TCR spoke with Jordi Vásquez, Environmental Scientist, Ram Verma, Chief, Market Instruments and GHG Compliance Branch, and Gerold Mateo Senior Hydroelectric Power Utility Engineer, from the California Department of Water Resources (DWR) about their recently released verified GHG performance metric for water – the first in California!

DWR manages the State Water Project (SWP), which supplies water to more than 27 million people and 750,000 acres of farmland. The metric identifies the amount of GHGs emitted per acre foot of water transported by the State Water Project.

DWR is a long-time member of The Climate Registry and a founder of the Water-Energy Nexus Registry, which is administered by TCR on behalf of California EPA. Read on “for insights” on how DWR developed the metric, lessons learned along the way, and how it is helping them help others in the water sector measure and manage their emissions.

What’s DWR’s history with the Water-Energy Nexus Registry?

DWR: DWR has been a member of TCR since 2010 and prior to that DWR reported to TCR’s predecessor, the California Climate Action Registry (CCAR). DWR works with water agencies to mitigate the impacts of climate change, primarily by helping them better understand and manage the GHGs within their own operations. Given that’s an important part of DWR’s role, it made sense to be a founding member of the Water-Energy Nexus Registry. It provides a good framework for how agencies can understand the energy impacts of their water operations so they can save money and reduce emissions.

Why did you decide to develop a GHG performance metric?

DWR: Protecting the environment is one of DWR’s goals, and we want to support the water sector to achieve carbon neutrality. We also know that water conservation is an important issue to the public. Developing the metric helps us do a number of things:

  • We understand our own emissions better so we can reduce our carbon footprint.
  • Water districts receiving water from the SWP can use the metric to understand the emissions of their water supply chains so they can improve efficiency in their systems , and costs associated with their operations.
  • Customers can better understand the carbon intensity of the water they purchase, and the wider implications of water usage.

Plus, the metric is in one centralized place on the Water-Energy Nexus Registry website so it is easy for the public and contractors to access.

What was the process for developing your metric?

DWR: We already had an accurate emissions inventory that includes Scopes 1,2, and 3 so it was pretty straightforward to develop the metric – it was only an additional couple of steps when we were reporting our emissions to TCR.

The hardest part was determining which of our regularly reported emissions pertained to water delivery. TCR helped guide us through that process. Once we figured that out, all we had to do was (1) flag these sources in the reporting tool (CRIS), and then they were transferred to the Water-Energy Nexus Registry, and (2) calculate our total annual water delivery. The metric was calculated automatically based on that information.

What tips would you give to water agencies thinking about developing their own GHG performance metric?

DWR: It definitely helps if you have a history of GHG reporting, but don’t let that stop you. In fact, our number one tip is to just get started. It will become easier over time. We have over 300 facilities under our control and our initial challenge was to collect all the emissions data and their sources. But we overcame that hurdle and now we can quantify our emissions at a detailed and accurate level.

It also helps to be part of a larger group and working with others in TCR or the Water-Energy Nexus Registry. It is great to learn about what others are doing, even if they have different water usages and emissions profiles.

And, the last thing is to use the resources that are available to you – you don’t need to reinvent the wheel. TCR and the Water-Energy Nexus Registry provide guidance, trainings and a streamlined process for reporting and benchmarking your emissions. They’re a great resource when you’re starting out.


California DWR wrote a piece about publishing California’s first-ever GHG metric for the water sector – read it here!