On July 8, 2026, the SDG Local Action series hosted its webinar “Ensuring the accessibility of municipal water.” The event featured two cities with very different starting points but a shared imperative: securing water access for their residents. Bogotá (Colombia) shared how a 2024 supply crisis pushed the city to redesign its water bill as a behavioural policy tool. Windhoek (Namibia) presented over 56 years of experience managing direct potable reuse — and how the city is scaling that system today. The session explored how cities, whether responding to sudden shocks or decades-long scarcity, can combine infrastructure, behaviour change, and careful risk management to build lasting water resilience.
Water scarcity looks different depending on where you stand. For Bogotá, it arrived suddenly in April 2024, when the Chingaza reservoir system — source of nearly 70% of the city’s supply — dropped to levels not seen in decades. For Windhoek, it has been a decades-long condition of life in one of the driest capitals on Earth, addressed since 1968 through one of the world’s longest-running direct potable reuse programmes. Both cities shared their experiences during the SDG Local Action webinar, offering two very different but complementary models for how local governments can secure water access under mounting pressure.
The video recording of the webinar is available on our YouTube channel – in English, Spanish and French.
Bogotá: turning a bill into a behavioral policy tool
When Bogotá’s water crisis hit in 2024, city officials quickly recognised that the challenge was not purely technical. Reservoirs could be monitored and rationing schedules enforced, but changing how nearly three million households related to water required something else: a shift in habits, beliefs, and culture. The city’s Public Innovation Lab (iBO), together with the water utility EAAB, treated this as an adaptive challenge rather than an engineering problem alone.
The starting point was a behavioural science workshop that brought together more than 30 experts and generated 144 ideas and identified three root causes of wasteful consumption: information gaps, behavioural habits, and weak incentives or sanctions. From there, the team redesigned the city’s core communication tools, most notably the water bill itself — historically a purely transactional document that few residents actually read.
The redesign process was rigorous:
- 21 insights distilled from citizen research
- 12 prototypes developed through ideation
- 25 prototype iterations
- more than 40 validation sessions with citizens, combining eye-tracking and focus groups
- 4 technical, legal, and regulatory validation rounds
The result, rolled out to 2.6 million households in November 2024, transformed the bill into what the city now calls a “behavioural public policy tool.” It compares a household’s consumption to city and neighbourhood averages, translates cubic meters into litres people can visualise (a bottle-by-bottle breakdown), and flags any increase in usage clearly and early.
The bill redesign was one of several complementary interventions, including a WhatsApp-based reporting channel for water misuse, a graphic campaign for common areas, and community initiatives such as #JuntosPorElAgua, which rewarded neighbourhoods that achieved the highest savings. By April 2025, with Chingaza recovered to 39.98%, the crisis was formally declared over — but the redesigned bill remains in place, and the city’s Secretary of Culture is now measuring its longer-term impact on consumption behaviour.
Bogotá’s experience offers a clear lesson for other municipalities: public services can keep innovating well after the emergency passes, and everyday touchpoints with citizens — a bill, a notification, a household comparison — can carry as much weight as new pipes or reservoirs when it comes to building water resilience.
Windhoek: sustaining reuse as a permanent pillar of supply
Windhoek’s relationship with water reuse is older than most water utilities’ entire operating history. In the 1950s, the city’s population was growing explosively — increasing by more than 10% a year at times — while it sat in a desert climate with no river, lake, or other meaningful surface water source nearby. A 1958 Executive Commission concluded bluntly that existing sources, including boreholes already “sorely overtaxed,” could not keep pace with demand. After reviewing the alternatives, the city’s 1960 water supply report was equally direct: reclaiming water from the sewage works was “the key to the whole report,” and every effort should be made to secure a supply from that source. Water reuse was not one of several options — it was identified as the only feasible path forward.
Windhoek’s solution was water reuse: treating wastewater to drinking-water standards and returning it directly to the supply. Windhoek moved on that conclusion, commissioning the world’s first direct potable reclamation (DPR) plant, which began production on 18 October 1968, just in time to avert another drought and immediately supplying 15–25% of the city’s potable water. What began as an emergency measure has since become one of the most established components of the city’s water mix, currently reclaiming 20,000–21,000 m³ per day.
Today, that legacy translates into concrete strategy rather than experimentation. Windhoek’s water supply approach rests on a few clear, data-driven pillars:
- Expanding reclamation, with a built-in ceiling — a phased plan will lift reclamation capacity from the current 20,000–21,000 m³/day to 30,000–31,000 m³/day with a second plant (DPR2) by 2029 (phase 1), and further to 40,000–41,000 m³/day in a following phase (phase 2) — while deliberately capping total reclamation at no more than 50% of demand, a ceiling that reflects the city’s careful, risk-managed approach to relying on a single augmentation source.
- Managing demand under stress — annual water demand ranges from 26 million m³ in a normal year to a suppressed 22.1–24.7 million m³ during drought, a demonstrated track record of consumption management under pressure.
- Cutting losses in the network — the city is candid about an ongoing challenge: non-revenue water losses of 25–30%, driven by frequent pipe breaks, undetectable underground leaks, free water use and communal facilities in informal settlements, and uncollected supply. Addressing this loss rate — including through a shift toward pre-paid metering — is now treated as a priority alongside expanding reclamation capacity, since every cubic meter saved reduces pressure on the DPR system.
- Building a buffer for the next drought — artificial recharge of the southern aquifer adds 2.5 million m³ per yearplus natural recharge. Combined with DPR, the aquifer could sustain the city for more than four years under suppressed demand even without a functioning dam source.
Taken together, today’s Windhoek water strategy is less about proving that reuse can work — that question was settled over half a century ago — and more about scaling it responsibly, cutting losses in the distribution network, and diversifying storage so that no single source carries the full weight of the city’s supply.
Two paths, one imperative
Bogotá and Windhoek arrived at water resilience from very different starting points: one through a sudden crisis that forced rapid behavioural innovation, the other through decades of sustained investment in reuse infrastructure now being carefully scaled and diversified. Yet both illustrate a shared principle: securing municipal water is not only an engineering challenge, but it also requires cities to combine technical solutions with the tools, incentives, and communication strategies that shape how citizens actually use water, day by day.