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Instream flow rights

Since 1973 the Colorado Water Conservation Board has been the one body that can hold a water right to leave water in the stream. Each right is a reach between two points with a schedule of flows, or a natural lake level, and it sits in the priority line like any other decree. This is the Board's own tabulation, joined to the site's structure dossiers.
288
Division 1 reaches · 1,738 mi · 39 lakes
194
Division 2 reaches · 933 mi · 87 lakes
153
Division 3 reaches · 1,065 mi · 48 lakes
405
Division 4 reaches · 2,539 mi · 84 lakes
518
Division 5 reaches · 2,355 mi · 150 lakes
261
Division 6 reaches · 1,429 mi · 45 lakes
113
Division 7 reaches · 865 mi · 49 lakes

Reach lines from the CDSS ISF_Reach layer; click a line for its case and schedule. The same layer is a chip on the statewide map.

By water district

DistrictReachesMilesLakes
WD1 South Platte: Greeley to Balzac 24.9
WD3 Cache La Poudre River 68409.74
WD4 Big Thompson River 1474.7
WD5 St. Vrain Creek 23112.69
WD6 Boulder Creek 36234.714
WD7 Clear Creek 26127.52
WD8 South Platte Cheesman to Denver Gage 1182.4
WD9 Bear Creek 1683.0
WD23 Upper South Platte 41313.16
WD48 Laramie River 1783.32
WD65 Arikaree River 530.7
WD76 Sand Creek 16.2
WD80 North Fork of South Platte 28175.22
WD10 Fountain Creek 1265.9
WD11 Arkansas: Headwaters to Salida 92409.046
WD12 Arkansas: Salida to Portland 35215.66
WD13 Wet Mountain Valley 2593.431
WD15 Saint Charles 853.3
WD16 Cucharas River 625.41
WD18 Apishapa River 14.5
WD19 Purgatoire River 425.5
WD67 Arkansas: Las Animas to Stateline 15.1
WD79 Huerfano River 1035.33
WD20 Rio Grande 78523.113
WD21 Alamosa La Jara 11102.53
WD22 Conejos Creek 22152.418
WD25 San Luis Creek 1456.48
WD26 Saguache Creek 15125.13
WD27 Carnero Creek 967.7
WD35 Trinchera Creek 437.83
WD28 Tomichi Creek 50375.76
WD40 North Fork/Tribs. 59354.216
WD41 Lower Uncompahgre River 431.7
WD42 Lower Gunnison River 557.6
WD59 East River Basin 124688.142
WD60 San Miguel River Basin 45255.92
WD61 Paradox Creek 216.5
WD62 Upper Gunnison River 83532.912
WD63 Dolores River Basin 17141.7
WD68 Upper Uncompahgre River 1582.46
WD73 Little Dolores River 12.5
WD36 Blue River Basin 60245.915
WD37 Eagle River Basin 79389.748
WD38 Roaring Fork River Basin 92448.676
WD39 Rifle/Elk/Parachute Creeks 28157.3
WD45 Divide Creek 955.6
WD50 Muddy/Troublesome Creeks 954.2
WD51 Upper Colorado/Fraser Rivers 173492.79
WD52 Piney/Cottonwood Creeks 16120.3
WD53 Tribs. North of Colorado River 34250.32
WD70 Roan Creek Basin 438.2
WD72 Lower Colorado River 14102.6
WD43 White River Basin 52340.21
WD44 Lower Yampa River 24148.6
WD47 North Platte River Basin 34185.330
WD54 Slater/Timberlake Creeks 25120.7
WD56 Green River Basin 421.8
WD57 Middle Yampa River 640.6
WD58 Upper Yampa River 116571.914
WD29 San Juan River Basin 16106.73
WD30 Animas River Basin 41202.820
WD31 Los Pinos River Basin 552.626
WD32 McElmo Creek Basin 223.2
WD33 La Plata River Basin 622.8
WD34 Mancos River Basin 426.0
WD69 Disappointment Creek Basin 259.5
WD71 West Dolores Creek/Tribs. 24261.7
WD77 Navajo River Basin 117.0
WD78 Piedra River Basin 1293.1

Read the sources

Tabulation fetched 2026-10-25 from Colorado's open-data copy of the DWR ISF tool (2434 rows). Termini and seasons are the Board's; the decreed amounts are in each right's dossier. Recreational in-channel diversions (the whitewater parks) are municipal rights, not CWCB rights, and are not on this page yet. Advisory, not administration. Report a problem →