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SILVER LAKE

Structure dossier · WDID 0604238 · RESERVOIR · NORTH BOULDER CREEK · DWR record · probably BOULDER CITY OF’s (matched on DWR’s contact or an EPA intake name; verify below)

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 2026-10-12 20:12 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DWR’s own records name no owner for a ditch, reservoir or well, so this comes from the source shown and can be out of date.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

Where this structure is measured

GageFlowing nowRecordHow we know
SILVER LAKE OUTLET SILOUTCO 21.76 cfs 2023–2026, 906 days DWR telemetry mapping
SILVER LAKE SILLAKCO — — co-located, 193 m

A green link is DWR's own: either its telemetry inventory maps this WDID to that station, or the station is named for this WDID (0700553 → 0700553A). An amber one is ours — the station sits within 250 m and shares a distinctive word with this structure's name, which is a strong hint rather than a DWR statement that this gage meters this structure. Wrong? Tell us.

Flowing now

21.76 cfs as of 2026-10-12 17:15 (3.0 h ago)

Provisional 15-minute telemetry from SILOUTCO ↗ (SILVER LAKE OUTLET). Raw, not the approved record — it is never merged into the diversion history below. DWR publishes the official diversion record after the water year closes and is approved, which is why that record ends months back while this reads minutes ago.

In short

SILVER LAKE holds 11 decreed rights on NORTH BOULDER CREEK. A call at RURAL DITCH on BOULDER CREEK (1862-05-09), and 1 other currently reaches it: fully called out. 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: only 2 analog year(s) have both flow and a complete administration record; 4 needed. In a median year over its last 15 recorded years it diverts 2,434 acre-feet. It was a party to 5 court cases that also touched 13 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.

Dam safety

Dam SILVER LAKE (completed 1887)
Hazard class High
Condition at last inspection Satisfactory (2026-08-20)
Storage restriction None on file
Normal storage 3,987 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

● Fully called out — call at RURAL DITCH (BOULDER CREEK, priority 1862-05-09).

● Fully called out — call at HOWELL DITCH (BOULDER CREEK, priority 1860-04-01).

Which of its rights are out of priority?

The outlook for the weeks ahead is not computable for this structure: only 2 analog year(s) have both flow and a complete administration record; 4 needed. 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 1887-09-23 — 133rd most senior of the 1867 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: ERIE COAL CR DITCH (1894-03-20). Immediately behind: 0601561 (1900-12-31).

On NORTH BOULDER CREEK at river mile -12.9, it is 9th of 14 down the reach. Immediately upstream: ISLAND LAKE. Immediately downstream: GLACIER SUMMER CITY D.

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 (11)

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
18615.13780 1887-09-231907-03-13 807.3 AF 0.0 — Municipal, Commercial +3 CA4842
20699.00000 1906-09-031907-03-13 807.3 AF 0.0 — Municipal, Commercial +3 CA4842
28738.00000 1928-09-061953-09-28 322.3 AF 0.0 — Municipal, Commercial +3 CA15037
33602.00000 1941-12-311953-09-28 3020.0 AF 0.0 — Municipal, Commercial +3 CA15037, CA12111
45290.38350 1954-12-311974-12-31 0.0 cfs 0.0 250.0 cfs Municipal 86CW0123, W7852
52595.52594 1993-12-301994-12-31 0.0 cfs 0.0 55.185 cfs Irrigation, Municipal +5 94CW0284
52795.00000 1994-07-191994-12-31 0.0 cfs 0.0 55.185 cfs Irrigation, Municipal +5 94CW0284
52958.00000 1994-12-291994-12-31 0.0 cfs 0.0 4.5 cfs Municipal, All beneficial uses 94CW0285, 03CW0440
55141.00000 2000-12-202000-12-31 0.0 cfs 0.0 200.0 cfs Irrigation, Municipal +8 19CW3129, 00CW0226
60963.00000 2016-11-282016-12-31 0.0 cfs 0.0 21.9 cfs Municipal 16CW3160
61357.00000 2017-12-272017-12-31 0.0 cfs 0.0 100.0 cfs Municipal 16CW3160

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 18615.13780 · peaks at 11 of 11 seasons
AprMayJunJulAugSep
middle right · admin 52595.52594 · peaks at 11 of 11 seasons
AprMayJunJulAugSep
most junior right · admin 61357.00000 · peaks at 11 of 11 seasons
AprMayJunJulAugSep

Snow sets the clock here. In the driest third of snow years (3 seasons), the call settled in for the season around June 3; in 1 of them it never lifted at all. In the middle third (5 seasons), the call settled in for the season around June 24 (June 17 to July 8 across those years); in 1 of them it never lifted at all. In the wettest third (3 seasons), the call settled in for the season around June 24; in 2 of them it never lifted at all.

Snow years ranked by the district’s April 1 snow-water percentile across 3 SNOTEL sites; 11 seasons carry both a snow reading and a judgeable call record. How the past played out, not a forecast.

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 2,434 AF. Its most recent year on record, 2025, came in at 3,101 AF — 127% of that, and 12th 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 3,386 13th lowest of 15 · 139% of median 3,012 88 91.4
2012 2,256 4th lowest of 15 · 93% of median 3,065 87 53.9
2013 2,415 7th lowest of 15 · 99% of median 1,911 88 65.0
2014 2,434 8th lowest of 15 · 100% of median 3,425 89 102.8
2015 3,869 14th lowest of 15 · 159% of median 2,929 36 265.9
2016 2,554 10th lowest of 15 · 105% of median 3,112 39 133.1
2017 2,347 5th lowest of 15 · 96% of median 2,706 54 108.9
2018 1,074 1st lowest of 15 · 44% of median 2,522 24 61.5
2019 2,473 9th lowest of 15 · 102% of median 3,191 47 88.7
2020 2,600 11th lowest of 15 · 107% of median 2,319 38 118.0
2021 2,362 6th lowest of 15 · 97% of median 701 43 201.3
2022 1,434 3rd lowest of 15 · 59% of median 1,236 98 75.8
2023 15,541 15th lowest of 15 · 638% of median 8,328 303 128.2
2024 1,258 2nd lowest of 15 · 52% of median 2,274 27 122.2
2025 3,101 12th lowest of 15 · 127% of median — 58 136.3

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
CheckStateDetail
identity complete name, type, and water source all on file
decreed rights on file 11 right(s), seniority decoded
diversion record stale 2468 measured days, but newest is 472 day(s) before the data's end (target 450)
record continuity sparse 23% of the irrigation seasons in 1974-2025 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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