Warm-season and cool-season turfgrasses were not reviewed by the WUCOLS IV regional committees. Data here is from Harivandi, et. al., 2009 publication, Managing Turgrasses During Drought. The complete publication is cited below.
Water requirements for Warm-season and Cool-season Turfgrasses
| Type | Common name | Optimal Irrigation* (% ET0) | Deficit Irrigation** (% ET0) |
| Warm season | Common bermudagrass | 60 | 40 |
| Hybrid bermudagrass | 60 | 40 | |
| St. Augustinegrass | 60 | 40 | |
| Seashore paspalum | 60 | 40 | |
| Zoysiagrass | 60 | 40 | |
| Buffalograss | 60 | 40 | |
| Kikuyugrass | 60 | 40 | |
| Cool Season | Tall fescue | 80 | 60 |
| Perennial ryegrass | 80 | 60 | |
| Kentucky bluegrass | 80 | 60 | |
| Fineleaf fescues | 80 | 60 | |
| Creeping bentgrass | 80 | 60 | |
| Rough bluegrass | 80 | 60 |
* Optimum irrigation is the amount of water needed for most efficient growth, maximum quality, and best appearance.
** Deficit irrigation provides sufficient water to maintain adequate appearance with less growth (relative to optimum irrigation).
Note: For turfgrass blends, the species with the highest water requirement will generally determine the irrigation level for the blend. For instance, if a blend contained perennial ryegrass and common bermudagrass, then it would be irrigated at 80% ET0 for optimal performance. If the sward appears to be overwatered, however, then a downward adjustment in irrigation level would be warranted.
Harivandi, A. M. 2009. Managing Turfgrass During Drought. Oakland: University of California Agriculture and Natural Resources Publication 8395, https://anrcatalog.ucanr.edu/pdf/8395.pdf.