water is provided by various county and a few city systems. several of these systems actually serve parts of neighboring counties and cities as well. the cobb-marietta water authority serves not only cobb, but also parts of neighboring paulding and cherokee counties, for example. during drought or other emergency, cities and counties can enact outdoor water-use restrictions, however some cross-jurisdiction water systems have also acted to put bans in place. in late september 2007, the state environmental protection division of the georgia department of natural resources, stepped-in with its first-ever ban, covering most of the northern half of the state. while surface water is by far the primary source of water for the region, the drought had many systems (and a few wealthy homeowners) drilling new wells for ground water, though the local water table is around deep, on average.