SDG 6: Clean water and sanitation

Within the sixth Sustainable Development Goal, the United Nations have defined several specific tasks to be accomplished. Tasks 6.1–6.6 include concrete deadlines by which they should be achieved, while tasks 6.a and 6.b pertain to more general issues. It is worth briefly outlining their specifics.

Goal 6.1 Three requirements are combined in Goal 6.1: affordability, universality (coverage), and safety (quality and dependability). This entails going beyond basic “network connections” to provide a service that is consistent, complies with standards, and is affordable for all populations, including those living in rural and informal settlements. Key challenges include: (1) a high share of non-revenue water, which raises unit costs; (2) weak mechanisms for subsidizing connections and tariffs for the poorest; (3) a lack of quality monitoring (microbiology, metals, pesticides) and Water Safety Plans. Block tariffs with a “lifeline block” (a cheap minimum consumption bundle) are one example of a policy tool. Other tools include subsidies for new connections rather than for consumption, professionalization of rural operators (a shift from purely volunteer “community management” to models with maintenance and service), micro-networks, and hybrid solutions (combining central networks with local treatment systems). According to Korcelli (2008), integrating commercial tanker providers within a regulatory framework enhances quality and reduces the “last mile” cost in the Global South’s megacities, such as Lagos and Dhaka. Namibia and other resource-constrained nations demonstrate that, with strict regulations and unambiguous public outreach, potable-standard reuse may be both economical and safe.

Task 6.2 According to Task 6.2, open defecation must be eradicated and universal access to appropriate and equitable sanitation and hygiene must be guaranteed by 2030, with special consideration paid to the needs of women, girls, and those in vulnerable situations. The complete sanitation chain is covered by this activity, which extends beyond the construction of toilets. It includes safe fecal containment (on-site/sewer), emptying, transport, and treatment, as well as safe end use or disposal. Treating sewered and non-sewered systems equally, regulating desludging services, zoning technology and tariffs, and contracting services in “white spots” are all important aspects of the Citywide Inclusive Sanitation (CWIS) approach in urban areas (Citywide Inclusive Sanitation, 2025). In order to eradicate open defecation, infrastructure must be adjusted to reflect shifts in hand hygiene, school-based education, and social norms (such as CLTS). India’s Swachh Bharat projects have demonstrated that in order to produce long-lasting health advantages, rapid toilet expansion must be accompanied by maintenance and “beyond the toilet” services (fecal sludge management). Access to restrooms is only one aspect of gender sensitivity; other aspects include managing menstrual hygiene, ensuring safety and privacy in educational institutions and medical facilities, and implementing inclusive design (for older individuals and people with disabilities). Modularity, mobility, and energy independence of solutions are crucial in vulnerable environments (South Sudan, Yemen) where minimum WASH standards are necessary to reduce diarrhea and cholera. Task 6.3 According to Task 6.3, we should reduce pollution, close illegal dumpsites, limit the use of dangerous chemicals and other hazardous materials, cut the amount of untreated wastewater in half, and greatly increase recycling and the safe reuse of materials globally to improve water quality by 2030. Implementing 6.3 entails a deliberate change from a “discharge” mentality to comprehensive pollutant load management, where pollution sources are located, reduced, and handled with consideration for resource recovery and environmental quality. First and foremost, regulation and enforcement are essential. This includes risk-based monitoring that addresses micropollutants, pharmaceuticals, and vectors of antimicrobial resistance, as well as precise emission permits and sectoral standards supported by pre-treatment programs for high-risk industries (such as tanneries, mining, and chemical manufacturing).

Second, context-appropriate infrastructure is required. Decentralized wastewater treatment systems (DEWATS) are effective when combined with biogas and nutrient (nitrogen and phosphorus) recovery in areas where traditional sewer networks are ineffective or too expensive. In agriculture, landscape filters and buffer zones are required to reduce nutrient runoff into waterways. Third, a circular economy strategy serves as the basis for the safe, appropriate reuse of treated wastewater in industry and agriculture. This method is based on pay-for-performance treatment models and well-defined quality requirements for various applications.

International practice offers tangible proof of effectiveness. Spain and Italy have created comprehensive reuse rules for arid regions, Israel has adopted agricultural wastewater reuse nationwide, and Indonesia is testing DEWATS along small, highly contaminated waterways. However, improving municipal solid-waste management—which includes closing all routes by which waste enters water bodies and getting rid of illegal dumpsites—is a crucial prerequisite for success because without it, even the best treatment systems won’t produce long-lasting improvements in water quality.

According to Task 6.4, to solve water scarcity and drastically lower the number of people affected by it, we must assure sustainable withdrawals and supplies of drinking water by 2030 and greatly boost water-use efficiency across all sectors. Achieving Goal 6.4 necessitates combining municipal, industrial, agricultural, and energy policies within a river-basin management framework in order to stabilize hydrological balances (abstractions not exceeding resource renewal) and increase water productivity (more value added per cubic meter used). In order to protect fundamental requirements and environmental flows, the first step is to shift from “sectoral” thinking to a portfolio strategy, which combines supply-side interventions (new sources, retention, controlled aquifer recharge, MAR) with consistent demand management (efficiency, price, standards). The key to increasing actual, not just technical, efficiency in agriculture—which uses the majority of “blue water”—is to modernize irrigation (drip, precision irrigation, optimizing timing and doses based on evapotranspiration), introduce price signals that reflect resource scarcity, and change cropping patterns in deficit basins (moving away from highly “water-hungry” species). To prevent poverty from getting worse, these signals must be used in conjunction with safeguards for smallholders, such as social quotas, blended tariffs, or vouchers.

A further condition for balancing the water budget is controlling and licensing wells and expanding managed aquifer recharge (MAR): infiltration basins, retention ponds, and aquifer storage and recovery (ASR) systems that store surpluses in the wet season to reduce pressure on water bodies in the dry season.

Systematic consumption audits, the use of closed-loop systems and condensate recovery, a move to low-water cooling (dry or hybrid), and less “water-hungry” technologies and diversification of the mix toward sources with a minimal water footprint are some examples of organizational and technological solutions that improve water productivity in industry and energy without sacrificing output. Reducing non-revenue water is a top priority for the water utility industry, and this includes smart metering, pressure control, active leak detection (such as acoustic techniques), and network division into DMAs. Without constructing additional intakes, these actions simultaneously increase service reliability, reduce operating expenses, and open up a “virtual source” of water. In order to maintain a minimal consumption bundle for households (the lifeline), economic regulatory tools such as progressive tariffs, consumption standards, and pay-for-performance savings contracts should be created to send a strong efficiency signal. Experiences from several areas demonstrate that the quality of institutions and strict environmental restrictions determine how effective a tool is. Both the potential and the limitations of water rights markets are demonstrated by the Murray-Darling Basin in Australia. Trading mechanisms are effective and increase allocative efficiency, but only when they are combined with strict environmental caps, thorough abstraction metering, oversight to prevent abuses, and consideration of externalities for farming communities and ecosystems. As demonstrated by Israel and Jordan, desalination can permanently enhance the water balance when paired with reliable demand control, wastewater recycling, and source diversification. However, this requires strong regulatory frameworks, energy intensity solutions, and responsible brine management. In turn, Cape Town demonstrates how intelligent demand management—progressive tariffs, close resident communication, quick leak repairs, and pressure reduction—can postpone “Day Zero.” However, institutionalizing conservation practices and making investments in resilience (retention, MAR, alternative sources) are necessary for this effect to last over the long run. The integration of policy and water accounting at the river-basin scale is what unites these pathways: public permit registries, consistent data on abstractions and recharge, frequent quality monitoring, and a defined allocation hierarchy that prioritizes people and ecosystems. Only then, from small-scale farm irrigation to large-scale investments, do individual actions culminate in a macro effect of stable balances and increased water yield. To put it another way, when efficiency, fairness, and ecology are planned as complementary components of a single strategy, Goal 6.4 is successful.

The implementation of integrated water resources management (IWRM) at all levels, especially through transboundary collaboration, is assumed in Task 6.5 by 2030. Goal 6.5 is the “backbone” of SDG 6 since it combines environmental and development goals, grounds them in real stakeholder participation and water diplomacy, and arranges water administration according to the logic of the river basin. In actuality, this entails shifting from sectoral, disjointed decisions to hydrological-scale planning, in which water is distributed among users only when acceptable environmental loads and flows have been established. .

At the national level, the most important things are accurate hydrological data, public permit registries, clear allocation rules that prioritize water for people and ecosystems, and the consolidation of competencies (to prevent “many owners” of the same river). Institutions can only be held responsible for results rather than only inputs in such a system, which also allows for the development of a logical decision hierarchy from drought and flood plans to tariffs and incentives to local expenditures in retention and network upgrades. Treaties based on benefit-sharing (energy from storage, irrigation, navigation, and flood protection), cooperative early-warning systems, and long-term basin organizations like the Mekong River Commission are all part of 6.5, which is about institutionalizing dependency at the transboundary level. In practice, there are two extremes: effective coordination on the Rhine (ICPR) and Danube (ICPDR), where shared monitoring, quality standards, and emergency protocols reduce transaction costs; and challenging disputes in the Tigris-Euphrates, Indus, or Blue Nile basins, where a lack of trust and insufficient data impede investment and climate adaptation. Hard analytical skills (water accounting, scenario modeling, environmental flow assessment), stable funding (including mechanisms that combine water, agricultural, and energy funds), and the integration of water plans with spatial planning, agriculture, and energy are thus necessary for the implementation of IWRM. The “soft” components—involving women, Indigenous peoples, and local communities in decision-making; openness and dispute-resolution procedures; interoperable data systems; and reporting standards—are equally crucial. The only way to guarantee that the other elements of SDG 6 (service access, water quality, efficiency, and ecosystem protection) do not conflict but rather support one another is to combine basin-scale planning, rule-based allocation, shared information infrastructure, and cooperation institutions. By 2020, we must preserve and restore water-related ecosystems, such as wetlands, rivers, lakes, groundwater, mountains, and forests, according to Task 6.6, the final one in this category. Since wetlands, rivers, lakes, groundwater, forests, and mountain regions form the biogeophysical “foundation” of water services—stabilizing flow regimes, filtering pollutants, and storing water—protecting and restoring aquatic ecosystems remains a prerequisite for the success of the other SDG 6 components, even though the deadline for 6.6 passed in 2020. To link the water agenda with the climate agenda, an analytical approach must first identify the key hydromorphological and biogeochemical mechanisms and then translate them into concrete interventions. These interventions include re-establishing river connectivity by removing or upgrading barriers, creating fish passages, and re-establishing floodplain corridors that lower flood peaks while increasing retention and the ability of watercourses to purify themselves; re-naturalizing river valleys and wetlands to improve landscape retention and ecosystems’ capacity to absorb nutrients; protecting buffer zones and riparian vegetation to reduce agricultural runoff; and protecting and restoring peatlands, which are excellent stores of both water and carbon. Environmental flows are a crucial component; basin plans that determine and enforce them allow for the reconciliation of ecosystem needs and human water security. At the same time, invasive species control (by prevention, early detection, and prompt action) keeps food webs stable and water quality from deteriorating. Practice demonstrates that it is possible to combine conservation objectives with climate adaptation: in Central Europe, restoring landscape retention—small retention features, afforestation, and flood meadows—buffers both drought and flood episodes, lowering the costs of hydrological extremes for water management and agriculture. The Dutch “Room for the River” program has become a model for combining flood protection with ecosystem improvement by setting levees back, restoring floodplains, and giving rivers more space. Economic mechanisms like payments for ecosystem services (PES), which incentivize upstream landowners to take retention actions, remote monitoring and Earth observation to report indicator 6.6.1 and track changes in the extent of water-related ecosystems, and a deep integration of agricultural policies with water protection—through conditionality of payments, subsidies for retention solutions, buffer-strip standards along watercourses, and incentives to reduce nutrient pressures—are all necessary for the effective implementation of this agenda. To put it another way, Goal 6.6 is the “binding agent,” not a “add-on.” Without re-naturalized wetlands, landscape buffers, restored river connectivity, and enforced environmental flows, it will be challenging to maintain water quality (6.3), balance withdrawals and recharge (6.4), and guarantee dependable water and sanitation services (6.1–6.2). Conversely, well-designed monitoring, financing, and cross-sector integration instruments can turn ecosystem protection into a real, measurable improvement in water security.

Tasks 6.A and 6.B serve as complementary pillars for achieving Goal 6; the former organizes the movement of resources, technologies, and competencies on a global scale, while the latter grounds them in the local fabric where daily decisions regarding infrastructure maintenance and operation are made. 6.A mainly focuses on the architecture of support, which includes knowledge and technology transfer, blended and concessional financing, the development of regulatory institutions and human capacity in developing nations, and the capacity to organize, carry out, and sustain projects related to water storage, desalination, effective water management, wastewater treatment, and reuse. There are a number of boundary criteria that affect how effective such assistance is. First, a fit-for-context strategy and technological neutrality are required. To prevent “technology dumping,” which is the deployment of sophisticated solutions in environments without financial or service support, technologies must align with local hydrological, energy, and institutional realities. Second, capacity building needs to encompass the entire state capability cycle, including investment programming, multi-criteria analysis, public procurement, supervision and quality control, operations and maintenance, laboratories and water-quality monitoring, tariff mechanisms, and consumer social protection. It cannot be limited to one-time trainings. Third, grants, concessional loans, and private funding should all be used in mixed models with transparent and well-defined risk-sharing. Durability in capital-intensive fields, like desalination, depends on integrated energy policy (cost and carbon footprint), brine management, and user-side demand reduction; in wastewater management, it depends on quality frameworks for industrial pre-treatment, fit-for-purpose reuse, and resource-recovery pathways (biogas, nitrogen, phosphorus). Supporting nature-based solutions in addition to “grey” infrastructure is essential for storage and retention, as is the advancement of digital technologies such as hydrological modeling, remote sensing, integrated SCADA systems, and open data standards. Last but not least, donor fragmentation and “projectization” compromise 6.A’s efficacy; harmonization frameworks and the use of national planning and budgeting mechanisms boost assistance absorption and the longevity of outcomes. Task 6.B puts more emphasis on the agency of local institutions and end users, without which even the most well-funded programs remain vulnerable. Enhancing community involvement entails co-ownership of choices and duties throughout the whole water and sanitation service chain, not simply discussions. Water user associations, maintenance committees, and operators of non-sewered sanitation systems play an important role in rural and peripheral areas; there, durability depends on professionalized management, financial transparency, service procedures, and equitable compensation—rather than placing all the burden on volunteers.

Bringing in “last-mile” providers, controlling fecal sludge collection and treatment services, establishing technology zones, and establishing tariffs that are both socially acceptable and communicate efficiency signals are all necessary components of an inclusive approach to sanitation (CWIS) in urban areas. Because they typically bear the time and safety costs of fetching water and using infrastructure, women’s and girls’ participation is not an add-on but rather a functional requirement. Their presence in decision-making bodies results in designs that take menstrual hygiene, safety, and privacy into consideration. Additionally, participation increases bill collection, speeds up response times to failures, boosts the “social license” for investments, and makes it easier to enforce use rules (such as abstraction limitations during drought). Social accountability tools, such as citizen-participatory water budgets, grievance and mediation systems, and social audits, as well as citizen tools for water quality and outage monitoring are complementary measures. However, they must be connected to data-quality standards and privacy protection to support official oversight rather than producing an unreliable, parallel information stream. 6.A and 6. B ‘s shared denominator is the principle of co-producing services: investments are transformed into long-lasting service quality only when they are rooted in local structures, which include clear water rights, intelligible allocation rules, transparent tariffs, and true co-governance. International cooperation and capacity building create the financial, technological, and institutional “skeleton.” Stated differently, 6.A without 6.B runs the risk of technology transfer without acceptance and maintenance, whereas 6.B without 6.A may become trapped in a cycle of chronic underfunding and poor capacity. For water and sanitation to become a stable, robust system of public services rather than a project event, both activities must be integrated and implemented at the river-basin scale in accordance with spatial, agricultural, and energy plans.