Integrating the management of groundwater and surface water, which were once treated as separate resources in most western states, has become the norm in recognition of their hydrologic connection and because of its importance in providing cheap, reliable water storage. US Water Alliance, a coalition of municipal water utilities, agricultural leaders, and environmental interests, has held a series of meetings promoting the idea of “One Water Management” and developing a network to share information and advance its agenda of “adaptive, integrative water management planning”

One notable exception is California where regulation and management of surface water and groundwater remain separate and distinct.