About Basement Risk Check

An independent homeowner resource for metro Detroit, built on public data.

Basement Risk Check is an independent resource based in southeast Michigan. We built the Basement Risk Index, a 0–100 score that rates 1,100 neighborhoods and 116 communities across Wayne, Oakland, and Macomb counties on their exposure to basement water.

The person behind the index

The person who stands behind the numbers is Aaron Karns of Livonia.

Aaron and his wife bought their Livonia house in 2014. Every heavy rain, a 20 foot stretch of the basement collected an inch or two of water. They could see it seeping through the south and west walls. Water also pooled near the east wall, and that one made no sense, because nothing was seeping through there.

The answer arrived by accident. Sitting in the living room during a storm, Aaron heard dripping inside the fireplace. He opened it up and found water coming down the chimney, directly above the spot in the basement nobody could explain. A new chimney cap and tuckpointing fixed it for about $2,200. The south and west walls were solved with regrading and landscaping the family did themselves, work that would have run $5,000 to $7,000 hired out.

The lesson that became this site: the cause of basement water is often invisible from the basement. You cannot fix what you have not correctly diagnosed, and the diagnosis starts with knowing what your house and your neighborhood are actually up against.

Aaron spent about five years, roughly 2003 to 2008, as a field technician for Inspection Services Company, a construction materials testing firm based in Plymouth. He tested soil compaction, soil bearing capacity, asphalt, and concrete on commercial and residential jobsites across southeast Michigan, from Detroit to Ann Arbor. Two things from those jobsites stuck with him. On one neighborhood development, freshly poured basement walls cracked and bowed inward before a single stick of framing went up, because the backfill soil was so saturated that the ground moved underfoot and the weight of the wet soil alone was enough to break concrete. On other sites, crews pumped water out of excavations before every pour, because the clay soil here simply does not drain. Southeast Michigan basements sit in that clay.

After the field work, Aaron earned a Master of Arts in International Economics and Development from Eastern Michigan University in 2011, where he also completed his bachelor’s degree, then spent six years in market research analyzing and interpreting data. The index on this site is what happens when someone with dirt under his fingernails and a data habit gets a wet basement of his own.

Why we built it

In June 2021, storms put tens of thousands of metro Detroit basements underwater in a single weekend and brought a federal disaster declaration to Wayne County. Talking to neighbors afterward, one thing kept coming up: almost no one knew their street had a history of flooding, even though the records existed the whole time. They were just scattered across census tables, city databases, and disaster filings that no ordinary homeowner would ever assemble.

So we assembled them. The goal is simple: let any metro Detroit homeowner see their neighborhood's basement-flood risk, and understand why, before the next storm instead of after.

How the Basement Risk Index works

The Index weighs each neighborhood's housing vintage and the region's soil and drainage characteristics against documented metro Detroit flood history. The largest single driver is housing age: sump pumps, exterior weeping tile, and backwater valves only became standard in homes built after the 1960s, and metro Detroit's heavy clay soil holds water against the older foundations that came before. We score every neighborhood relative to the rest of the metro, so the number tells you where you stand.

Higher scores reflect greater structural exposure. It is a model of relative risk built from history and regional factors, not a prediction for any individual property. The full formula and weightings are published on our methodology page, along with the public data sources behind every score.

Our standards

• Public records, cited. Every figure traces to public data, and our methodology is published in full.
• Independent. The scores reflect public data only, not any contractor, advertiser, or agency.
• Privacy-first. We do not sell or share personal information.
• Honest about limits. Suburban scores are modeled from housing data and labeled as such. Nothing is overstated.

How we are funded

Basement Risk Check is free for homeowners. We sustain the resource by connecting homeowners who request it with one licensed, insured waterproofing contractor in their area, and we may be compensated for that referral. The data and rankings are never altered by that relationship, and the methodology is published. The risk data remains free for homeowners, journalists, and community resource pages to use and cite.