From the sounds of your weather description, you must not be near Vancouver. If I'm not mistake, there are areas farther east where there is very little rainfall during the summer.

If you're looking for something that doesn't need as much water, some native grasses might work well.

One option would be buffalo grass, although I'm not sure how well it would do with your winters. It would do fine during the summer heat, but might stay dormant for a long time. I'm not sure if it's native as far west as you are, but it may still grow there. It can be somewhat difficult to start from seed, and expensive to start from sod (plugs are an option and are between sod and seed in cost and ease of establishment). Buffalograss spreads by stolons. If you don't mind a lawn that is a little long, it can be left without mowing, because it usually only gets about 10 cm tall. If you get a variety that produces seeds, it can be a problem for people with allergies.

Streambank and western wheatgrass are cool season grasses that require very little water to grow. I think western wheatgrass is better looking than streambank wheatgrass, but it is harder to get started and much more expensive. Both spread by rhizomes.

A non-native wheatgrass that is much less expensive and is easy to get started is crested wheatgrass. Older varieties are bunchgrasses, but newer varieties (Ephraim and Roadcrest come to mind) spread by rhizomes.

If you're looking for more traditional choices, fescues tend to require less water than Kentucky bluegrass. Some varieties grow very slowly and may stay short enough that they don't require mowing. Most varieties are bunchgrasses, and some have fairly wide leaves. Newer varieties have finer leaves and some newer varieties spread slowly through rhizomes.