Drought does not begin affecting a community only when a reservoir is nearly empty or a riverbed has dried up. Long before conditions become that severe, reduced precipitation can begin changing surface-water supplies, groundwater levels, utility operations, water demand, and source-water quality.
Your faucet may continue to work normally throughout a drought, but the water system behind it may be operating under increasingly difficult conditions.
Quick answer: Drought can reduce reservoir storage, streamflow, groundwater recharge, and well productivity. Water utilities may respond by changing water sources, increasing groundwater pumping, modifying treatment, introducing conservation measures, or imposing water-use restrictions. The exact effects depend heavily on the community and its water sources.
This guide explains how drought affects local water supplies, private wells, water quality, utilities, water restrictions, and household water use—and what homeowners can do when dry conditions persist.
In This Guide
- How Local Water Supplies Work
- How Drought Reduces Water Supply
- Groundwater and Private Wells
- How Drought Can Affect Water Quality
- Can Drought Affect Water Pressure?
- How Drought Affects Water Utilities
- Water Restrictions During Drought
- Long-Term Infrastructure Challenges
- What Homeowners Can Do
- What Private-Well Owners Should Watch
- Frequently Asked Questions
Understanding How Local Water Supplies Work
For most households, getting water is as simple as opening a faucet. The system behind that faucet is much more complex.
Public water systems may obtain water from:
- Rivers
- Lakes
- Reservoirs
- Groundwater aquifers
- A combination of surface water and groundwater
- Imported water from another watershed or regional supplier
Surface-water supplies depend on precipitation, snowmelt, streamflow, reservoir storage, and watershed conditions.
Groundwater is water stored below the surface in soil and rock formations that can supply wells.
Many rural households obtain water directly from private wells, while cities may operate large municipal well fields as part of a public water system.
Public drinking water typically undergoes treatment appropriate to its source before entering the distribution network.
From there, pumps, tanks, reservoirs, valves, and miles of water mains help deliver water to homes and businesses at usable pressure.
No two communities are exactly alike. A city relying on a large reservoir may experience drought differently from a community dependent on shallow groundwater or a household supplied by a private well.
How Drought Reduces Overall Water Supply
Drought usually develops gradually.
When precipitation remains below normal for weeks, months, or years, several parts of the water cycle can be affected.
Reservoir Levels Can Fall
Reservoirs receive water from rainfall, snowmelt, rivers, and streams.
During drought, reduced inflow can cause reservoir storage to decline. Hot, dry weather may also increase evaporation losses from exposed water surfaces.
If withdrawals continue while inflow remains low, stored water can steadily decrease.
River and Stream Flows Can Decline
Reduced precipitation and snowmelt can also reduce streamflow.
For communities that depend on rivers or streams for source water, lower flow can mean less water is available for withdrawal.
Demand Can Increase at the Same Time
Drought often occurs during hot weather, when household and agricultural demand may rise because of:
- Lawn irrigation
- Landscape watering
- Agricultural irrigation
- Evaporative losses
- Outdoor recreational water use
The result can be a difficult combination: less water entering the system while demand remains high or increases.
Utilities May Rely More Heavily on Groundwater
Where groundwater is available, utilities may increase groundwater pumping when surface supplies decline.
This can help compensate for short-term surface-water shortages, but groundwater is not an unlimited reserve.
If pumping exceeds recharge for an extended period, groundwater levels can fall.
Aquifer Depletion and Private-Well Problems
Groundwater is often an important buffer during drought because aquifers can continue supplying water after surface-water conditions deteriorate.
But drought affects groundwater too.
Groundwater is replenished through recharge, when water from precipitation, streams, irrigation, or other sources moves downward through soil and rock.
During a drought, reduced precipitation can mean reduced recharge.
At the same time, pumping may increase as households, farms, and utilities try to compensate for reduced surface-water availability.
This creates a double pressure on aquifers: less water may be entering while more water is being withdrawn.
What Happens to Private Wells?
As groundwater levels decline, the depth from the land surface to the water table can increase.
For some wells, that may mean:
- Reduced yield
- Intermittent loss of water
- Changes in pump performance
- More sediment
- A need to lower or modify pumping equipment
- In severe cases, deepening or replacing the well
Shallow wells can be especially sensitive to falling groundwater levels.
However, the effect on an individual well depends on its depth, construction, aquifer, pumping rate, nearby pumping, and local geology.
For more information about testing and managing private-well water, see our Well Water Testing and Treatment Guide.
Groundwater Recovery Can Be Slow
A heavy rainstorm may quickly raise the level of a pond or stream, but aquifers can respond much more slowly.
Water has to infiltrate through soil and rock before reaching groundwater storage, and some aquifers recharge over long periods.
For that reason, groundwater problems can continue even after visible drought conditions begin to improve.
How Drought Can Affect Water Quality
Drought is not only a water-quantity problem.
Changes in source-water volume, temperature, flow, and pumping can also affect water quality and complicate treatment.
Some Substances May Become More Concentrated
When less water is available for dilution, concentrations of certain naturally occurring minerals, salts, nutrients, or pollutants can change.
The exact effect varies greatly according to the watershed and contaminant.
Drought does not mean that every contaminant automatically increases, but it can alter source-water chemistry in ways that utilities need to manage.
More Groundwater Pumping Can Change Source-Water Chemistry
If a utility or household begins pumping from different wells, at greater depths, or from different aquifers during a drought, the water chemistry may also change.
Groundwater sources can differ in:
- Hardness
- Iron
- Manganese
- Arsenic
- Salinity
- Other naturally occurring minerals
This does not mean drought will produce the same water-quality problem everywhere. It means changing sources can require additional monitoring and treatment adjustments.
Warm Water Can Favor Algal Growth
Warm surface-water conditions combined with nutrients and other favorable environmental conditions can contribute to cyanobacterial harmful algal blooms.
These blooms can create:
- Taste and odor problems
- Operational challenges for treatment plants
- In some cases, cyanotoxins that require specific monitoring and treatment
Do not judge public drinking water solely by a temporary change in taste or smell. If your tap water changes noticeably, check notices from your water utility or contact the utility directly. A sensory change can have many possible causes.
Treatment May Become More Complex
Changing source-water conditions may require utilities to adjust:
- Treatment processes
- Chemical dosing
- Source-water blending
- Monitoring frequency
- Algae-management strategies
- Corrosion-control operations
These changes can increase operating costs even when customers continue receiving water normally.
Can Drought Cause Lower Water Pressure?
Drought by itself does not automatically lower the pressure at your faucet.
Public water systems use pumps, tanks, reservoirs, valves, and pressure zones to maintain appropriate pressure across the distribution system.
However, drought can indirectly contribute to pressure problems when:
- Demand becomes unusually high
- Storage tanks are drawn down rapidly
- A supply source becomes unavailable
- Pumping or treatment capacity is constrained
- The utility deliberately changes operations
- Local infrastructure is already under stress
Some utilities may also use pressure management as one of several demand-management tools, although restrictions on outdoor water use are generally much more visible to customers.
If only your home has low pressure, drought may not be the cause. A partially closed valve, plumbing leak, pressure regulator, clogged fixture, or other household problem can also reduce pressure.
How Drought Affects Water Utilities
Water utilities have to manage both immediate supply problems and longer-term risks during drought.
Possible operational challenges include:
- Reduced source-water availability
- Changing source-water quality
- Higher treatment costs
- Greater dependence on backup sources
- Additional groundwater pumping
- Higher energy use
- Greater monitoring needs
- Customer communication and conservation programs
A utility may also need to purchase water from another supplier, activate normally unused wells, modify source-water blending, or increase conservation efforts.
Drought Can Also Affect Utility Finances
Conservation creates an unusual financial challenge.
A utility may have to spend more money responding to drought while customers are simultaneously being asked to purchase less water.
Long droughts can therefore affect:
- Operating costs
- Capital planning
- Water rates
- Infrastructure investment
Mandatory Water Restrictions During Drought
When voluntary conservation is not enough, local or state authorities may introduce mandatory water-use restrictions.
The specific rules vary by location.
Restrictions may address:
- Lawn watering days
- Hours when irrigation is allowed
- Car washing
- Pool filling
- Decorative fountains
- Washing sidewalks or driveways
- Commercial or agricultural water use
The primary objective is to reduce nonessential demand so available supplies can be preserved for higher-priority uses.
For more practical conservation ideas, see our guide to saving water during drought restrictions.
Long-Term Infrastructure Challenges
Repeated or prolonged drought can influence decisions that extend far beyond the current dry season.
Communities may consider investments such as:
- New or deeper wells
- Expanded reservoir capacity
- Interconnections with neighboring water systems
- Water-reuse projects
- Leak detection and water-main replacement
- Advanced treatment
- Additional groundwater monitoring
- Demand-management programs
Some communities may also diversify their water sources to reduce dependence on a single reservoir, river, or aquifer.
These projects can take years to plan, permit, finance, and construct.
Land Subsidence Can Be a Groundwater Concern
In some aquifer systems, heavy groundwater pumping can compact underground sediments and cause the land surface to sink.
This process, known as land subsidence, can damage infrastructure and permanently reduce groundwater-storage capacity in some settings.
It is not an inevitable consequence of every drought, but it is an important long-term groundwater-management issue in heavily pumped regions.
Drought, Climate, and Long-Term Water Planning
Drought is a natural part of climate variability, but communities increasingly plan for a wider range of possible future conditions.
Water planning may consider:
- Changes in precipitation
- Snowpack
- Earlier snowmelt
- Higher temperatures
- Evaporation
- Population growth
- Agricultural demand
- Groundwater depletion
- Wildfire impacts on watersheds
Some droughts also develop unusually rapidly. These events are sometimes called flash droughts.
Monitoring organizations such as the U.S. Drought Monitor and the National Integrated Drought Information System help communities track drought conditions and water-supply indicators.
For a broader discussion, see our guide to the connection between climate conditions and drought.
How Homeowners Can Prepare During Drought
You cannot control how much rain falls, but you can reduce unnecessary household water use.
1. Fix Leaks
Leaking toilets, faucets, irrigation systems, and pipes can waste water continuously. Repairing leaks is one of the easiest ways to reduce household demand without changing daily habits.
2. Follow Local Restrictions
Check your water supplier's website for current drought stage, irrigation schedules, restrictions, and conservation requests.
3. Reduce Outdoor Water Use
Outdoor irrigation can represent a substantial share of household water demand in dry climates.
Depending on local rules and landscape needs, consider:
- Watering only when necessary
- Using drip irrigation
- Repairing broken sprinkler heads
- Adding mulch
- Choosing drought-tolerant landscaping
- Avoiding irrigation during the hottest part of the day
4. Use Water-Efficient Fixtures
Efficient toilets, showerheads, faucets, washing machines, and dishwashers can reduce long-term household water consumption.
5. Run Full Loads
When practical, run dishwashers and washing machines with full loads rather than many small loads.
6. Pay Attention to Changes in Your Water
If your utility changes sources during drought, you may notice differences in taste, hardness, mineral content, or other characteristics.
If a change is great or unusual, check the utility's notices rather than trying to diagnose the cause yourself.
What Private-Well Owners Should Watch During Drought
Private well owners have additional responsibilities because there is no municipal utility monitoring the water entering their homes.
During prolonged drought, watch for:
- Reduced water flow
- A pump running unusually often
- Air entering plumbing
- Changes in pressure
- New sediment
- Changes in color, taste, or odor
- Changes in neighboring well performance
If well yield declines significantly, a licensed well professional can evaluate:
- Water level
- Well depth
- Pump position
- Pump condition
- Well construction
- Possible options for improving supply
A change in well water deserves investigation. Do not assume that unusual color, taste, odor, sediment, or reduced flow is simply a harmless consequence of drought.
Should You Test Well Water During or After a Drought?
Private well owners should maintain a regular water-testing program regardless of drought conditions.
Additional testing can be useful when:
- Water quality noticeably changes
- The well has been modified or deepened
- Nearby pumping patterns change
- A new contaminant concern is identified locally
- The property has experienced flooding after a drought
Which contaminants to test depends on local geology, land use, well construction, and state or local guidance.
For more information, see our private well water guide.
Drought and Drinking-Water Filtration
Drought does not automatically mean every household needs a new water filter.
If you receive public water, begin with information from your utility.
Review:
- Consumer Confidence Reports
- Drought notices
- Source-water changes
- Boil-water or other advisories when issued
If a particular drinking-water concern is identified, choose treatment based on that concern rather than simply assuming that drought requires a specific filter.
Different technologies are designed for different purposes.
Our Types of Drinking Water Filtration Systems guide explains gravity filtration, activated carbon, reverse osmosis, distillation, sediment filtration, and other approaches.
Considering countertop gravity filtration? See our Berkey® Water Filter Systems comparison guide for current system sizes and filter configurations.
Frequently Asked Questions
Can drought cause a city to run out of water?
Severe or prolonged drought can create serious supply shortages, particularly in communities with limited storage, few backup sources, or already stressed water resources. Utilities generally respond well before supplies are completely exhausted by increasing conservation measures, changing sources, or imposing restrictions.
Does drought automatically make tap water unsafe?
No. Public water systems must continue meeting applicable drinking-water requirements. Drought can change source-water conditions and make treatment more challenging, but utilities adjust treatment and monitoring accordingly.
Can drought change the taste of tap water?
Yes, it can indirectly contribute to changes in taste if the source water, mineral content, treatment, temperature, or algal conditions change. A taste change does not identify the cause, so contact the utility if it is persistent or unusual.
Can drought affect private wells?
Yes. Falling groundwater levels can reduce yields in some wells, particularly shallower wells or those in heavily pumped aquifers.
Can a well run dry during drought?
A well can stop producing usable amounts of water if the groundwater level falls below the pump intake or below the depth accessible to the well. The likelihood depends on well construction and local aquifer conditions.
Will an aquifer refill as soon as it starts raining?
Not necessarily. Groundwater recharge can be slow, and some aquifers may require prolonged periods of favorable precipitation before water levels recover significantly.
Does drought always lower household water pressure?
No. Utilities actively manage pressure. Drought may contribute indirectly to pressure problems through high demand, storage constraints, source limitations, or operational changes, but household plumbing issues can also cause low pressure.
Why do cities restrict lawn watering during drought?
Outdoor irrigation can represent a large portion of water demand in some communities. Restricting nonessential outdoor use can preserve water for drinking, sanitation, firefighting, healthcare, businesses, and other priority needs.
Can drought increase harmful algal blooms?
Warm water, nutrients, low flow, and other environmental conditions can favor cyanobacterial blooms in some water bodies. Drought is only one part of this more complex set of conditions.
Should I test my tap water because there is a drought?
If you receive regulated public water, check your utility's information first. Private-well owners may have more reason to consider additional testing when water levels, well operation, or water characteristics change.
Does boiling water solve drought-related water-quality problems?
No. Boiling is useful only in specific circumstances, primarily for certain microbial concerns when authorities specifically recommend it. It does not solve most chemical or mineral-related water-quality issues.
Can drought increase arsenic in well water?
Research has found associations between drought and elevated arsenic risk in some groundwater settings, but the effect is not universal and cannot predict arsenic concentrations in individual wells. Testing is needed where arsenic is a local concern.
What is the best thing homeowners can do during drought?
Follow local restrictions, repair leaks, reduce unnecessary outdoor water use, monitor utility notices, and pay attention to changes in private-well performance if you use one.
Final Thoughts
Drought affects much more than rainfall totals or the appearance of reservoirs.
As dry conditions persist, communities can experience changes in:
- Reservoir storage
- River and stream flows
- Groundwater levels
- Private-well performance
- Source-water quality
- Water-treatment costs
- Conservation requirements
- Long-term infrastructure planning
The effects are not identical everywhere. A large metropolitan system with multiple sources may be able to adapt differently than a rural community dependent on a single aquifer.
For homeowners, the most useful response is to stay informed about local conditions, follow water-use restrictions, reduce unnecessary consumption, and investigate significant changes in tap or well water rather than guessing at the cause.
Drought is not simply a shortage of rain. It is a water-supply challenge that can affect the entire system—from rivers and aquifers to treatment plants, wells, pipes, and ultimately the water available at home.