Why SAWPA’s Water Use Efficiency Tools Are Necessary
In 2018, the California Legislature enacted two bills – Senate Bill 606 and Assembly Bill 1668 – to establish new regulations for long-term improvements in water use efficiency. These two bills require urban water suppliers* to implement permanent water use reporting and meet agency-wide targets that will be enforceable in the long-term.
SAWPA has several tools that can assist agencies located in the Santa Ana River Watershed comply with the new laws. These resources include:
SAWPA can help agencies calculate outdoor water demands in their service areas using 2015 aerial mapping data at 3-inches-per-pixel resolution. To create outdoor water budgets by parcel, the data was analyzed to identify different landscape types such as turf grass, trees, shrubs, and pools.
Customer Parcel Water Budget Tool
This technology allows agencies to analyze outdoor water budgets at the parcel level and compare them to billing data. Because the tool is web-based, aerial mapping data can be accessed without using up storage space on an agency’s server.
Matching Customer Meters to Landscape Measurements
SAWPA has partnered with Miller Spatial Services to help agencies digitize the locations of their customers’ water meters and assign each meter location to an outdoor water budget. This is being done through GIS software using the 2015 aerial mapping dataset, which identifies different categories of landscape type by parcel.
Making Water Conservation a California Way of Life Legislation (SB 606 and AB 1668)
Under the new laws, suppliers’ water use will be compared to a target that is calculated using the formula below. The legislation refers to this target as the “urban water use objective.” Instead of basing the target on prior use, as was done with the emergency drought regulations in 2015, the formula calculates the volume of water that is needed to efficiently meet the needs of a supplier’s customers.
The Urban Water Use Objective formula accounts for local conditions such as population, weather and irrigable area. It is important to have tools that can aggregate this data so the objective and water usage can be reported by water agencies to the State annually.
Urban Water Use Objective Formula (Simplified)
For a full explanation of the Urban Water Use Objective Formula, please see the Making Water Conservation a California Way of Life Primer available at the State Water Board’s Water Conservation Portal website:
State Provided Aerial Imagery
In 2021, the state provided a 2018 aerial mapping dataset at a resolution of 1-foot-per-pixel that can be used by agencies to calculate their water use objectives.
State Levied Fines
Using SAWPA water use efficiency tools can help agencies avoid fines that will be levied in the long-term for those that do not meet their objective. These fines would be levied on the agencies, not individual customers.
Fine-tuning the SAWPA Tools
More work is needed by the state before water suppliers can start reporting against calculated objectives (i.e. budgets). For example, some landscape areas are unique to certain parts of California. The state will work with water agencies to develop standards for swimming pools, spas and other features. SAWPA will continue to engage with the state and fine tune any SAWPA-led aerial mapping efforts as specific standards are developed.
*A water supplier, either publicly or privately owned, that directly provides potable municipal water to more than 3,000 end users or that supplies more than 3,000 acre-feet of potable water annually at retail for municipal purposes.