2024 U.S. Data Center Energy Usage Report from LBL

Shehabi, A., Smith, S.J., Hubbard, A., Newkirk, A., Lei, N., Siddik, M.A.B., Holecek, B., Koomey, J., Masanet, E., Sartor, D. 2024. 2024 United States Data Center Energy Usage Report. Lawrence Berkeley National Laboratory, Berkeley, California. LBNL-2001637

2024 United States Data Center Energy Usage Report

Our local supervisors here in Prince William County, and our neighboring counties have been approving data centers without any plan. Loudoun County and Prince William, VA, have used "lenient" approvals to build a massive tax base that funds schools, social services, local government, and parks without that could not have been afforded without massive property tax increases. The need for high-capacity transmission lines and additional transmission has forced a reactive and haphazard response to the demands for power and other infrastructure.  We need to look at and plan for what is happening- the creation of a regional data center hub of global proportions.

About a year and a half ago the Lawrence Berkeley National Laboratory (LBL) issued a very important report, for planning infrastructure and the future of our nation. The article below is excerpted from that report cited above.

The Energy Act of 2020 called for an update to Lawrence Berkeley National Laboratory’s prior study entitled United States Data Center Energy Usage Report (2016). This report estimates historical data center electricity consumption back to 2014, relying on previous studies and historical data. This report also provides a forecasted range of future demand out to 2028 based on trends and the most recent available data. The figure below provides an estimate of total U.S. data center electricity use including servers, storage, network equipment, and infrastructure from 2014 through 2028.

U.S. data center annual energy use remained stable between 2014–2016 at about 60 TWh, continuing a minimal growth trend observed since about 2010. In 2017, the overall server installed base started growing and Graphic Processing Unit (GPU)-accelerated servers for artificial intelligence (AI) became a significant enough portion of the data center server stock that total data center electricity use began to increase. By 2018 data centers consumed about 76 TWh, representing 1.9% of total U.S. electricity consumption.

from LBL

 Since 2017 U.S. data center energy use has continued to grow at an accelerating rate, reaching 176 TWh by 2023, representing 4.4% of total U.S. electricity consumption. Lawrence Berkeley National Laboratory went on to forecast total data center energy use after 2023. It is presented as a range of the various scenarios of future equipment shipments and operational practices, as well as variations in cooling technology. There is a tradeoff between water use and energy use for cooling.

Cooling systems, such as shifting to liquid base cooling or moving away from evaporative
cooling determine a significant portion of energy use. Together, the scenario variations provide a range of total data center energy estimates, with the low and high end of roughly 325 and 580 TWh in 2028, as shown above.

Assuming an average capacity utilization rate of 50%, this annual energy use range would
translate to a total power demand for data centers between 74 and 132 GW. This annual
energy use also represents 6.7% to 12.0% of total U.S. electricity consumption forecasted for 2028.

Historically, data center electricity use increased substantially from 2000–2005, roughly
doubling during that period. During the early and mid-2010s, a shift from on-premises data
centers to colocation or cloud facilities helped enable efficiency improvements that allowed data center electricity use to remain nearly constant at a time when the data center industry grew significantly. During this period, improved cooling and power management, increased server utilization rates, increased computational efficiencies, and reduced server idle power allowed growth without increased energy use.

While many of these efficiency strategies continue to provide significant energy efficiency improvements, the expansion of data center services and new types of hardware has ended the era of generally flat data center energy use. The rapid growth in accelerated servers has caused current total data center energy demand to more than double between 2017 and 2023, and continued growth in the use of accelerated servers for AI services could cause further substantial increases by the end of this decade.

The current and possible near-future surge in energy demand highlights the need for future research to understand the early-stage, rapidly changing AI segment of the data center industry and identify new efficiency strategies to minimize the resource impacts of this growing and increasingly significant sector in our economy. The estimates in their report are based on a “bottom-up” energy use that calculates total electricity use from an installed base of data center equipment.

The lack of direct energy data available in a sector with rapidly evolving technologies limits the analysis. The results of the study with all its limitations indicate that the electricity consumption of U.S. data centers is currently growing at an accelerating rate. The compound annual growth rate was approximately 7% from 2014 to 2018, increasing to 18% between 2018 and 2023. Lawrence Berkeley National Laboratory estimates that the growth rate will range from 13% to 27% between 2023 and 2028. Many of those projects are already under construction and the GPUs ordered.

This surge in data center electricity demand needs to be understood in the context of the much larger national electricity demand that is expected to occur over the next few decades as our nation experiences a combination of electric vehicle adoption, onshoring of manufacturing, hydrogen utilization, and the electrification of industry and buildings. We as a nation need to meet data centers’ future energy needs, but also an economy-wide expansion of electricity infrastructure to meet all future needs.

PWC Environmental Sustainability Annual Report

The Prince William County Office of Sustainability has released its first Environmental Sustainability Annual Report, highlighting progress, success stories and ongoing efforts to advance environmental sustainability across the community. 

The report provides a comprehensive look at how the county is implementing the Community Energy and Sustainability Master Plan, or CESMP, and advancing the Environment goal outlined in the 2025–2028 Strategic Plan. It showcases innovative initiatives, measurable outcomes and collaborative efforts taking place across county agencies and the community. 

Let’s step back and review a little background:

In November, 2020 the Prince William Board of County Supervisors (BOCS) adopted the Climate Mitigation and Climate Resiliency goals: reducing greenhouse gas emissions to 50% below 2005 levels by 2030, sourcing 100% of countywide electricity from renewable sources by 2035, achieving 100% renewable energy in county government operations by 2030 and reaching carbon neutrality in county government operations by 2050. 

Then, Prince William County Board of Supervisors authorized the creation of a Sustainability Commission and Sustainability Office.  The first step was to hire a consultant to develop the Community Energy and Sustainability Master Plan (CESMP), which was to provide the road map for how the county will reach its climate goals.

If you read the CESMP (which was adopted in 2023) you will see that there are no realistic scenarios that achieve those goals in the stated time frame. “It was found that due to limited span of control, all five goals will not likely be met through County action alone. It is expected that there would be a gap in emissions reductions needed to hit our 2030 target even if all 25 high priority actions are implemented. It is recommended that the actions are implemented to the best of the County’s ability and to evaluate whether or not to bridge the potential remaining emissions reductions gap using high quality carbon offsets in 2030.” Nonetheless, we need to work towards a more sustainable future, even if we cannot meet the goals in the allotted time frame.

The Office of Sustainability’s mission is to integrate environmental sustainability across county government and the community to help meet the needs of a growing and evolving county. Undeterred by the challenge, their work supports the Board of County Supervisors’ vision of meeting current community needs while protecting quality of life and resources for future generations. 

To date, 17 of the plan’s 25 high-priority actions have been initiated, with 10 currently in active implementation. A great journey begins with a single step. Prince William County has begun moving towards our future. 

“We are excited to share Prince William County’s first Environmental Sustainability Annual Report, which highlights our progress in clean energy, sustainable mobility and long-term planning,” said Giulia Manno, Director of the Office of Sustainability. “This report helps our community stay informed, celebrate achievements and identify opportunities to work together for continued progress.”  

Since 2015, more than 3,100 residential solar systems have been installed across Prince William County. The county has also registered more than 7,600 battery electric and plug-in hybrid vehicles. Since 2021, the county has installed 85 electric vehicle charging stations at county facilities. In addition, rooftop solar systems have been designed for several county buildings. 

The county is also making progress in protecting natural resources and improving environmental resilience. In early 2025, Prince William County completed the restoration of 4,785 feet along Powell’s Creek in the Montclair community, helping reduce flooding and improve water quality. Additionally, a Bandalong trash collection system installed in Neabsco Creek removed 2,185 pounds of debris in 2025, helping prevent trash from entering the Potomac River. 

“This report reflects our commitment to building a more sustainable and resilient Prince William County,” said County Executive Chris Shorter. “The progress highlighted here shows how we are putting our Strategic Plan into action while continuing to invest in the long-term well-being of our community.”

These are all very small steps compared to the challenges faced in achieving the climate and sustainability goals. The challenge was made more difficult by the vast expansion of approved data center operations in the county. Through 2023, the Metropolitan Washington Council of Governments (MWCOG)  updated Greenhouse Gas (GHG) Inventory Summaries show that Prince William County’s community-wide net emissions increased by 22% between 2005 and 2023.

Nonetheless, while total emissions rose by 22%, the county experienced a 42% growth in population since 2005. The per-capita climate footprint is shrinking. While individuals may be getting more efficient, the rapid scale of development is outpacing those gains. Emissions from commercial buildings (mostly data centers) and on-road transportation remain the primary contributors to the greenhouse gas emissions.

MWCOG notes that the county’s forests and trees currently sequester approximately 368,000 metric tons of carbon annually which offsets about 7% of emissions. However, the rapid development that the county has been experiencing has reduced the tree cover. The July 2025 Tree Cover Fact Sheet reported a net loss of 1,952 acres of tree cover on developed or developing lands. This was the result of losing 2,311 acres (largely to impervious surfaces like roads and buildings) while only gaining 360 acres through new growth or planting.

The tree canopy in the Metropolitan Washington region as a whole dropped from 51.3% in 2014 to 49.6% in 2023, local data suggests Prince William has consistently remained below the regional average and the MCOG regional goal of 50% canopy coverage. 

The Environmental Impact of Data Centers

At the last meeting of the Potomac Watershed Roundtable Julie Bolthouse, Director of Land Use, at the Piedmont Environmental Council gave a presentation titled "The Environmental Impact of Data Centers.” The Piedmont Environmental Council (PEC) has extensively documented the environmental impact from data centers, in Virginia, which hosts the world's largest concentration of data centers in the world. I would like to present a few highlights from her talk.

Data Centers are no longer the office parks of the last century that employed lots of people (remember AOL, now long gone). They are now hyperscale behemoths which employ only a handful of people for landscape, security, and a few operators. According to PEC research, the expansion of the data center industry poses significant risks to energy grids, water resources, air quality, and local ecosystems.

This is especially true in Virginia which has three times the mega watts (MW) and square feet of data centers than anywhere else in the nation. Currently, there are about 70 million square feet of data centers now operating in Virginia; however, there are 285 million square feet of data centers that are approved or in the pipeline.

Along with the massive increase in square footage of data centers, is skyrocketing energy demand. In 2025 data centers used 24 Gigawatts (GW) of electricity in Virginia by 2030 data centers are forecast to use 57 GW in Virginia. A gigawatt (GW) is equivalent to the energy generated by a nuclear reactor or gas plant. Dominion Energy of Virginia has received 70 GW of load request and have 48 GW in contracts for power-21 GW of this is in the final stages of contract.

Due to the demand strain, Dominion Energy is providing incremental load. For example, when Dominion Energy receives a request for 300 MW of power, they start the customer with 25 MW and Dominion Energy vamps them up over time.

This all seems wildly out of control and unplanned be each locality only looks at land use. The locality does not look at the power demand or where the power lines will go. More concerning is that the cost of transmission lines and generation is spread amongst all power customers. The old model allocated costs assuming that residential growth is what was driving the growth in power demand, and large customers like data centers receive discounted rates. Of the transmission projects on Dominion Energy’s books:

• $2.4 billion for transmission lines that will provide power only for data centers
• $3.3 billion for transmission lines that will server data centers and other customers
• $1.8 billion for transmission lines that will serve others

Data centers are also impacting the air quality in our region. Data centers rely on massive diesel backup generators for outages. In Loudoun County alone, permits exist for over 4,000 generators with a combined capacity of 11 gigawatts. In all of Virginia there are 10,000 Tier II permitted diesel generators. In Sterling alone, there are 2,000 older Tier II diesel generators. . A PEC-commissioned study found that on-site power emissions could result in up to $99 million annually in health-related damages due to premature mortality and respiratory diseases. This is mostly from PM 2.5 micrograms/m3.

New power plants proposal are also impacting air quality. PJM is modeling that Virginia is going to triple their power generation and that is going to come primarily from gas turbines with data centers installing on-site gas turbines. DEQ recently changed their rules to allow data centers to essentially use their back up generators as peaker plants to avoid tanking down the grid.

Finally, water. Depending on the cooling system, a single data center can consume 3–5 million gallons of water daily, 60%-80% of this water use is consumptive. Julie warns that this usage stresses local watersheds and the Potomac river, especially during drought conditions which we have been experiencing the past few years. In Loudoun, the reclaimed water from the wastewater treatment plant is maxed out at 697 million gallons/day (90% of this is going to data centers). So the Loudoun County data centers draw an additional 952 million gallons of potable water to cool the data centers. While data centers represent only 1-2% of the water drawn from the Potomac River on average, in summer, data centers are 9-12% of the consumptive use of the Potomac River.

The wastewater from data centers contains high levels of salinity and total dissolved solids, corrosion inhibitors, biocides, chlorine, phosphates and other additives. The wastewater treatment plants can’t effectively remove all these contaminants.

The Key Environmental Impacts 

In summary Julie highlights several critical areas where data centers affect the environment:

• Energy Consumption & Grid Strain: This demand from data centers has led Dominion Energy to delay the retirement of coal plants and expand natural gas infrastructure to maintain reliability, threatening state climate and decarbonization goals.
• Water Usage: Depending on the cooling system, a single data center can consume 3–5 million gallons of water daily. This growing water use stresses local watersheds and the Potomac River, especially during drought conditions.
• Air Quality & Public Health: Data centers rely on massive diesel backup generators for outages. These generators increase the small particulate matter in our air.
• The data center buildout converts thousands of acres of agricultural land and forests into impervious surfaces, leading to increased stormwater runoff and pollution in local waterways.
• Local Community Impacts: Proximity to residential areas brings persistent noise pollution from industrial cooling fans and light pollution from 24/7 facility operations.

Prince William County Prefers Concentrated Development

Based on recent approvals and rezonings it is clear that the Prince William Board of Supervisors and Planning Department prefer concentrated development for Prince William County. They rationalize that they can use building techniques to protect the Occoquan Watershed as a substitute for maintaining open wooded areas. This rationalization is based on the belief that concentrated development paired with advanced technological mitigation can manage environmental impacts better than the "status quo" of rural development. I do not believe that they are right.  

The Board and Planning staff have argued that large-scale development allows for "unprecedented levels of environmental protection" that would not occur if the land remained privately owned and developed at lower densities. This is true, but it has served to protect the Occoquan Watershed for all of Northern Virginia.

Supporters, including Supervisor Kenny Boddye, argue that developers can implement specialized stormwater management systems that filter sediment and pollutants more effectively than the natural runoff from a privately owned 5-acre lot. There is no research for this argument either for or against.

Proponents also suggest that low-density rural development is less protected because the county has limited authority to regulate what chemicals (like fertilizers) private homeowners use or to prevent them from clear-cutting their own property. However, there are no restrictions on what chemicals hundreds of individual homeowners can use either. Small lot communities are notorious for their intense fertilization and management of the appearance of the community.

Though high-density approvals often come with proffered conservation easements that legally preserve a portion of the forest in perpetuity, there may be limited benefit to the watershed. The "edge effect" changes the soil moisture and temperature. This kills off sensitive native plants and allows hardy invasives to take over the ground layer. Within a decade, the small area forest has no "recruitment"—meaning no young native trees are growing to replace the old ones and it dies. The proffers contain no allowance for maintaining the forest.  In the Occoquan Watershed, a 50-acre contiguous forest is exponentially more valuable than five 10-acre "preserved" patches surrounded by pavement. The latter will almost certainly succumb to the "choke" within 15 years.

County staff have noted that while wooded areas help with traditional pollutants, "modern" concerns like increasing salinity (from road salt) are regional issues that require infrastructure-based management strategies rather than just land preservation. However, Extensive research, primarily led by the Occoquan Watershed Monitoring Laboratory (OWML) and published in journals like Nature, confirms a direct link between population growth and rising sodium levels in the Occoquan Reservoir. Average sodium concentrations at the dam have nearly tripled since the 1980s, now frequently exceeding health advisory limits. 

Research shows that for every 100 additional people per km², impervious cover in the watershed increases by 3%. This expansion leads to higher road salt application, with salt spikes occurring even as regional snowfall has decreased by 40% over the last century. In addition, approximately 64% of salt ions in the reservoir originate from the population via reclaimed water. You have more people and you have more salt. Also, research by Bhide et al. (2021) found that roughly 32% of the sodium mass in finished drinking water comes from the treatment plant itself due to chemicals (like sodium hydroxide) added to buffer pH and prevent pipe corrosion. 

The Planning Department's approach often involves "condensing development down" to specific areas, which they believe allows for larger contiguous blocks of undisturbed forest to be saved through cluster development provisions. However, the Planning Department has presented the arguments for the same density of housing on a clustered development for increasing the density of housing by 28 times. The Maple Grove plan for 279 houses naturally creates more total asphalt and roof area than 9 houses that could have been developed on that site by right. The "less impact" argument isn't about the total amount of impact, but about the intensity of impact per person. 

Despite these arguments, several major environmental and regulatory bodies have disputed the idea that these techniques can substitute for natural wooded areas. Fairfax Water & the NVRC have warned that runoff from new high-density sites could negatively affect drinking water for the nearly million residents that rely on the Occoquan Reservoir for their water supply.

Environmental groups note that large-scale development like the could lead to of tons of additional sediment flowing into the reservoir watershed annually and the Chesapeake Bay. Civic associations and community groups argue that approving high-density projects like Hoadly Square within the Occoquan Reservoir Protection Area (ORPA) "chips away" at the protection district right after its adoption.

Stormwater BMP’s -What you need to know

Last Friday the Potomac Watershed Roundtable met in Frying Pan Park in Fairfax, VA. One of the speakers was Allie Wagner, a Water Resource Planner at the Northern Virginia Regional Commission (NVRC). Allie was there to introduce us to the “Stormwater Best Management Practice (BMP) Maintenance Guidebook.” Recently updated and released. This guidebook is intended to be a  comprehensive resource developed by the Northern Virginia Regional Commission (NVRC) to help private property owners, homeowners' associations (HOAs), and business operators manage and maintain stormwater systems effectively.

The primary purpose of the guidebook is to reduce stormwater pollution—the leading cause of degraded local waterways—by ensuring that BMPs like rain gardens and detention ponds are properly maintained. According to the NVRC, property owner awareness of maintenance responsibilities varies, with owners of "resale" homes often unaware of their obligations compared to HOAs or businesses. Owners are typically responsible for maintaining specific features like rain gardens (ensuring 72-hour drainage), permeable pavers (sediment removal), and clearing vegetation from dry/wet ponds.

The guidebook attempts to provide practical, non-regulatory guidance and includes an introduction to how these systems function and why maintenance is critical. Guidance on how to identify problems, such as clogged pipes, erosion, or standing water.  Tools for budgeting routine and non-routine maintenance expenses. And contact information for local government agencies across Northern Virginia's member jurisdictions

The guidebook contains 14 Detailed BMP Fact Sheets for the most common BMP’s including:

• Dry Ponds (Extended Detention) and Wet Ponds (Retention).
• Rain Gardens (Bioretention Facilities) and Vegetated Swales.
• Permeable Pavement, Sand Filters, and Infiltration Trenches.
• Green Roofs and Rain Barrels.

an example from NVRC

According to NVRC, unmaintained BMPs can fail, leading to:         

• Increased discharge of nutrients, sediment, and toxins into the Potomac River and Chesapeake Bay.
• Potential flooding or erosion on-site.
• Possible violations of local ordinances or maintenance agreements with local governments.

Above and below are examples of two practices. You can find the guide and complete sheets for these practice at this link.

The Heat Island Effect from Data Centers

 (PDF) The data heat island effect: quantifying the impact of AI data centers in a warming world

Marinoni, Andrea et al, The data heat island effect: quantifying the impact of AI data centers in a warming world, March 2026, DOI:10.48550/arXiv.2603.20897 License CC BY-NC-ND 4.0

The article below is excerpted from the papers cited above. 

The urban heat island (UHI) effect plays a key role in the impact of anthropogenic activities on climate change and global warming. In a recent paper Andrea Marinoni at the University of Cambridge and their colleagues saw that the amount of energy needed to run a data center had been steadily increasing and was likely to “explode” in the coming years, so they wanted to quantify the impact.

From humble origins as rudimentary storage facilities to their current status as the lifeblood of the Internet and the Cloud, data centers have become foundational pillars supporting our digital lives.  Yet, their energy footprints and building structures are having an impact on climate change.

The researchers utilized 20 years of satellite measurements of land surface temperatures and cross-referenced the data against the locations of more than 8,400 AI data centers. To eliminate the possibility of impact from the urban heat island effect and recognizing that surface temperature could be affected by other factors, the researchers eliminated data centers in or near urban locations (like Loudoun County) and instead focused their investigation on only on data centers away from populated areas.

The goal was to quantify the land surface temperature increase caused by the establishment of an AI hyperscaler in a location, determine the region of influence of this increase; and estimate the population affected by the temperature increase.

from Marinoni, Andrea et al

They found that the average land surface temperature increase across the data centers was 2.07°C in the months after an AI data center started operation. The land surface temperature increase minimum and maximum were 0.3 °C and 9.1 °C, respectively. The 95th percentile of the land surface temperature increase after the AI data centers began operations is between 1.5°C and 2.4°C.

In addition, the researchers found that the impact of land surface temperature increase impacted a very large area and reached up to 10 km distance from the AI hyperscaler facilities. The data heat island effect seems to reduce its intensity to 30% within 7 km around the data centers. It was pointed out in 2023 by Kilgore et al that "Data centers account for 2.5% to 3.7% of global GHG emissions," which exceeds the greenhouse gas emissions from the aviation industry recorded at 2.4%. 

from Marinoni, Andrea et al

The increasing demand for AI-based services, processes and operations is leading to the proliferation of data centers worldwide that are extremely power hungry. This study shows a rather remarkable impact of the AI data centers on their local regions, which was found to be consistent across data centers worldwide and extends for several kilometers around the AI hyperscalers. The consistency, scale and extent of these effects lead the researchers to suggest that data centers are creating local climate zones - that they call the data heat island effect - is real, significant, and may have a non-trivial impact on global warming and climate transformation.

The data heat island effect could have a significant impact on the on planet since  the trends of data center energy consumption are expected to show a steep growth in the foreseeable future. The data heat island effect could become an additional factor in the changing climate, hence having a robust impact on communities at local, regional, and international level.

Review of Interventions to preserve Groundwater

 Global cases of groundwater recovery after interventions | Science

How communities are reversing groundwater depletion: lessons from 67 global success stories | UC Santa Barbara - Bren School of Environmental Science & Management

Global groundwater depletion is accelerating, but is not inevitable | The Current

Scott Jasechko, Global cases of groundwater recovery after interventions. Science 391,1218-1228(2026).DOI:10.1126/science.adu1370

The article below is excerpted from the article cited above and the UC Santa Barbara press releases linked above.

Groundwater supplies about 50% of the drinking water for the people on our planet. In addition, groundwater also supplies 40% of the irrigation water that feeds the people. Groundwater is essential. However, we are using groundwater at an unsustainable rate-faster than it is being recharged. The result is that mankind is depleting groundwater reserves at an accelerating rate.

In 2024 Scott Jasechko, an associate professor in the university’s Bren School of Environmental Science & Management, and his team at UC Santa Barbara compiled the largest assessment of historical assessment of historical groundwater levels around the world, spanning nearly 1,700 aquifers and 300 million water level measurement. That work presented a picture of dwindling groundwater resources and accelerating declines. But it also found that there are places where groundwater levels have stabilized or recovered. Groundwater declines of the 1980s and ’90s reversed in 16% of the aquifer systems the authors had historical data for. 

That finding served as the basis for the current study which looks at the success stores to understand the strategies that achieved them and might be applicable in other areas. Groundwater is the savings account for our fresh water resources. It is replenished by deposits from rain, snowmelt and surface infiltration. Communities can spend a lot of money building infrastructure to hold water above ground. But if you have the right geology, you can store vast quantities of water underground, which is much cheaper, less disruptive and less dangerous than building dams. The stored groundwater also supports the region’s ecology. Groundwater recharge can store six times more water per dollar than surface reservoirs.

Groundwater recovery can benefit economies and ecosystems. The benefits of groundwater recovery can include (i) halting land subsidence, (ii) slowing seawater intrusion, (iii) reducing drought vulnerability, (iv) restoring groundwater-dependent ecosystems, and (v) improving groundwater accessibility halting land subsidence,

However, there are also downsides to groundwater recovery. In some cases, recovering groundwater levels have introduced new challenges, such as (i) intensified flood hazards, (ii) compromised building stability, (iii) heightened liquefaction risks, (iv) degraded agricultural soils, and (v) increased pollution exposure

Right now, groundwater is being overdrawn. We can address these by enacting policies and creating infrastructure to reduce the demand on groundwater. Alternative water sources can offset groundwater demand or even be used to recharge the groundwater aquifer. The current study tries to organize 67 unique combination of factors to identify trends. They found two-thirds of the cases involved interventions from multiple categories, but finally broke the strategies into three categories.

Alternative water supplies

81% of the groundwater success stories included an alternative water source that helped offset groundwater demands. Professor Jasechko suspects part of this strategy’s appeal is that it requires the least behavioral change, the communities did not have to reduce total water use. But accessing alternative supplies is often expensive and can end up displacing the issue to another location.

Policy and market interventions

In contrast, policy changes benefit from low overhead and energy costs. They also most directly target the behaviors that led to drawdown in the first place. However, they often have major impacts on local economies that have relied on groundwater use for a long time.

Artificial groundwater recharge

Groundwater recharge can eliminate the need to reduce pumping, but the water needs to come from somewhere, and getting it into the aquifer requires energy. In addition, it potentially introduces contaminants into the aquifer.

Dr. Jasechko summarized his findings among the 67 cases of groundwater recovery reviewed into 10 themes. These include (i) the prevalence of cases involving multiple interventions, (ii) the high number of cases involving alternative water sources, (iii) reductions in pumping in some cases, (iv) the importance of sound implementation and enforcement strategies, (v) the possibility for groundwater recovery to begin shortly after some interventions, (vi) the potential upsides to gradual policy implementation, (vii) spatial variability in groundwater recovery trends, (viii) the impermanence of groundwater recovery, (ix) the importance of considering groundwater quality, and (x) direct and indirect impacts of climate variability on groundwater levels.

Jasechko et al

First, two-thirds of the groundwater recovery cases involve two or more of the three types of interventions (i.e., alternative water supplies, policy or market changes, and artificial recharge). Most (81%) groundwater recovery cases involve access to alternative water sources to offset groundwater demands. These alternative water sources can be from nearby surface water,  from recycled municipal water, from interbasin surface water transfers, or from reductions in upstream river diversions to enable more river water to reach a depleted aquifer farther downstream.

Groundwater recovery often coincides with reduced groundwater withdrawals. In some cases, groundwater withdrawals declined after policy . In other cases, groundwater withdrawals declined after the shutdown or relocation of industries or the reduction in irrigated acreage as cultivated lands were urbanized.

The magnitude of groundwater recovery can vary widely within a given area. Further, groundwater recovery is not always ubiquitous, with some monitoring wells recording groundwater storage increases but others capturing continued declines. Ground subsidence from excessive groundwater withdrawal was not reversed, it was only slowed or stalled.

Groundwater-level trends in shallower unconfined aquifers were found to differ from deeper confined aquifers because shallower and deeper aquifers often have different storage coefficients and different rates of groundwater recharge and groundwater withdrawals. The examples discussed in the paper (especially the detail provided on Be

This study is not a guarantee that any particular intervention will work elsewhere. It does not perform causal inference, but it provides what Dr. Jasechko calls a "menu of options" for resource managers, backed by documented outcomes from real-world cases across six continents. Dr. Jasechko’s collaborator, UC Santa Barbara professor Debra Perrone, is now working to build a comprehensive database of all locations where interventions have been attempted, including those that failed, which would enable more systematic analysis of what works and why.