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Downspouts, Grading & Gutters: The 3 Drainage Mistakes That Sink Puget Sound Driveways
Quick summary: Most of the driveway settling we see around Western Washington traces back to one of three common, fixable drainage mistakes: downspouts draining too close to the concrete, poor grading that sends water toward the driveway instead of away from it, and gutters that are clogged, damaged, or missing entirely. None of these are complicated to spot once you know what to look for, and catching them early is a lot cheaper than dealing with a sunken driveway later. This guide walks through all three, plus a quick checklist you can run through on your own property this weekend.
We walk a lot of driveways for inspections, and it's genuinely surprising how often the same three issues show up, sometimes all three on the same property. None of them are dramatic on their own. A downspout draining a foot too close to the slab, a yard that slopes just slightly the wrong way, a gutter that's been clogged since last fall. But given enough time and enough rain, any one of these can slowly erode the soil under a driveway and lead to settling.
The good news is that all three are things a homeowner can actually check for without any special tools, and catching them early is one of the more useful things you can do heading into wet season.
Mistake 1: Downspouts draining too close to the driveway
This is the one we see most often. A downspout is supposed to move water away from your home and off to a spot where it can drain safely, but a lot of them end up dumping water right at the edge of a driveway, walkway, or foundation instead. Over time, that concentrated stream of water works on the soil in that one spot every single time it rains, which in our climate is a lot.
What to look for: stand at the base of each downspout during or right after a rain and watch where the water actually goes. If it's pooling against the driveway, running along the edge of the slab, or disappearing into the soil right next to the concrete, that's worth addressing.
The fix here is usually simple and inexpensive: a downspout extension that carries water several feet further away, ideally to a spot where it can drain into the yard, a dry well, or a proper drainage system rather than straight onto or next to the concrete.
Mistake 2: Grading that sends water toward the driveway instead of away from it
Ground around a home is supposed to slope gently away from the house and any adjacent concrete, so water naturally runs off instead of pooling. Over the years, though, grading can shift. Landscaping projects, settling soil, added mulch or garden beds, and even just natural erosion can all change the slope of a yard enough that water starts running toward a driveway or foundation instead of away from it.
What to look for: after a decent rain, walk the perimeter of your driveway and note any spots where water is pooling, sitting for more than an hour or two, or clearly running toward the slab rather than away from it.
This one's a little more involved to fix than a downspout, since it usually means adding soil to build up the slope in the right spot, but it doesn't have to be a major project. Sometimes it's a small regrading job in just one problem area rather than the whole yard.
Mistake 3: Gutters that are clogged, damaged, or missing
This one's easy to overlook because it's not directly about the ground, it's about what happens before water ever reaches it. A clogged or damaged gutter doesn't do its job of channeling roof runoff to the downspouts in a controlled way. Instead, water overflows the gutter and pours off the roofline in an uncontrolled sheet, often landing much closer to the foundation and driveway than it would if the gutter system were working properly.
What to look for: during a rain, check whether water is overflowing the gutters anywhere, running down the siding, or pouring off a section of roofline that doesn't have a gutter at all. Fall is when this tends to get worse locally, since falling leaves clog gutters right around the same time our heaviest rain arrives. Chris Whalen, a senior inspector at 1-866-SLABJACK notes from much local experience that “If a downspout is dumping next to the slab or the grade is holding water against it, that needs to be corrected whether we lift the concrete or not”.
Why these three matter more here than in a lot of places
Western Washington's soil, especially the glacial till and clay-heavy pockets common from Everett down through Tacoma, doesn't drain particularly well on its own, and our wet season means these mistakes get tested a lot more than they would in a drier climate. A downspout draining in the wrong spot might not matter much somewhere that gets rain a few times a month. Around here, where it can rain for weeks at a stretch, that same mistake gets a lot more opportunity to do damage. We've written more about how Western Washington's wet season puts extra stress on sinking concrete if you want the fuller picture of why this time of year matters so much.
Your quick homeowner checklist
Run through this after your next decent rain, it only takes about 15 minutes:
Stand at each downspout during or right after rain and confirm water is being carried well away from the driveway, walkway, or foundation, not draining right at the edge of the concrete.
Walk the perimeter of your driveway and note any spots where water pools, sits for more than an hour or two, or visibly runs toward the slab instead of away from it.
Check your gutters for overflow, sagging, or visible clogging, especially right after leaves have started falling.
Look for any section of roofline without a gutter at all, and note where that water lands when it rains.
Check for any new gaps, dips, or unevenness where your driveway meets your garage, porch, or another slab, since this can be an early sign that one of these issues has already started affecting the soil underneath.
When it's more than just drainage
Fixing these three things is genuinely one of the best things a homeowner can do to protect a driveway long term, but it's worth knowing that not every settled driveway is a drainage issue, and fixing drainage after a slab has already settled won't lift it back into place. We cover that distinction in more detail in our post on why fixing your drainage won't fix your sunken concrete, and vice versa. If you've already got a section of driveway that's visibly sunk or uneven, addressing the drainage mistakes above is still worth doing, but the settled section itself will need to be lifted separately.
What to remember...
Downspouts draining too close to a driveway, poor grading, and clogged or damaged gutters are three of the most common, and most fixable, causes of drainage-related driveway settling we see around the Puget Sound.
All three are things a homeowner can check for on their own after a rain, with no special tools needed.
Our clay-heavy soil and extended wet season mean these mistakes tend to do more damage here than they would in a drier climate.
Fixing drainage protects your driveway going forward, but it won't lift concrete that's already settled, that's a separate repair.
Drainage Mistake FAQ
How do I know if my downspout is too close to my driveway?
Watch where the water goes during a rain. If it's pooling against the slab edge or draining into the soil directly next to the concrete, it's likely close enough to cause problems over time. Extending it several feet further away is usually a simple, inexpensive fix.
Can bad grading alone cause my driveway to sink?
Yes, poor grading that sends water toward a driveway instead of away from it is a common contributor to soil erosion and settling in this region. It's not the only cause of driveway settling, but it's one of the more common and fixable ones.
How often should I check my gutters in the Puget Sound area?
Checking them in early fall, before leaves drop and our heaviest rain arrives, is a good habit here, along with a follow-up check once most of the leaves have fallen. A clogged gutter can undo the benefit of a properly extended downspout pretty quickly.
Will fixing these three things stop my driveway from ever settling?
It significantly reduces the risk of drainage-related settling, but concrete can also settle for reasons unrelated to drainage, like soil compaction or disturbance from past construction. Fixing these three drainage mistakes is genuinely worthwhile, but it's not a guarantee against every type of settling.
If you've checked your downspouts, grading, and gutters and you're still seeing signs of a sinking driveway, or if you're not sure what's causing it, schedule a free inspection and we'll take a look and give you a straight answer.
