Land and waterway managers labored hard over the course of a century to control California’s unruly rivers by building dams and levees to slow and contain their water. Now, farmers, environmentalists and agencies are undoing some of that work as part of an accelerating campaign to restore the state’s major floodplains. The Ferguson Group has worked with the Northern California Water Association and the Sacramento River Settlement Contractors, leaders of efforts to reactivate Sacramento River basin floodplains, for decades.