Long-term water resources data collection network is shrinking

Though nearly 71% of the Earth is covered in water, less than 3% of Earth’s water is fresh water, and only about 0.3% is readily available to humans in lakes, streams, rivers, and wetlands.  Reliable accounting of this limited resource is therefore fundamental to manage freshwater allocations to both ecosystems and society.  Networks of stream gages, known as “hydrometric networks,” have traditionally provided scientists with long-term records of water flow, water height, and other water quality variables.  However, a recent study finds that the global hydrometric network is not keeping pace with freshwater monitoring needs around the world.  The number of stream gaging stations reporting data to publicly available data repositories, called Water Information Systems, is declining.

Freshwater Initiative researcher Julian Olden is a co-author on a new study which proposes prioritizing stream monitoring by identifying watersheds that rely on hydrologic data for conservation initiatives.  The authors explain that long-term data, and thus a hydrometric network of monitoring stations, is needed for sustainable water management.  Here, knowledge is power: it is imperative to know how much water is available, where it is available, and when it is available.

Long-term hydrologic data collected through hydrometric networks is used to evaluate climate effects on freshwater resources, to track changes in river or stream flow patterns, and to improve flood and drought forecasting.  However, two of the largest Water Information Systems, the Global Runoff Data Centre and the United States Geological Society’s National Water Information System, are shrinking in monitoring capacity due to financial vulnerability, weakening infrastructure, and shifting priorities away from long-term data collection.

The authors argue that shrinking Water Information Systems may compromise human responsiveness to water challenges and the ability to monitor freshwater biodiversity.  It is not possible to respond to global water crises if researchers cannot forecast them for lack of long-term data.  The authors identified watersheds with a “High Monitoring Need” that should be prioritized for their water scarcity, high flood risk, or high biodiversity.  Coupled with policy recommendations for the maintenance of hydrometric networks, this prioritization strategy may secure the continuation of long-term data needed for sustainable water management.

You may visually explore the data used in this study, including stream gage distribution and stressed watersheds in the United States, here.

You may read the full study, published in Nature Sustainability, here.