How to Test Your Yard's Drainage in 30 Minutes (No Tools)

TL;DR: Dig a hole 12 inches deep and 12 inches wide, fill it with water, and time how long it takes to drain. Water should drop at least 1 inch per hour; if the hole is still full after 2 hours, your soil has a drainage problem that can push water toward your foundation. The test costs nothing and takes about 30 minutes including the wait.

_Last reviewed: July 2026 · 6 min read_

You've noticed the same soggy patch every time it rains, or maybe your basement smells musty after a storm and you're not sure if the yard is the cause. Before you call a landscaper or a waterproofing company, you can find out yourself with a shovel, a garden hose, and half an hour.

Okoniq Property Hub lets you log drainage test results and photos by property so you can track whether a problem area is getting worse season over season.

What is the percolation test and why does it matter?

The percolation test, sometimes called a perc test, measures how fast water moves through your soil. It's the same basic test septic system installers use before approving a leach field, just scaled down for a homeowner's afternoon.

Dig a hole 12 inches deep and 12 inches across in the area you're worried about, usually within 10 feet of the foundation or in a low spot where water collects. Fill it completely with water from a hose and let it soak in once, this saturates the surrounding soil so your real measurement isn't skewed by dry ground soaking up the first fill. Then fill it a second time, mark the water level with a stick or tape on the shovel handle, and start a timer.

Healthy, well-draining soil moves water at 1 to 2 inches per hour. Clay-heavy soil often drains at half an inch per hour or slower. If your hole is still mostly full after 2 hours, you're dealing with soil compaction, high clay content, or a grading problem that's sending water where it shouldn't go.

How do you read the results correctly?

Measure the water drop every 30 minutes for at least 2 hours, longer if the water hasn't moved much. Write down the inches dropped at each check, not just the final number, because a hole that drains fast for the first hour and then stalls tells you something different than one that's slow the whole way through.

If the first hole drains too fast, over 3 inches an hour, that's rare but can mean overly sandy soil that won't hold moisture for grass or plants. Most yards with drainage complaints fall on the slow end. A rate under half an inch per hour near the foundation is the number that should prompt action, especially if that spot is downhill from a downspout. Poor grading combined with a slow-draining spot is a common combination behind downspouts dumping water in the wrong place.

Where in the yard should you actually test?

Test within 10 feet of the foundation first, then any low spot where water visibly pools during or after rain. These are the two locations most likely to cause structural or basement problems, so they matter more than the middle of the lawn.

Run a second test at least 20 feet from the house in an area that looks healthy, so you have a baseline for what "normal" drains like on your property. Soil type can vary significantly across a single lot, a spot near a driveway with compacted fill dirt can drain at a completely different rate than 30 feet away in native topsoil. If you've had water in the basement after storms, also check the grade right along the foundation wall; ground should slope away from the house at roughly 6 inches of drop over the first 10 feet. Combine your perc test results with a quick grading check, since slow drainage plus flat or negative grading is what typically leads to downspout mistakes that send water into your basement.

| Drainage Rate | What It Means | Action Needed | |---|---|---| | 1-2 in/hour | Normal, healthy soil | None | | 0.5-1 in/hour | Slow, workable with amendments | Add organic matter, monitor | | Under 0.5 in/hour | Poor drainage, standing water risk | French drain, grading fix, or dry well |

What should you do if your yard fails the test?

If your test hole drains slower than half an inch per hour near the house, the fix depends on what's causing it. Compacted soil from construction or heavy foot traffic can sometimes be improved with core aeration and adding 2 to 3 inches of compost worked into the top 6 inches of soil, a project you can do yourself over a weekend for under $100 in materials.

If the slow drainage is closer to the foundation and paired with negative grading, a French drain is usually the more reliable fix. A basic gravel-and-pipe French drain runs $10 to $25 per linear foot if you hire it out, less if you dig it yourself. For a persistent low spot 15 to 20 feet from the house, a dry well, essentially a gravel-filled pit that collects and slowly releases water, can handle runoff that a simple regrade won't solve.

Whatever you choose, don't ignore a failed test near the foundation. Standing water within a few feet of your house for more than a day or two after rain is one of the more common precursors to the kind of hydrostatic pressure that shows up later as signs of a slab leak under your floor or cracked foundation walls.

How often should you re-test your yard?

Re-test any problem spot once a year, ideally in spring after the ground has thawed and before the heaviest rain season in your region. Soil compaction changes over time from freeze-thaw cycles, new landscaping, or even parking a vehicle on the lawn repeatedly, so a spot that passed 3 years ago can fail today.

If you've made a fix, a French drain, regrading, or amended soil, re-test the same hole location 6 months later to confirm the improvement held. A one-time test tells you where you stand today; annual testing tells you whether your yard is trending toward a real problem before it becomes an expensive one.

FAQ

How long should a drainage test hole take to drain?

A 12-inch hole in healthy soil should drain at least 1 inch per hour, meaning it empties within roughly 12 hours at most, though most well-drained yards clear a shallow hole in 2 to 4 hours.

Can I do a drainage test without digging a hole?

You can do a simpler surface test by pouring 5 gallons of water on a flat area and timing how long standing water remains visible, but it's less accurate than the 12-inch perc test since it doesn't measure how water moves through subsurface soil layers.

What soil type drains the worst?

Heavy clay soil drains the worst, often under half an inch per hour, because clay particles are small and pack tightly, leaving little room for water to pass through compared to sandy or loamy soil.

Does yard drainage affect my basement?

Yes, poor yard drainage is one of the most common causes of basement water intrusion, since water that doesn't absorb into the soil runs downhill toward the foundation and can push through cracks or seep under slabs during heavy rain.

How much does fixing bad yard drainage typically cost?

Simple fixes like regrading or adding compost run under $200 in materials for a DIY weekend project, while a professionally installed French drain typically costs $1,000 to $3,000 depending on length and soil conditions.

This is educational information, not engineering advice. Call a licensed drainage contractor or civil engineer if your yard fails the test repeatedly or if you're seeing foundation cracks alongside standing water.