A compiled reference of 20 verified statistics on basement water risk and how to control it: how common flooding is in the United States, why standard homeowners insurance does not cover it, and what a sump pump and basement waterproofing actually cost. Every figure is drawn from a named public source (FEMA and Ready.gov flood data, and published sump pump and basement waterproofing pricing) and independently checked before publishing.
What protection costs
Typical price ranges for the main ways to keep a basement dry.
Source: This Old House sump pump and basement waterproofing pricing, 2026 (thisoldhouse.com).
Key statistics
Key takeaways
Flooding is the country's most common disaster, it can happen anywhere, and the standard homeowners policy excludes it, so keeping the basement dry falls to the property owner. The numbers below trace the risk and the cost of managing it.
Floods are the most common natural disaster in the United States.
Most homeowners insurance does not cover flood damage; flood insurance is a separate policy.
The NFIP has 4.7 million policyholders and nearly $1.3 trillion in coverage.
Sump pump installation averages about $1,400, from $500 to $4,000.
Waterproofing a 1,000-square-foot basement averages about $13,640.
Interior waterproofing averages about $3,000; exterior runs about $7,000 to $15,000.
How we built this report
Every figure was compiled in September 2026 from named public sources and verified against the original before publishing.
- Compiled from primary sources
FEMA National Flood Insurance Program data, Ready.gov flood guidance, and published sump pump and basement waterproofing pricing.
- Government data for the risk claims
Flood-prevalence and insurance figures come only from FEMA and Ready.gov, read from the agencies' own pages.
- Only explicitly stated figures
We include only numbers a named source states directly, and attribute each inline at the point it appears.
- Independent review
Written by one co-founder, reviewed by the other before publishing.
Scope note: FEMA and Ready.gov figures describe flood risk and the National Flood Insurance Program, not basement flooding specifically, which can also come from groundwater, sewer backup, or plumbing failures that flood insurance may not cover. Cost figures are provider ranges that vary by home, water table, region, and severity. Confirm coverage with your insurer and costs with a licensed contractor.
Basement water risk and protection, by the numbers
All 20 figures, grouped into three themes, each from a named public source and independently verified against the original.
The flood risk, and the insurance gap
Water is the most common disaster the country faces, and the coverage most owners assume they have does not apply. According to Ready.gov (ready.gov), floods are the most common natural disaster in the United States, and both Ready.gov and FEMA (fema.gov) state plainly that most homeowners insurance does not cover flood damage, which requires a separate policy.
Statistic 1
Floods are the most common natural disaster in the United States.
Ready.gov (2026)
Statistic 2
Most homeowners insurance does not cover flood damage; flood insurance is a separate policy.
FEMA / Ready.gov (2026)
Statistic 3
Floods can happen anywhere, not only in designated high-risk areas.
FEMA (2026)
Statistic 4
The National Flood Insurance Program has 4.7 million policyholders nationwide.
FEMA (2026)
Statistic 5
The NFIP is the nation's largest single-line insurance program, providing nearly $1.3 trillion in coverage against flood.
FEMA (2026)
Statistic 6
NFIP flood insurance is available in 22,600 participating communities, and required for high-risk-area homes with federally backed mortgages.
FEMA (2026)
Statistic 7
Just six inches of moving water can knock a person down, and one foot can sweep a vehicle away.
Ready.gov (2026)
What this means: Two facts do the work here: flooding is everywhere and getting a payout for it is not automatic. For a property owner, that reframes a sump pump and waterproofing from optional upgrades into the primary, and often only, financial defense against basement water.
What a sump pump costs
The first line of defense is the pump in the pit. According to This Old House (thisoldhouse.com), sump pump installation costs about $1,400 on average, with most homeowners paying $500 to $4,000, and a battery backup, the part that matters most when a storm also cuts the power, adds only $150 to $250.
Statistic 8
Sump pump installation costs about $1,400 on average, with most homeowners paying $500 to $4,000.
This Old House (2026)
Statistic 9
Sump pump replacement typically costs $350 to $1,000, including materials and labor.
This Old House (2026)
Statistic 10
A backup battery adds about $150 to $250.
This Old House (2026)
Statistic 11
The pump unit itself runs $90 to $1,000 for a submersible and $80 to $800 for a pedestal.
This Old House (2026)
Statistic 12
Installing a new sump basin can cost $500 to $1,200 in labor alone.
This Old House (2026)
Statistic 13
Discharge piping runs $150 to $400 above ground and $250 to $2,000 buried.
This Old House (2026)
What this means: A sump pump is cheap relative to the flood it prevents, and the backup battery, the least expensive line item, is the one that decides whether it works during the storm that knocks out power. It is a small, verifiable piece of equipment whose condition is easy to check and easy to neglect.
What basement waterproofing costs
When water is getting in through the structure, not just pooling, waterproofing is the fix, and the cost depends heavily on whether the crew works inside or has to excavate. According to This Old House (thisoldhouse.com), waterproofing a 1,000-square-foot basement averages about $13,640, with interior methods near $3,000 and exterior excavation running $7,000 to $15,000.
Statistic 14
Waterproofing a 1,000-square-foot basement averages about $13,640 (roughly $12,447 to $14,833).
This Old House (2026)
Statistic 15
Interior waterproofing averages about $3,000, ranging $2,000 to $6,000.
This Old House (2026)
Statistic 16
Exterior (excavation-based) waterproofing averages about $7,000, ranging $7,000 to $15,000.
This Old House (2026)
Statistic 17
Weeping (drain) tile costs $60 to $120 per linear foot; subfloor drain tile $25 to $55.
This Old House (2026)
Statistic 18
A French drain runs $10 to $100 per linear foot.
This Old House (2026)
Statistic 19
Professional epoxy crack injection costs $800 to $1,500 per crack.
This Old House (2026)
Statistic 20
Waterproof paint or sealer costs $1 to $8 per square foot.
This Old House (2026)
What this means: The order-of-magnitude jump from a $1-a-square-foot sealer to a five-figure exterior excavation is a diagnosis story: the fix has to match the source of the water. Catching a small crack or a failing drain early, when epoxy injection or interior drainage still solves it, is what keeps the job out of the excavator's price range.
Cite this study
Academic or press use: copy a ready-made reference. RapidEye is the publisher.
Quick FAQ
Does homeowners insurance cover basement flooding?
No. Most homeowners insurance does not cover flood damage, according to FEMA and Ready.gov (fema.gov, ready.gov); flood insurance is a separate policy, most often through the National Flood Insurance Program. Floods are the most common natural disaster in the United States and can happen anywhere, not only in high-risk areas.
How much does a sump pump cost to install?
Sump pump installation costs about $1,400 on average, with most homeowners paying $500 to $4,000, according to This Old House (thisoldhouse.com). Replacement runs $350 to $1,000, a battery backup adds $150 to $250, and installing a new sump basin can cost $500 to $1,200 in labor alone.
How much does basement waterproofing cost?
Waterproofing a 1,000-square-foot basement averages about $13,640, according to This Old House (thisoldhouse.com). Interior methods average about $3,000 ($2,000 to $6,000) and exterior excavation-based waterproofing about $7,000 ($7,000 to $15,000); epoxy crack injection runs $800 to $1,500 per crack.
How common is flooding in the US?
Floods are the most common natural disaster in the United States and can happen anywhere, according to FEMA and Ready.gov (fema.gov, ready.gov). The National Flood Insurance Program has 4.7 million policyholders and provides nearly $1.3 trillion in coverage, and just six inches of moving water can knock a person down.
Data sources
Every figure traces to one of these named public sources, each checked against the original before publishing. We name each source and show its root domain, but do not hyperlink external sources; internal links stay live.
Federal Emergency Management AgencyNational Flood Insurance Program datafema.gov
Ready.gov (DHS)Flood preparedness and safety guidanceready.gov
This Old HouseSump pump and basement waterproofing cost guidesthisoldhouse.com