Opportunities for improving current statewide urban water use reporting

EXISTING STATEWIDE WATER USE REPORTING

Currently, California collects utility-level water use metrics through three channels: the State Water Resources Control Board (SWRCB) conservation reporting, Department of Water Resources (DWR) Urban Water Management Plans, and SWRCB Drinking Water Program public water system statistics (PWSS).  

These sources provide similar but distinct water use data online over overlapping dates.  Starting in 2013, SWRCB has reported monthly averages online while also tracking mandatory water reductions and enforcement. DWR has annual usage data from 2010 available online in excel format but is updated only once every five years. Lastly, the public water system data available online has tracked annual use (2011-2013) and monthly use (2013-2014) updated on an annual basis. 

Because each state agency collects data differently, the end result is a compilation of usage information of varying metrics, scales, and without context. The absence  of standardization and an inconsistent reporting structure significantly hinders and delays attempts to perform rapid and accurate analyses to compare current water use patterns within and across agencies and to project future trends and program effectiveness.

Current Statewide Urban Water Use Data World

Local factors such as evapotranspiration, irrigable area, and demographic characteristics need to be integrated with existing usage data to enable “apples to apples” comparisons of urban water use.  The California Data Collaborative has worked to supplement existing statewide urban water use reporting with that key context through novel data integration (evapotranspiration, population) and partnering with remote sensing experts (irrigable area).

Adding in key context

LIMITATIONS OF REPORTING TOTAL AND AVERAGE WATER USE BY UTILITY

The current monthly and annual total production and average water use statistics collected by the state obscure the substantial variation within urban water retailers whose populations vary from a few thousand to over four million, sit in vastly different microclimates and have widely different land use characteristics. This wide variation prevents meaningful comparisons across agencies. This data fails to capture temporal and intra-agency variations. Together these key contextual variables allow for meaningful benchmarking of water use at an aggregate level.  For example, utilities often have rebate programs, conservation outreach and rate shifts ongoing simultaneously. With only total or average water use data available, it makes analyzing what has worked to achieve water efficiency challenging, if not impossible, at a statewide level.

NEW DATA INFRASTRUCTURE TO POWER A QUANTUM LEAP FORWARD

A coalition of local water utility managers have come together to test the value of integrating and standardizing customer use data.   By providing their daily metered water use data along with the key contextual information described above (ET, irrigable area, population) to the Strategic California Urban Water Use Analytics (SCUBA) data warehouse.  The increased knowledge from the Data Collaborative analytics is intended to provide utilities with a radically more rapid view of program effectiveness, cost per program and how to better reach and respond to customer water use behaviors.  In addition, statewide data integration and standardization will allow for comparative analyses of customer usage changes attributed to water conservation initiatives such as turf rebates and public outreach as well as projections of future patterns.

This new SCUBA data warehouse will help routinize best in class econometric evaluations such as measuring the impact of service area specific rates on their unique customer water demand.  These measurements will support water managers in implementing rate structures that have both a conservation price signal and ensure revenue stability with less water sales.   That underlying data infrastructure has broader uses in providing analytics to water utility managers better, faster, and cheaper to power targeted marketing, program evaluation and demand forecasting.  We’ll elaborate those in the upcoming posts, but the underlying value of measuring demand management actions at the customer level is simple. California needs prudent water management to navigate an uncertain future, and, as Peter Drucker’s famous quote suggests, “you can’t manage what you can’t measure."

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