Infrastructure Challenges: It’s Not Just the Weather

Overview of Recent Water Main Breaks

From January 1 through January 31, 2026, WSSC crews responded to an alarming 360 water main breaks and leaks. The high volume of active issues, with approximately 48 new reports on January 31 alone, ultimately prompted the utility to issue an "Essential-Water-Use-Only" request to customers. This action was a direct response to the overwhelming number of simultaneous breaks and leaks, which strained repair resources.

Beyond Weather: The Role of Aging Infrastructure

Although extreme weather conditions can trigger a spike in water main breaks, the underlying challenge for WSSC Water is rooted in the aging infrastructure and a replacement rate that is not keeping pace with the system’s needs. More than 40% of WSSC's 5,977 miles of water mains are over 50 years old. Many of these pipes are made from brittle cast iron or are unlined, and were installed between 1916 and 1976. As a result, a significant portion of the system has reached or surpassed its intended design life.

Replacement Rate Lagging Behind System Age

The planned pipe replacement rate for the WSSC system is 33 miles per year. For a network totaling 5,977 miles, this pace would result in a complete system replacement every 181 years. However, since 2018, WSSC has replaced only 22 to 25 miles of pipe annually, extending the replacement cycle to more than 200 years. No set of water mains is designed to last such an extended period. Consequently, as the infrastructure continues to age faster than it is being replaced, WSSC faces an inevitable increase in pipe failures.

Comparison with Fairfax Water’s Response and System Age

For context, consider Fairfax Water’s experience during the same period. Following Winter Storm Fern in late January 2026, Fairfax Water also reported a significant number of water main breaks throughout Northern Virginia. However, while WSSC Water reported more than 360 breaks and leaks and implemented an essential-use-only mandate, Fairfax Water managed the situation without issuing a similar broad conservation request.

On January 31, 2026, the Fairfax Water dashboard reported 8 active leaks being addressed and a total of 125 repairs completed during the preceding 30 days.

System Size and Performance Comparison

Fairfax Water maintains approximately 4,027 miles of water mains compared to WSSC’s 5,977 miles. Despite having about 67% of the miles of pipe and experiencing the same weather conditions, Fairfax Water’s number of breaks in January 2026 was only 36% of WSSC’s total. This disparity highlights differences in infrastructure age and maintenance effectiveness between the two utilities.

Relative Infrastructure Age

Fairfax Water’s distribution system is considerably younger than those of WSSC and DC Water. The median age of Fairfax’s water mains is 40 years, and approximately 56% of the mains have been in service for 30 years or less. In contrast, WSSC’s water mains have a median age of 53 years, underscoring the larger proportion of older, more failure-prone pipes in WSSC’s system.

We Need to Maintain the Riparian Buffers we Keep

The Chesapeake Bay Protection Act requires that we keep the riparian buffers-the vegetated areas bordering rivers and streams that act as the "last line of defense" for watershed health. These 50-foot strips of trees are highly effective natural filters that purify water before it reaches the main channel. The riparian buffers serve to remove nutrients pollution, remove sediment and assist in the breakdown some pesticides and herbicides.

Plants and soil microbes capture and transform excess nitrogen and phosphorus from fertilizers or animal waste. Some studies show buffers can reduce nitrate levels by up to 95%. Dense vegetation and leaf litter slow runoff, allowing up to 90% of suspended solids (dirt and grit) to settle out instead of clouding the water. Finally, microbes in the moist, organic-rich soil of a riparian buffer can metabolize and neutralize some common pesticides and herbicides, such as metachlor, much faster than bare fields. 

Watershed & Flood Management

Healthy riparian soils are naturally porous and rich in organic matter, allowing them to absorb high volumes of precipitation and surface runoff. Deep roots from trees, shrubs, and native grasses create a network that holds soil in place and facilitates water infiltration deep into the ground. A thick floor of leaf litter, twigs, and fallen logs acts as an absorbent layer that captures nutrients and further slows the movement of water. Native plants, such as sedges and rushes, are key indicators of a healthy, functioning "riparian sponge".

The riparian buffer including the streambanks and the substrate beneath the channel, acts as a large reservoir that retains water during high-flow conditions and releases it during dry periods to maintain streamflow. This  "natural sponge," buffers regulate the flow of water through the entire watershed. 

During heavy rains, the riparian buffers slow the velocity of floodwaters and provide temporary storage, which reduces peak flows and protects downstream communities from damage. Slowing the water allows more of it to soak into the ground, replenishing the local water table and maintaining steady stream flows even during dry summer months. Deep, interlacing root systems from trees and shrubs anchor the soil, preventing riverbanks from collapsing during high-flow events. 

Environmental & Aquatic Health

Buffers create a stable microclimate essential for many native species. The tree canopies provide shade that can keep water temperatures 3°C to 5°C cooler. This is critical for cold-water species like brook trout, which require high oxygen levels found in cooler water. Leaf litter and woody debris (fallen branches) that fall into the stream provide the primary food source for aquatic insects, which in turn feed fish and amphibians. Stretches of riparian forest serve as essential travel paths for terrestrial animals, connecting fragmented habitats across a developed landscape. 

Economic Value

There are also economic benefits of maintaining these natural systems.  Watershed conservation is often significantly cheaper than building new water treatment plants. However, these thin strips of trees along rivers are highly vulnerable to invasive species because they are essentially "all edge" and no "interior." Unlike deep forests, these narrow bands lack a protective core, making them easy targets for aggressive non-native plants and insects.

Structural Collapse via Invasive Vines

Thin strips are frequently dominated by invasive vines that physically overwhelm and kill the very trees meant to protect the waterway.  Vines like Oriental bittersweet and Chinese wisteria wrap tightly around trunks. As the tree grows, the vine "girdles" it, cutting off the flow of water and nutrients and ultimately killing the tree.  Aggressive climbers such as  English ivy and Mile-a-minute grow over the canopy, blocking sunlight and eventually starving the trees.  The added weight of these vines makes trees top-heavy and more likely to snap or blow over during high winds or heavy snow. 

Degraded Riparian Functions

When invasive species replace native trees in narrow strips, the critical services these buffers provide to the river are compromised.  Many invasive plants, like Japanese knotweed, have shallow root systems compared to native trees. This leads to a loss of streambank stability, increased soil erosion, which clogs the river with sediment and lowers water quality.  Invasive plants often fail to provide the same dense, high-level shade as native canopies. This allows more of the sun’s heat to reach the water, raising temperatures and depleting oxygen, which can be lethal for fish like trout.  Invasive leaf litter often decomposes at different rates than native leaves, altering the food source for aquatic insects at the base of the river's food web. 

The "Edge Effect" Vulnerability

Because these strips are narrow, they are exposed to constant "edge effects" that favor invaders over natives. Rivers act as highways for invasive seeds, which are easily deposited by floodwaters onto the disturbed, high-light edges of narrow buffers.  Invasive plants like Tree of Heaven (Ailanthus altissima) use "allellopathy"—releasing toxic chemicals into the soil—to prevent native seedlings from ever getting established.  Narrow strips dry out faster than deep forests. Invasives are often more drought-tolerant, allowing them to out-compete native trees that are already stressed by their exposed position.

In Virginia, narrow riparian buffers are highly susceptible to "edge-adapted" invasive species that thrive in the sunlight and disturbed soil common along riverbanks. We have all seen the narrow strips of dead trees wrapped in the vines of the invasive species.  The  species that are currently of high concern for Virginia's:

• Tree-of-Heaven (Ailanthus altissima): A fast-growing tree that outcompetes natives and serves as the primary host for the Spotted Lanternfly, another destructive invasive species.
• Japanese Stiltgrass (Microstegium vimineum): This annual grass blankets forest floors near streams, suppressing native groundcover through dense growth and chemical release (allelopathy).
• Oriental Bittersweet (Celastrus orbiculatus): A woody vine that spirals around tree trunks, eventually girdling and strangling them to death.
• Porcelain-berry (Ampelopsis brevipedunculata): A vigorous climber that smothers canopies, much like Kudzu, but is specifically aggressive in moist, sunny riparian edges.
• Japanese Knotweed (Reynoutria japonica): Notorious for its deep, aggressive root systems that can damage infrastructure; it forms dense monocultures that destabilize stream banks.
• Multiflora Rose (Rosa multiflora): A thorny, thicket-forming shrub that creates impenetrable barriers and displaces native vegetation.
• Autumn Olive (Elaeagnus umbellata): A shrub that fixes nitrogen in the soil, altering the chemistry to favor its own growth while shading out sun-dependent native plants.
• Hydrilla (Hydrilla verticillata): An aquatic plant that clogs waterways and displaces native aquatic life, often spreading via fragments moved by water or boaters. 

These wooded areas need to be managed to maintain their environmental function and prevent these buffers from becoming dead tree stands that will ultimately only serve as wildfire fuel. In Virginia, wildfires are a growing threat, driven by a convergence of climatic, ecological, and human factors. While Virginia typically sees most fires in the spring and fall, the risk is becoming more intense and unpredictable. In 2025 Spring Season: 437 wildfires were suppressed between February and April, burning over 8,100 acres and destroying 22 homes.

In the future the threat could be greater. Average temperatures which have risen over 2°F since 1900 in some regions—increase evaporation, causing forest fuels and soil to dry out more quickly. The 2025 Virginia Climate Assessment noted an increase in "short-term and flash droughts," which rapidly turn lush vegetation into dry fuel.  Combined with greater variability in wind patterns and humidity creates a "recipe for extreme fire behavior."

To control the wildfire risk, we need to control the spread of invasive plant species and the creation of dead tree stands. Riparian buffers left after development of wooded parcels must have continual management of invasive plant species. Successful management of these species requires a multi-year commitment, as many can resprout from small root fragments. 

• Prioritize Tree-Saving: Focus first on removing invasive vines from the canopy. Use the "window" method: cut vines at shoulder height and again at the base to kill the upper sections without pulling them down, which can damage the tree.
• Mechanical Removal: Hand-pull small infestations early in the spring (April–May) when the soil is soft and roots are smaller. Ensure you remove the entire root to prevent regrowth.
• Strategic Herbicide Use: For established woody plants like Tree-of-Heaven or Autumn Olive, "cut-stump" or "basal bark" treatments are often more effective than pulling. Always follow EPA-approved labels and avoid spraying near water during rain to prevent runoff.
• Proper Disposal: Never compost invasive plant debris. Bag seeds and fruit in plastic and dispose of them with regular trash to prevent accidental spreading.
• Re-plant with Natives: Once an area is cleared, immediately plant native alternatives like Black Willow or Serviceberry to stabilize the soil and shade out potential new invaders.  

NERC 2025 Reliability Assessment

 2025 Long-Term Reliability Assessment Overview

The North American Electric Reliability Corporation (NERC) released its 2025 Long-Term Reliability Assessment on January 29, 2026, highlighting significant reliability concerns for the PJM Interconnection. Over the past year, PJM’s risk designation shifted dramatically from "Normal" to "High Risk," primarily due to a staggering 69% projected increase in summer peak demand. This surge is attributed largely to the proliferation of data centers and artificial intelligence workloads. Simultaneously, PJM faces reduced supply reserve margins and expedited retirements of fossil-fueled generators, compounding these reliability risks.

from NERC

Key Drivers of Reliability Risks

Several critical factors contribute to PJM’s challenges:

• Rapidly rising demand from data centers, especially in Northern Virginia, is outpacing available supply.
• Accelerated retirement of baseload power plants—driven by policies like the Virginia Clean Economy Act (VCEA)—has reduced firm generation resources more quickly than reliable replacements can be integrated.
• The region is shifting toward weather-dependent resources, which increases the system’s vulnerability.
• Transmission infrastructure development is lagging, making it difficult to accommodate new loads and generation.

The VCEA, in particular, has been identified as a major contributor to PJM’s "High Risk" designation. This legislation mandates rapid retirement of fossil-fuel generators and promotes intermittent energy sources while failing to anticipate the explosive growth in data center demand. As a result, PJM is struggling to maintain adequate supply and reliability.

Grid Congestion and Economic Bottlenecks

The main cause of grid congestion has shifted in recent years. While previous challenges revolved around integrating geographically dispersed renewables—creating cost pressures in regions like MISO and ERCOT through 2024—the primary driver in 2025 and 2026 is a concentrated demand shock from data centers in PJM’s Northern Virginia corridor. This localized surge is creating immediate reliability and economic bottlenecks.

• From 2025 onward, congestion is most acute due to the unprecedented growth and concentration of new demand in PJM Interconnection. The electricity consumption surge from AI-driven data centers in Northern Virginia, now the world’s largest data center market, is overwhelming existing transmission capacity and resulting in years-long backlogs for new grid connections.
• The crisis in PJM centers around aging infrastructure unable to support overwhelming, localized demand—posing direct threats to both economic development and grid reliability in key load centers.

• Implementing targeted reliability initiatives

PJM Market Outcomes and Regulatory Responses

The results of the PJM Base Residual Auction for the 2027/2028 Planning Year, released December 17, 2025, reflected the region’s challenges. For the first time, the entire 13-state PJM footprint failed to meet its target reliability standards—driven by explosive demand from data centers and regulatory price controls. The auction price was capped due to a legal settlement intended to prevent runaway price spikes that could have severely impacted households and businesses across the region.

In typical markets, higher prices attract new suppliers. However, the extraordinary growth in data center demand has outstripped the energy sector’s ability to respond, especially given the industry’s regulatory structure designed to guarantee reliable service for all. PJM now has a significant backlog of new power projects awaiting construction. Historically, the grid was sized for stable demand and already paid for; new infrastructure increases capital costs for all users, not just new entrants.

Compounding these market pressures, many PJM states began retiring older fossil-fuel generation just as data center demand spiked, resulting in power shortages. The December 2025 auction price cap, again due to a legal settlement, was put in place to shield customers from potentially crippling increases across the entire region.

The cap reflects regulators’ belief that it would be unfair to make consumers pay "scarcity prices" for shortages resulting from policy decisions—such as permitting massive data center developments without adequate planning for power needs or transmission upgrades. State-level “Clean Energy Standard” laws in Virginia, Maryland, and Illinois have accelerated the retirement of dispatchable fossil-fueled power, outpacing the connection of new resources. Administrative delays in permitting and construction have further exacerbated the problem.

Reserve Margin and Emergency Measures

The December 2025 Base Residual Auction failed to secure enough "firm" power, such as coal, gas, or nuclear, to achieve the 20% reserve margin. The grid will enter the 2027/2028 year with only a 14.8% margin. To bridge this gap, the Virginia Department of Environmental Quality (DEQ) changed its guidance policy to allow data centers to legally operate their backup generators. This action included suspending certain environmental rules and provisions of the VCEA, permitting the use of Tier II diesel generators to prevent rolling blackouts that could result from the price cap-induced shortages.

Environmental and Public Health Implications

While these measures keep the "lights on" for residents and businesses, they come with significant environmental costs. Northern Virginia has, in effect, become a "de facto diesel power plant" during periods of extreme weather, undermining the core goals of the Virginia Clean Economy Act, which aimed to reduce carbon emissions. This shift has led to a larger regional carbon footprint and increased emissions of harmful air pollutants, such as particulates and nitrogen oxides (NOx), which pose serious public health risks.

The Virginia DEQ acknowledges that it has never performed a cumulative emissions modeling exercise for these clusters of backup generators. Under the latest guidance, if PJM declares a "Grid Stress Event" (such as a 48-hour cold snap), generator zones in Ashburn and Gainesville would become the main power source for data centers. This scenario could result in thousands of diesel engines running simultaneously near schools and homes, potentially releasing up to half of the region’s annual NOx budget within just a few days.

Operational Realities and Community Impact

In the most recent cold snap, PJM did not issue a mandatory Energy Emergency Alert (EEA) 3 that would have forced all participants off the grid. Nevertheless, several data center operators voluntarily switched to their backup generators to alleviate grid stress, ensuring that homes and families had electricity during peak demand.

Local advocacy groups, including the Coalition to Protect Prince William and the Piedmont Environmental Council (PEC), documented "hundreds and perhaps thousands" of diesel generators operating in Loudoun and Prince William Counties during such events. Data centers are not required to notify the state when backup generators are activated, creating a "blind spot" for public agencies, while residents are left to observe, hear, or smell the generators without official oversight.

 

Is the DMV falling from 1st World Status

 The residents of Montgomery and Prince George’s counties were under an urgent essential-water-use-only request from Tuesday, January 27 and remains in effect as continued through the weekend. 

This was due to the high number of water main breaks the system was experiencing threatening water pressure. Usually, WSSC can allow leaks to be left in place without disrupting customer service or overall system operations and get to them when they can. However in the recent cold snap following winter storm Fern, this approach could not work. To maintain system pressure, WSSC Water inspectors had to shut down broken/leaking mains before dispatching repair crews to the break to keep system pressures stable.

WSSC Water reported a sharp increase in water main breaks and leaks in late 2025 and early 2026, largely attributed to extreme cold temperatures affecting the Potomac River and the utility's aging infrastructure. 

from WSSC website

During Fiscal Year 2025, WSSC Water recorded 2,259 breaks and leaks. This was an significant increase (over 33%) from the 1,697 reported in FY 2024.WSSC typically averages nearly 1,800 breaks and leaks annually, making the FY 2025 count well above average.

During the current winter season, since November 1, 2025 until January 31, 2026, crews have responded to 906 breaks and leaks. From January 1-31, 2026, WSSC crews had responded to 360 breaks and leaks. This finally resulted in the  "Essential-Water-Use-Only" request due to the high volume of active breaks and leaks (approximately 48 reported on January 31 alone.

While the spike in breaks is triggered by extreme weather, WSSC Water and system observers point to a combination of aging materials and historic funding gaps as causing the current crisis.   Over 40% of the 5,977 miles of water mains are more than 50 years old. Many consist of brittle cast iron or unlined pipes installed between 1916 and 1976 that are reaching or have exceeded their design lifespan.

The replacement rate, which is currently planned at 33 miles per year is insufficient for a system with 5,977 miles of pipe. That would be a system replacement every 181 years.  While 33 miles was the target replacement rate, WSSC has actually replaced 22-25 miles of water pipe annually since 2018. Bringing the system replacement time span to over 200 years. No set of pipes will last that long. WSSC will experience increasing pipe failure.

 WSSC Water faces high levels of debt service (roughly 33% of total expenses) and water consumption that has remained "flat" for decades, which limits revenue. To address this, the utility proposed a $4.8 billion six-year Capital Improvements Program (CIP) for FY 2026–2031. In the Strategic Plan (FY 2025–2027)  WSSC stated that they plan to prioritize asset replacement based on maintenance history, soil conditions, and pipe material rather than age alone. They have also begun using zinc-coated ductile iron pipe, which is designed to last 100 years.

The FY 2026 budget will be impacted by the costs allocated to WSSC from repair and remediation from the collapsed section of the Potomac Interceptor, sanitary sewer line that collapsed on January 19 and overflowed into the Potomac River for 10 days releasing 400-600 million gallons of raw sewage into the Potomac River. DC Water reports that at the end of January that  the collapse site now isolated from the river using a section of the C&O Canal and work has begun to clearing the blockage in the damaged pipe section to allow the repairs to begin. As work progresses at the site, the environmental assessment and cleanup must also begin. DC Water is performing water quality sampling and surveying the areas impacted by the overflow into the Potomac, working in coordination with federal, state, and local partners to evaluate environmental effects and determine appropriate remediation measures.

The full cost of cleanup and remediation is still being determined. DC Water will share the expenses with their wholesale sewage customers—WSSC Water, Loudoun County, and Fairfax County—in proportion to their allocated pipe capacity for their sewage that is treated at Blue Plains.

In 2025, the "WSSC Planning and Reporting Act of 2025" was signed into law aimed to improve asset management standards and restore service reliability. The law mandates several critical milestones intended to reform the utility's management and oversight:

• Independent Review: WSSC Water must coordinate with the Department of Legislative Services to hire a third-party consultant to evaluate the utility's efficiency, sustainability, and budgeting processes.
• Reporting (October 1, 2027): The Office of Program Evaluation and Government Accountability must report its findings and recommendations to the General Assembly by this date.

Final Review (October 1, 2028): The Department of Legislative Services will issue a final report on the findings to the General Assembly.

Global Water Bankruptcy the New Reality

 In January 20, 2026, the United Nations University's Institute for Water, Environment and Health (UNU-INWEH) released a report titled "Global Water Bankruptcy." The report warns that some regions of the world have surpassed temporary water stress  and crisis and entered a state of irreversible water bankruptcy—a condition in which they cannot return to previous water levels. The world is using up its water savings (groundwater, lakes, ecosystems and glaciers) and can not survive on the annual precipitation. Below I have excerpted some of the content and summarized the major points.

Loss of Wetlands and Transformation of Water Systems

Over the past fifty years, the world has lost approximately 410 million hectares of natural wetlands. Groundwater now supplies about half of all domestic water and more than 40% of water used for irrigation, directly tying both drinking water security and food production to rapidly depleting aquifers. Around 70% of the world’s major aquifers are experiencing long-term decline, and excessive groundwater extraction has caused significant land subsidence spanning over 6 million square kilometers. In these areas—including over 200,000 square kilometers of urban and densely populated areas where close to 2 billion people live—land is sinking by up to 25 centimeters per year, permanently reducing groundwater storage and increasing flood risk. 

The rate of decline in water reserves is only accelerating. The authors report that since 1990 more than half of the earth's major lakes have declined. Mankind has drastically exceeded the planet's capacity to provide clean fresh water. Using technology and mining groundwater created the illusion that the planet's abundance of fresh water was greater than it actually was. 

 Human intervention over the past century has drastically altered the global water cycle. Construction of dams, diversions, drainage works, and canals has transformed river systems. Changes in land use, elimination of forests, irrigation, and groundwater pumping have shifted evapotranspiration and recharge patterns. Greenhouse gas emissions have warmed the atmosphere and oceans, changing precipitation, snowpack, glacier mass balance, and the intensity of weather extremes. Population growth, urbanization, and economic development have escalated water demand for agriculture, industry, energy, and cities.

Alteration of River Systems and Wetland Loss

About one-third of global river basins now experience significant changes in flow, whether from human modification or climate shifts. In some of the world’s most densely populated river basins—including the Colorado, Indus, Yellow, Tigris–Euphrates, Murray-Darling, and São Francisco—environmental flows are routinely reduced or eliminated entirely, weakening ecosystems’ ability to recover. In many cases, the "normal" baseline to which crisis managers once hoped to return has effectively disappeared.

Wetlands, which act as the "shock absorbers" of the water cycle, are disappearing even faster than forests. Since 1970, about 35% of natural wetlands have been lost, with wetlands vanishing three times more quickly than forests. As wetlands disappear, their water-storage and drought-buffering functions are lost as well.

The drying of river corridors and wetlands interacts with heat and drought, intensifying wildfire risk. Reduced soil and vegetation moisture, drained peatlands, and decreased surface water buffer contribute to more frequent and severe wildfires, which in turn affect air quality, carbon emissions, and watershed function.

In Summary:

Global Water Bankruptcy Overview

• The world is experiencing a state of Global Water Bankruptcy, where water use over the long term exceeds renewable resources and safe depletion thresholds.
• This condition causes irreversible damage to water systems, affecting billions of people and threatening global stability.
• Water bankruptcy occurs when both renewable and non-renewable water resources are depleted beyond safe limits.
• Persistent water shortages have turned once-episodic droughts into permanent conditions in many regions.

Importance of Water for Development

• Water is fundamental to life. Growing populations and economic development drive increasing demand for water, impacting food security, public health, and environmental resilience.
• Water insecurity is a systemic risk that impedes progress toward the 2030 Agenda for Sustainable Development.

Consequences of Water Bankruptcy

• 2.2 Billion people lack access to safe drinking water and sanitation, with over 4 billion experiencing severe water scarcity each year.
• Major rivers and lakes are shrinking, wetlands are disappearing, and widespread groundwater depletion leads to land subsidence.

Global Water Crisis and Its Misconceptions

• The narrative of a global water crisis has dominated discussions for decades, focusing on shortages and competition for resources.
• Calling the situation a crisis suggests that improved management can restore past conditions, but many systems are already degraded beyond recovery.
• Human activities are reshaping the global water cycle and causing significant environmental changes.
• Major rivers are drying up, lakes are shrinking, and aquifers are being depleted, leading to chronic water shortages and declining water quality as demand continues to increase.

Shrinking Water Bodies Groundwater and Ecosystem Loss

• Over half of the world’s large lakes have declined since the early 1990s, affecting water security for nearly a quarter of the global population.
• Wetlands are disappearing at three times the rate of forests, causing significant biodiversity loss and economic costs.
• Mankind is using up the groundwater. Groundwater supplies about 50% of domestic water and more than 40% of irrigation globally, but many aquifers are being depleted faster than they can recharge.
• Land subsidence and salinization are direct results of unsustainable groundwater extraction, threatening infrastructure and increasing flood risks.

Lake Corpus Cristi in 2012 and 2025

Threats to Food Systems and Livelihoods

• Agriculture accounts for more than 70% of global freshwater withdrawals, with 3 billion people living in areas facing declining water storage.
• Water shortages result in food insecurity and economic shocks in many locations, especially in low- and middle-income countries where agriculture is the main source of income.

Global Water Bankruptcy: A New Reality

• The world is now confronting Global Water Bankruptcy, where long-term water use exceeds renewable inflows and safe depletion thresholds.
• Many human-water systems can no longer return to previous baselines, indicating a shift from crisis to a persistent state of failure.

Importance of International Cooperation

• The upcoming UN Water Conferences in 2026 and 2028 provide opportunities to recognize Global Water Bankruptcy and realign international priorities accordingly.
• Develop diagnostics to distinguish between water stress, crisis, and bankruptcy.
• Support vulnerable communities through fair transitions and equitable reforms. However, sharing is not an international strong suit. Governments are more likely to see their water resources as necessary for their citizens. 

Sewage Continues to Flow into the Potomac River

On January 19^th, 2026, a massive pipe that moves millions of gallons of sewage ruptured and sent wastewater flowing into the Potomac River northwest of Washington, D.C that has repair crews scrambling. Nine days later, DC Water reports that they are  nearing “full containment” of the sewage spill. Meanwhile, 40-60 million gallons of sewage flowed into the Potomac River each day.

The spill was caused by a 72-inch (183-centimeter) diameter sewer pipe that collapsed late Monday, January 19^th shooting sewage out of the ground and into the river. DC Water spokesperson John Lisle said the utility estimates the overflow at about 40-60 million gallons each, but it’s not clear exactly how much has spilled into the river since the overflow began.

The spill occurred in Montgomery County, Maryland, along Clara Barton Parkway, which hugs the northern edge of the Potomac River near Chesapeake and Ohio Canal National Historic Park. Crews are removing lock gates on the C & O Canal and are setting up pumps to divert the sewage into the canal, rerouting it away from the river and back into the sewage system downstream. This is reported to be an enclosed section of the canal, thank goodness.  

DC Water teams and contractors are working around the clock maintain the bypass system day and night to keep the pumps and equipment operating, even as temperatures remain well below freezing. The pumps require frequent cleaning and maintenance because sewage containing fats, oils, grease, wipes, and other debris in the wastewater cause blockages. When blockages occur, pumps must be temporarily taken offline for service, which reduces system capacity until the issue is resolved.

Additional pumps have arrived and are being installed to add redundancy and increase overall pumping capacity.  This added capacity will help further reduce the wastewater levels and support progress towards achieving full containment. To help this along, residents in Fairfax, Loudoun, and Montgomery counties that are served by the interceptor are encouraged to avoid flushing wipes or disposing of grease down drains, which helps support ongoing emergency operations. By the way, none of those items should be flushed anyway.

DC Water emphasizes that there is no impact to the drinking water supply from this overflow. The Washington Aqueduct’s main intakes for drinking water are upstream from the break.

The bypass system, installed with cooperation from the National Park Service, uses a contained section of the C & O Canal running about 2,700 feet to carry wastewater around the damaged section of pipe and back into the Potomac Interceptor further downstream. Monitoring shows that flow rates are increasing by about 40 million gallons a day after re-entering the sewer system. All the flows then are directed to DC Water’s Blue Plains Advanced Wastewater Treatment Plant.

A U.S. Environmental Protection Agency spokesperson said the agency was coordinating with DC Water, the Maryland Department of the Environment and other federal, state and local authorities to assess the impact on the environment from the Potomac Interceptor sanitary sewer overflow. The federal agency oversees DC Water’s sewer operations under a 2015 federal consent decree.

An EPA survey of wastewater infrastructure needs from 2022 estimated that the District of Columbia needs roughly $1.33 billion to replace or rehabilitate structurally deteriorating sanitary or combined sewers within the next 20 years. DC Water had allocated $625 million in its Capital Improvement Program for projects to rehabilitate the Potomac Interceptor over the next 10 years. They just did not do it soon enough, and this little disaster will and repair will probably end up increasing the cost significantly and moving up the schedule.

Water delivery and sewage removal systems have a long life span, they are just pipes, pumps and valves, but the life span is not infinite. This sewer interceptor dates from the 1960’s so it is about 60 years old. We reward short sighted behavior. In order to have cheaper water and sewer, a near realistic replacement cost schedule was not built into the customer rates for almost 80 years. 

DC Water systems are the oldest in the region.  The system was mismanaged by the city for years and by 1996 some portions of the water delivery system were 100 years old and the sewage system was almost the same age. The water and sewage rates in place in  Washington DC   by 1996 covered the costs to purchase water from the Washington Aqueduct, deliver the water and treat the sewage and replace 0.33% of the system each year. That meant a system with an expected life of 80 years had a planned replacement life of 300 years, an unrealistic and irresponsible repair and replacement rate.

In 2012 that began to change after increasing incidence of failures in the system and DC Water announced that they had tripled the replacement rate to 1% (with of course the increase in water rates) so that in 100 years the system would be replaced. It is likely, given the age of the water system in Washington DC the increase in replacement rate was probably necessary to address what was failing each year. Broken water mains or sewage pipes in Washington DC region are so common they are only mentioned in traffic reports unless they are spectacularly large.

from DC Water

WSSC Customers only Essential Water Use

 WSSC Water is urging all 1.9 million customers in Montgomery and Prince George’s counties to only use water for essential purposes effective immediately. At this time, water is safe and there is no need to boil before essential use. 

The urgent essential-water-use-only request was issued due to the predicted increase in the number of water main breaks and leaks brought on by the frigid temperatures, including break locations that have not yet been identified. At this time, WSSC Water is aware of 34 breaks/leaks.

Following the guidance below could avoid a Boil Water Advisory and help preserve water for system storage and fire protection as crews work to repair breaks/leaks across a 1,000-square-mile service area. 

Until further notice, all customers are being urged to:

• Use water only as necessary – i.e., take shorter showers and quickly turn off faucets from running at full force.
• Limit flushing toilets (do not flush after every use).
• Limit using washing machines and dishwashers.

Because of the extreme cold and the possibility of pipes freezing inside customers’ homes, WSSC Water continues to advise customers to leave a faucet running on a trickle when they are home to keep water moving through the pipes. The amount of water used to keep water flowing at a trickle through pipes will have minimal impact on demand and may save customers from costly repairs caused by frozen or broken pipes in their homes. It is also advisable to open cabinet doors to expose pipes to your home’s warmth.

Customers are also urged to immediately report any water surfacing or flowing down streets, sidewalks or rights of way. Identifying and repairing hidden breaks as quickly as possible is critical to maintaining reliable water service to customers.

There is a direct connection between dropping water temperatures in the Potomac River and the increase in water main breaks.  According to the WSSC, they typically see an increase in breaks a few days after the Potomac River temperature hits a new low as the colder water hits the distribution system. The dropping water temperature can “shock” water mains, and though the pipes become accustomed to the cold water; whenever water temperatures hit a new low, there follows a spike in breaks.

On average, WSSC crews repair more than 1,800 water main breaks and leaks each year, with the vast majority of them, approximately 1,200, occurring between November and February. WSSC has already repaired approximately 300 breaks since November this year.  Last winter as seen below, the total number of breaks was above average. There is a large percentage of the distribution system that is quite old.

WSSC Water spends approximately $17 million each year for emergency water main repairs alone, with about $10 million spent November through February. During a typical year, WSSC Water crews repair more than 1,800 water main breaks and leaks, approximately 65 % of which (1,152) occur between November and February. 

Aging infrastructure is a critical factor in breaks and leaks. The older pipes are “shocked” by the colder water, causing them to break. Approximately 42% of the water mains in WSSC Water’s system are more than 50 years old. 

The Occoquan Model Run

Last Thursday the Prince William Conservation Alliance held a community presentation on the newly completed 2040 Occoquan Land Use Report, titled “Bubbling up: What Did the Occoquan Model Find Beneath the Surface?” The presentation had an introduction by Normand Goulet, the Director for the Northern Virginia Regional Commission (NVRC) Division of Environmental and Resiliency Planning, a short presentation by Dr. Stanley Grant, Director of the Occoquan Reservoir Monitoring Laboratory and featured Dr. Siddharth Saksena, one of the report’s primary authors. The below discussion is taken directly from their talks and the report itself available for review on NVRC website.

Mr. Goulet gave the background and history of why this report exists. Dr. Grant covered what are the current water quality challenges faced by the Occoquan Reservoir as a water supply for 1.2 million people.  Finally, Dr. Saksena covered the limitations of the model and the findings.

When the Digital Gateway rezoning was being considered, Fairfax Water took the unusual step to ask that Prince William County convene the Occoquan Basin Policy Board and oversee a Comprehensive Study of the proposed PW Digital Gateway Comprehensive Plan Amendment (CPA)  and the 2040 Comprehensive Plan Update to evaluate their impact on water quality in the Occoquan Reservoir before any action is taken. Instead, the PW Digital Gateway CPA and 2040 Comprehensive Plan Update that eliminated the Rural Crescent were approved in 2022 and the request was sent to the NVRC, though the funding to undertake the assessment was not approved until February 2024. It took until late last year to complete the work.

The Occoquan Watershed Model was developed to evaluate the impact of land use decisions and compare potential land use scenarios and their impact on the Occoquan Reservoir water quality. It turns out that the model is old, does not have a groundwater  component, and the framework used is no longer being supported and it has significant quality challenges. The Occoquan Model is the Frankenstein result of attaching a Hydrological Simulation Program–FORTRAN model (that is rather ancient in computer modeling terms -note the FORTRAN programing language) to a CE-QUAL-W2 model that is not fully calibrated.  

A CE-QUAL-W2 model is a two dimensional water quality model that is extensively used by government agencies like  the USGS and EPA for water management tasks. Its applications are centered on simulating how waterbodies respond to operational and environmental changes. Researchers apply the model to predict how rising air temperatures or changes in watershed land use will trigger algal blooms or increase sediment phosphorus release. It is centered on runoff and temperature.

Dr. Saksena reported that the team calibrated the model using data from the years 2013 to 2017, with land use conditions benchmarked to 2016. The future simulations were conducted for the period 2039–2041 and compared to the baseline period of 2013–2015. The team consisting of the Department of Civil and Environmental Engineering and the Occoquan Watershed Monitoring Lab at Virginia Tech that conducted the study found that the location accuracy was around 70% and the ability to predict whether streamflow would increase or decrease was also around 70%. Other model quality parameters were lower.

Though the entire goal was to understand how future urban growth and future climate might affect water quantity and quality (for selected nutrients) in the Occoquan Watershed, they used a regression model to predict the key input- rate of development in the basin. They assumed that the rate of building in the past would continue into the future. The location of construction in Prince William County was informed by the Small Area Plans and Activity Center areas where potential denser redevelopment would occur including Yorkshire, Digital Gateway, Old ARC land data centers, and other areas.

Because this key variable- rate of development is assumed to stay the same as the baseline period the usefulness of this work to evaluate potential risks the Occoquan Reservoir, a key drinking water source, is limited.

Within the above discussed limitations the study simulated how projected developments (such as roads and buildings) and changes in rainfall patterns could influence streamflow and water pollution levels. It is to be noted that the original development of the FORTRAN portion of the model predates knowledge of the connection of streamflow to groundwater. So the impacts to groundwater and the groundwater streamflow interface is not addressed beyond noting that more impervious surfaces result in higher peak flow (flooding).

Multiple scenarios were explored, including a future with just urban growth, and combinations of urban growth, climate influence, and changes in average treated (reclaimed) water discharged from the Upper Occoquan Service Authority (UOSA). These simulations covered the five sub-watersheds and the reservoir area. Key findings show that by 2040, urban land is expected to grow from about 29% to 39% of the watershed area, increasing the amount of impervious surface and reducing natural areas. This is likely to lead to more runoff and higher flows in local streams, especially under more extreme climate, where flow increases of up to 70% were simulated in some areas.

In order for the model to calculate impervious area, the zoning from the comprehensive plan was used for underdeveloped and undeveloped lands. This resulted in the following values that were used to calculate impervious area acreage increases for each transect category in the comprehensive plan;  T-0/A-1 = 3.5%,  T-1/SR-1 = 11%,  T-2/R-4 = 29% , T-3/R-6 = 38%,  T-4/R-16 = 43.5%, T-5 was calculated at 55%, and T-6 was calculated at 65%. The problem with this is that it is not reflective of what is happening in Prince William County now. The rezoning of Longleaf at Kettle Run, Alderwood at Kettle Run and Hawthorn at Kettle Run was over 1,200 acres alone. Four more rezoning are in progress in just the middle Broad Run area alone. The other areas are experiencing both the changes made to the Comprehensive Plan and continual up-zoning requests. 

These are the development inputs assumed in the report

The higher streamflow the model predicted will carry more pollutants into the reservoir. The study found that in extreme scenarios, nutrient pollutants like phosphorus and ammonia may increase by more than 50% and 60%, respectively. While some variability was seen, the amount of pollution entering the water system is expected to rise because of stronger stormflows. This makes clear that the volume of water moving through the system, not just pollutant concentrations, is a key driver of future water quality conditions. If you don’t have enough forested lands and you increase rainfall (on average to 120% of historic average rainfall) you get flooding and more nutrient pollution into the Occoquan Reservoir. The model is incapable of predicting any other type of pollution.  

The study concludes that both urban growth and climate variability could significantly impact the watershed and its water quality by 2040. Even if some scenarios don’t show large changes in pollution levels on average, seasonal events or heavy storms could cause meaningful impacts on reservoir health.

To protect the Occoquan Reservoir we need better and more detailed modeling, the ability to test changes in outcome if building rates change or zoning changes are requested along with continued monitoring. There are also important limitations to consider. There is tremendous uncertainty in the exact locations where new development will occur and the actual rate that it will occur at. The difference in impervious surface. Additionally, only a handful of pollutants (such as nutrients and sediment) were modeled; contaminants such as PFAS and salts, which are increasingly of concern, were not addressed by this model and the assessment.

To improve future assessments, a next-generation modeling framework is being developed by Virginia Tech, called the Occoquan Watershed Modeling Framework (OWMF).

The Formation of Streams

 The Birth and Growth of Streams

Streams and rivers are an essential part of our water supply, but where do they come from? Streams form through the combined effects of gravity and the accumulation of water from various sources, including rain, melting snow, and underground springs. These initial flows are typically small, but as they travel across the landscape, they eventually merge to form larger river systems.

Headwaters and Surface Runoff

Streams begin at a high point known as the headwaters or source. When precipitation exceeds the soil’s capacity to absorb water, the excess flows downhill as surface runoff, collecting in lower areas. This runoff carves out small, temporary trenches called rills, which widen and deepen into larger channels known as gullies over time. Some streams are also sustained by springs or the water table. The water table, marking the upper boundary of groundwater, must maintain contact with a stream to continue feeding it. When a riverbank intersects a saturated layer of earth, groundwater seeps out, supporting the stream’s flow even during dry periods.

How Streams Become Rivers

As water continues its downhill journey toward its base level—such as the Bay or Occoquan Reservoir—small streams join together to form larger bodies of water. Examples of these smaller streams or rivers include Broad Run, Cedar Run, Slate Run, Bull Run, and Catharpin Creek, which all contribute to a larger “parent” river like the Occoquan River. The specific location where two streams or a tributary and a river meet is known as a confluence. This branching network of tributaries, which gathers water from a defined land area, is referred to as a watershed or drainage basin.

The Importance of Groundwater

Groundwater is a crucial source of water for streams and rivers, often providing 30% to over 50% of their total annual flow. This steady, slow-moving contribution is called baseflow, acting as a “savings account” that sustains streams over time.

Gaining Streams and the Water Table

In many areas, streams are classified as “gaining” streams because they receive a direct supply of water from the ground. For groundwater to enter a stream, the water table—the top of the underground saturated zone—must be higher than the stream’s water level. Water naturally moves from regions of high pressure (saturated ground) to lower pressure (the open stream channel), seeping through the streambed and banks. However, if groundwater is excessively withdrawn or if groundwater recharge is reduced—such as by increasing impervious surfaces through land use change—the connection between groundwater and the stream can be severed.

Groundwater’s Role in Sustaining Flow

Groundwater is the main reason why many rivers continue to flow even during extended periods without rain. While rainwater, or runoff, reaches a river quickly, groundwater may take days, months, or even years to move through soil and rock before eventually seeping into a stream. This process provides a steady flow between rainstorms, ensuring a reliable minimum water supply that supports aquatic life and meets human needs during dry spells. This process is also why land use changes may take decades to impair stream flow.

Ecological Impacts of Groundwater and Streams

The interaction between groundwater and streams does more than maintain water levels; it also supports ecological health. Because groundwater remains at a fairly constant temperature throughout the year, it keeps streams cooler in summer and warmer in winter, creating vital “thermal refuges” for fish and other aquatic life. As water circulates between the ground and the stream, it transports carbon, oxygen, and nutrients that nourish complex ecosystems within he hyporheic zone—the saturated sediment layer just beneath the streambed. Without the groundwater flow streams loose this ability to support the living ecology.

Human Impacts on Groundwater and Streams

Human activities, changes in land use, and climate change can disrupt the natural connection between groundwater and streams. Excessive pumping from wells can lower the water table below the level of a stream, causing the stream to lose water to the ground or even run dry. Another significant impact comes from impervious surfaces, such as pavement and buildings, which prevent rainwater from soaking into the ground and recharging groundwater. This eventually leads to a lower water table and reduced baseflow in local streams.

Drought Expands

All of the Potomac watershed is currently in drought. The U.S. Drought Monitor Map released last Thursday shows shows 88.8% of the Potomac Basin in Severe Drought and  11.2% in Moderate Drought. The current conditions have triggered the Virginia Department of Environmental Quality (DEQ) to issue a drought warning advisory for 22 counties and 13 cities, and expanded the drought watch advisory to now include 61 counties and 18 cities in Virginia.  For now, the Potomac River’s flows are adequate to meet the water demands of the Washington metropolitan area, but are well below normal for this time of year.

A drought warning advisory is intended to increase awareness that the onset of a significant drought event is imminent and includes the following areas:

• Northern Virginia: Arlington, Fairfax, Fauquier, Loudoun, and Prince William counties and the cities of Alexandria, Fairfax, Falls Church, Manassas, and Manassas Park. 
• Roanoke River: Bedford, Campbell, Charlotte, Franklin, Halifax, Henry, Mecklenburg, Patrick, Pittsylvania, and Roanoke counties and the cities of Danville, Martinsville, Roanoke, and Salem. 
• Shenandoah: Augusta, Clarke, Frederick, Page, Rockingham, Shenandoah, and Warren counties and the cities of Harrisonburg, Staunton, Waynesboro, and Winchester.  

 Here in Prince William County Virginia rainfall averages approximately 44 inches per year, but varies from year to year. Last year we were about 9 inches short of average and in the first 4 months of this water year we have had about half the usual amount of rainfall.  Climate forecasts are for our region to get wetter with more intense rainstorms and droughts to get more severe. (ICPRB).

This precipitation deficit continues and has resulted in further declines and sustained much-below normal streamflow, groundwater, and soil moisture levels throughout most of the Commonwealth, especially in the Piedmont and Blue Ridge regions. Reservoir levels remain largely normal, except for Smith Mountain Lake, which is 0.26 feet below Warning level (791.5 ft) and Lake Moomaw, which is currently 1.48 feet below the watch threshold.

from DEQ

DEQ is working with local governments, public water works, and water users in the affected areas to ensure that conservation and drought response plans and ordinances are followed. Be alert for drought response notifications. Though, at least we do not have to worry about people water their lawns and plants and using more water when they should be conserving (which happened two summers ago).

The Magnificent Woodland

We are now entering the seventh year of my woodland restoration project. My property is just over ten acres, with about three acres dedicated to lawn and ornamental gardens. The remaining seven acres consist of woodland, much of which falls within the Chesapeake Bay's "resource protected area" (RPA).

When we first arrived, I didn’t worry about dead trees—they’re an important part of nature’s renewal process. A thriving forest features living trees that are part of a complex ecosystem along with understory shrubs and groundcover. Natural succession means saplings will eventually replace aging trees. For years, my approach to the RPA was one of benign neglect, letting nature protect the stream.

However, around ten years ago, I saw signs that something was going wrong. Invasive insects, rampant vines, and a dramatic increase in deer and other wildlife started to damage the woodland. Deer favor native plants, eating young tree saplings while leaving invasive species like autumn olive untouched. As gaps appeared in the canopy, invasive vines and shrubs moved in instead of young native trees.

The woodland before Wetland Studies and Solutions began work in this section

Woodlands play a crucial role in ecological balance. The tree canopy—made up of leaves, branches, and bark—acts as a shield during storms, intercepting and slowing rainfall. A mature tree can hold over 100 gallons of water during a single rain event, and this slows water flow. By catching raindrops before they hit the ground, vegetation reduces erosion and keeps soil from clogging up with particles. Water intercepted by trees either drips down or runs along trunks, reaching the ground slowly and helping prevent rapid surges that can overload storm drains.

Trees and natural plants transform soil, making it more absorbent. Their deep root systems create channels for water to soak in rather than collecting on the surface. As roots grow and decay, they contribute organic material, binding soil into stable aggregates and enhancing its ability to store water—even where soils are compacted by urban activity. Fallen leaves and decaying plant matter form a spongy layer that further traps water, allowing it to filter gently into the earth.

Plants and trees also act as pumps, returning water to the atmosphere through evapotranspiration. Roots draw moisture from the earth, which is then released as vapor through leaf pores, while water caught on surfaces evaporates directly back into the air. This ongoing cycle clears space in the soil, so it’s ready to absorb rain again.

Finally, stems, stalks, and leaves slow water movement over the land. Dense growth like tall grass and shrubs creates friction, lowering water speed. Riparian buffers—like my woodland along Chestnut Lick—help slow floodwaters and reduce erosion, preventing bank collapse and minimizing downstream flooding.

credit Steve Ward

Last summer we came to the conclusion that the money and time that has been poured into the woodland was worth it. However, we also realized that this project will never end. 

Impacts of Land Use Change on a Watershed

A watershed is an area of land that collects precipitation, such as rainfall and snow, and directs it into a common water body—whether a stream, river, or, in the case of Prince William County, the Occoquan Reservoir. Land use changes can dramatically alter the natural functioning of watersheds, with impacts beginning almost immediately after land is cleared, leveled, or developed with roads and impervious surfaces. These changes result in increased volume and speed of stormwater runoff. Over the course of 20 to 50 years, initial disturbances lead to lasting ecological and physical transformations. When 35–50% of a forested watershed is replaced by impervious surfaces—well above the 10% threshold where significant degradation typically starts—the movement and fate of water within the landscape are permanently altered.

When Impacts Happen

Watersheds respond quickly to shifts in land use. The removal of vegetation and the installation of pavement cause stormwater runoff to become nearly instantaneous during rainfall events, with surface runoff reaching up to 16 times that of undisturbed areas. This dramatic increase highlights the immediate impact of development. To address these concerns, stormwater management measures are often integrated into development plans, aiming to slow, capture, and treat runoff before it enters local water bodies.

• Short-Term (1–10 Years): Substantial increases in streamflow and sediment loads occur soon after clear-cutting and construction activities.
• Long-Term (20–50 Years): Over decades, cumulative effects emerge, such as persistent deficits in soil moisture and changes in water flow pathways due to road networks and infrastructure.

What are the Impacts to the Watershed

When impervious surfaces account for 35–50% of a watershed, notable hydrological and ecological changes take place. Pavement and buildings prevent precipitation from soaking into the soil. Under natural conditions, much of the rainfall infiltrates the ground, helping to replenish aquifers. However, when surfaces are sealed, infiltration declines sharply, which in turn reduces groundwater recharge.

During dry periods, streams depend on groundwater—known as baseflow—to maintain their flow. A high percentage of impervious cover reduces this recharge, lowering groundwater levels and separating streams from their underlying water sources. This results in reduced streamflow during dry spells and can transform perennial streams into intermittent ones.

Hydrological Changes

Flashier Streams: Stormwater runoff reaches streams more rapidly and in larger volumes, causing higher peak flows and more frequent flooding.

Reduced Groundwater Recharge: Impervious surfaces prevent water from infiltrating the soil, leading to lower water tables and streams that may dry up during summer months, ultimately causing streams to become intermittent.

Physical and Water Quality Changes

Increased speed and volume of stormwater runoff erode stream banks, cause incision (downcutting), and result in "blowouts" that destroy aquatic habitats. Stormwater runoff collects contaminants such as oils, heavy metals, road salts, and nutrients (nitrates and phosphates) from paved surfaces, and carries them directly into waterways without the natural filtering effects of forests. Rainwater heats up as it travels over sun-exposed pavement, raising stream temperatures and stressing or killing sensitive aquatic organisms. The reduced groundwater availability limits natural cooling, resulting in higher temperatures in urban and suburban areas.

Ecological Decline

At high levels of development, sensitive species such as trout and salamanders disappear, leaving only more pollution-tolerant organisms. The removal of old-growth trees eliminates deep roots and canopies that previously provided carbon storage, pollutant trapping, and soil stabilization, leading to further ecological imbalance.

Role and Limitations of Green Infrastructure & LID Features

Green Infrastructure (GI) and Low Impact Development (LID) are increasingly promoted as solutions to watershed challenges. These approaches focus on natural processes—such as infiltration, evaporation, and transpiration—to manage water where it falls. However, their effectiveness is generally limited to handling the first inch of rainfall, making them an incomplete solution for all impacts of land use change.

Unlike forests, which are self-sustaining, GI requires ongoing maintenance. For example, permeable pavements must be vacuumed to prevent clogging, and bioswales need sediment removal to maintain infiltration rates. Research suggests that Green Infrastructure should be designed for future climate scenarios, including increased storm intensity, to ensure sustainability over a 20-year lifecycle.

While GI and LID strategies can reduce the impacts of 35–50% development, they typically result in a "managed" watershed that is more costly to operate and more vulnerable to extreme weather events than a natural system. In watersheds with 35–50% impervious cover, Green Infrastructure is moderately effective at improving groundwater recharge, but its success depends on implementation density, storm event scale, and system maintenance. Unlike forests, GI systems require routine human intervention, such as vacuuming permeable pavements and maintaining bioswales, which are ineffective as roadways and in regions with frequent freeze-thaw cycles.

Green Infrastructure aims to slow down water movement and promote infiltration. It is most effective for frequent, low-intensity rainfall events (typically less than 0.8 to 1.0 inch). In these cases, dense GI installations can capture and infiltrate enough water to closely mimic natural forested conditions. Studies of urban catchments with approximately 35% impervious cover have shown that retrofitting with GI elements like rain gardens and porous pavements can increase infiltration and reduce total surface runoff.

In highly urbanized areas with 64% impervious cover, only about 2.4% of rainfall naturally infiltrates the ground. Implementing infiltration practices in zones with high impervious surfaces can raise this rate to roughly 5.2%, doubling recharge. This is still far below the recharge in a natural environment which is about 50%.

 

from U.S. EPA

 References:

Pegah Jalali, Sergey Rabotyagov, Quantifying cumulative effectiveness of green stormwater infrastructure in improving water quality, Science of The Total Environment, Volume 731, 2020, 138953, ISSN 0048-9697, https://doi.org/10.1016/j.scitotenv.2020.138953.

 https://www.mdpi.com/2073-4441/11/10/1992

Alam, T.; Mahmoud, A.; Jones, K.D.; Bezares-Cruz, J.C.; Guerrero, J. A Comparison of Three Types of Permeable Pavements for Urban Runoff Mitigation in the Semi-Arid South Texas, U.S.A. Water 2019, 11, 1992. https://doi.org/10.3390/w11101992

 Zuo, Shangjun. (2025). Green Infrastructure / LID for Urban Stormwater Management. Science and Technology of Engineering, Chemistry and Environmental Protection. 1. 10.61173/pz840329.