Last updated: November 7, 2026
Short answer: Earth fissures are cracks in the ground that form when land sinks after heavy groundwater pumping. The Arizona Geological Survey (AZGS) says they occur in five Arizona counties, including Maricopa. Before you buy, check the AZGS Natural Hazards in Arizona Viewer, read the seller's disclosures and ask a qualified professional about anything unusual.
Key takeaways
- AZGS says earth fissures come from land subsidence tied to groundwater withdrawal.
- Fissures crop out in Cochise, La Paz, Maricopa, Pima and Pinal counties, per AZGS.
- AZGS maps are a starting point. AZGS says a blank area on a fissure map does not prove no fissures are present.
- For some rural land sales, Arizona's A.R.S. 33-422 affidavit of disclosure asks whether the property is subject to fissures or expansive soils.
Want to talk it through? Book a time to chat with me (30 minutes, 9 AM–7 PM Arizona time).
¡Qué tal! I'm Rosie Armenta. If you are relocating to Avondale, AZ, earth fissures may be a new term for you. They are not something to panic about, but they are worth a few minutes of homework before you commit to a home, especially if you are looking at larger lots or land at the edge of the valley.
What is an earth fissure?
The AZGS Earth Fissures and Subsidence page (checked November 7, 2026) describes fissures as cracks on valley floors caused by basin subsidence linked to extensive groundwater withdrawal. They range from hairline cracks to open ground cracks. AZGS says monsoon rains can quickly widen and deepen them.
| AZGS fact | What it says |
|---|---|
| Where fissures crop out | Cochise, La Paz, Maricopa, Pima and Pinal counties |
| Study areas | 26 earth fissure study areas covering about 1,400 square miles |
| Mapped fissures | About 169 miles mapped, plus about 180 miles unconfirmed |
| Size | Up to 2 miles long, 15 to 25 feet wide and up to 90 feet deep |
| First recorded | Near Eloy in 1929 |
How can earth fissures affect a home?
AZGS lists common damage, including cracked or separated foundations and walls, broken pipes and utility lines, disrupted drainage and damaged well casings. AZGS also says fissures and subsidence can reduce property values. That is why it pays to look before you buy, not after.
How do I check a home I'm considering?
- Open the AZGS Natural Hazards in Arizona Viewer and look at the area around the address. AZGS says it publishes its newest fissure data there.
- Remember the map limits. AZGS map notes say a blank area does not prove fissures are absent, and a site-specific answer may need geotechnical analysis.
- Read the seller's disclosures closely. My post on what sellers have to disclose in Avondale, AZ covers the SPDS.
- Use your inspection period. Point out any long cracks in the yard, walls or slab to your home inspector. See what happens at an Arizona home inspection.
- Ask a geotechnical professional if anything looks unusual. AZGS recommends consulting a geotechnician about the extent of fissuring.
What about rural land outside city limits?
If you buy land that is not in a subdivision, in an unincorporated area, A.R.S. 33-422 can apply. It says a seller of five or fewer parcels of that kind of land gives the buyer a written affidavit of disclosure at least seven days before transfer. The form asks whether the property is subject to fissures or expansive soils, and whether it is in a FEMA floodplain. The buyer can rescind within five days after receiving the affidavit.
Example only: a made-up checklist, not a real Avondale property.
| Example only | What a buyer might do |
|---|---|
| Home on a city lot | Check the AZGS viewer, read the SPDS, mention cracks to the inspector |
| Home on rural acreage | All of the above, plus read the A.R.S. 33-422 affidavit if it applies |
| Long crack seen near the lot | Ask a geotechnical professional before the inspection period ends |
What if I find a fissure on or near my property?
AZGS says to keep people and pets away, email AZGS at azgs-info@email.arizona.edu, alert your municipal or county emergency managers, keep runoff and irrigation water out of the fissure, and consult a geotechnician about protecting your home.
Save this for your inspection period, and share it with anyone relocating to the West Valley.
Want help reviewing a home's disclosures before you buy? Book a time to chat with me (30 minutes, 9 AM–7 PM Arizona time), or call or text me at 623-295-5770.
Frequently Asked Questions
What causes earth fissures in Arizona?
AZGS says they form from basin subsidence linked to extensive groundwater withdrawal.
Are there earth fissures in Maricopa County?
Yes. AZGS lists Maricopa County among the five Arizona counties where fissures crop out. Check the AZGS viewer for a specific area.
Where can I see an earth fissure map?
AZGS publishes its current fissure data in the Natural Hazards in Arizona Viewer and posts study-area maps in its online library.
If the map shows nothing, is the home in the clear?
Not necessarily. AZGS says a blank map area does not prove fissures are absent, and a site-specific answer may need geotechnical analysis.
Can an earth fissure damage a house?
AZGS lists cracked or separated foundations and walls, broken pipes and disrupted drainage among common damage.
Does a seller have to disclose earth fissures?
For some rural land sales, the A.R.S. 33-422 affidavit asks about fissures. For other homes, read the seller's disclosure statement and ask questions in writing.
Who should I call if I see a long crack in the yard?
Tell your home inspector, and ask a geotechnical professional. AZGS also asks people to report fissures to AZGS.
Do monsoon storms make fissures worse?
AZGS says torrential monsoon rains can rapidly widen and deepen fissures, so keep runoff out of them.
I'm a real estate agent, not a geologist or a geotechnical engineer. I can't tell you whether a fissure is present at a specific property. Please rely on AZGS maps and a qualified geotechnical professional for those answers.
This article is general information, not legal, tax, or financial advice. Please talk with a licensed attorney, CPA, or lender about your situation.
About the author
Rosie Armenta | West USA Realty. Avondale (85392) is her home base, and she helps buyers and sellers across the West Valley in English and Spanish. Book a time to chat with me (30 minutes), or call or text 623-295-5770. Selling? Get a home value report.
Rosie Armenta | West USA Realty | Equal Housing Opportunity
Information was checked on November 7, 2026, from the Arizona Geological Survey Earth Fissures and Subsidence page, the AZGS Earth Fissure Map of Maricopa County record and A.R.S. 33-422. Maps and laws can change, so please confirm current details with AZGS and a qualified professional.