California has a rich and varied stock of water resources, which has enabled it to survive years of drought. But although scientists have long known that surface and groundwater are interdependent (both for recharge and with respect to pollution), the state has treated the state’s surface water and groundwater as legally and institutionally separate resources. This allowed the 40% of the state’s water supply coming from groundwater to go dangerously unregulated, which finally led the state legislature to take action. California’s Sustainable Groundwater Management Act (SGMA), which came into force in 2015, provides that groundwater has to be sustainably managed for long-term reliability; the Act also sets up a system of management for groundwater.

In a new article titled “California Groundwater Management, Science-Policy Interfaces, and the Legacies of Artificial Legal Distinctions” in Environmental Research Letters, Professor Dave Owen and colleagues have turned their collective legal, scientific, and policy lenses on the SGMA. While applauding the Act’s belated legal recognition of the interconnection between surface and groundwater, they ask what happens next. Law is not a magic wand that, once waved, solves problems. While California law has finally caught up to the scientific reality of water resources, the real work is still ahead, since the institutions, management practices, government resources, and even mindsets that were forged under the prior regime will not change automatically now that the new legislation is in place.

The article provides a roadmap to ensure that once a scientific error is corrected in legislation, other related policy and institutional changes can occur. Drawing on legal research and extensive consultations with governmental and nongovernmental stakeholders, the authors identify the areas where efforts are still needed to truly integrate the management of groundwater and surface water. More importantly, they provide an analytical rubric that can be used in other contexts where it is essential to harmonize policy and legal frameworks with science.

The heart of their argument is that the “science-policy interface,” often discussed in the broader academic literature, is a misnomer, and that in fact multiple interfaces or points of intersection require attention. Their analysis leads to a second broad point: all the energy and political will galvanized toward enacting legislation must not be allowed to dissipate once the law is enacted. The successful passage of desired legislation that corrects a scientific misunderstanding is only the beginning, not the end, of a long process.

Californians can rejoice that the state legislature has belatedly recognized that depletion or pollution of groundwater can deplete or pollute surface water and vice versa (among other deleterious effects), but Professor Owen and his coauthors convincingly demonstrate that hard work remains to implement a statewide groundwater-management system that accounts for surface water. Will policy makers meet the timelines set in SGMA to identify or create responsible agencies and ensure that 127 high and medium priority groundwater basins reach sustainability by 2040? The article offers a clear blueprint for those working in the water resources area, but policymakers working in other fields should also observe and take lessons from this experience. The article will be an important resource for policy makers in California and further afield.