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Water Division 3: the Rio Grande
Water Division 3 is the Rio Grande basin in Colorado, including the San Luis Valley creeks the statute names one by one. C.R.S. § 37-92-201(1)(c)
It holds 18,451 decreed water-right records (11% of the state) and the most senior ditch priorities on record in any division, from 1852. Its water court and division engineer are in Alamosa.
Division 3 at a glance
| Measure | Division 3 | Among the seven |
|---|---|---|
| Decreed water-right records | 18,451 | fifth most, 11% of the state |
| Records with an absolute amount | 16,429 | 89% of the division |
| Records that are conditional only | 78 | rank 7 of 7 |
| Distinct structures (WDIDs) | 15,689 | rank 5 of 7 |
| Well permit records | 43,581 | fourth most, 7% of the state |
| Ditch priorities dated before statehood (Aug. 1, 1876) | 653 | of 2,128 ditch priorities |
| Calls in effect, Oct. 2026 | 9 | dated snapshot, see below |
Counts pulled from the Colorado Division of Water Resources on October 16, 2026 DWR net amounts DWR well permits. A "record" is one decreed priority, so a ditch with three decrees counts three times; a well permit record is not a water right (see well permit vs. water right).
Colorado's oldest ditches, over its most-tapped aquifers
No division has older ditch priorities still decreed absolute. The most senior in Division 3 date from Apr. 10, 1852: the SALAZAR D on Rito Seco and the SAN LUIS PEOPLES D on Culebra Creek, followed by the SAN PEDRO D on Culebra Creek (1852), the ACEQUIA MADRE D on Costilla Creek (1853), the CERRO CNL on Costilla Creek (1853). All five are older than any ditch priority in the other six divisions.
The statute's long sentence for this division is worth reading. It does not stop at the Rio Grande drainage: it names the San Luis Valley creeks one by one, from San Luis and Saguache creeks to Sand or Medano Creek, and closes with every creek rising in the La Garita Mountains that flows east into the valley.
Underneath, the record is mostly wells: 13,772 of the division's records are wells, 75%, the highest share of any division. The two most-recorded sources are the valley's confined aquifer (6,514 records) and its unconfined aquifer (3,457).
The largest flow rights are not diversions at all. 4 of the five biggest are U.S. Forest Service rights decreed for minimum streamflow, led by USFS QP23W on the Conejos River at 2,828.6 cfs, which keep water in the stream. And the division has the fewest conditional-only records of the seven (78): few decrees here are for projects not yet built. For a well on a valley property, start with the well permit search.
What the statute puts in Division 3
Division 3: Division 3 consists of all lands in the state of Colorado in the drainage basin of the Rio Grande and all of its tributaries, and all lands in the drainage basins of the San Luis creek, Saguache creek, Tuttle creek, Carnero creek, La Garita creek, Sand or Medano creek, Big Spring creek, Little Spring creek, Mosca creek, Sierra Blanca creek, and all of their tributaries, and all lands in the drainage basins of all other creeks between Trinchera creek and Sand or Medano creek, and lands in the drainage basins of all other creeks which have their sources of water supply in the La Garita mountains and flow eastward into the San Luis valley.
The oldest ditch priorities in Division 3
The five most senior ditch priorities in the division that still carry an absolute amount, ranked by DWR's administration number, one per structure. Each name links to the record in DWR's own system.
| Structure | Source | Appropriated | Net absolute | Decreed uses |
|---|---|---|---|---|
| SALAZAR D | RITO SECO | Apr. 10, 1852 | 2 cfs | Storage, Irrigation, Recreation, Fishery, Stock, Augmentation, Other, Wildlife |
| SAN LUIS PEOPLES D | CULEBRA CREEK | Apr. 10, 1852 | 21 cfs | Irrigation |
| SAN PEDRO D | CULEBRA CREEK | Apr. 30, 1852 | 19.5 cfs | Irrigation |
| ACEQUIA MADRE D | COSTILLA CREEK | Jan. 1, 1853 | 5.05 cfs | Irrigation |
| CERRO CNL | COSTILLA CREEK | Jan. 1, 1853 | 5.5 cfs | Irrigation |
Ditches only: ranked across every structure type, the top of the list is taken by well and compact-accounting records dated earlier than any ditch (in some divisions, wells dated Dec. 31, 1850). Priority, not size, decides who is curtailed first in a call; read prior appropriation for why.
The largest decreed rights
Ranked by net absolute amount, flow and storage separately because cubic feet per second and acre-feet measure different things. Big flow numbers often belong to power plants, whitewater parks and minimum streamflow rights; the decreed uses column shows which.
Flow rights (cfs)
| Structure | Source | Appropriated | Net absolute | Decreed uses |
|---|---|---|---|---|
| USFS QP23W | CONEJOS RIVER | Mar. 2, 1907 | 2,828.6 cfs | Minimum streamflow |
| USFS QP37N | RIO GRANDE | Jun. 3, 1905 | 2,044 cfs | Minimum streamflow |
| USFS QP23U | CONEJOS RIVER | Jun. 3, 1905 | 1,736.6 cfs | Minimum streamflow |
| USFS QP27C | ALAMOSA RIVER | Mar. 2, 1907 | 1,113 cfs | Minimum streamflow |
| RGWUA RECHARGE PROJECT | RIO GRANDE | Nov. 1, 1959 | 1,018 cfs | Recharge |
Storage rights (acre-feet)
| Structure | Source | Appropriated | Net absolute | Decreed uses |
|---|---|---|---|---|
| SANCHEZ RES | CULEBRA CREEK | Jul. 28, 1908 | 77,213 AF | Irrigation |
| PLATORO RESERVOIR | CONEJOS RIVER | Jun. 1, 1905 | 53,571 AF | Storage, Irrigation, Industrial, Domestic, Augmentation, Other |
| CLOSED BASIN PROJECT | UNCONFINED SAN LUIS VALLEY | Jul. 31, 1963 | 43,520 AF | Irrigation, Industrial, Recreation, Fishery, Domestic, Minimum streamflow, Other, Wildlife |
| MILL CR RES | MILL CREEK | Jun. 3, 1903 | 35,728 AF | Irrigation, Recreation |
| SANTA MARIA RES | NORTH CLEAR CREEK | Sep. 22, 1902 | 21,653 AF | Irrigation, Augmentation, Recharge |
A structure's net absolute amount is DWR's sum of its decreed transactions; the decree itself, read through how to read a decree, controls what the right can actually divert and when.
What the water is decreed for, and what diverts it
| Decreed use | Records carrying it | Share |
|---|---|---|
| Irrigation | 10,421 | 56% |
| Domestic | 6,604 | 36% |
| Stock | 6,189 | 34% |
| Commercial | 829 | 4% |
| Wildlife | 724 | 4% |
| Fire | 537 | 3% |
| Structure type | Records | Share |
|---|---|---|
| Well | 13,772 | 75% |
| Ditch | 2,700 | 15% |
| Spring | 760 | 4% |
| Reservoir | 525 | 3% |
| Minimum Flow | 467 | 3% |
| Pipeline | 94 | 1% |
A record can carry several uses, so the shares add up to more than 100%. Use codes are DWR's own, as published with the net amounts data.
Streams, water districts and counties
Sources with the most decreed records: Groundwater: Confined San Luis Valley (6,514); Groundwater: Unconfined San Luis Valley (3,457); Groundwater: Rio Grande (1,475); Groundwater: Conejos River (930); Rio Grande (657); Saguache Creek (560). "Groundwater:" entries are wells drawing on that stream's alluvium or on a named aquifer.
| Water district | Decreed records |
|---|---|
| 20 | 9,238 |
| 21 | 1,136 |
| 22 | 1,980 |
| 24 | 541 |
| 25 | 1,014 |
| 26 | 1,690 |
| 27 | 1,532 |
| 35 | 1,320 |
The district number is the first two digits of every WDID in it, and each district is typically covered by a water commissioner. Districts are numbered across the state, not within the division, which is why the numbers here are not consecutive.
Counties with the most records here: Saguache (4,952); Rio Grande (4,346); Alamosa (3,783); Conejos (3,121); Costilla (1,545); Mineral (445); Hinsdale (208); Archuleta (9). Division lines follow drainage, so a county can appear in two divisions; place a parcel with the DWR map viewer rather than by county.
Calls in effect on October 16, 2026
When this page's data was pulled, DWR listed 9 active administrative records in Division 3 (9 calls). The 5 with the oldest priority dates are below, oldest priority first; an older calling priority curtails more junior rights on that stream.
| Stream | Calling right | Priority date | Call set |
|---|---|---|---|
| SANGRE DE CRISTO CREEK | SANGRE DE CRISTO D | May 31, 1863 | Mar. 23, 2026 |
| TRINCHERA CREEK | TRINCHERA GARLAND CANAL | May 31, 1867 | Sep. 30, 2026 |
| LA JARA CREEK | MC CUNNIFF D | Mar. 31, 1870 | Aug. 9, 2026 |
| SAN LUIS CREEK | HALL D 1 | May 1, 1870 | Mar. 30, 2026 |
| UTE CREEK | NEWTON D 2 | May 1, 1872 | Oct. 14, 2026 |
Water court, water clerk and division engineer
- Water court: Alamosa County Courthouse, Alamosa Colorado Judicial Branch · Oct. 2026. Applications are heard by the Division 3 water judge, designated each year by the Colorado Supreme Court C.R.S. § 37-92-203(2). The court's own page publishes the monthly resume of applications Water Division 3.
- Water clerk: in the office of the clerk of the district court, Alamosa County C.R.S. § 37-92-204(1)(b).
- Division engineer: office in Alamosa C.R.S. § 37-92-202(1)(b). The division engineer administers rights on the ground and places curtailment orders.
Interstate compacts codified in Title 37 that govern this division's rivers:
- Rio Grande Compact (with New Mexico and Texas) C.R.S. title 37, article 66
- Amended Costilla Creek Compact (with New Mexico) C.R.S. title 37, article 68
Each compact is an agreement between states, ratified by the General Assembly and codified in the article cited. See the Colorado River Compact for how that works on the largest of them.
The other six divisions
- Division 1: South Platte (58,418 decreed records)
- Division 2: Arkansas (20,249 decreed records)
- Division 4: Gunnison (22,396 decreed records)
- Division 5: Colorado (27,726 decreed records)
- Division 6: Yampa, White and North Platte (17,878 decreed records)
- Division 7: San Juan and Dolores (8,081 decreed records)
All seven side by side, with the map, are on Colorado's seven water divisions.
Common questions
Where is the water court for Division 3?
At the Alamosa County Courthouse in Alamosa. The water clerk keeps filings in the Alamosa County district court clerk's office (C.R.S. § 37-92-204(1)(b)), and the division engineer's office is in Alamosa.
What is the oldest water right in Colorado?
Among ditch priorities still decreed absolute, the most senior on DWR's records are in Division 3: the SALAZAR D and the SAN LUIS PEOPLES D, both appropriated Apr. 10, 1852, as recorded on October 16, 2026. Some well and compact-accounting records carry dates earlier than any ditch, which is why this ranking counts ditches only.
Is the San Luis Valley in Water Division 3?
Yes. C.R.S. § 37-92-201(1)(c) puts the Rio Grande basin and the San Luis Valley creeks it names, from San Luis Creek and Saguache Creek to the creeks flowing east out of the La Garita Mountains, in Division 3.
Which counties are in Water Division 3?
By number of decreed records: Saguache, Rio Grande, Alamosa, Conejos, Costilla, Mineral. Hinsdale and Mineral counties are split with other divisions, so place a specific parcel with the DWR Map Viewer.