Free Assessment
HomeCommunities › Holly Township
Basement Risk Index™ · Community Report

Basement Flood Risk in Holly Township, Michigan

23BRI / 100
MODERATE RISK
Ranked #73 of 117 metro Detroit communities

Holly Township, Michigan carries a Basement Risk Index of 23 out of 100, ranking #73 of 117 communities across metro Detroit, which is below the metro Detroit average. The score is driven by housing age and soil: 23% of Holly Township homes were built before 1960, the era before sump pumps, exterior weeping tile, and backwater valves were standard, and the region's heavy clay soil holds water against those older foundations.

Holly Township basement risk at a glance

Basement Risk Index23 / 100 (MODERATE)
Metro rank#73 of 117
Homes built before 196023%
Peak building era2000s (20% of homes)
Median year built1987
Median home value$213,800
Median household income$69,943
Owner-occupied74%
Neighborhoods analyzed2

Source: Basement Risk Index, derived from U.S. Census Bureau ACS housing data and municipal flood records. Index weightings are proprietary.

When Holly Township was built

The housing stock in Holly Township peaked in the 2000s, when about 20% of today's homes were built. In total, 23% of Holly Township homes predate 1960. That matters because basements built before the 1960s typically lack the sump pumps, perimeter drain tile, and backwater valves that became standard later, leaving many on their original, aging clay drain tiles.

2020 or later
0%
2010s
8%
2000s
20%
1990s
19%
1980s
10%
1970s
13%
1960s
7%
1950s
9%
1940s
3%
Before 1940
11%

How basement risk varies inside Holly Township

We score 2 individual neighborhoods inside Holly Township. Of those, 0 fall in the high or severe band, 0 are elevated, and 2 are moderate or lower. Risk is rarely uniform across a city, so the most useful number is the one for your own block, which a free assessment pins down.

0Severe
0High
0Elevated
1Moderate
1Lower

What this means for Holly Township homeowners

Holly Township scores in the moderate band, but moderate is not zero on clay soil. Prevention is cheap relative to a flooded basement, and a free check tells you what you are working with.

Why Holly Township homes face basement risk

Basement flooding in Holly Township is mostly a function of housing age and soil. Older homes were built with clay drain tiles that crack and clog over decades, and the dense clay across southeast Michigan holds water against foundations rather than letting it drain.

How Holly Township compares

Holly Township's Index of 23 is below the metro Detroit median of 32. It ranks #73 of 117 communities region-wide.

Does insurance cover it?

Often not. Standard Michigan homeowners policies commonly exclude sewer backup and groundwater unless you carry a specific endorsement. Before the next storm, it is worth reading our guide on whether insurance covers basement flooding in Michigan and checking your declarations page.

What to do about it

  1. Lower risk is not zero risk on the region's clay soil, a free prevention check takes about 30 minutes.
  2. Watch for symptoms after storms; what you see at your own home matters more than any average.
  3. Maintain gutters and grading, the two cheapest protections any Michigan home has.
See Holly Township on the full metro Detroit Basement Risk Index map →

Get your free Holly Township basement assessment

A licensed, insured local waterproofing contractor will inspect your basement and foundation. No cost, no obligation. We work with one contractor per area; your request is never sold to a list.

Licensed & insuredNever sold to lead listsResponse within minutes

Nearby communities

Rose Township · 17Groveland Township · 15Springfield Township · 10Highland Township · 19White Lake Township · 18

Homeowner guides

Does insurance cover basement flooding?What to do when your basement floodsThe 2021 metro Detroit floodsWhat keeps a Michigan basement dry

Frequently asked questions

Is Holly Township at high risk for basement flooding?

Holly Township scores 23 out of 100 on the Basement Risk Index, ranking #73 of 117 metro Detroit communities (MODERATE risk). The score reflects how much of the local housing stock predates modern basement drainage, on the region's clay soil.

Why does housing age matter so much in Holly Township?

Sump pumps, exterior weeping tile, and backwater valves only became standard in the 1960s and 70s. 23% of Holly Township homes were built before 1960, with the largest share built in the 2000s. Many still rely on original clay drain tiles that fail over time.

Does homeowners insurance cover basement flooding?

Often not. Standard policies commonly exclude groundwater and sewer backup unless you carry a specific rider. See our Michigan insurance guide.

Is the assessment really free?

Yes. A licensed local contractor inspects your basement and foundation at no cost and no obligation. If repairs are recommended, you decide whether to proceed.