Science Moab talked to Dr. Crystal Tulley-Cordova about sustainable water practices in Navajo communities. 

Crystal Tulley-Cordova, Ph.D., is a principal hydrologist in the Navajo Nation Department of Water Resources, doing water-related research and projects since 2013. Dr. Tulley-Cordova told Science Moab that the knowledge and experiences she has gained over the years help her assist Navajo communities to use their current knowledge about water to build sustainable water projects, seek funding for water-related research, and protect and manage water resources across the Navajo Nation.

Science Moab: You had this background and interest in water and hydrology and then and then you took it to specifically applying your interests in water and hydrology on the Navajo Nation. Can you describe the path that got you to your current role?

Tulley-Cordova: For me, it was really about having a better understanding of the place that I come from, the Four Corners region of the United States, and having an understanding of different parts of the water cycle and being able to quantify that information for the use of water managers within the Navajo Nation.

Our Indigenous knowledge is passed down through oral history and discussion: Both of my grandmothers told me that all water is connected. [In my research,] I was really looking at the thumbprint of water, looking at stable isotopes of water. Water looks different isotopically throughout the world, and by using stable isotopes, I am able to see the connection among all water sources, meaning the precipitation that comes in the form of rain and snow, groundwater springs and streams, both ephemeral and perennial, and have the opportunity to look at that connection with lakes as well. That’s what my research really did.

Science Moab: Can you describe the hydrology of the larger Navajo Nation and just talk about where the water comes from?

Tulley-Cordova: In addition to my research of looking at stable isotopes, I also did an evaluation of hydroclimatic regions in the Navajo Nation. [Hydroclimate is the scientific field that combines hydrology and climate to study how water and its processes impact Earth’s climate. -ed.]

When you drive through the Navajo Nation, either from east to west or from north to south, what you can definitely see are changes in vegetation. Those changes in vegetation allow us to make hypotheses that there are most likely changes in precipitation that contribute to what vegetation may be available in different regions. As a scientist, it’s important to be able to have an understanding of these different precipitation regions throughout the Navajo Nation. It’s important to have that understanding because then you can better understand where your recharge sources are. It’s always important to have sustainability in your system.

Science Moab: I also know that some of your work has dealt with issues of safe drinking water. I was wondering if you could talk a little bit about those issues within the Navajo Nation and how you and others are working to address them.

Tulley-Cordova: Approximately 30% [of the Navajo Nation] does not have running water. An effort that we made in collaboration with the Indian Health Service was to be able to help construct as well as get information out about 58 new transitional water points. We have 110 Navajo communities, and of those, 58 didn’t have watering points. In addition, through a program called Navajo Safe Water, it is possible to get a five-gallon jerry can as well as disinfecting tablets so that you can not only gain access to water, but you can store water safely as well. This was all funding that had been appropriated through the federal CARES Act in collaboration with the Indian Health Service.

Science Moab: Are there any topics or that are meaningful to you that you think should be put out there? 

Tulley-Cordova: I definitely think one topic, not only for the Navajo Nation but also for the western states at large, is drought. What needs to be understood is that when you’re in extended periods of drought, a few precipitation events doesn’t get us out of that drought. You would need an extensive amount of precipitation to be able to help us recover from that drought over an extended period of time, definitely longer than the few days that we receive constant precipitation.

In July, I visited the second-largest reservoir in the Navajo Nation, and it was dry. I know it’ll take a significant amount of precipitation to bring that system back so that people in that area are able to use the water in that reservoir for farming practices that they have done for generations.