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Water Division 1: the South Platte
Water Division 1 is the South Platte basin: all Colorado land draining to the South Platte, the Big Laramie, the Arikaree, the Republican forks, the Smoky Hill, and Sandy and Frenchman creeks. C.R.S. § 37-92-201(1)(a)
It holds 58,418 decreed water-right records, more than any other division and 34% of the state. Its water court sits in Greeley, and most of its rights are not ditches at all but wells.
Division 1 at a glance
| Measure | Division 1 | Among the seven |
|---|---|---|
| Decreed water-right records | 58,418 | most, 34% of the state |
| Records with an absolute amount | 43,641 | 75% of the division |
| Records that are conditional only | 3,022 | rank 2 of 7 |
| Distinct structures (WDIDs) | 43,256 | rank 1 of 7 |
| Well permit records | 347,256 | most, 53% of the state |
| Ditch priorities dated before statehood (Aug. 1, 1876) | 899 | of 3,180 ditch priorities |
| Calls in effect, Oct. 2026 | 17 | 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).
A groundwater division with an 1859 core
Division 1 is usually described by its rivers, but its records describe wells. Wells and well fields account for 40,287 of the 58,418 decreed records here, 69%. The single most-recorded source is not the South Platte itself but the groundwater alongside it, and three more of the top sources are bedrock formations: the Laramie-Fox Hills, the Arapahoe and the Denver, which Title 37 names together with the Dawson-Arkose C.R.S. § 37-90-103(6)(a). Douglas County, not Weld, carries the most records in the division (12,345).
The surface-water core is older than the state. The most senior ditch priority still decreed absolute is the LOWER BOULDER DITCH on Boulder Creek, appropriated Oct. 1, 1859, and 899 ditch priorities here predate statehood. Seniority that old is still enforced: on October 16, 2026 the most senior call in the division was on South Boulder Creek, by a right with an appropriation date of May 1, 1860.
The groundwater count matters for anyone buying property here: a well permit is not a decreed right, and Division 1 alone has 347,256 well permit records, 53% of the state's total.
What the statute puts in Division 1
Division 1: Division 1 consists of all lands in the state of Colorado in the drainage basins of the South Platte river, the Big Laramie river, the Arikaree river, the north and south forks of the Republican river, the Smokey Hill river, Sandy and Frenchman creeks, and streams tributary to said rivers and creeks.
The oldest ditch priorities in Division 1
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 |
|---|---|---|---|---|
| LOWER BOULDER DITCH | BOULDER CREEK | Oct. 1, 1859 | 24.98 cfs | Irrigation, Municipal, Commercial, Industrial, Recreation, Fishery, Fire, Domestic, Augmentation, Other, Wildlife, All beneficial uses |
| MCBROOM DITCH | BEAR CREEK | Nov. 1, 1859 | 3.42 cfs | Irrigation, Municipal, All beneficial uses |
| SMITH GOSS DITCH | BOULDER CREEK | Nov. 15, 1859 | 29.22 cfs | Irrigation |
| HOWELL DITCH | BOULDER CREEK | Dec. 1, 1859 | 5 cfs | Irrigation |
| MEAD & POLAR STAR DITCH | NORTH CLEAR CREEK | Dec. 31, 1859 | 69.2 cfs | Industrial, Other |
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 |
|---|---|---|---|---|
| FARMERS HIGHLINE CANAL | CLEAR CREEK | Dec. 1, 1910 | 1,441.32 cfs | Storage |
| JACKSON LAKE RES | SOUTH PLATTE RIVER | Dec. 31, 1929 | 1,357.87 cfs | Irrigation, Augmentation, Recharge |
| RIVERSIDE CANAL | SOUTH PLATTE RIVER | Oct. 25, 1910 | 1,000 cfs | Storage |
| LARIMER WELD IRR CANAL | CACHE LA POUDRE RIVER | Sep. 9, 1901 | 1,000 cfs | Storage |
| BARNES DITCH | BIG THOMPSON RIVER | Jan. 14, 1893 | 1,000 cfs | Storage |
Storage rights (acre-feet)
| Structure | Source | Appropriated | Net absolute | Decreed uses |
|---|---|---|---|---|
| BONNY RES | SOUTH FORK REPUBLICAN RIVER | Dec. 3, 1948 | 351,460 AF | Storage, Irrigation, Recreation, Fishery |
| ANTERO RES | SOUTH FORK SOUTH PLATTE RIVER | Oct. 8, 1907 | 85,600 AF | Irrigation |
| ELEVEN MILE RES | SOUTH PLATTE RIVER | Jul. 10, 1926 | 81,917 AF | Irrigation, Municipal, Fire, Domestic |
| CHEESMAN RES | SOUTH PLATTE RIVER | Dec. 31, 1929 | 79,064 AF | Irrigation, Municipal, Commercial, Industrial, Fire, Domestic, Augmentation, Power generation |
| NORTH STERLING RES | SOUTH PLATTE RIVER | Jun. 15, 1908 | 69,446 AF | Irrigation, Municipal, Commercial, Industrial, Recreation, Fishery, Fire, Domestic, Stock, Augmentation, Wildlife |
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 | 31,606 | 54% |
| Domestic | 28,675 | 49% |
| Stock | 19,786 | 34% |
| Commercial | 17,624 | 30% |
| Augmentation | 17,418 | 30% |
| Municipal | 16,289 | 28% |
| Structure type | Records | Share |
|---|---|---|
| Well | 27,418 | 47% |
| Well Field | 12,869 | 22% |
| Ditch | 6,222 | 11% |
| Reservoir | 5,976 | 10% |
| Spring | 2,182 | 4% |
| Pipeline | 1,393 | 2% |
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: South Platte River (16,031); Groundwater: Laramie Fox Hills (4,548); Groundwater: Arapahoe (4,417); Groundwater: Denver (3,533); South Platte River (3,048); Cache La Poudre River (1,851). "Groundwater:" entries are wells drawing on that stream's alluvium or on a named aquifer.
| Water district | Decreed records |
|---|---|
| 01 | 8,956 |
| 02 | 7,331 |
| 03 | 4,905 |
| 04 | 1,819 |
| 05 | 2,403 |
| 06 | 2,727 |
| 07 | 3,627 |
| 08 | 16,434 |
| 09 | 2,565 |
| 23 | 3,195 |
| 48 | 159 |
| 49 | 52 |
| 64 | 2,706 |
| 65 | 133 |
| 76 | 16 |
| 80 | 1,390 |
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: Douglas (12,345); Weld (7,181); Jefferson (5,927); Larimer (5,704); Elbert (4,530); Boulder (4,269); Park (3,565); Adams (3,538). 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 17 active administrative records in Division 1 (16 calls, 1 nonconsumptive call). 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 |
|---|---|---|---|
| SOUTH BOULDER CREEK | JONES DONNELLY DITCH | May 1, 1860 | Oct. 15, 2026 |
| RALSTON CREEK | BLUNN RES | Jun. 6, 1861 | Oct. 14, 2026 |
| BOULDER CREEK | GREEN DITCH | Sep. 15, 1862 | Oct. 16, 2026 |
| TURKEY CREEK | INDEPENDENT HIGHLINE DITCH | Nov. 1, 1862 | Oct. 16, 2026 |
| SOUTH PLATTE RIVER | LAST CHANCE DITCH 2 | Mar. 3, 1868 | Oct. 14, 2026 |
Water court, water clerk and division engineer
- Water court: Weld County Courthouse, Greeley Colorado Judicial Branch · Oct. 2026. Applications are heard by the Division 1 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 1.
- Water clerk: in the office of the clerk of the district court, Weld County C.R.S. § 37-92-204(1)(b).
- Division engineer: office in Greeley 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:
- South Platte River Compact (with Nebraska) C.R.S. title 37, article 65
- Republican River Compact (with Kansas and Nebraska) C.R.S. title 37, article 67
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 2: Arkansas (20,249 decreed records)
- Division 3: Rio Grande (18,451 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 1?
The Division 1 water court sits at the Weld County Courthouse in Greeley, and the water clerk keeps the division's filings in the Weld County district court clerk's office (C.R.S. § 37-92-204(1)(b)). The division engineer's office is also in Greeley.
What is the oldest water right in Division 1?
Among ditch priorities still decreed absolute, the most senior is the LOWER BOULDER DITCH on Boulder Creek, appropriated Oct. 1, 1859, as recorded by DWR on October 16, 2026. The next most senior ditches, on Boulder Creek, Bear Creek and the Clear Creek drainage, also date from the last months of 1859.
Which counties are in Water Division 1?
Division lines follow drainage, not counties, so some counties are split. By number of decreed records the largest are Douglas, Weld, Jefferson, Larimer, Elbert, Boulder. To place a specific parcel, use the DWR Map Viewer with the division layer on.
Why does Division 1 have so many water rights?
Mostly because of wells. Wells and well fields are 69% of the division's 58,418 decreed records, drawing on the South Platte alluvium and the Denver Basin bedrock formations, on top of a dense network of ditches with priorities back to 1859.