Water providers have an ongoing need for estimates and forecasts of the total population and the number of housing units and households within their service areas. The Portland State University (PSU) Population Research Center (PRC) has prepared annual population, housing unit, and household estimates each year since 2014 for the water service areas of the municipalities and water districts in the Regional Water Providers Consortium (RWPC), as well as the wholesale customers of the Portland Water Bureau (PWB) that are not Consortium members. Previous estimates used the 2010 Census as a baseline, with boundaries collected in 2013 and updated in 2019. For this report, population, housing unit, and household counts from the 2020 Census were allocated to each water service area using boundaries as of March 2022. This report includes a description of the methodologies used to allocate the April 1, 2020 census data and prepare estimates for July 1, 2021. Tables 1 and 2 present these estimates in detail for each provider. Under the current agreement between PRC and PWB, future work will include updates to the estimates each year from 2022 to 2025, and forecasts through 2060.