This report expands the Water Science Strategy that was begun in the USGS Science Strategy, “Facing Tomorrow’s Challenges—U.S. Geological Survey Science in the Decade 2007–2017” (U.S. Geological Survey, 2007). The report looks at the relevant issues facing society and develops a strategy built around observing, understanding, predicting, and delivering water science for the next 5 to 10 years by building new capabilities, tools, and delivery systems to meet the Nation’s water-resource needs. This report begins by presenting the vision of water science for the USGS and the societal issues that are influenced by, and in turn influence, the water resources of our Nation. The essence of the Water Strategic Science Plan is built on the concept of “water availability,” defined as spatial and temporal distribution of water quantity and quality, as related to human and ecosystem needs, as affected by human and natural influences. The report also describes the core capabilities of the USGS in water science—the strengths, partnerships, and science integrity that the USGS has built over its 130-year history.

Nine priority actions are presented in the report, which combine and elevate the numerous specific strategic actions listed throughout the report. Priority actions were developed as a means of providing the audience of this report with a list for focused attention, even if resources and time limit the ability of managers to address all of the strategic actions in the report. Priority actions focus on the following:

• Improve integrated science planning for water. 
• Expand and enhance water-resource monitoring networks.
• Characterize the water cycle through development of state-of-the-art 3-D/4-D hydrogeologic framework models at multiple scales. 
• Clarify the linkage between human water use (engineered hydrology) and the water cycle (natural hydrology).
• Advance ecological flow science. 
• Provide flood-inundation science and information. 
• Develop rapid deployment teams for water-related emergencies. 
• Conduct integrated watershed assessment, research, and modeling. 
• Deliver water data and analyses to the Nation.

The body of the report is presented as a hierarchal set of 5 goals, 14 objectives, and 27 strategic actions that the USGS should undertake to advance water science through year 2022. 
The goals deal with:

1. Providing society the information it needs regarding the amount and quality of water in all components of the water cycle at high temporal and spatial resolution, nationwide; 
2. Advancing our understanding of processes that determine water availability; 
3. Predicting changes in the quantity and quality of water resources in response to changing climate, population, land use, and management scenarios;
4. Anticipating and responding to water-related emergencies and conflicts; and 
5. Delivering timely hydrologic data, analyses, and decision-support tools seamlessly across the Nation to support water-resource decisions.

Scientific information produced on water resources would be without value if it were not communicated to society in a fashion that can inform decisions and actions. Therefore, the chapter following the goals describes how the USGS should inform, involve, and educate society about the science it produces. This includes discussions on local outreach and the use of social media for effective communication.

This report concludes with a chapter devoted to the crosscutting science issues of the Water Mission Area with the other USGS Mission Areas: Climate and Land Use Change, Core Science Systems, Ecosystems, Energy and Minerals, Environmental Health Science, and Natural Hazards. Not one of these Mission Areas stands alone—all must work together and integrate their actions to fulfill the USGS science mission for the future. This final chapter identifies the important linkages that must be realized and maintained for this integration to occur.