Lawn-type grasses aren't native to the (very arid, water-poor) ecosystem there and so having a lawn is really going to demand significant inputs. Especially when well-irrigated, your lawn is however being recognized by the native animals as a rich, highly nutritious, and high-moisture-containing source of food - so it's understandable that their instincts are driving them to take every opportunity to benefit from what you're providing. But I should first ask to clarify - Are these wild, native rabbits or non-native domesticated varieties? Either way, if you must have a lawn, you'll need to exclude things that eat grass. If you're only having (native rabbit) conflicts, then a rabbit-proof fence will be the most effective solution over the long term. Rabbit-proof fencing should be small-aperture welded wire (1" openings or less) that extends above ground 2-3 feet and ideally should extend below ground 6" deep and at least a foot out (an L-shaped undiggable apron extending out towards the rabbits) to prevent overdigging. If by chance the rabbits you're encountering are non-native, domestic stock (whether owned or free-living feral), you should also contact your City/County about removal and probably a non-release ordinance to prevent further growth of the population. Domestic-origin rabbits can and have become very problematic for the people and wildlife of numerous communities across the country, including a couple in Oregon - which is why I want to ask and clarify.