A Stanford-led study warns that hotter and drier conditions could double water bills by midcentury in certain cities. Published in Nature Sustainability, the work is the first to model how climate shifts, infrastructure spending and household demand may worsen an existing affordability problem.
Lead author Jennifer Skerker noted that climate change strains supplies and pushes utilities to fund costly new projects for reliability. In places already burdened by aging systems, these added expenses passed to customers can drive many households into financial distress.
US tap water prices have risen three times faster than inflation in two decades, mainly from old infrastructure. Climate pressures now add another layer, the researchers said.
The team used Santa Cruz, California, as a case study. The city depends on local surface water and one reservoir. After low-cost conservation steps, further resilience requires major investments such as wastewater reuse.
Models linked future climate scenarios with utility choices on infrastructure and pricing. Results showed median bills could nearly double by midcentury. The share of households above the EPA affordability limit might rise from 19% to 35%. For the poorest residents, monthly costs could climb from about $60 to $111 in current dollars, with over 5% spending up to a third of income on water.
Early large-scale desalination offered high reliability but raised costs sharply. Delayed spending kept bills lower yet risked shortages in dry years. The framework can apply to other vulnerable cities like Los Angeles or Cape Town. Senior author Sarah Fletcher stressed that current financing models put adaptation and affordability on a collision course, requiring broader state and federal action.
