River Flows hit all time low Around the World

In October the  World Meteorological Organization (WMO) released their report for worldwide water resources for 2023. The year 2023 marked the driest year for global rivers in over three decades, signaling critical changes in water availability in an era of growing demand.

The Key messages of the report:

• 2023 was driest year for global rivers in 33 years
• Glaciers suffer largest mass loss in 50 years
• Climate change appears to be making the hydrological cycle more erratic
• WMO highlights that only north America and Europe (and a few other places like Israel) have extensive monitoring networks that share data. WMO calls for better monitoring and data sharing.

WMP report that the last five years have had widespread below-normal conditions for river flows, and subsequently reservoir inflows have also been below normal. This reduces the amount of water available for communities, hydropower, agriculture and ecosystems, further stressing global water supplies, according to the State of Global Water Resources report.

Glaciers suffered the largest mass loss ever registered in the last five decades. 2023 is the second consecutive year in which all regions in the world with glaciers reported ice loss.

With 2023 being the hottest year on record (until 2024 data is in), elevated temperatures and widespread dry conditions contributed to prolonged droughts. But there were also a significant number of floods around the world. The extreme hydrological events were influenced by naturally occurring climate conditions – the transition from La Niña to El Niño in mid-2023 – as well as human induced climate change.

from State of Global Water Resources report.

“Water is the canary in the coalmine of climate change. We receive distress signals in the form of increasingly extreme rainfall, floods and droughts which wreak a heavy toll on lives, ecosystems and economies. Melting ice and glaciers threaten long-term water security for many millions of people. And yet we are not taking the necessary urgent action,” said WMO Secretary-General Celeste Saulo.

“As a result of rising temperatures, the hydrological cycle has accelerated. It has also become more erratic and unpredictable, and we are facing growing problems of either too much or too little water. A warmer atmosphere holds more moisture which is conducive to heavy rainfall. More rapid evaporation and drying of soils worsen drought conditions,” she said.

“And yet, far too little is known about the true state of the world’s freshwater resources. We cannot manage what we do not measure. This report seeks to contribute to improved monitoring, data-sharing, cross-border collaboration and assessments,” said Celeste Saulo. “This is urgently needed.”

The State of Global Water Resources report series offers a comprehensive and consistent overview of what we know of water resources worldwide. It is based on input from dozens of National Meteorological and Hydrological Services and other organizations and experts. This was the third year for the State of the Global Water Resources report,  and is the most comprehensive to date, with new information on lake and reservoir volumes, soil moisture data, and more details on glaciers and snow water equivalent. So much more needs to be done. 

Because some of the most available monitoring data is from North America and Europe those areas had more detailed information and insight. North America, for instance, was affected by the 2020–2023 North American drought, but is also subject to groundwater depletion, in particular in California and in the High Plains. The average groundwater level in 2023 was below normal or much below normal in a high proportion of wells over a large part of North America, in particular in the western and midwestern United States,

High precipitation directly contributes to an increase in groundwater levels through the recharge of aquifers. High precipitation also tends to reduce groundwater abstraction, as more surface water is available, less irrigation (or lawn watering) is necessary and the soil moisture is higher, which indirectly contributes to an increase in groundwater levels.

Data were collected over the period covering the last 20 years, from 2004 to 2023.  It is not straightforward to identify the reasons behind these regional trends, because groundwater is under the influence of climatic variables and other anthropogenic variables, such as abstraction and land use/ land cover changes. Some aquifers have a rapid response time between the change in the boundary conditions (such as a groundwater recharge) and the corresponding change in groundwater level, however the response time in other aquifers can be several years or decades long. It is difficult to utilize general observations with this type of time lag to for policy and manage resources. Nonetheless, it needs to be done.

Currently, 3.6 billion people face inadequate access to water at least a month per year and this is expected to increase to more than 5 billion by 2050, according to UN Water.  We do not have enough monitoring here  in the United States to adequately understand and manage our water resources. We are merely responsive to shortages not proactive. The Prince William County Board of Supervisors recently took the first step locally.

At the request of the Sustainability Commission, the Prince William Board of County Supervisors (Board) accepted the Sustainability Commission Resolution Number (Res. No.) 24-013 to direct County staff to assess the sustainability of the County’s groundwater supply related to climate change, urbanization, and other stressors.

Public Works staff worked with the United States Geological Survey (USGS) and Virginia Tech’s Occoquan Watershed Monitoring Laboratory (VT/OWML) to develop the scope of the study. A joint proposal was received from the USGS and VT/OWML with a total cost of $480,000, the request for $500,000 includes any contingency costs that may arise above this cost proposal.

In November, the Prince William  Board of County Supervisors voted to transfer - $500,000 from Contingency to the Department of Public Works for a countywide Groundwater Study.