Concerns about water affordability have centered on access to networked services in low-income countries, but have grown in high-income countries as water, sewer, and stormwater tariffs, which fund replacement of aging infrastructure and management of demand, have risen. The political context includes a UN-recognized human right to water and a set of Sustainable Development Goals that explicitly reference affordable services in water, sanitation, and other sectors. Affordability has traditionally been measured as the ratio of combined water and sewer bills divided by total income or expenditures. Subjective decisions are then made about what constitutes an “affordable” ratio, and the fraction paying more than this is calculated.