Gov. Jerry Brown won crucial early approval from federal wildlife officials Monday for his $16 billion proposal to re-engineer California’s north-south water system, advancing his plan to build two giant tunnels to carry Northern California water to the south even though much about the project remains undetermined. The National Marine Fisheries Service and U.S. Fish and Wildlife Service gave their green light by finding that the project would not mean extinction for endangered and threatened native species of salmon and other fish.