SAN FRANCISCO (AP) – Gov. Jerry Brown is scaling back his troubled proposal for overhauling California’s water system – at least for now. State official Karla Nemeth wrote Wednesday that the Brown administration is now looking at building a single giant water tunnel instead of two. California would build a second one later if money is found for it. The project would pipe water from Northern California through a four-story-high tunnel. Los Angeles’ giant Metropolitan Water District and its millions of urban customers are expected to be some of the main beneficiaries. California water districts had balked at the $16 billion cost of the two tunnels. The new plan marks the latest in Brown’s four-decade effort to redo the water system left by his father, the late Gov. Pat Brown. The single tunnel still would be California’s biggest water project in decades.