The federal Water Quality Portal gives disparate water quality data sets and resources a home on the Web
Crater Lake in Oregon is famous for its clear blue waters. Researchers use water clarity data to explore the resources offered by the Water Quality Portal. Credit: Sobolevnrm
Source: Water Resources Research

Understanding the state of Earth’s aquatic systems is crucial to sustaining agriculture, protecting water resources, mitigating hazards, and even safeguarding national security. But the data on the globe’s aquatic systems are collected by researchers from hundreds of different organizations and research groups, and data modeling, observational methods, formats, and data access can be inconsistent between these groups. Furthermore, not all of these data are available on the Web. These discrepancies confound the efforts of scientists to research freshwater systems.

To address this challenge, the U.S. Environmental Protection Agency (EPA), the U.S. Geological Survey (USGS), and the National Water Quality Monitoring Council have collaborated to produce the Water Quality Portal (WQP), a single Web interface that aggregates more than 297 million water quality records from more than 2.7 million distinct sites and offers data services as well. In a new study, Read et al. describe the framework of the WQP and conduct a case study of water clarity across the United States to demonstrate some of the project’s capabilities.

The goal of the WQP is to offer researchers a common data standard, Web services, and a Web interface for freshwater quality data. It was first launched in 2012, with records from more than 450 organizations and three primary data sources: the USGS National Water Information System (NWIS), the U.S. Department of Agriculture’s Sustaining the Earth’s Watersheds–Agricultural Research Data System (STEWARDS), and the EPA Storage and Retrieval (STORET) system. The data can be queried by type of collection site, time, and geography, as well as water quality variables—from temperature and water level to complex physical, chemical, or biological characteristics. The data model the project uses as a standard is the Water Quality Exchange model, developed by the Environmental Information Exchange Network.

To test the capabilities of the WQP, the authors looked at regional water clarity in lakes, reservoirs, and impoundments (reservoirs formed by dams) across the United States. Specifically, they used used WQP to analyze data records of Secchi depth measurements, which are calculated using an opaque disk (a Secchi disk) lowered into waters to gauge the depths at which the disk ceases to be visible from the surface. They were able to identify large-scale regional and seasonal changes in water clarity: Lakes in the southern United States had the lowest clarity, those in the Northeast had the highest, and those in the Midwest displayed the greatest seasonal variability.

According to the authors, large-scale water quality research using a water clarity metric like their case study could offer significant economic and ecological benefits, just one example of the kind of research possible using WQP resources. An exceptional volume and variety of water quality data are now available to the public, and community use and engagement will only help to improve the data model, quantity, and tools available. Such community use will strengthen scientific understanding of Earth’s aquatic systems. (Water Resources Research,, 2017)

—Lily Strelich, Freelance Writer


Strelich, L. (2017), Water quality database offers new tools to study aquatic systems, Eos, 98, Published on 17 March 2017.

Text © 2017. The authors. CC BY-NC-ND 3.0
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