Private household water and energy use are closely linked, especially in areas of intermittent water supply where more than one billion people live globally. However, the demand-side Water-Energy Nexus at the household level is often overlooked in empirical econometric studies. Based on a household survey (n = 1872) on water and energy in the Pune Metropolitan Region, India, we find statistical relationships between intermittent water supply and household electricity demand. More than 90 % of the surveyed households use water storage to cope with water supply intermittency, low-income households are particularly affected. Electricity consumption for water access accounts for 27 % of total household electricity consumption. Using a Discrete-Continuous Choice model, we identify significant impacts from factors such as household size and income, electricity price, and particularly the duration of water supply and the use of large water storage on household electricity demand. Our results indicate that households with 24-h water access consume 30 % less electricity than those with 12-h daily access. Extending municipal piped water supply by 1 h per day for all households could reduce total household electricity consumption by 3 %. Our findings suggest that water supply intermittency is a massive cause of unnecessary emissions in cities around the world that has thus far received hardly any attention. The significant amount of electricity used to access water reveals a hidden water affordability problem that can be more prevalent during droughts. Our analyses highlight the demand-side Water-Energy Nexus from an econometric perspective and emphasize the importance of breaking down silos in resource management.