BLUNN RES ☆ My Water

Who owns it

• City of Arvada (local government) — probable match, from the National Inventory of Dams (USACE) ↗; verify before relying on 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DWR’s own records name no owner for a ditch, reservoir or well, so this comes from the source shown and can be out of date.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

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

0.0 cfs as of 2026-10-16 03:00 (2.4 h ago)

Zero is a real reading: the gage is reporting, and it says this structure is not diverting right now.

Provisional 15-minute telemetry from ARVINLCO ↗ (ARVADA (BLUNN) RESERVOIR INLET FROM RALSTON CREEK). 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

BLUNN RES holds 46 decreed rights on RALSTON CREEK. As of 2026-10-01, 21 of them are out of priority under a call at admin 7449.00000 placed by WANNAMAKER DITCH. Its 25 most senior rights, back to 1860-05-16, keep diverting. 8 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 6,647 acre-feet. That use is rising by about 575.2 acre-feet a year over 15 years (p=0.0075331703386321). It was a party to 15 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 (14 checked). The detail, with its method, is in the cards below.

Dam safety

Source: DWR Dam Safety’s jurisdictional-dam inventory (damsafety/damsafetydaminfojd), refreshed weekly. DWR’s record for this dam carries no WDID and no matched NID id, so it is joined by name and position: “BLUNN” 0.258 mi away. More than half of Colorado’s jurisdictional dams can be reached no other way; judge the match before relying on it. Hazard class describes the consequence of failure, not the likelihood of it. DWR’s dam record.

Current administration

● Junior rights called out — call at WANNAMAKER DITCH (CLEAR CREEK, priority 1870-05-23).

Which of its rights are out of priority?

Under today's controlling call (WANNAMAKER DITCH, priority 1870-05-23): 21 of this structure's 46 rights are out of priority now. (8 call(s) state no district and sit outside this one — not judged, not assumed.) In the 5 past years most like this one (2025, 2023, 2022, 2024, 2018), 7 of the rights shown below were out at least one week in at least one analog year.

Where it sits in line

Priority 1860-05-16 — 30th most senior of the 1815 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: 0700873 (1860-05-16)☆. Immediately behind: RALSTON RES (1860-05-16)☆.

On RALSTON CREEK at river mile 47.9, it is 9th of 24 down the reach. Immediately upstream: LONG LAKE RES LOWER☆. Immediately downstream: TUCKER RES☆.

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 (48)

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 15.126 cfs decreed rate, the average day over the last 6 year(s) had 7.526 cfs in priority (50% of the decree). No call in effect is a free river — that was 1.3% of days.

On 1637 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 8 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 →

Checked against DWR's own analysis

DWR publishes a day-by-day out-of-priority analysis for some rights. Where it exists we score this page against it — computed live, so it reflects what the code does right now, not what a memo once said. Agreement on this structure: 97.3% on whether a day was curtailed, and 90.1% of days land on DWR's exact percent of the day.

Legal record & documents

170 decreed actions on record across 33 court cases: 17CW3210, 22CW3133, 11CW0237, 22CW3132, 05CW0112, 96CW0148, 20CW3119, 13CW3068, 06CW0098, 97CW0373 and 23 more below.

754 imaged documents on DWR’s shelf for this structure — 747 water-court documents across 45 cases, including 46 decrees. Every row opens the scanned PDF at DWR. Listing as of 2026-09-05.

Imaged documents at DWR. DWR keeps the scanned documents for this structure — decrees, rulings, plats, correspondence — in its Laserfiche archive. Open the list directly: imaged documents for 0703308 ↗ (indexed by structure, not by case — the cases listed above appear within the list).

Other DWR records for this structure: DWR’s page for this structure ↗ — net amounts, water rights, transactions & adjudication history, and diversion records, all on that one page. On this site: the district’s full legal picture →

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.

DWR’s own out-of-priority analysis

The Division of Water Resources computes its own daily priority analysis for this structure (analysisservices/callanalysisbywdid) — the authoritative answer to “could this right legally divert that day”, from the agency that administers the river. Shown beside, never blended into, the climatology above: different method, different span, and you should know whose number is whose.

DWR’s series is cached for a scoped set of structures (the rights that move the most water, bracketed most-senior and most-junior) — absence of a right here means it isn’t in that set yet, not that it is never curtailed.

Structures it shares court cases with

This structure was a party to 15 court cases that also touched 25 other structures — changes of water right, augmentation plans, exchanges. Being parties to the same case does not by itself mean water moved between them; which way it ran, and how much, is in the decree.

3 further shared cases not shown — the most specific are listed first, since a case binding two structures says more than one binding a dozen.

Also a party to 8 omnibus adjudications (05CW0112, 23 structures; 85CW0409, 22 structures; W8083, 21 structures). Those settled many rights at once and are listed separately: they say these structures were adjudicated together, not that they deal with each other.

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 6,647 AF. Its most recent year on record, 2025, came in at 7,544 AF — 114% of that, and 10th 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.

Trends for this structure

Recorded use is rising over its last 15 recorded years (+575 AF/yr, Mann-Kendall p=0.008).

Its reference gage, Arvada (Blunn) Reservoir Release to Ralston Creek: no clear flow trend.

Every gage and reach in this district →

How good is our record of it?

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

Recent watch events

• 2026-10-13 — legal document update (case 22CW3133)