President Barack Obama on Friday signed a massive infrastructure bill designed to control floods, fund dams and deliver more water to farmers in California’s drought-ravaged Central Valley. Obama signed the $12 billion bill in a distinctly low-key act. Controversial provisions that critics fear could harm fish in the Sacramento-San Joaquin Delta were wrapped inside a package stuffed with politically popular projects, ranging from Sacramento-area levees to clean-water aid for beleaguered Flint, Mich.