Tables of vegetative water use in California
The following tables were taken from Vegetative Water Use in California, 1974, Bulletin No. 113-3, April 1975, State of California, The Resources Agency, Department of Water Resources.
- Table 1. Summary of average pan evaporation in California.
- Table 6. Summary of estimated potential evapotranspiraiton in California.
Table 1. Summary of monthly average pan evaporation in California climate zones, in inches.1
| North-eastern Mountain Valleys | North Coast Coastal Valleys and Plains | North Coast Interior Valleys | Sacramento Valley | San Joaquin Valley | Central Coast Coastal Valleys and Plains | Central Coast Interior Valleys | South Coastal Valleys and Plains2 | South Coast Interior Valleys2 | |
|---|---|---|---|---|---|---|---|---|---|
| ZONE | 3 | 1 | 2 | 4 | 5 | 8 | 6 | 9 | 10 |
| Jan | 0.8 | 0.7 | 1.2 | 1.5 | 1.3 | 2.5 | 2.3 | 2.5 | 2.4 |
| Feb | 1.3 | 1.3 | 1.6 | 2.4 | 2.3 | 2.9 | 2.9 | 3.3 | 3.2 |
| Mar | 2.8 | 2.6 | 3.1 | 3.9 | 4.2 | 4.1 | 4.3 | 4.1 | 4.4 |
| Apr | 4.8 | 3.2 | 4.4 | 5.7 | 5.9 | 5.1 | 5.6 | 4.9 | 5.5 |
| May | 6.4 | 4.2 | 6.4 | 7.5 | 8.3 | 6.0 | 7.3 | 5.8 | 6.5 |
| Jun | 7.5 | 4.6 | 7.6 | 9.3 | 9.6 | 6.3 | 7.9 | 6.6 | 7.7 |
| Jul | 10.1 | 4.5 | 9.1 | 10.1 | 10.0 | 6.8 | 8.6 | 7.0 | 8.8 |
| Aug | 9.0 | 4.3 | 8.0 | 8.6 | 8.5 | 6.1 | 7.7 | 7.0 | 8.6 |
| Sep | 6.3 | 3.6 | 6.0 | 6.8 | 6.3 | 5.0 | 6.2 | 5.8 | 6.8 |
| Oct | 3.8 | 2.3 | 3.6 | 4.6 | 4.4 | 4.3 | 5.0 | 4.6 | 5.1 |
| Nov | 1.3 | 1.5 | 1.6 | 2.2 | 2.1 | 3.0 | 3.1 | 3.6 | 3.2 |
| Dec | 0.7 | 1.0 | 1.0 | 1.4 | 1.0 | 2.1 | 2.1 | 3.1 | 2.6 |
| M-O3 | 50.7 | 29.3 | 48.2 | 56.5 | 57.2 | 43.7 | 52.6 | 45.8 | 53.4 |
| J-D4 | 54.8 | 33.8 | 53.6 | 64.0 | 63.9 | 54.2 | 63.0 | 58.3 | 64.8 |
|
1Evaporation from USWB - Class "A" pans located in irrigated pasture (or comparable) environment. 2No evaporation data (irrigated pasture environment) available. Monthly evaporation rates listed are subjective estimates based upon dry land pan evaporation and other climatological data. 3March through October (principal growing season) 4January through December |
Table 6. Summary of estimated monthly potential evapotranspiraiton in California climate zones, in inches.1, 2
| North-eastern Mountain Valleys | North Coast Coastal Valleys and Plains | North Coast Interior Valleys | Sacramento Valley | San Joaquin Valley | Central Coast Coastal Valleys and Plains | Central Coast Interior Valleys | South Coast Coastal Valleys and Plains3 | South Coast Interior Valleys3 | Southern California Desert4 | |
|---|---|---|---|---|---|---|---|---|---|---|
| ZONE | 3 | 1 | 2 | 4 | 5 | 8 | 6 | 9 | 10 | 11 |
| Jan | 0.6 | 0.5 | 0.8 | 1.1 | 0.9 | 1.8 | 1.6 | 1.8 | 1.7 | 2.7 |
| Feb | 1.0 | 1.0 | 1.2 | 1.8 | 1.7 | 2.1 | 2.1 | 2.4 | 2.4 | 3.6 |
| Mar | 2.1 | 2.0 | 2.4 | 3.0 | 3.2 | 3.1 | 3.3 | 3.1 | 3.3 | 5.9 |
| Apr | 3.7 | 2.5 | 3.4 | 4.4 | 4.5 | 3.9 | 4.3 | 3.8 | 4.2 | 7.6 |
| May | 5.0 | 3.3 | 5.0 | 5.8 | 6.5 | 4.7 | 5.7 | 4.5 | 5.1 | 10.1 |
| Jun | 5.8 | 3.6 | 5.9 | 7.3 | 7.5 | 4.9 | 6.2 | 5.1 | 6.0 | 11.4 |
| Jul | 7.9 | 3.5 | 7.1 | 7.9 | 7.8 | 5.3 | 6.7 | 5.5 | 6.9 | 11.6 |
| Aug | 7.0 | 3.4 | 6.2 | 6.7 | 6.6 | 4.8 | 6.0 | 5.5 | 6.7 | 9.6 |
| Sep | 4.9 | 2.8 | 4.6 | 5.2 | 4.8 | 3.8 | 4.8 | 4.5 | 5.2 | 8.5 |
| Oct | 2.8 | 1.7 | 2.7 | 3.4 | 3.3 | 3.2 | 3.8 | 3.4 | 3.8 | 6.3 |
| Nov | 0.9 | 1.1 | 1.2 | 1.6 | 1.5 | 2.2 | 2.3 | 2.6 | 2.3 | 3.5 |
| Dec | 0.5 | 0.7 | 0.7 | 1.0 | 0.7 | 1.5 | 1.5 | 2.2 | 1.8 | 2.0 |
| M-O | 39.2 | 22.8 | 37.3 | 43.7 | 44.3 | 33.7 | 40.8 | 35.4 | 41.2 | 71.0 |
| J-D | 42.2 | 26.1 | 41.2 | 49.2 | 49.0 | 41.3 | 48.3 | 44.4 | 49.4 | 82.8 |
|
1Potential ET = ET of grass. 2Calculated from statewide average ET/Ep coefficient and area average Ep, except as noted. 3No evaporation data (irrigated pasture environment) available. PET estimates based upon estimated evaporation. 4An estimate of ET-grass for Imperial Valley. Calculated by W. 0. Pruitt, U.C. Davis, from ET by alfalfa (excluding 2 weeks following cutting) as observed by Robert D. LeMert, USDA-ARS, Brawley. (A 10-15% lower ET by grass than by alfalfa was assumed.) 5March through October (principal growing season). 6January through December. |
Reference: Vegetative Water Use in California, 1974. State of California, The Resources Agency, Department of Water Resources. Bulletin No. 113.3, April 1975.