DAN MAHAN DITCH ☆ My Water

In short

DAN MAHAN DITCH holds 1 decreed right on HUERFANO RIVER. No active call senior to its rights reaches its district today (17 active calls checked), so it is in priority now. 16 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: no gage record for this year at this date, so there is nothing to find analogs for. In a median year over its last 15 recorded years it diverts 707 acre-feet. That use is rising by about 62.5 acre-feet a year over 15 years (p=0.00025020473635706253).

Assembled from the figures on this page — every number above is checked against them before it is shown (8 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 (17 active call(s) checked).

16 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: no gage record for this year at this date, so there is nothing to find analogs for. 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 1866-04-17 — 9th most senior of the 930 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: PEDRO GOMEZ DITCH (1865-06-01)☆. Immediately behind: JACK ALLEN DITCH (1866-05-01)☆.

On MAINSTEM at river mile 49.1, it is 703rd of 1001 down the reach. Immediately upstream: 7914253☆. Immediately downstream: 7914268☆.

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 (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 2.5 cfs decreed rate, the average day over the last 6 year(s) had 2.21 cfs in priority (88% of the decree). No call in effect is a free river — that was 0.0% 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.

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: 06/12/1889.

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 7900533 ↗ (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 →

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 707 AF. Its most recent year on record, 2025, came in at 1,105 AF — 156% of that, and 14th lowest of the 15 years with a recorded volume.

Trends for this structure

Recorded use is rising over its last 15 recorded years (+62 AF/yr, Mann-Kendall p=0.000).

Its reference gage, Spanish Peaks Jv Recharge Pond: no clear flow trend.

Every gage and reach in this district →

How good is our record of it?

Grade B (8/10 points) — the components below are the finding; the letter alone is not.