Drainage & Grading Cost Calculator — Winnipeg (2026)

It ranges widely by fix. Downspout extensions run $150 to $600, regrading a foundation perimeter $2,000 to $8,000, a French drain $50 to $120 per linear foot, and a catch basin with drain line $1,200 to $3,500. A whole-yard regrade with topsoil and sod typically lands between $5,000 and $15,000 depending on lot size and how much fill is needed.

Roughly six inches of fall over the first ten feet from the foundation — about a two percent slope. That’s enough to move water away reliably without looking severe. If water pools against your foundation during rain or the spring melt, the grade is negative and fixing it should come before any other landscaping work.

Backfill around a foundation settles for years after construction, and Winnipeg’s clay shrinks during dry spells. Together those slowly flatten a grade that was correct when the house was built, and eventually reverse it. It happens gradually enough that most homeowners don’t notice until a wet spring makes it obvious.

A negative grade is ground that slopes back toward your house rather than away from it, directing surface water against the foundation. It’s the single most important drainage problem to fix, because no patio, deck or garden built on top of it will perform, and water against a foundation is what leads to basement moisture and structural movement in clay soil.

They work, but they’re often not the first answer here. Our clay doesn’t percolate, so systems that rely on water soaking into surrounding soil underperform compared to sandy ground. French drains work well in Winnipeg when they carry water somewhere — to daylight or a proper outlet — rather than relying on dispersal. Surface grading usually solves more for less.

Often not, in Winnipeg. A dry well works by letting collected water disperse into surrounding soil, which our dense clay largely prevents. In practice they fill and stay full. In sandy soil they’re an excellent solution; here, moving water across the surface to a suitable outlet is usually the more reliable approach.

At least six feet, and ten is better, onto ground that slopes away. A single downspout delivers hundreds of gallons off a roof during one storm, and dumping that beside a foundation in non-absorbent clay is a leading cause of basement moisture. Extending downspouts is the cheapest and often the most effective drainage fix available.

Well away from the foundation — at minimum six to ten feet — and onto ground that carries the water away rather than back toward the house. Sump lines discharging right beside the foundation create a loop where the pump pulls water from the weeping tile and returns it to the same place, running the pump constantly.

Because frozen ground absorbs nothing. An entire winter’s snowfall converts to water over a couple of weeks in March or April, on top of a surface behaving like concrete. Whatever your yard does with water, it does all at once. Drainage in Winnipeg should be designed for the melt, not for average rainfall.

Yes, more than most people realize. Snow shovelled against the house all winter concentrates that entire volume of meltwater right at the foundation exactly when the ground can’t absorb it. Piling snow away from the house, on ground that drains away, is a free habit that meaningfully reduces spring water problems.

Common signs include water pooling within a few feet of the foundation, a damp-smelling basement, white chalky efflorescence on basement walls, a sump pump that cycles constantly, low spots holding water more than 24 hours, and patios or walkways settling in one area. Any of these is worth investigating before the next spring melt.

Yes, and it’s a common cause of failure. Water moving through or under a patio base washes out granular material, which causes uneven settling. Under a deck, poor drainage saturates the soil around footings and accelerates frost movement. That’s why drainage should be corrected before or during hardscape construction, not after.

The City of Winnipeg has historically offered subsidy programs supporting basement flood protection measures such as backwater valves and sump pit installation. Program eligibility, covered work and subsidy amounts change over time, so check the City’s current program details directly. It can meaningfully offset the interior portion of flood protection work.

Yes, always. Grading and drainage are the foundation every other element sits on, and correcting them afterward usually means tearing up finished work. It’s the least visible money you’ll spend in a yard and the most consequential — a beautiful patio built over a drainage problem is a temporary patio.

Downspout and sump discharge extensions are typically a half-day. Regrading a foundation perimeter with fill, topsoil and sod usually runs two to four days. A French drain or catch basin system depends on length and access but commonly takes two to five days. Weather matters — nobody should be shaping grade in saturated clay.