The Sustainable Groundwater Management Act - SB 1168 and SB 1319 (Fran Pavley, D-Agoura Hills) and AB 1739 (Roger Dickenson, D-Sacramento) - established the first significant groundwater management plan in California history. Though the act will apply statewide, much of its authority is invested with local governments. The legislation requires "groundwater sustainability agencies" to oversee all medium- and high-priority groundwater basins, as defined by the Department of Water Resources (DWR), by June 30, 2017. For many adjudicated basins - such as Scott Valley - existing watermasters can be designated as authorities. In unmanaged areas, the counties generally would manage groundwater. Regardless of who's in charge, supervising agencies must devise plans for achieving groundwater sustainability within 20 years. For most groundwater basins, sustainability plans must be in place by 2022. For basins subject to "critical overdraft conditions," plans must be in place by 2020. Under the act, groundwater managers have the power to regulate and even to suspend pumping from groundwater basins. Administering agencies can respond to violations vigorously, imposing fees and fines. Annual reports must be submitted to the DWR for each basin so the department can track progress toward aquifer stability. The legislation allows for direct intervention by the state if local agencies are unable to effectively manage groundwater in their jurisdictions. Much about the new law, however, remains fuzzy. For example, it is unclear how groundwater sustainability agencies will exercise their authority, or resolve conflicts when water-rights priorities are contested. Members of the public could sue if they opposed a groundwater sustainability plan. And because the act applies to Indian lands in some circumstances, it may trigger tribal sovereignty issues. Complicating the legal landscape is Proposition 1, the $7.5 billion water bond appearing on California's statewide ballot this month. Its disparate spending proposals include $2.7 billion for unspecified water storage projects, dams, and reservoirs, and $900 million to prevent or clean up groundwater contamination. Opponents maintain the initiative is a holdover from a pork-laden bond measure the Legislature removed from the ballot in 2010 and 2012 but now hopes voters will pass amid a drought. The greatest uncertainty remains how the groundwater legislation will intersect with decades of common law governing California water rights - including, perhaps, application of the public trust doctrine to the extraction of groundwater.