French drain and sump pump installer leads

What it is not is a list of houses with wet basements. We have not measured that and do not claim it. What we measured is the ground.

Contributing area — the number that sizes the run

Contributing area is the square meters of upstream ground that drain to a given wall. It is computed per wall rather than per property, because a property number averages a nine-square-meter side yard together with the hillside behind the kitchen and tells you neither.

It is sampled at nine points beside the wall and re-sampled at every displaced footprint position, then published with its range and the distribution it came from — never as a bare maximum, and rounded to the precision it actually has. A range is more useful to you than a confident single figure, because the range is where your contingency goes.

Standing water — the number that places the pit

Every closed depression in the bare-earth surface is filled to the point where it spills, so no water is left with nowhere to go. The depth it filled to is kept, not discarded, because a real hollow beside a house is the whole point.

Depths and extents are reported within 20 m of the footprint and outside every building. Anything under 3 cm is measurement noise and is not counted.

The arithmetic was checked against ground where the answer is known: a bowl cut into a 2% slope fills to its spill point at 0.28 m predicted against 0.289 m measured.

Flow paths — where a trench would actually intercept

Water is routed, not shaded, and it spreads the way overland flow actually behaves. Near-single-channel in a gully, dispersive across a lawn — which is how overland flow behaves and is exactly the distinction that decides whether a straight run catches anything.

Buildings act as walls in the model, so water routes around a house rather than through it. Neighboring structures matter here more than people expect; a garage can be the reason a channel arrives at one corner.

Before any of this runs, the surface has to clear a gate: the median step between adjacent elevations must exceed 0.004 m. Below that the surface is a coarse source stretched onto a fine grid, and every channel drawn from it would be interpolation dressed as measurement. The engine refuses the address instead.

Getting the right house

Identity is decided by graded evidence, strongest first, and the engine stops the moment it has an identification. Every answer names how strongly the building was identified — because a building we identified and a building we merely located are not the same claim.

The building is identified from the evidence available before anything is measured, and the grade of evidence that answered ships with the result. Where the only thing available is the nearest outline, that locates a building rather than identifying one.

That last path is the guess, it is reported as one, and it is excluded from territory lists entirely. Where nothing identifies a structure at all, the address is refused rather than measured on the nearest roof.

How a property qualifies

Building established, identified at high confidence, and at least 3 m of wall with ground the engine called as falling toward the structure — meaning the direction survived displacing the outline one meter in each of sixteen directions, seventeen positions, all agreeing on the sign. Walls that lean but were not called are reported separately and qualify nobody.

Pricing and the two guarantees

From $14 per property: 25 for $450, 100 for $1,600, 500 for $7,000, or $35 each held exclusively to you for twelve months. Separate from the Solo ($99/mo, 25 lookups) and Pro ($399/mo, 200 lookups) platform plans, and not metered against them.

A refusal is never billed. When we cannot tell which building an address names, we say so and charge nothing. If the building is wrong, the property is replaced free.