Denver Pro Landscape fixes yard drainage in Denver and the surrounding suburbs with regrading, French drains, buried downspout lines, dry wells, catch basins and swales. Call or request a free quote and we’ll read the grade first.
Call (720) 650-0165 or get a free quote.
How much does yard drainage cost in Denver?
It depends on the fix, the slope and the access. A French drain, a dry well, a catch basin and regrading each price differently, and the city permit application fee, where one applies, is $425. Get itemized quotes from licensed contractors after the grade has been read.
| Work | City fee |
|---|---|
| Denver Sewer Use and Drainage Permit application, where one applies | $425 |
The first four rows are ranges from third-party cost guides, including Denver-specific data, because we don’t publish a fixed drainage price list. The wall, rock and sod rows come from our own Denver landscaping cost guide pages. The permit fee is the city’s.
What moves a drainage quote up or down
- Length and depth. Trench footage is the main driver on any pipe job.
- Where the water can go. A long run to a legal outlet costs more than a short one.
- Access. A side yard too narrow for a machine means hand digging.
- Soil. Dry clay is slow to dig, excavated clay has to be hauled off, and drain rock has to be brought in.
- What’s in the way. Sprinkler lines, tree roots, gas and electric all slow a trench down.
- Restoration. Putting back sod, rock or planting is part of the job.
- Permits and engineering. A city permit, a stamped grading plan or a soils report adds cost and time.
Why does water pool in Denver yards?
Mostly clay and timing. The Colorado Geological Survey says the bentonite clays under much of Colorado can expand up to 20 percent by volume when wet, and clay takes water in slowly. Denver’s roughly 15 inches of yearly moisture tends to arrive in bursts, snowmelt or a summer downpour, so flat or settled lots pond.
Clay that swells
The USDA’s description of the Denver soil series is deep, fine-textured soil with more than 35 percent clay in the subsoil and slow to very slow permeability. Water sits on it. When it does soak in, the clay swells. The Geological Survey puts the force at up to 30,000 pounds per square foot, and its homeowner publication on swelling soils makes the key point: it’s uneven wetting that does the damage. One soggy corner lifts while the dry side stays put, and that difference is what cracks slabs and racks door frames.
Rain and snowmelt that arrive in bursts
Denver’s normal precipitation adds up to about 14.5 inches a year, with May the wettest month at 2.16 inches. Averages hide the problem, though. The National Weather Service record for a single May day is 6.50 inches, and the wettest month on the books saw 8.57 inches. March is the snowiest month at a normal 11.5 inches, and that snow melts onto ground that’s often still frozen or already full.
Lots that settle
Backfill around a foundation keeps settling for years. On older lots in Washington Park and Congress Park, the original grade has often gone flat or tipped back toward the house. Newer builds in Aurora, Centennial and Highlands Ranch show the same thing sooner, as loose backfill packs down. The freeze and thaw of a Denver winter keeps working on whatever water is trapped there.
How much slope should a yard have away from the house?
At least 6 inches of fall within the first 10 feet. That’s the Denver Residential Code standard for grading around a foundation. Where lot lines, walls or other barriers make that impossible, the code calls for drains or swales instead, and hard surfaces within 10 feet of the house must slope away at 2 percent or more.
Farther out, the city’s homeowner runoff guide gives a simple target for lawns, patios, driveways and side-yard swales: a quarter inch of fall per foot. Hold a two-foot level flat and the downhill end should sit at least half an inch off the ground. On swelling soil the Geological Survey’s older guideline is steeper still, 12 inches in 10 feet. We shoot grades with a level before recommending anything, because a yard that looks flat is often tipped the wrong way by an inch or two.
On sloped lots closer to the foothills, the problem flips. Water sheets downhill too fast, strips beds and lands on a neighbor. There the answer is shaping swales and terraces to slow it and steer it.
Do I need a French drain, or will regrading fix it?
Start with grade. If surface water can be steered away by reshaping soil, regrading is the simpler, longer-lasting fix. A French drain, a gravel trench with perforated pipe, earns its place when water is trapped below the surface, when a low spot has no natural outlet, or when the lot is too tight to reshape.
Regrading and swales
Scope: cut the high spots, fill and compact the low ones, restore fall away from the house and shape a shallow swale to carry water to the street or alley. The local caveat is clearance. Denver’s guide says never to pile fill against siding or fences, and foundations should show at least 6 inches of concrete above the soil line. On older homes that don’t have it, the guide suggests landscape plastic under mulch or rock in place of raising the grade.
French drains
Scope: a trench lined with filter fabric, perforated pipe bedded in washed rock, and a solid pipe run to an outlet. The local caveats are the city’s. Denver’s homeowner guide says underground drain piping needs a city permit, has to be solid-wall PVC that daylights at least 10 feet from the front property line, and requires a licensed plumber or drain layer to do the work and call for inspections. It also warns that pop-up outlets and drain pits can back water up along the outside of the pipe and into a basement. We scope buried pipe with those rules on the table, and we’ll tell you when a job crosses into permit territory.
Downspouts and splash blocks
Scope: get roof water away from the wall. The city’s guide recommends concrete splash blocks as the most durable, no-maintenance option, and says tip-out extensions should always be left down. The Geological Survey’s swelling-soil guidance is to carry roof runoff at least 10 feet from the building. This is often the cheapest fix on the lot, and it’s the first thing we check.
Dry wells and catch basins
Scope: a catch basin collects surface water at a low point and sends it down a pipe; a dry well stores water underground so it can soak away. The local caveat is the soil. A dry well only works where the ground drains, and Denver’s guide limits gravel infiltration pits to free-draining soils, sized by an engineer and built under a Sewer Use and Drainage Permit. In tight clay we treat a dry well as a last resort.
Terraces and retaining walls
Scope: break a slope into level steps so water slows down and soaks in. In Denver, any wall over 12 inches high needs a zoning permit, and retaining walls over six feet need engineering plan review and a building permit.
Planted swales and permeable surfaces
Scope: shallow planted channels, gravel paths and permeable patios that let water spread and soak instead of running off. The city’s guide makes the case for this: letting runoff cross landscaped areas instead of piping it all to the street cuts street flooding and lowers irrigation demand. It fits the water-wise approach Denver’s climate rewards, and it means less irrigation demand later.
How does a drainage project work from first call to final walkthrough?
Seven steps: a site walk, measuring the fall, a plan and written quote, permits and utility locates, the dirt and pipe work, a water test, then restoring the surface. Small regrades are often a day of site work. Drains with trenching usually take several days, and anything needing a city permit waits on review first.
- First call and site walk. We ask when and where the water shows up, then walk the yard looking at downspouts, low spots, the grade at the foundation and how the neighbors’ lots sit. A walk soon after a storm tells us the most. Plan on about an hour.
- Measuring the fall. We take level readings at the foundation, 10 feet out, and at wherever the water could exit. Those numbers decide whether reshaping soil can do the job alone. It happens on the same visit.
- Plan and written quote. You get the simplest fix that works, where the water will go, and what it costs. If there’s a cheaper option and a more thorough one, you see both and choose.
- Permits and locates. Buried utilities get marked through Colorado 811, which by law needs at least three business days’ notice. If the city wants a permit, review time is added here, and that part isn’t ours to speed up.
- Dirt work and pipe. We regrade, trench, lay fabric, rock and pipe, and set any basins. If the clay is saturated we stop, since working wet clay smears it and packs it tighter. A simple regrade is often a day. Trenching jobs usually run several.
- Water test. Before anything gets covered, we run a hose and watch where the water goes. If it hesitates anywhere, we fix it then. Under an hour.
- Restore and walk through. The surface goes back as rock, mulch, planting or sod, and we show you the outlets and what needs to stay clear. Allow half an hour.
Do I need a permit to regrade or add drainage in Denver?
It can, so check first. Denver’s Department of Transportation and Infrastructure lists changes to site grading and drainage, along with landscaping and retaining walls, among the residential projects that need a Sewer Use and Drainage Permit. The application fee is $425. A grading plan stamped by a Colorado engineer is required in a floodplain or for below-grade entrances.
The city’s permit requirements, effective August 17, 2026, add some useful detail. The application runs through Denver’s online e-permit system. A contractor’s licence isn’t required to submit it, and the permit is issued to the property owner. Plot plans have to show drainage flow arrows, swales, downspouts and extensions, and discharge points. The city can also ask for a stamped soils report when grading changes are proposed. Whether a small regrade in your yard needs any of this is the city’s call, so we ask before we quote. Suburbs run their own permit desks with their own answers.
Where can yard drainage legally go in Denver?
To the street, an alley or an approved storm connection, without crossing a neighbor’s property. The Denver Residential Code says surface drainage must go to a storm sewer conveyance or another approved collection point that doesn’t create a hazard. Denver’s homeowner guide adds two rules: never slope your lot onto a neighbor, and never connect to the sanitary sewer.
Sidewalks are the catch. The same guide treats the sidewalk as the adjacent owner’s responsibility, so water that crosses it and freezes is your problem, while alleys and gutters are built to carry flow. For sump pumps that run now and then, it suggests a 2 inch pipe to a splash block near the front of the house, draining toward the street, and warns against running small discharge pipes more than five feet because they freeze shut. A pump that runs constantly is a groundwater problem, and the guide sends those to an engineer.
What materials go into a yard drain that lasts in Denver clay?
Solid-wall PVC for anything that carries water away, perforated pipe wrapped in washed rock and filter fabric for anything that collects it, and concrete splash blocks at the downspouts. Denver’s homeowner guide calls for solid-wall PVC that daylights, meaning it runs downhill to open air with no restrictions, so debris flushes out on its own.
- Solid-wall PVC. Smooth inside, holds a steady slope and can be cleaned out. It’s the right pipe for downspout lines and outlet runs. It fails when it’s laid too flat.
- Corrugated flexible pipe. Cheap and quick to lay, but it sags between supports and its ridges hold sediment. We don’t use it for buried outlet runs.
- Perforated pipe in washed rock. The working part of a French drain. Water enters through the rock, drops into the pipe and leaves.
- Filter fabric. In clay, fine particles migrate into drain rock and clog it. Fabric around the rock slows that down.
- Catch basins and grates. For low points on patios and at the base of slopes. They need a real outlet and an occasional cleanout.
- River rock and cobble. For lining swales and armoring spots where water lands.
- Compacted fill. For rebuilding grade at the foundation. The Geological Survey notes that compacted, impervious backfill helps keep moisture from getting down along the wall.
- Landscape plastic and fabric. Denver’s guide suggests heavy plastic under mulch within 4 feet of the house, and porous fabric beyond that so water can soak in where it’s safe.
What are the signs a yard needs drainage work?
Water still standing a day after rain, a soggy or mossy strip along the foundation, mulch and soil washing out of beds, a damp basement, or ice forming in the same low spot every winter. Denver’s homeowner guide notes that a basement that gets wet the same day as a storm usually points to site drainage.
- Downspouts that empty right at the corner of the house.
- Gutters that overtop in an ordinary rain, which usually means a clog.
- A gap where a patio or walk has pulled away from the foundation.
- Soil that has sunk along the wall or around window wells.
- Water shooting up where a downspout meets a buried pipe.
Cracked slabs, sticking doors and stair-step cracks in walls are a different conversation. Those are for a soils or structural engineer, and the city’s guide says the same about any severe drainage problem.
When is the best time of year for drainage work in Denver?
Whenever the ground is workable and dry enough to shape, which in Denver is most of spring through fall. Late summer and fall are ideal because the fix is in before March snow and May rain test it. Frozen ground stops trenching, and saturated clay shouldn’t be graded at all, since it smears and compacts.
There’s a 2026 wrinkle for Denver Water customers. Under the Stage 1 drought rules, lawn watering ended after September 30, 2026, and new grass can’t be established without an approved variance. So a regraded area can’t simply be re-sodded right now. We finish those with rock, mulch or drip-watered planting, or leave the soil shaped and ready for sod installation once it’s allowed again.
What should be planted or watered near the foundation?
As little as possible. Colorado Geological Survey guidance for swelling soils is to keep grass, shrubs, flowers and sprinkler systems at least 5 feet from the foundation, trees at least 15 feet from any building, and thirsty trees like cottonwood, willow and Russian olive at least 20 feet away. Rock or mulch belongs next to the house.
Denver’s guide lines up with that. It says to use irrigation sparingly near the home, to keep spray heads away from it entirely, and to keep mulch off the siding. If a bed by the wall has to stay, it gets a few low-flow drip emitters and nothing more. Trees matter in the other direction too: the Geological Survey notes that water-loving trees close to a house can dry the clay and shrink it, which moves a foundation just as surely as swelling does.
Example scopes: typical Denver drainage fixes and the math
None of these is a job we’re claiming. They’re common situations, laid out so you can see how the ranges above combine.
Example scope: settled grade along a 40 foot foundation wall
For a lot like this, picture an older house where the soil along the back wall has sunk flat and two downspouts empty at the corners.
- Pull back the existing rock or mulch.
- Add and compact fill to restore 6 inches of fall in the first 10 feet.
- Set concrete splash blocks at both downspouts.
- Shape a shallow swale toward the side yard and re-lay the rock.
The local complication is clearance: the new grade still has to leave 6 inches of foundation showing below the siding. The grading is small hand work on one wall, plus a couple of cubic yards of rock for the swale.
Example scope: 60 foot French drain across a soggy back lawn
A typical case is a low spot mid-yard that holds water for days, with enough fall to reach the alley.
- Trench 60 feet, line it with filter fabric.
- Lay perforated pipe in washed rock through the wet area.
- Run solid-wall PVC from there to a daylight outlet.
- Backfill and restore the surface.
The local complication is the rulebook: Denver’s guide calls for a permit, solid-wall PVC and a licensed plumber or drain layer on buried piping. The city permit application fee of $425 applies if a permit is required, and restoring a 2 foot wide strip with sod waits until new grass is allowed.
Example scope: sloped back yard shedding onto a patio
For a yard that tilts toward the house and sends sheet flow across the patio:
- Build a 2 foot tall, 30 foot long terrace wall partway up the slope.
- Place drain rock behind the wall.
- Cut a swale at its base to carry water to the side yard.
The local complication is permitting, since any wall over 12 inches needs a Denver zoning permit. Price the wall and the swale grading as separate lines on the quote.
How do I keep yard drainage working after the job?
Keep the slopes, keep the outlets clear and keep water off the foundation. The Colorado Geological Survey calls continual maintenance of properly designed slopes the most critical part of landscaping on swelling soil. Clean gutters yearly, refill any soil that settles near the house, and check outlets and splash blocks each spring and fall.
- Walk the house during or just after a rainstorm and watch what the gutters and downspouts actually do.
- Fill small depressions near the wall or window wells flush with soil as they appear.
- Caulk the joint where a patio or walk meets the foundation. The city’s guide says to expect to redo it about every five years.
- Don’t let new edging, beds or a shed block a swale.
- Keep pipe outlets free of leaves, mulch and ice.
Denver neighborhoods and suburbs we serve
The right mix depends on the lot. A flat parcel in Berkeley or Park Hill needs a different plan than a walkout lot in Littleton or Arvada with grade to work with. We handle grading and drainage across Denver and the surrounding suburbs, including Aurora, Lakewood, Westminster and Thornton. Local pages:
Drainage usually touches other work. Related services: retaining walls, irrigation, sod installation and landscape design.
If water is sitting where you don’t want it, call (720) 650-0165 or request a free quote. We’ll measure the fall and lay out the simplest fix that protects the house and the yard together.