DILLON RESERVOIR ☆ My Water

Who owns it

• Denver Board of Water Commissioners (public utility) — as reported to the National Inventory of Dams (USACE) ↗.

DWR’s own records name no owner for a ditch, reservoir or well, so this comes from the source shown and can be out of date.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

In short

DILLON RESERVOIR holds 14 decreed rights on BLUE RIVER. No call currently reaches it that we can lawfully attribute, so none of its rights are being curtailed by one. 21 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 59,703 acre-feet. It was a party to 5 court cases that also touched 18 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.

Dam safety

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

● In priority — no active call senior to this structure's rights affects its district (25 active call(s) checked).

21 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 (25 active call(s) checked), so none of its 14 rights is administratively curtailed today. (21 call(s) state no district and sit outside this one — not judged, not assumed.) In the 5 past years most like this one (2002, 2012, 2022, 2018, 2004), 8 of the rights shown below were out at least one week in at least one analog year.

Where it sits in line

Priority 1895-05-01 — 154th most senior of the 1247 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: BUFFALO DITCH (1895-05-01)☆. Immediately behind: F W S DITCH (1895-06-15)☆.

On MAINSTEM at river mile 19.9, it is 45th of 205 down the reach. Immediately upstream: OLD DILLON RESERVOIR PUMP STATION☆. Immediately downstream: DILLON SNOW RETURN FLOW☆.

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 (21)

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.

Legal record & documents

23 decreed actions on record across 15 court cases: 11CW0021, 17CW3114, 07CW0232, 87CW0376, 87CW0218, 20CW3088, 03CW0039, 81CW0353, 09CW0153, W0741 and 5 more below.

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 3604512 ↗ (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 →

Structures it shares court cases with

This structure was a party to 5 court cases that also touched 18 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.

Also a party to 4 omnibus adjudications (CA1806, 58 structures; 87CW0257, 40 structures; 85CW0026, 14 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 59,703 AF. Its most recent year on record, 2024, came in at 51,061 AF — 86% of that, and 6th 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 shows no clear trend over its last 15 recorded years — which is itself worth knowing.

Its reference gage, Blue River below Dillon: no clear flow trend.

That is its measured record. Extended backwards from a retired neighbour's gage, the same station reads decreasing over 106 years — both records, and why they differ.

Every gage and reach in this district →

How good is our record of it?

Grade A (9/10 points) — the components below are the finding; the letter alone is not.