A prolonged drought can make your lawn suffer damage rather quickly. During periods where you must cut back on water usage, you can still care for your lawn and keep the grass from dying off completely. If you can occasionally water your lawn, do so in the morning so less will evaporate. When you do water, use a soaker hose on areas where the sun is most intense and on areas you most want to protect. Keep your grass mowed high so roots will grow deeper. Try to keep off of the lawn as much as possible since foot traffic can speed up damage. Droughts which are predicted to last for extended periods will lead to brown lawns so have the right expectations for such situations.