WSPC02454

• File Number: 8283.200
• Description: Colorado River Basin-Colorado River Computer Models-Colorado River Decision Support System
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 12/1/1995
• Title: San Juan River Basin Modeling-San Juan Special Water Right Operations
• Water Supply Pro - Doc Type: Report/Study

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TRANSBASIN DIVERSIONS

In Irrigation Division 7. there are six structures which export water from the San Juan
basin, including its tributaries. The most significant are the diversions by the San Juan Chama
Project which is discussed in detail elsewhere in this documentation. The remaining structures are
briefly discussed below.

The Treasure Pass Diversion Ditch (WDID 294669) diverts near the top of Wolf Creek Pass
from the headwaters of Wolf Creek. a tributary of the West Fork of the San Juan River. It is
owned by private individuals who use the water for irrigation in the San Luis Valley. The water
is delivered into the South Fork of the Rio Grande (Irrigation Division 3). Reasonably complete
records of the historic diversions through this structure have been maintained by the USGS
(through 1981) and the Division of Water Resources 11981 to date). The structure typically
diverts during the runoff months of June and July and over the 20-year period 1974-1993, the
average annual diversions were approximately 235 acre-feet.

The Don Lafont Ditches No.1 and No.2 (WDID 784671) divert from the headwaters of
the East Fork of the Piedra River and deliver the water into tributaries of the Rio Grande (Irrigation
Division 3). The structures are owned and operated by the Colorado Division of Wildlife which
uses the imported water for numerous wildlife programs in the San Luis Valley. Reasonably
complete records of the historic diversions have been maintained by the Division of Water
Resources. The majority of the water is diverted during the runoff months of June and July,
occasionally extending from May to August. The average annual diversion has been approximately
225 acre,feet.

The Williams Creek - Squaw Pass Diversion (WDID 784672) diverts water from the
headwaters of Williams Creek, a tributary of the Piedra River and delivers it into the headwaters
of Squaw Creek. a tributary of the Rio Grande (Irrigation Division 3). The ditch is owned and
operated by numerous individuals that use the water for irrigation and augmentation. Intermittent
records of the historic diversions have been maintained by the USGS (through 1980) and the
Division of Water Resources (1980 to date). The majority of the water is diverted during the peak
runoff month of June and July and have averaged about 170 acre-feet annually.

The Weminuche Pass Ditch (WDID 3146371 diverts water from the headwaters of the Los
Pinos River (Pine River) and delivers it into Weminuche Creek, a tributary of the Rio Grande
(Irrigation Division 3). The ditch is owned and operated by the Colorado Division of Wildlife which
uses the water for various wildlife programs. Reasonably complete records of the historic
diversions have been maintained by the USGS (through 1982) and the Division of Water Resources
(1982 to date). The majority of the diversions are made during the months of May. June and July
and average approximately 1,360 acre-feet per year.

The Pine River - Weminuche Pass Ditch (WOlD 314638) also diverts from the headwaters
of the Los Pinos River into Weminuche Creek, a short distance from WOlD 314637. The structure
is owned in part by private individuals and in part by the San Luis Valley Water Conservancy
District. The water is used for irrigation and for augmenting wells in the San Luis Valley.
Reasonably complete records of the historic diversions have been maintained by the USGS
(through 1982) and the Division of Water Resources (1982 to date). Average annual diversions
are approximately 430 acre-feet per year.

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