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Bishop, Keeler, and South Owens Lake have CIMIS irrigation stations that can be used to determine with some accuracy how much water is needed based on weather. These can be complicated to use, however. These tables, developed by a previous Farm Advisor, provide a good place to start. Please use common sense and monitor your plants’ conditions. Adjust as needed.
Note: A sprinkler’s output can exceed your soil’s maximum infiltration rate, especially in clay. You may need to break up your irrigation into small, repeated cycles to avoid runoff. Monitor your irrigation to see if this happens to you.
Lawns, Flowers, Vegetable Gardens, Newly Planted Trees
| Daily Temp. °F | Sand | Sandy Loam | Clay | |||
How much? | How often? | How much | How often? | How much? | How often? | |
| 90 to 100°+ |
¾” | 2 days |
1” | 3 days |
1 ½” | 5 days |
| 80 to 90° | 3 days | 4 days | 6 days | |||
| 70 to 80° | 4 days | 5 days | 8 days | |||
| 60 to 70° | 5 days | 7 days | 10 days | |||
Shrubs, Vines, Pasture, Trees Under 3 Years Old
| Daily Temp. °F | Sand | Sandy Loam | Clay | |||
How much? | How often? | How much | How often? | How much? | How often? | |
| 90 to 100°+ |
1 ½” | 5 days |
2” | 7 days |
3” | 10 days |
| 80 to 90° | 6 days | 8 days | 12 days | |||
| 70 to 80° | 8 days | 10 days | 15 days | |||
| 60 to 70° | 10 days | 14 days | 20 days | |||
Mature Fruit and Shade Trees Over 3 Years Old
| Daily Temp. °F | Sand | Sandy Loam | Clay | |||
How much? | How often? | How much | How often? | How much? | How often? | |
| 90 to 100°+ |
2 ¼” | 7 days |
3” | 10 days |
4 ½” | 15 days |
| 80 to 90° | 9 days | 12 days | 18 days | |||
| 70 to 80° | 11 days | 15 days | 23 days | |||
| 60 to 70° | 15 days | 20 days | 30 days | |||
Average Monthly Inches of Water Evapotranspiration (ETo) for Bishop, CA
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
1.77 | 2.60 | 4.58 | 5.95 | 7.04 | 7.63 | 8.12 | 7.36 | 5.43 | 4.05 | 2.36 | 1.75 |
This document was adapted from R. Gildersleeve's original and CIMIS data.
