FrontMatter -- Preface -- Contents -- Summary -- 1 Introduction -- 2 CLEANER and the Observatory Approach -- 3 Grand Water Challenges and Research Questions -- 4 Implementing Environmental Observatories -- References -- Acronyms -- Appendixes -- Appendix A Water Science and Technology Board -- Appendix B Biographical Sketches for Committee on the Collaborative Large-scale Engineering Analysis Network for Environmental Research (CLEANER).