Smarter Water Meters Can Help Enforce Water Restrictions

People are moving to sun-drenched areas. The problem is that many of the popular areas also have a shortage of freshwater. The issue is well-known in Southern California, Nevada, and Arizona, but it also affects other fast-growing regions that lack freshwater sources, such as many cities in the Middle East and Asia.

Traditional solutions include imposing water restrictions, digging deeper wells, building longer water pipelines to more remote sources, and renegotiating water rights with adjacent regions. Desalination plants are also increasingly used in regions that are near a source of seawater. All of these approaches are intensely political, as they tend to be costly, have environmental implications, and often involve undesirable tradeoffs.

The Use of Water Restrictions

The default solution is to enact temporary water restrictions and hope that Mother Nature refills the aquifers and reservoirs. Sometimes this works. Other times, the temporary restrictions remain for years. A challenge is how to enforce water restrictions on those homes that refuse to comply.

The worst abusers have their water supply turned off. A less draconian approach is to install a restrictor. This device is added behind the water meter and reduces the maximum water flow to 1 gallon per minute. This is adequate for a sink but an annoyance for a toilet, shower, or washing machine, or for a large family. An irrigation system with this level of water flow would be ineffective.

Such restrictors also raise the issue of fairness, since a large family may legitimately need more water for basic functions compared with a person living alone. That person may be very wasteful but not raise an alert because their overall use is modest.

Freshwater Disaggregation Is Just around the River Bend

A more equitable approach would be to disaggregate the use of water within the home, just as some utilities disaggregate electricity use to discern how individual homes use power. Similar technology can be applied to water meters to determine whether water goes toward personal use (e.g., drinking or brushing teeth), washing machines, dishwashers, toilets, leaky pipes, or bulk uses (e.g., irrigation, filling pools, or car washing).

This capability is not speculative. Fluid Science Services and Flume make meters that clamp on a water line, use ultrasound waves to measure instantaneous water flow, and identify how much water is used for different applications. The logic for water disaggregation is more straightforward than for electric disaggregation because there are fewer usage types, and these usage types tend to have distinct patterns that are easy to identify. The analysis is sent to the smartphone of the homeowner.

Going with the Flow into the Future

The Fluid and Flume meters are added to an existing water system. The next step on the technology roadmap is to integrate smart water meters that can connect to the advanced metering infrastructure operated by utilities. Currently, several water meter companies have announced analytics that can flag the presence of leaks along with accounts that may have violated water conservation restrictions. However, so far none have announced full disaggregation for water applications.

The advantage of full disaggregation is that the utility can take the initiative to educate the homeowner about how to conserve water in a way that is highly customized for the individual. This kind of support is starting to happen with disaggregation data from electric meters. Applying disaggregation technology to water meters, particularly in areas that are under water stress, is an effective way to reduce use with minimal impact on citizens with higher water needs.