IRRIGATION IN NORTHERN COLORADO. 
9 
APRIL 
10 20 
MAY 
10 20 
JUNE 
10 20 
AUGUST SEPT. 
10 20 10 20 
normal run-off and 25,000 acre-feet as returned seepage. The greater 
part of this flow is intercepted by canals and reservoirs before it 
reaches the river. 
The foreign water turned into the Cache la Poudre River has 
averaged 35,000 acre-feet for a number of years. The Grand River 
ditches of the Water 
Supply & Storage" 
Co. bring over about 20 oo 
11,500 acre-feet |500 
from the Grand 
River drainage area. 
Ditches of the 500 
Water Supply & o 
Storage Co. and the 
North Poudre Irri- 
gation Co. draw 
about 3,500 acre- 
feet from the Mich- 
igan River drainage 
area. The remain- 
der, 20,000 acre- 
feet, is brought 
over from the La- 
ramie River drain- ° i450 ° 
age area by the 
Skyline Ditch of 
the Water Supply 
& Storage Co., the 
Greeley-Poudre ir- 
rigation district's 
tunnel, the Sand 
Creek feeder of the 
Worster Reservoir, 
and others. The 
greater part of this 
foreign water is 
diverted by the 
North Poudre Val- 
ley, and the Larimer County Canals. The Greeley-Poudre district, 
having no land under irrigation, usually sells the tunnel water to 
the highest bidder. The record of discharge of the river at the 
canyon rating station includes all foreign water passing that point. 
The amount of water obtained by pumping from wells does not 
exceed 5,000 acre-feet annually and is generally used late in the 
2000 
1500 
1000 
^5500 
g5000 
4000 
3500 
3000 
2500 
1500 
500 
Fig. 2. — Discharge of tlie Cache la Poudre River at the rat- 
ing station at the mouth of the canyon during the period of 
the investigation compared with the average for approxi- 
mately 35 years. 
