When it becomes too dry, bermuda grass just becomes dormant. Finally, there are water conservers. These plants have ways to reduce water loss. Manzanita has leaves with a vertical orientation which reduces solar radiation and thus transpiration. Water loss from plant leaves is called transpiration.
Oaks have leaf surface hairs that reduce air movement across leaves.
Other plant adaptations include small leaves, grey color, and leathery leaves. There are several things you can do for more efficient watering. First, apply two to four inches of mulch under the plant canopy. Mulch is one of the best ways to maintain soil moisture within the zone of actively growing roots. It can consist of pine needles, leaves, bark, wood chips, straw, compost, or any other organic materials.