Did you know that there are hundreds of miles of irrigation ditches and canals throughout Paradise Valley? Only 15% of the water diverted (about 5 feet of water per acre annually) is actually used for irrigation. The remainder goes in to groundwater tables or returns to the main stem of the Yellowstone. These ditches and canals create habitat for plants and wildlife. They also act like beavers and help store water for later use - what is commonly referred to as groundwater recharge. As water flows through ditches, some of it moves down through the soil where it eventually collects in to what we call the water table. Then it slowly moves via gravity where some of it eventually meets back up with the Yellowstone River and flows down river. This "slower" water flow helps contribute water flows later in the summer when snowpack melt is at a minimum.
The blue lines in the below satellite image of Paradise Valley show various ditches and canals that have been built over the last 150 years (Livingston is on the right and Gardiner is in the upper left).
Click here or on the image below to watch a 3D flyover of Paradise Valley and visualize how these ditches and canals fit in to the Upper Yellowstone ecosystem.
Here are some additional facts about irrigation in our area.
Roughly 25,370 irrigated acres of pasture and hay are in Paradise Valley within Park County, about 10% of the total 244,300 privately owned acres (over 50% of the remaining land is public).
Irrigated acres (after livestock use) can produce up to 6x the forage for wildlife than non-irrigated lands.
The 30 year average in-stream flow of water on the Yellowstone River at Corwin Springs is 2M acre/ft annually from April-Sep. Roughly 80k acre/ft (4%) of that is used for irrigation annually.
"In 1957, construction of a 525 foot siphon under the Yellowstone River brought water from the west-side Park Branch Canal to the east side of the Yellowstone River. Thus was an additional 3,000 acres irrigated in Paradise Valley. In 1960, a section of Highway 89 was built over the siphon (MM 33.9E)."
- Doris Whithorn, Paradise Valley on the Yellowstone, p. 89.
This siphon still operates today, providing irrigation and groundwater storage to the east side of the lower half of Paradise Valley.