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Key findings

Bismarck, ND ranks #1 for basement water risk (80/100), driven most by expansive / clay soil.
Tucson, AZ ranks lowest of the 187 metros studied (36/100).
Expansive clay and severe freeze–thaw are the biggest risk multipliers across the ranking.

Journalists and bloggers are welcome to cite these findings with a link to this page.

Full ranking of 187 metros

#	Metro	Risk Index	Top factor
1	Bismarck, ND	80	expansive / clay soil
2	Burlington, VT	80	winter freeze–thaw
3	Davenport, IA	80	high basement prevalence
4	Fargo, ND	80	expansive / clay soil
5	Grand Forks, ND	80	expansive / clay soil
6	Green Bay, WI	80	winter freeze–thaw
7	Kenosha, WI	80	winter freeze–thaw
8	Madison, WI	80	winter freeze–thaw
9	Milwaukee, WI	80	winter freeze–thaw
10	Portland, ME	80	winter freeze–thaw
11	Bangor, ME	76	winter freeze–thaw
12	Boston, MA	76	high basement prevalence
13	Bridgeport, CT	76	high basement prevalence
14	Cambridge, MA	76	high basement prevalence
15	Cedar Rapids, IA	76	high basement prevalence
16	Chicago, IL	76	high basement prevalence
17	Cincinnati, OH	76	high basement prevalence
18	Concord, NH	76	winter freeze–thaw
19	Des Moines, IA	76	high basement prevalence
20	Detroit, MI	76	winter freeze–thaw
21	Duluth, MN	76	winter freeze–thaw
22	Evansville, IN	76	high basement prevalence
23	Grand Rapids, MI	76	winter freeze–thaw
24	Hartford, CT	76	high basement prevalence
25	Kalamazoo, MI	76	winter freeze–thaw
26	Lansing, MI	76	winter freeze–thaw
27	Lewiston, ME	76	winter freeze–thaw
28	Manchester, NH	76	winter freeze–thaw
29	Minneapolis, MN	76	winter freeze–thaw
30	Montpelier, VT	76	winter freeze–thaw
31	Nashua, NH	76	winter freeze–thaw
32	New Haven, CT	76	high basement prevalence
33	Peoria, IL	76	high basement prevalence
34	Pittsburgh, PA	76	high basement prevalence
35	Providence, RI	76	high basement prevalence
36	Rockford, IL	76	high basement prevalence
37	Rutland, VT	76	winter freeze–thaw
38	Saint Louis, MO	76	expansive / clay soil
39	Saint Paul, MN	76	winter freeze–thaw
40	Springfield, MA	76	high basement prevalence
41	Stamford, CT	76	high basement prevalence
42	Albany, NY	72	high basement prevalence
43	Ann Arbor, MI	72	winter freeze–thaw
44	Aurora, IL	72	high basement prevalence
45	Buffalo, NY	72	high basement prevalence
46	Charleston, WV	72	heavy precipitation
47	Cleveland, OH	72	high basement prevalence
48	Cranston, RI	72	high basement prevalence
49	Dayton, OH	72	high basement prevalence
50	Erie, PA	72	high basement prevalence
51	Fort Wayne, IN	72	high basement prevalence
52	Harrisburg, PA	72	high basement prevalence
53	Huntington, WV	72	heavy precipitation
54	Indianapolis, IN	72	high basement prevalence
55	Jersey City, NJ	72	heavy precipitation
56	Kansas City, MO	72	expansive / clay soil
57	Louisville, KY	72	heavy precipitation
58	Naperville, IL	72	high basement prevalence
59	Omaha, NE	72	expansive / clay soil
60	Philadelphia, PA	72	high basement prevalence
61	Rochester, MN	72	winter freeze–thaw
62	Rochester, NY	72	high basement prevalence
63	Scranton, PA	72	high basement prevalence
64	South Bend, IN	72	high basement prevalence
65	Springfield, IL	72	high basement prevalence
66	Syracuse, NY	72	high basement prevalence
67	Toledo, OH	72	high basement prevalence
68	Warren, MI	72	winter freeze–thaw
69	Warwick, RI	72	high basement prevalence
70	Worcester, MA	72	high basement prevalence
71	Yonkers, NY	72	high basement prevalence
72	Akron, OH	68	high basement prevalence
73	Allentown, PA	68	high basement prevalence
74	Baltimore, MD	68	heavy precipitation
75	Billings, MT	68	expansive / clay soil
76	Bowling Green, KY	68	heavy precipitation
77	Bozeman, MT	68	expansive / clay soil
78	Canton, OH	68	high basement prevalence
79	Casper, WY	68	expansive / clay soil
80	Cheyenne, WY	68	expansive / clay soil
81	Columbia, MO	68	expansive / clay soil
82	Columbia, MD	68	heavy precipitation
83	Columbus, OH	68	high basement prevalence
84	Edison, NJ	68	heavy precipitation
85	Frederick, MD	68	heavy precipitation
86	Great Falls, MT	68	expansive / clay soil
87	Gulfport, MS	68	expansive / clay soil
88	Laramie, WY	68	expansive / clay soil
89	Lexington, KY	68	heavy precipitation
90	Lincoln, NE	68	expansive / clay soil
91	Missoula, MT	68	expansive / clay soil
92	Morgantown, WV	68	heavy precipitation
93	New Orleans, LA	68	expansive / clay soil
94	Newark, NJ	68	heavy precipitation
95	Rapid City, SD	68	winter freeze–thaw
96	Sioux Falls, SD	68	winter freeze–thaw
97	Springfield, MO	68	expansive / clay soil
98	Topeka, KS	68	expansive / clay soil
99	Trenton, NJ	68	heavy precipitation
100	Washington, DC	68	heavy precipitation
101	Aurora, CO	64	expansive / clay soil
102	Baton Rouge, LA	64	expansive / clay soil
103	Colorado Springs, CO	64	expansive / clay soil
104	Denver, CO	64	expansive / clay soil
105	Dover, DE	64	heavy precipitation
106	Fort Collins, CO	64	expansive / clay soil
107	Hattiesburg, MS	64	expansive / clay soil
108	Jackson, MS	64	expansive / clay soil
109	Juneau, AK	64	winter freeze–thaw
110	Lafayette, LA	64	expansive / clay soil
111	Newark, DE	64	heavy precipitation
112	Overland Park, KS	64	expansive / clay soil
113	Shreveport, LA	64	expansive / clay soil
114	Virginia Beach, VA	64	heavy precipitation
115	Wichita, KS	64	expansive / clay soil
116	Wilmington, DE	64	heavy precipitation
117	Alexandria, VA	60	heavy precipitation
118	Anchorage, AK	60	winter freeze–thaw
119	Boise, ID	60	winter freeze–thaw
120	Fairbanks, AK	60	winter freeze–thaw
121	Idaho Falls, ID	60	winter freeze–thaw
122	Mobile, AL	60	heavy precipitation
123	Nampa, ID	60	winter freeze–thaw
124	Norman, OK	60	expansive / clay soil
125	Oklahoma City, OK	60	expansive / clay soil
126	Richmond, VA	60	heavy precipitation
127	Roanoke, VA	60	heavy precipitation
128	Savannah, GA	60	heavy precipitation
129	Tulsa, OK	60	expansive / clay soil
130	Asheville, NC	56	heavy precipitation
131	Charlotte, NC	56	heavy precipitation
132	Fayetteville, AR	56	expansive / clay soil
133	Fort Smith, AR	56	expansive / clay soil
134	Greensboro, NC	56	heavy precipitation
135	Houston, TX	56	expansive / clay soil
136	Little Rock, AR	56	expansive / clay soil
137	Memphis, TN	56	heavy precipitation
138	Ogden, UT	56	high basement prevalence
139	Provo, UT	56	high basement prevalence
140	Raleigh, NC	56	heavy precipitation
141	Salt Lake City, UT	56	high basement prevalence
142	Atlanta, GA	52	heavy precipitation
143	Augusta, GA	52	heavy precipitation
144	Austin, TX	52	expansive / clay soil
145	Bellevue, WA	52	heavy precipitation
146	Birmingham, AL	52	heavy precipitation
147	Charleston, SC	52	heavy precipitation
148	Chattanooga, TN	52	heavy precipitation
149	Columbus, GA	52	heavy precipitation
150	Dallas, TX	52	expansive / clay soil
151	El Paso, TX	52	expansive / clay soil
152	Eugene, OR	52	heavy precipitation
153	Fort Worth, TX	52	expansive / clay soil
154	Huntsville, AL	52	heavy precipitation
155	Jacksonville, FL	52	heavy precipitation
156	Knoxville, TN	52	heavy precipitation
157	Miami, FL	52	heavy precipitation
158	Montgomery, AL	52	heavy precipitation
159	Nashville, TN	52	heavy precipitation
160	Orlando, FL	52	heavy precipitation
161	Portland, OR	52	heavy precipitation
162	Salem, OR	52	heavy precipitation
163	San Antonio, TX	52	expansive / clay soil
164	Seattle, WA	52	heavy precipitation
165	Spokane, WA	52	heavy precipitation
166	Tacoma, WA	52	heavy precipitation
167	Tampa, FL	52	heavy precipitation
168	Albuquerque, NM	48	expansive / clay soil
169	Columbia, SC	48	heavy precipitation
170	Greenville, SC	48	heavy precipitation
171	Hilo, HI	48	river / lake / flood proximity
172	Las Cruces, NM	48	expansive / clay soil
173	Rio Rancho, NM	48	expansive / clay soil
174	Santa Fe, NM	48	expansive / clay soil
175	Honolulu, HI	44	expansive / clay soil
176	Fresno, CA	40	expansive / clay soil
177	Henderson, NV	40	expansive / clay soil
178	Las Vegas, NV	40	expansive / clay soil
179	Los Angeles, CA	40	expansive / clay soil
180	Reno, NV	40	expansive / clay soil
181	Sacramento, CA	40	expansive / clay soil
182	San Diego, CA	40	expansive / clay soil
183	San Jose, CA	40	expansive / clay soil
184	Mesa, AZ	36	expansive / clay soil
185	Phoenix, AZ	36	expansive / clay soil
186	Scottsdale, AZ	36	expansive / clay soil
187	Tucson, AZ	36	expansive / clay soil

The bigger picture (sourced facts)

Only about 16–17% of new U.S. homes are built with a basement — roughly 73% are slab-on-grade — and basements are concentrated in the colder North (New England ~67%, West North Central ~62%). — U.S. Census Bureau & HUD, Survey of Construction (2024–25)
The U.S. EPA estimates about 1 in 15 American homes has an elevated radon level (at or above 4 pCi/L), and radon is often highest on the lowest level of a home — typically the basement. — U.S. Environmental Protection Agency — A Citizen's Guide to Radon
FEMA estimates that just one inch of water inside a home can cause roughly $25,000 in damage — and standard homeowners insurance excludes flood damage. — Federal Emergency Management Agency (FEMA)
Expansive (reactive) clay soils — which swell when wet and shrink when dry — occur across a large share of U.S. states and are concentrated in Texas, Colorado, California, Wyoming and the Dakotas. — U.S. Geological Survey (USGS)
Expansive-soil damage is costly: widely-cited estimates range from about $2.3 billion a year (Jones & Holtz, 1973) to $15 billion or more in later estimates, and the ASCE is commonly cited that roughly one in four U.S. homes experiences some expansive-soil damage. — American Society of Civil Engineers (ASCE) / published literature
Mold can begin to grow within 24–48 hours of water intrusion, so controlling basement and crawl-space moisture quickly matters. — U.S. Environmental Protection Agency — Mold & Moisture guidance
More than one in five U.S. households depends on a septic system to treat its wastewater — and a failing system is a common, costly home problem. — U.S. Environmental Protection Agency — SepticSmart
Expansive, shrink–swell clay soils are a leading cause of cracked and sunken concrete — slabs, driveways and walkways — as the ground beneath heaves and settles with changes in moisture. — U.S. Geological Survey (USGS)

See all statistics & sources →

Methodology

Each metro is scored 1–5 on five factors drawn from public regional soil and climate data, then summed and scaled to 100: soil expansiveness, freeze–thaw severity, annual precipitation, basement prevalence, and water proximity.

Limitations: this is an awareness index built from regional characteristics, not official flood-zone data or a property-level rating. Scores are directional estimates for planning and education, not a substitute for a professional inspection.

The 2026 Basement Water Risk Index

Key findings

Full ranking of 187 metros

The bigger picture (sourced facts)

Methodology