Grading · drainage · erosion control · Wrenfield & the Amber Valley · field book no. 34

Move the water first. The dirt is easy.

Thornapple Grading & Drainage has spent thirty-five years learning where the Amber Valley wants its water to go, and cuts every grade so it goes there on purpose — swales at a minimum fall, basins where the township wants them, and soil that stays on the site through the first storm and every one after.

Pads from $0.14 / sq ft · swales cut to a 1.5% minimum fall · silt fence up before the first bucket · (555) 033-5518 · field@thornapplegrade.example

From the field book — the rates on this page are the spring 2026 page, changed twice since 2019 and both times because diesel made us. A rate that moves without a reason is not a rate; it is a mood.

The rate page · spring 2026

Rough & final grade$0.14 / sq ft

Cut, fill and fine grade to ±0.5 in, rover-verified at the corners

Swales & surface drainage$3.20 / lin ft

Cut to a 1.5% minimum fall, outlets armored with riprap

Sediment basinfrom $2,400

Cut to the permit drawing, trash rack and riser set, outlet stabilized

Silt fence & erosion blanket$2.10 / lin ft

Installed before the first cut, inspected after every storm

Topsoil spread & finish$0.09 / sq ft

Your stockpiled loam screened, spread and dragged

Foundation & trench backfill$7.40 / lin ft

Bedded on stone, placed in lifts, compacted to 95% Proctor

Rates

Printed, pinned to the office door

The same page every estimate is written from — the page the last customer read and the next one will. If your site wants something the page does not name, the walk prices it in writing before the work: the page constrains us exactly as much as it informs you.

  1. Walk 1

    Shoot the water

    We walk the parcel in dry weather and read where the valley sends water now, then plan where it will send it after. Every grade on the site answers to that plan.

  2. Day 1

    Perimeter first

    Silt fence, stabilized entrance, inlet protection — the controls go in and get photographed before any iron moves. The township inspects the edges before the middle.

  3. The cut

    Grade & drain

    Swales to a 1.5 percent minimum fall, basins to the permit drawing, pads to ±0.5 in. Spoils either walk across the site or ride out once, priced on the page.

  4. Ongoing

    Inspect & maintain

    After every half-inch of rain and weekly regardless: fence patched, basins dredged, logs written. Erosion control is a maintenance job wearing a construction hat.

  5. Close

    Green it & sign off

    Topsoil back, blanket down, seed in, and the stabilization the permit requires verified before the last truck leaves. The record closes the job, not the weather.

The sequence

How the valley grades

Water decides the order of operations on every Thornapple site. The perimeter goes in before the first cut and the last thing we leave is ground green enough to keep itself — everything in between is just dirt, and dirt is the easy part.

2025 — 2026

From the field book, photographed

Swale day, Amber Flats
Swale day, Amber Flats — a mile of fall cut at 1.5 percent
The basin, Wrenfield school
The basin, Wrenfield school — riser set, rack on, outlet riprapped
Pad grade, the Ott lot
Pad grade, the Ott lot — ±0.5 in at the corners, seeding the same week
Perimeter, Millbrook site
Perimeter, Millbrook site — fence and entrance in before the first cut
Trench day, Cider Road
Trench day, Cider Road — bedding stone, lift-compacted backfill
The Hart basin
The Hart basin — core re-packed, first fill watched

Back of the book

The valley, measured

Figures from the bound field books, 1991 through last season. Every number is countable, and the books sit on the office counter if you would rather count them yourself.

1,180
sites graded and drained since 1991
0
notices of violation in eleven years of permit inspections
9 ft
of rain the valley averages — all of it planned for
35
field books, one counter, no locked drawer
Thornapple is the only outfit in the valley whose erosion-control logs I have never had to chase. Fence up before the first cut, basins dredged before I ask, and the stabilization photo arrives with the invoice. My file on them is the thinnest one I keep — which is exactly what a file should be.
D. Wexler — watershed technician, Amber Valley district
A dozer shaping a graded site

Erosion control

The first storm is the real inspection

A grade is a hypothesis until it rains. Perimeter controls go in before the first cut, basins get dredged after every event, and a log is written whether the inspector visits or not — because the week nobody looks is the week the valley does.

The permit stays clean, or we clean it

If a notice of violation names our controls, the repair, the fine and the re-inspection are ours, not yours. Eleven years of permits in the valley and the clause has never been used — which is why we can keep offering it.

Q&A

Readers of the field book ask

Do I need a permit to regrade my property?

In the Amber Valley, yes — the moment you disturb more than an acre, or anything the district calls a watercourse. We draw the application, the plan set and the inspection schedule as part of the work, and the permit fee is on the page, not in the fine print.

When does the silt fence actually go in?

Before the machine, on every job. The fence, the stabilized entrance and the inlet protection are photographed the day they go in — the district asks for the photographs, and so does our own field book.

What is a sediment basin doing that a pond is not?

Slowing water long enough to drop its soil. A basin is temporary plumbing with a trash rack and a riser, dredged and removed at closeout; a pond is landscape with a core and a spillway. We dig both, but only one of them on purpose gets stocked with fish.

Can you grade through the rainy stretch?

Trench and finish work, yes; long open slopes, no. A freshly cut slope in a two-inch rain is a regrade with a deadline, so we phase cuts to keep exposed soil ready to blanket inside a day. The calendar bends; the water does not.

Field book no. 35 opens in April · spring grades book four weeks out · (555) 033-5518

Letters answered in a day

Write to the field office

Parcel, plan if one exists, and what the water does now that you wish it did not. Answers come from the office in a day and from the field book in three. field@thornapplegrade.example