SAN DIEGO ---- Thanks to swelling reservoirs, Southern Californians won't notice at all this summer that the Sierra mountain snowpack that helps make sure local faucets continue to flow was at its lowest level in two decades this winter, state and regional officials said last week. However, some said, if the Sierra snowfalls are meager again next year, Southern Californians could face water shortages in 2008. San Diego County water suppliers draw some of their water from the melting snowpack in the Sierras. One San Diego County water leader said several factors raise questions about Southern California's increasing dependence upon...