The top 100 global water questions: Results of a scoping exercise

•We identify 100 priority global water-research questions for the coming decade•The are in six thematic areas connecting local to scale•Questions about governance and knowledge production cut across all scales•These offer a shared framework interdisciplinary water research Water is vital resource critical sustainable development. Human survival, energy food production, healthy ecosystems dependent on availability. security also impacted by at core of adaptation climate change. Yet, pressure freshwater resources growing, stress risk increasing both scale. The challenge therefore complex requires action multiple levels: from household access sanitation; managing safety human populations ecosystem health; working through political technical challenges scarcity distribution; understanding dynamics cycle how it being identified this scoping review suggestions priorities these different levels provide researchers funding agencies with language talk disciplines interests. Global presents problem societies will become more acute as impacts change escalate. connects practical sanitation households hydroclimates Anthropocene. To ensure successful deployment attention resources, necessary most pressing research. Here, we present results exercise conducted sector. More than 400 respondents submitted an excess 4,000 potential questions. Drawing expert analysis, highlight indicative domains: settlements; management; scarcity; hydroclimate-ecosystem-Anthropocene dynamics; multi-level governance; production. These multi-scalar guiding nature space decades. IntroductionThe 2020 United National World Development Report describes “medium which experience impact change.”1UN WaterWater Climate Change, UN 2020.https://www.unwater.org/publications/world-water-development-report-2020/Date: 2020Google Scholar Extreme inequality economic population growth patterns combination complexity uncertainty future render human-water interactions “wicked” problem.2Bjornlund H. Nickum J.E. Stephan R.M. wicked problems quality governance.Water Int. 2018; 43: 323-326https://doi.org/10.1080/02508060.2018.1452864Crossref Scopus (5) Google A one impossible define optimal solutions instead “tackling” strategies.3Duckett D. Feliciano Martin-Ortega J. Munoz-Rojas Tackling environmental problems: discourse its influence praxis Scotland.Landsc. Urban Plan. 2016; 154: 44-56https://doi.org/10.1016/j.landurbplan.2016.03.015Crossref (45) manage world that turbulent, uncertain, novel, ambiguous4Ramírez R. Wilkinson A. Strategic Reframing. Oxford University Press, 2016Crossref actions informed clear definitions scenarios. Complex necessitate bringing together understand interconnected implications sectors components world’s socio-ecological system. Appropriate strategies should then be better understood negotiated.5The water.in: Holden Resources: An Integrated Approach. Routledge, 2020: 427-445Google Where strategic lie addressing dynamic space?The emphasis evidence-based decision-making management, governance, policy-making.6Schiffer E. Mccarthy N. Asante F. Information Flow Acquisition Knowledge Governance Upper East Region Ghana. International Food Policy Research Institute (IFPRI), 2008Google Scholar, 7Amjad U.Q. Dalcanale Kayser G. Bentley P. Bartram Evidence-based domestic supply Malawi, Ecuador, Brazil.Water Policy. 20: 530-545https://doi.org/10.2166/wp.2017.184Crossref (3) 8Sutherland W.J. Woodroof H.J. need horizon scanning.Trends Ecol. Evol. 2009; 24: 523-527https://doi.org/10.1016/j.tree.2009.04.008Abstract Full Text PDF PubMed (165) process empirical evidence informs decision making remains under-explored frequently de-politicized.9Oliver K. Boaz Transforming policy practice: creating new conversations.Palgrave Commun. 2019; 5: 60https://doi.org/10.1057/s41599-019-0266-1Crossref (41) development goals (SDGs) (specifically SDG 6: Clean Sanitation) explicit recognition water-energy-food nexus10Conway van Garderen E.A. Deryng Dorling S. Krueger T. Landman W. Lankford B. Lebek Osborn Ringler C. et al.Climate southern Africa’s water–energy–food nexus.Nat. Clim. Chang. 2015; 837-846https://doi.org/10.1038/nclimate2735Crossref (256) Scholar,11Mdee Disaggregating orders - politics nexus Wami-Ruvu river basin , Tanzania.Water Altern. 2017; 10: 100-115Google require set guide processes. Critique sector suggests often driven, where conduct specific satisfy clients’ sponsors’ short-term needs, expense longer-term issues.12Brown L.E. Mitchell Folkard Wright Beharry-Borg Berry Brierley Chapman Clarke S.J. al.Priority determined UK practitioners makers.Sci. Total Environ. 2010; 409: 256-266https://doi.org/10.1016/j.scitotenv.2010.09.040Crossref (60) However, limited committed research, hegemony contestation forms constitute “water science,” considerable predicted future,13Brown Kookana urban clean sanitation.One Earth. 1: 10-12Abstract (4) 14Bhaduri Bogardi Siddiqi Voigt Vörösmarty Pahl-Wostl Bunn S.E. Shrivastava Lawford Foster al.Achieving perspective.Front. Sci. 4: 64https://doi.org/10.3389/fenvs.2016.00064Crossref (98) 15Venot J.-P. Vos Molle Zwarteveen M. Veldwisch G.J. Kuper Mdee Ertsen Boelens Cleaver al.A bridge over troubled waters.Nat. Sustain. 2021; 92https://doi.org/10.1038/s41893-021-00835-yCrossref 16Too much not enough.Nat. 659https://doi.org/10.1038/s41893-021-00766-8Crossref (11) there recognized current collaborative future-oriented methodologies actively engage policymakers, practitioners, their formulation.17Setty Jiménez Willetts Leifels water, hygiene learning under Sustainable Goal 6.Dev. Rev. 2020; 38: 64-84https://doi.org/10.1111/dpr.12475Crossref ScholarWell-packaged strong assumed enable robust rational decision-making18Head B.W. Reconsidering policy: Key issues challenges.Pol. Soc. 29: 77-94https://doi.org/10.1016/j.polsoc.2010.03.001Crossref (232) advance SDGs build capacity coherence among stakeholders.17Setty Hence, exercises (i.e. gathering analyzing within large spatial, organizational, temporal scales) useful mechanism efforts actors space.Similar have been undertaken agendas conservation,19Kark Sutherland Shanas U. Klass Achisar Dayan Gavrieli Y. Justo-Hanani Mandelik Orion scanning conservation: comparative study.PLoS One. 11: e0145978https://doi.org/10.1371/journal.pone.0145978Crossref (12) Scholar,20Rudd M.A. How research-prioritization affect conservation policy.Conserv. Biol. 2011; 25: 860-866https://doi.org/10.1111/j.1523-1739.2011.01712.xCrossref (63) microbiome,21Greenhough Read C.J. Lorimer Lezaun McLeod Benezra Bloomfield Brown Clinch D’Acquisto al.Setting agenda social science microbiome.Palgrave 18https://doi.org/10.1057/s41599-020-0388-5Crossref (16) agriculture.22Pretty Ashby Auburn Baulcombe Bell Bickersteth Burke al.The top importance agriculture.Int. Agric. 8: 219-236https://doi.org/10.3763/ijas.2010.0534Crossref (340) This piece extension al.’s work,12Brown key UK. Likewise, South Africa, experts collaboratively 54 consideration practitioners.23Siebrits Winter Barnes Dent M.C. Ekama Ginster Harrison Jackson Jacobs I. Kasan H.C. Africa developed participatory processes.Water SA. 2014; 40: 199-210https://doi.org/10.4314/wsa.v40i2.2Crossref (9) recently, Setty al. (2020) employed survey sanitation, (WaSH) professionals formulate professional sector.17Setty Such processes collective goal anticipated identifying gaps, planning, informing allocation scarce while facilitating stakeholder deliberation.12Brown Scholar,19Kark Scholar,23Siebrits ScholarThis paper future. Our starting point was question what questions? decades.Results discussionSurvey responsesThe received 459 individual responses 81 countries territories, representing one-third Nations member states, 325 English 134 Spanish. Countries highest number were, descending order, Kingdom (79), India (71), Spain (31), Colombia (19), Peru (18), Mexico (17), Argentina (15), (13) Tanzania (13), 60% participants (Table S1; Figure S2). 22 did indicate countries. In dissemination survey, effort made encourage academics, government officials, non-governmental organizations, bodies, private widest possible spread water-related interest areas. There higher response education (?45%) compared agencies, organizations (NGOs), Respondents who indicated “Other” belonged such agriculture, finance trade digital technology, cooperatives, community-based (CBOs), philanthropic organizations. Three individuals affiliated sectors. Table 1 sets out overarching themes used organize produced our exercise. organized four scales link settlements hydroclimate represented 1.Table 1Big questionsThemeThematic questionWater settlementsWhat characteristics systems all?Water managementWhat pathways improve management settlements?Water populationsHow can competing demands users reconciled?Hydroclimate-ecosystem-Anthropocene dynamicsWhat interrelationships between hydrology, ecosystems, human-induced changes land, biota, climate?Multi-level governanceWhat water?Knowledge productionHow collectively work inform actions? Open table tab Supply demand: settlementsThematic question: all?The majority corresponded actual operationalization delivery, equity, affordability, inclusivity, accessibility, around providing all. primarily concerns intractable developing institutional capabilities deliver effective rather technologies.24Andrews Pritchett L. Woolcock Building State Capability: Evidence, Analysis, Action. 2017Crossref Scholar,25Das B.M. Hatzfeldt RISING TIDE New Look Gender Maitreyi Bordia Das Gaia Hatzfeldt.2017Crossref expert-led grouped theme reflected concern increases regions disparate demographic transitions uncertainties change, demand existing services invest infrastructure delivery rise. They has tensions, resulting competition local, national, levels. Already, estimated 20% groundwater exploited, likely 2050, aquifers exploited.26Piesse Demand Trends Point towards Rising Insecurity. Future Directions International, 1-8Google addition, high-income treat 70% industrial wastewater, whereas drops 38%, 28%, 8% upper-middle-income, lower-middle-income, low-income countries, respectively.27UN WaterWastewater: Untapped Resource. Water, 2017Google Therefore, refined list area suggest split all, operational systems, technological futures, responding change.Our following (23/100) broad area:Questions associated all1.How 6 targets drinking achieved 2030?2.How equitable affordable accessible all?3.How realistic achieving universal safely managed conditions?4.What obstacles implementation right context public model supply?5.What relationship dimensions (gender, caste, religion, wealth, age, etc.)?Delivery questions6.What (appropriate, affordable) provided challenging environments (e.g., flood prone areas, atoll islands, informal settlements, etc.)?7.What technologies/implementation approaches successfully sustainably implemented scale government/communities no "external" (NGO, international agency, etc.) input sector?8.To extent does concessional exacerbate weak regulatory frameworks opportunism investment, asset management?9.How concept fair tariffs applied rural or services?10.How designed help accelerate investment sustainability (financial resource) goals, particularly if relies investments, cross-agency cooperation and/or distributed monitoring compliance requirements too costly regulators enforce?11.Which non-economic incentives best demand?12.How design interventions embed health performance?13.How well-being improvement people provision safe measured, capitalized, included cost-benefit analysis system?Economic futures14.What possibility retrofitting properties (facilitated technology/byelaws) utilize rainwater graywater gardening potable supplies cannot compromised?15.What implementing metering efficient pro-poor pricing promoting efficiency?16.What viability using transfers artificial recharge strategically sustain aquifers?17.What some ways large-scale well local-scale sequestration, incorporated retrofitted into mainstream planning?18.How technologies water-supply-augmentation desalination wastewater treatment plants) mainstreamed remaining niche?19.How do natural capital thinking industry so green considered legitimate alternative end pipe gray solutions?20.How green/private utilized effectively support management?21.How poor (and subsequent coral degradation) populations?Climate-change-related questions22.How utilities other service providers resilient?23.What seawater intrusion coastal regions?Water managementThematic populations?Water pollution, fecal sludge, foremost facing world. estimate 80% sludge go untreated.27UN selected opinion raised address proposed 6.3, i.e., reducing risks environment pollution treating re-use wastewater. Questions confirmed similar stream ecology,28Wenger Roy A.H. C.R. Bernhardt E.S. Carter T.L. Filoso Gibson C.A. Hession W.C. Kaushal S.S. Martí al.Twenty-six ecology: assessment state science.J. North. Am. Benthol. 28: 1080-1098https://doi.org/10.1899/08-186.1Crossref (289) indicating strengthen improving interphase hydrological settlements.Existing nutrients like nitrate drinking-water sources largely governed fertilizer inputs discharges, hydrobiological processes, inevitably affects create conflicting interests stakeholders.29Schaider L.A. Swetschinski Campbell Rudel R.A. Environmental justice quality: socioeconomic disparities U.S. water?.Environ. Heal. Glob. Access Source. 18: 3https://doi.org/10.1186/s12940-018-0442-6Crossref outcome identifies range examine societal inequitable disadvantaged populations. Submitted draw efficacy national policies inequalities arise investigating pays what, losses benefits polluting activities, quality. Expert interviewees drew fact principle “polluter pays” may accepted theory, whether governments/regulators hold powerful polluters accountable.The ever-evolving diversity pollutants waste strongly resonates theme.30Albert J.S. Destouni Duke-Sylvester S.M. Magurran A.E. Oberdorff Reis R.E. Winemiller K.O. Ripple Scientists’ warning humanity biodiversity crisis.Ambio. 50: 85-94https://doi.org/10.1007/s13280-020-01318-8Crossref (184) direct fundamentally capability (or more) technologies. doing so, they interrogate advances agro-industrial accompanied pose knockon effects costs treatment31Gambhir R.S. Kapoor V. Nirola Sohi Bansal pollution: promising techniques purification process.J. Hum. 2012; 37: 103-109https://doi.org/10.1080/09709274.2012.11906453Crossref Scholar,32Kurniawan T.A. Sillanpää M.E. M.M.E.T. Nanoadsorbents remediation aquatic environment: problems.Crit. Technol. 42: 1233-1295https://doi.org/10.1080/10643389.2011.556553Crossref (102) emerging point-source micro-plastics, bioactive pharmaceuticals, endocrine disruptors, persistent organic pollutants, cosmetic products introduce significant additional costs. Additionally, flags failure keep contributing anti-microbial resistance many pathogens.33Graham D.W. Bergeron Bourassa M.W. Dickson Gomes Howe Kahn L.H. Morley P.S. Scott H.M. Simjee al.Complexities antimicrobial domesticated animal, human, systems.Ann. Acad. 1441: 17-30https://doi.org/10.1111/nyas.14036Crossref (65) ScholarQuestions 24–38 fall broadly encompass quality, future.Water safety, delivery24.How improved respect quality?25.What long-term chronic contamination agro-toxins agriculture?26.What intercatchment transfer relation chemical composition, invasive species, genetic integrity population?27.What trade, addressed level?28.What transboundary (really) bears cost?29.What laws, policies, information, institutions required accountable impact?Sanitation wastewater30.How responsible sources, pathways, removal, recovery (on land