The Utah Division of Water Resources maintains a municipal and industrial water use reporting program that is unique within the nation. By using a single method to calculate the amount of water delivered to every public water system in the state, Utah leads the country in comprehensive reporting.
Comprehensive Reporting Methodology
The division's method for calculating Gallons Per Capita per Day (GPCD) includes all potable and non-potable water delivered to residential, commercial, institutional, and industrial users. Because this accounting method strives to include all water delivered to customers, Utah's reported water use may appear higher than other states or regions that utilize different metrics.
GPCD Calculation Process
The calculation of GPCD involves summing potable and non-potable water delivered to public water system customers and dividing that total by the full-time population within the service area boundary. This annual figure is then averaged over the number of days in a year.
Census-Based Population Estimates
Population estimates also play a critical role in these reports. While some entities may calculate population based on average persons per household, the division utilizes Census Bureau estimates for the permanent resident population within a water provider's service area boundary.
Importance of Data Tracking
Tracking this data is essential for long-term planning and accountability. Water systems receiving state funds for improvements must demonstrate water savings resulting from those investments. The division uses 2015 water use as a baseline to evaluate progress toward regional and county-level water conservation goals for 2030.
New Legislative Designations
Under SB 119, passed during the 2023 general legislative session, specific water conservancy districts have been designated to determine consumptive use numbers for certain counties. The four largest districts, known as the Prepare60 Center, will report annual consumptive water use for Class 1 and Class 2 counties.
The following designations have been made:
Central Utah Water Conservancy District for Utah County
Jordan Valley Water Conservancy District for Salt Lake County
Washington County Water Conservancy District for Washington County
Weber Basin Water Conservancy District for Weber and Davis counties
Comparing Different Water Metrics
Unlike the division's GPCD metric, consumptive water use reporting only counts water consumed by customers and does not include water returned to the system. Consequently, GPCD and consumptive use figures are not directly comparable.
The division provides access to various datasets through the Open Water Data website. This resource includes interactive maps, data visualizations, and information regarding Municipal & Industrial Water Use, Water-Related Land Use, and Water Budgets. The data can be explored or downloaded in several formats and is summarized by basin, county, state, or water supplier boundaries.
