900 47 26.2
2014 1,220 7th lowest of 15 · 98% of median 1,128 43 47.0
2015 1,287 9th lowest of 15 · 103% of median 909 83 36.0
2016 1,295 10th lowest of 15 · 104% of median 1,179 57 35.3
2017 1,348 12th lowest of 15 · 108% of median 971 63 34.8
2018 1,303 11th lowest of 15 · 104% of median 1,174 44 29.8
2019 1,247 8th lowest of 15 · 100% of median 1,216 51 37.8
2020 846 4th lowest of 15 · 68% of median 462 47 39.8
2021 1,379 13th lowest of 15 · 111% of median 327 68 33.1
2022 1,070 5th lowest of 15 · 86% of median 1,372 39 96.3
2023 1,812 15th lowest of 15 · 145% of median 4,591 58 87.0
2024 1,577 14th lowest of 15 · 126% of median 1,207 73 82.2
2025 0 1st lowest of 15 · 0% of median 0 37 0.0

How good is our record of it?

Grade B (8/10 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 9 right(s), seniority decoded
diversion record current 2600 measured days, newest 382 day(s) before the data's end (DWR publishes ~1 year in arrears)
record continuity sparse 23% of the irrigation seasons in 1973-2025 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.

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