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HILLSBOROUGH DITCH

Structure dossier · WDID 0400523 · DITCH · BIG THOMPSON RIVER · DWR record

Hillsborough Ditch is a ditch on Big Thompson 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 13:31 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

  • The Hillsborough Extension Ditch CO. (nonprofit corporation) — probable match, from the Colorado Secretary of State business record ↗; verify before relying on it. A nonprofit corporation of this name, in good standing, with its principal office in Johnstown; matched on the name and the location, not confirmed by the company.

DWR’s own records name no owner for a ditch, reservoir or well, so this comes from the source shown and can be out of date.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
HILLSBOROUGH DITCH HILDITCO 2.31 cfs 2010–2026, 5,833 days DWR telemetry mapping
BIG THOMPSON RIVER BELOW HILLSBOROUGH DIVERSION BIGHILCO 28.6 cfs 1996–2026, 10,417 days co-located, 6 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

2.31 cfs as of 2026-10-14 10:45 (2.8 h ago)

Provisional 15-minute telemetry from HILDITCO ↗ (HILLSBOROUGH DITCH). 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

HILLSBOROUGH DITCH holds 7 decreed rights on BIG THOMPSON RIVER. No call currently reaches it that we can lawfully attribute, so none of its rights are being curtailed by one. 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 14,100 acre-feet. It was a party to 9 court cases that also touched 21 other structures.

Assembled from the figures on this page — every number above is checked against them before it is shown (6 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 (diversion). 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).

6 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?

No active call verifiably reaches this structure (19 active call(s) checked), so none of its 7 rights is administratively curtailed today. (6 call(s) state no district and sit outside this one — not judged, not assumed.) In the 5 past years most like this one (2008, 2006, 2015, 2007, 2012), 6 of the rights shown below were out at least one week in at least one analog year.

Right (priority)NowAnalog years outMajority out by
1861-11-10 4332 — 0 of 5 —
1874-10-15 9054 — 2 of 5 —
1878-04-15 10332 — 2 of 5 —
1881-10-06 11602 — 2 of 5 —
1896-10-20 17095 — 2 of 5 —
1926-02-01 43829 — 4 of 5 2026-09-27
2008-08-13 57934 — 4 of 5 2026-09-27
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 BIG THOMPSON RIVER BELOW HILLSBOROUGH DIVERSION around 2026-09-27 (the newest reading on file) — currently 31% of that gage's own median for this window — to pick the 5 most similar past years with complete administration records (2005–2026). 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 1861-11-10 — 8th most senior of the 1296 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: HANDY DITCH (1861-11-10). Immediately behind: HOME SUPPLY DITCH (1861-11-10).

On MAINSTEM at river mile 56.5, it is 413th of 487 down the reach. Immediately upstream: HFE/MLD HANDY/HOME SUPPLY PUMP. Immediately downstream: GREAT WESTERN PIT NO 1 RESERVOIR.

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 (7)

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
4332.00000 1861-11-101883-05-28 63.14 cfs 0.0 — Storage, Irrigation +7 02CW0339, 09CW0105 +7
9054.00000 1874-10-151883-05-28 8.25 cfs 0.0 — Irrigation, Municipal 14CW3160, 05/28/1883
10332.00000 1878-04-151883-05-28 54.0 cfs 0.0 — Storage, Irrigation +6 05/28/1883, 12CW0262 +3
11602.00000 1881-10-061883-05-28 45.69 cfs 0.0 — Storage, Irrigation +6 02CW0339, 09CW0105 +2
17095.00000 1896-10-201916-06-29 100.0 cfs 0.0 — Storage CA4862
43829.27790 1926-02-011970-12-31 13.0 cfs 0.0 — Other W0440
57934.00000 2008-08-132002-12-31 0.0 cfs 65.08 cfs 5.0 cfs Irrigation, Recreation +1 02CW0339, 02CW0336

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 much of this decree was in priority, by day

A right is in priority on a day when it is senior to every call administering this structure. Of its 284.08 cfs decreed rate, the average day over the last 6 year(s) had 210.126 cfs in priority (74% of the decree). No call in effect is a free river — that was 13.4% of days.

On 1352 days some rights were in priority and others were not — seniority splits a decree rather than switching it off. Calls are set and released at a time of day, not at midnight, so a day is counted by the hour: a call setting at 4pm costs that day a third of its rate, not all of it. A call began or ended mid-day on 30 of these days.

This is paper water. It is the decreed rate that was in priority — not water that was physically in the stream, and not water this structure diverted. A ditch can be in priority for 50 cfs on a day the creek carries five. What that distinction means →

YearMean in priority (Apr–Sep) Share of decreeFree-river days Days fully out
2026 84.3 cfs 30% 1 0
2025 151.06 cfs 53% 40 0
2024 166.41 cfs 59% 110 0
2023 200.51 cfs 71% 61 0
2022 135.31 cfs 48% 31 0
2021 271.29 cfs 96% 1 0
Show the last 120 days, day by day
DateIn priorityControlling call
2026-10-13 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-10-12 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-10-11 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-10-10 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-10-09 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-10-08 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-10-07 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-10-06 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-10-05 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-10-04 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-10-03 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-10-02 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-10-01 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-30 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-29 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-28 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-27 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-26 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-25 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-24 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-23 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-22 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-21 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-20 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-19 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-18 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-17 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-16 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-15 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-14 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-13 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-12 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-11 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-10 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-09 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-08 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-07 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-06 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-05 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-04 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-03 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-02 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-09-01 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-31 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-30 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-29 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-28 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-27 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-26 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-25 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-24 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-23 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-22 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-21 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-20 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-19 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-18 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-17 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-16 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-15 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-14 63.14 cfs (22%) HILLSBOROUGH DITCH, 1861-11-10 · Big Thompson River · same source, at or above the calling point
2026-08-13 63.14 cfs (22%) HILLSBOROUGH DITCH, 1861-11-10 · Big Thompson River · same source, at or above the calling point
2026-08-12 63.14 cfs (22%) HILLSBOROUGH DITCH, 1861-11-10 · Big Thompson River · same source, at or above the calling point
2026-08-11 63.14 cfs (22%) HILLSBOROUGH DITCH, 1861-11-10 · Big Thompson River · same source, at or above the calling point
2026-08-10 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-09 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-08 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-07 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-04-01 · Big Thompson River · same source, at or above the calling point
2026-08-06 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-08-05 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-08-04 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-08-03 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-08-02 63.14 cfs (22%) HILLSBOROUGH DITCH, 1865-02-25 · Big Thompson River · same source, at or above the calling point
2026-08-01 63.14 cfs (22%) HILLSBOROUGH DITCH, 1865-10-20 · Big Thompson River · same source, at or above the calling point
2026-07-31 63.14 cfs (22%) HILLSBOROUGH DITCH, 1865-10-20 · Big Thompson River · same source, at or above the calling point
2026-07-30 63.14 cfs (22%) HILLSBOROUGH DITCH, 1865-02-25 · Big Thompson River · same source, at or above the calling point
2026-07-29 63.14 cfs (22%) HILLSBOROUGH DITCH, 1865-02-25 · Big Thompson River · same source, at or above the calling point
2026-07-28 63.14 cfs (22%) HILLSBOROUGH DITCH, 1865-10-20 · Big Thompson River · same source, at or above the calling point
2026-07-27 63.14 cfs (22%) HILLSBOROUGH DITCH, 1865-10-20 · Big Thompson River · same source, at or above the calling point
2026-07-26 63.14 cfs (22%) HILLSBOROUGH DITCH, 1865-11-01 · Big Thompson River · same source, at or above the calling point
2026-07-25 72.135 cfs (25%) BIG T PLATTE R DITCH, 1865-11-18 · Big Thompson River · same source, at or above the calling point
2026-07-24 63.14 cfs (22%) HILLSBOROUGH DITCH, 1865-10-20 · Big Thompson River · same source, at or above the calling point
2026-07-23 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-22 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-21 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-20 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-19 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-18 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-17 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-16 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-15 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-14 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-13 63.14 cfs (22%) HILLSBOROUGH DITCH, 1863-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-12 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-11 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-10 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-09 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-08 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-07 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-06 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-05 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-04 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-03 63.14 cfs (22%) HILLSBOROUGH DITCH, 1864-05-01 · Big Thompson River · same source, at or above the calling point
2026-07-02 63.14 cfs (22%) HILLSBOROUGH DITCH, 1865-02-25 · Big Thompson River · same source, at or above the calling point
2026-07-01 63.14 cfs (22%) HILLSBOROUGH DITCH, 1865-10-20 · Big Thompson River · same source, at or above the calling point
2026-06-30 63.14 cfs (22%) BIG T PLATTE R DITCH, 1866-06-30 · Big Thompson River · same source, at or above the calling point
2026-06-29 63.14 cfs (22%) BIG T PLATTE R DITCH, 1867-03-01 · Big Thompson River · same source, at or above the calling point
2026-06-28 63.14 cfs (22%) BIG T PLATTE R DITCH, 1867-03-01 · Big Thompson River · same source, at or above the calling point
2026-06-27 63.14 cfs (22%) BIG T PLATTE R DITCH, 1867-03-01 · Big Thompson River · same source, at or above the calling point
2026-06-26 63.14 cfs (22%) BIG T PLATTE R DITCH, 1867-03-01 · Big Thompson River · same source, at or above the calling point
2026-06-25 63.14 cfs (22%) BIG T PLATTE R DITCH, 1867-03-01 · Big Thompson River · same source, at or above the calling point
2026-06-24 63.14 cfs (22%) BIG T PLATTE R DITCH, 1867-03-01 · Big Thompson River · same source, at or above the calling point
2026-06-23 63.14 cfs (22%) BIG T PLATTE R DITCH, 1867-03-01 · Big Thompson River · same source, at or above the calling point
2026-06-22 63.14 cfs (22%) BIG T PLATTE R DITCH, 1867-06-01 · Big Thompson River · same source, at or above the calling point
2026-06-21 63.14 cfs (22%) BIG T PLATTE R DITCH, 1867-06-01 · Big Thompson River · same source, at or above the calling point
2026-06-20 63.14 cfs (22%) BIG T PLATTE R DITCH, 1870-10-20 · Big Thompson River · same source, at or above the calling point
2026-06-19 63.14 cfs (22%) BIG T PLATTE R DITCH, 1870-10-20 · Big Thompson River · same source, at or above the calling point
2026-06-18 63.14 cfs (22%) BIG T PLATTE R DITCH, 1870-10-20 · Big Thompson River · same source, at or above the calling point
2026-06-17 63.14 cfs (22%) BIG T PLATTE R DITCH, 1870-10-20 · Big Thompson River · same source, at or above the calling point
2026-06-16 63.14 cfs (22%) BIG T PLATTE R DITCH, 1871-10-01 · Big Thompson River · same source, at or above the calling point
How this is worked out, and what it cannot tell you
  • This is a decreed rate that was in priority -- paper water, not water that was available or diverted.
  • Augmentation plans, exchanges and substitute supply plans let a structure divert lawfully while out of priority; none are modelled.
  • Calls on the river this source flows into are included without a position test, so curtailment can be over-reported where the calling point sits above the confluence.
  • DWR's administration is the authority. Scored against DWR's own call analysis, this method agreed on 95.5% of 85,822 structure-days (2026-08-29).
  • Calls considered for this structure: 3571, of which 2690 sit on a river it flows into.

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 4332.00000 · never out of priority in these seasons
AprMayJunJulAugSep
middle right · admin 11602.00000 · peaks at 11 of 11 seasons
AprMayJunJulAugSep
most junior right · admin 57934.00000 · 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 3 (April 8 to June 24 across those years). In the wettest third (3 seasons), the call settled in for the season around July 8 (June 17 to July 8 across those years); in 1 of them it never lifted at all.

Snow years ranked by the district’s April 1 snow-water percentile across 2 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 14,100 AF. Its most recent year on record, 2025, came in at 14,585 AF — 103% of that, and 9th lowest of the 15 years with a recorded volume.

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 recordDays recordedPeak (cfs)
2011 16,385 13th lowest of 15 · 116% of median 157 115.0
2012 17,263 15th lowest of 15 · 122% of median 163 75.6
2013 13,147 4th lowest of 15 · 93% of median 108 74.1
2014 13,518 5th lowest of 15 · 96% of median 140 84.5
2015 11,631 1st lowest of 15 · 82% of median 107 77.2
2016 14,733 10th lowest of 15 · 104% of median 113 116.8
2017 13,584 7th lowest of 15 · 96% of median 117 80.3
2018 13,541 6th lowest of 15 · 96% of median 123 77.7
2019 12,786 3rd lowest of 15 · 91% of median 110 79.3
2020 14,100 8th lowest of 15 · 100% of median 125 73.0
2021 15,943 11th lowest of 15 · 113% of median 152 76.1
2022 16,613 14th lowest of 15 · 118% of median 156 75.2
2023 11,877 2nd lowest of 15 · 84% of median 144 85.3
2024 16,145 12th lowest of 15 · 114% of median 141 78.0
2025 14,585 9th lowest of 15 · 103% of median 135 75.9

Call-derived yield: senior right divertible 100.0% of a median season / 61.2% dry-year.

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 7 right(s), seniority decoded
diversion record current 11762 measured days, newest 368 day(s) before the data's end (DWR publishes ~1 year in arrears)
record continuity patchy 73% of the irrigation seasons in 1950-2025 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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