CBT ALVA B ADAMS TUNNEL ☆ My Water

Who owns it

• Northern Water / USBR (Colorado-Big Thompson) — from Hydrohistorian's hand-curated transbasin register.

DWR’s own records name no owner for a ditch, reservoir or well, so this comes from the source shown and can be out of date.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

This is water crossing the divide

Cbt Alva B Adams Tunnel is the source end of the Alva B. Adams Tunnel (tunnel). It takes water from Colorado River headwaters at Grand Lake (Div 5) and delivers it to Big Thompson River at Estes Park (Div 1). Water leaving here is an export: it never reaches the rest of this basin.

The other end: Adams Tunnel 0404634

Metered as a facility: ADATUNCO, ADANETCO — the record for the crossing itself, which may run longer than the record for either structure.

Owner / operator: Northern Water / USBR (Colorado-Big Thompson)

From the site’s hand-curated register of transbasin facilities. Every crossing on one page →

In short

CBT ALVA B ADAMS TUNNEL holds 1 decreed right on EAST INLET. No active call senior to its rights reaches its district today (28 active calls checked), so it is in priority now. 23 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: this structure is not on the modelled flow network, so no reference gage can honestly stand in for it. In a median year over its last 15 recorded years it diverts 214,797 acre-feet. It was a party to 1 court cases that also touched 5 other structures.

Assembled from the figures on this page — every number above is checked against them before it is shown (7 checked). The detail, with its method, is in the cards below.

Current administration

● In priority — no active call senior to this structure's rights affects its district (28 active call(s) checked).

23 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?

The outlook for the weeks ahead is not computable for this structure: this structure is not on the modelled flow network, so no reference gage can honestly stand in for it. 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 1935-08-01 — 428th most senior of the 2208 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: CBT GRANBY RESERVOIR (1935-08-01)☆. Immediately behind: HAMILTON-CABIN CREEK DITCH (1932-07-02)☆.

Decreed rights (1)

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 550.0 cfs decreed rate, the average day over the last 6 year(s) had 270.457 cfs in priority (49% of the decree). No call in effect is a free river — that was 40.0% of days.

On 20 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 24 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 →

Legal record & documents

1 decreed actions on record across 1 court case: CA2782.

52 imaged documents on DWR’s shelf for this structure — 26 water-court documents across 1 case, including 1 decree. Every row opens the scanned PDF at DWR. Listing as of 2026-09-22.

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 5104634 ↗ (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 1 court case that also touched 5 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.

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 214,797 AF. Its most recent year on record, 2024, came in at 200,750 AF — 94% of that, and 4th lowest of the 15 years with a recorded volume.

Call-derived yield: senior right divertible 30.2% of a median season / 0.0% dry-year.

Trends for this structure

Recorded use shows no clear trend over its last 15 recorded years — which is itself worth knowing.

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.