The following tables are estimates of water use for Bishop, CA based on CIMIS weather data, Station #35.
The first table shows estimated plant use for each month. The second shows how much you can expect to irrigate. Both show values in inches. Obviously you will need to apply water more than once a week.
Irrigation efficiency here is not very high, which represents a typical yard in the Bishop area.
Your yard's needs will probably vary from Table 2, but it's a good place to start.
Table 1. Plant water needs in inches / month.
| Month | Tall Fescue Lawn | Bermudagrass Lawn | Drought-Tolerant Plants |
|---|---|---|---|
| Jan | 1.50 | 1.13 | 0.47 |
| Feb | 2.02 | 1.52 | 0.63 |
| Mar | 3.81 | 2.85 | 1.19 |
| Apr | 4.88 | 3.66 | 1.52 |
| May | 5.94 | 4.46 | 1.86 |
| Jun | 6.23 | 4.67 | 1.95 |
| Jul | 4.41 | 3.31 | 1.38 |
| Aug | 5.76 | 4.32 | 1.80 |
| Sep | 4.36 | 3.27 | 1.36 |
| Oct | 3.97 | 2.98 | 1.24 |
| Nov | 1.81 | 1.36 | 0.57 |
| Dec | 1.32 | 0.99 | 0.41 |
Table 2. Estimated irrigation requirement for a typical yard in inches / month.
Your yard will probably vary from this. Lawn irrigation efficiency herein is 45% and the drought-tolerant plants is 85%.
| Month | Tall Fescue Lawn | Bermudagrass Lawn | Drought-Tolerant Plants |
|---|---|---|---|
| Jan | 1.12 | 0.29 | - |
| Feb | 2.39 | 1.26 | - |
| Mar | 7.13 | 5.02 | 0.70 |
| Apr | 10.37 | 7.66 | 1.54 |
| May | 12.87 | 9.57 | 2.01 |
| Jun | 13.55 | 10.09 | 2.14 |
| Jul | 9.54 | 7.09 | 1.48 |
| Aug | 12.61 | 9.41 | 2.02 |
| Sep | 8.99 | 6.57 | 1.24 |
| Oct | 8.18 | 5.97 | 1.12 |
| Nov | 3.27 | 2.27 | 0.27 |
| Dec | 1.31 | 0.58 | -0.37 |