Using Data Analysis to Improve Household Water Conservation

Water utilities are in the business of selling water to their customers and derive some of their revenue from the volume of water their customers consume. Utilities are also stewards of a precious and limited resource. Utilities may need to ask their customers to conserve water for a number of reasons including: - The utility is facing supply shortages due to drought, - The utility reaching its treatment or storage capacity, - The utility is reaching the limits of its water rights, and - The utility has a growing customer base to serve. This presentation will tell the story of the Omaha Tribal Utilities Department (OTUD), a small drinking water utility serving the Omaha Tribe of Nebraska and Iowa, that has taken steps to promote household water conservation. OTUD's service territory has been in a high level of drought for the past few years, and the FEMA National Risk Index rates the chance of drought in OTUD's utility service area as 'Relatively High' compared to other parts of the United States. In addition, OTUD serves many less fortunate households, and there was a concern that high household water usage would lead to unaffordable bills. The Omaha Tribe strongly believes that water is sacred-'Ni Waxube' in their language. 'Sacred Water' is even written on their water tower. Residential water customers are responsible for approximately 90 percent of total water consumption for OTUD. The remaining non-residential customers include the school, medical center, government buildings, churches, and a handful of small businesses. It made sense for OTUD to focus primarily on examining residential consumption. OTUD believed that their households were using a higher-than-expected level of water. Residential customers use water in ways that are considered 'necessary' for modern life-for cooking, bathing, laundry, washing dishes, and cleaning. These uses of water are all inside of a home, and they should average about 60 gallons per person per day. Water is also consumed in ways that are considered 'unnecessary.' Some residences use water for outdoor purposes such as washing cars, watering lawns and flowers, and filling swimming pools that are not necessary to sustain life. Leaks are another form of unnecessary water use because they waste water but could be repaired. Outdated fixtures such as toilets, showerheads, and faucets can consume large amounts of water unnecessarily compared to modern fixtures. OTUD wanted to understand how their customers were using water and dug into their usage data for clues. The utility has an AMI system and has access to helpful, granular information on the water usage of each of their customers. Their meter software alerts the utility to the likelihood of a customer leak. They also looked at hour-by-hour water usage for all residential customers for an entire year to measure the volume of water consumed during the hours most residents would be asleep. OTUD also dug into demographic data on the community from the U.S. Census and from Tribal records. For example, they assessed the age of the housing stock in their service area to determine the likelihood that households had outdated fixtures. OTUD looked at several innovative measures to assess household water consumption. They compared high use months to average water usage for each customer to determine how many customers had irregular consumption patterns. They also calculated the percentage of annual water consumption for each customer during the summer months to see if customers used higher amounts of water seasonally. They compared monthly water consumption to expected usage based on household size, combining their meter data with Census data. The data analysis showed that water use for many residential customers exceeded 60 gallons per person per day. Of the three primary drivers of unnecessary water use-outdoor use, leaks, and outdated fixtures-the analysis concluded that OTUD had all three. This presentation will explain the data metrics that OTUD used to measure household water consumption and will also identify the Census tables that utilities can use to access key demographic information. Based on the data analysis, OTUD began a program of demand management. They realized that a single approach to reducing household water consumption would be unsuccessful because the high usage was caused by multiple factors, so they are considering multiple programs to reduce household water consumption. The first step is a program to repair leaks in the homes of customers. Many of OTUD's customers are less fortunate, and a large percentage of their customers live in housing owned by the Tribal Government, though the occupants pay the water bills directly. It made sense for the utility to conduct these plumbing repairs free of charge to the occupants, and they have started this effort already. There are noticeable reductions in water usage from homes where plumbing has been repaired. OTUD is also considering a program to replace what are expected to be outdated toilets, faucets, showerheads, and perhaps appliances in many of these homes. About 45 percent of their service territory's housing stock was built before 1980 when toilets used 5 gallons per flush and showerheads used 4.3 gallons per minute. The analysis showed that significant water reductions are likely from replacing these old fixtures with modern, water-efficient fixtures. The program will likely begin with houses owned by the Tribal Government but ideally will eventually serve all houses in the service territory. Because many households are less fortunate, these upgrades will be free of charge to the occupants. The utility is also considering ways to notify their customers about how their usage compares to neighbors and to a more efficient household and to offer specific advice about how to reduce water consumption. They are considering an innovative bill design that will allow customers to compare their usage to expected levels based on household size. The majority of houses in the service territory have four or more occupants. Some likely exceed 10 occupants. Multi-generational households and multi-family households are common. Setting a single water use gallon target for all households would be inaccurate. The presentation will explain all these efforts in detail and offer an update on where the programs stand, as this is an ongoing process at the time of abstract submission.