Lawn grass often requires 35 to 40 inches of irrigation water during the summer. Natural rainfall in northwest Oregon isn't usually adequate to keep a lawn green. Lawns require fertilizers, pesticides and herbicides to stay lush, but birds can become sick from eating insects treated with chemicals. The most practical way to reduce the environmental effects is to reduce the size of the lawn and use groundcovers. Lawn can be replaced by noninvasive groundcovers, zen gardens and statuary. Decks and patios can also be extended.