Seniority, absolute versus conditional water, and decreed uses for all 3,431 water rights on record in Boulder County, taken from the state's own records. Priority dates run from 1859-10-01 to 2022-04-06.
CFS on record: 21,177.3 absolute · 4,626.8 conditional. Flow (CFS) and volume (AF) are never added together.
Worth knowing: Boulder County has about 1.7x more acre-feet decreed as conditional than as absolute. Conditional water is decreed on paper but not yet put to beneficial use. A buyer or lender who does not separate the two is valuing a different asset than the one on the ground.
In a dry year the oldest rights are served first. This is how Boulder County's rights are distributed.
| Era | Rights | Share | |
|---|---|---|---|
| pre-1900 | 928 | 27.0% | |
| 1900-1949 | 812 | 23.7% | |
| 1950-1969 | 939 | 27.4% | |
| 1970-1999 | 679 | 19.8% | |
| 2000+ | 73 | 2.1% |
| Decreed use | Rights |
|---|---|
| Domestic | 1,932 |
| Irrigation | 1,843 |
| Municipal | 920 |
| Recreation | 645 |
| Stock | 563 |
| Industrial | 562 |
Ranked by the state's own priority administration number, the figure DWR uses to order rights by seniority.
| Priority | Structure | Source | Amount | Uses | Verify |
|---|---|---|---|---|---|
| 1859-10-01 | LOWER BOULDER DITCH | BOULDER CREEK | 24.981 CFS | Irrigation, Municipal, Commercial, Industrial, Recreation, Fishery, Fire, Domestic, Augmentation, Other, Wildlife, All beneficial uses | state record |
| 1859-10-01 | BOULDER CREEK | BOULDER CREEK | 0.019 CFS | Augmentation | state record |
| 1859-11-15 | SMITH GOSS DITCH | BOULDER CREEK | 29.2166 CFS | Irrigation | state record |
| 1859-11-15 | BOULDER CITY PL | NORTH BOULDER CREEK | 0.451 CFS | Irrigation, Municipal, Commercial, Industrial, Recreation, Domestic | state record |
| 1859-12-01 | HOWELL DITCH | BOULDER CREEK | 5.0 CFS | Irrigation | state record |
| 1860-04-01 | COMMUNITY DITCH | SOUTH BOULDER CREEK | 0.082 CFS | Irrigation, Municipal, Augmentation, Other | state record |
| 1860-04-01 | HOWARD DITCH | SOUTH BOULDER CREEK | 12.0639 CFS | Irrigation, Municipal, Commercial, Industrial, Recreation, Fire, Domestic, Stock, Augmentation, Other, Wildlife | state record |
| 1860-04-01 | LAFAYETTE PL | SOUTH BOULDER CREEK | 6.88 CFS | Irrigation, Municipal, Commercial, Industrial, Fire, Domestic, Augmentation, Other | state record |
| 1860-04-01 | LOUISVILLE PL | SOUTH BOULDER CREEK | 6.706 CFS | Irrigation, Municipal, Commercial, Industrial, Fire, Domestic, Augmentation, Other | state record |
| 1860-04-01 | CREEKSIDE RANCH POND DIVERSION | SOUTH BOULDER CREEK | 0.0203 CFS | Storage, Irrigation, Recreation, Fishery, Stock, Augmentation | state record |
This page is the summary. The full file for Boulder County covers every one of the 3,431 rights, with its priority date, seniority number, absolute and conditional amounts, decreed uses and a link to each official record, as a spreadsheet.
Buying, lending on, or listing irrigated ground here? Ask for the county file, or for a single property's water summary. The first one is on me.
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Records last updated 10 September 2026.