# Stormwater fee review

URL: https://municorn.us/services/stormwater-fee-review/
Updated: 2026-09-03
Tags: services, stormwater, rates

> **Cite as:** Municorn.us, "Stormwater fee review", https://municorn.us/services/stormwater-fee-review/ (updated 2026-09-03).
> **Licence:** CC BY 4.0 — https://creativecommons.org/licenses/by/4.0/ — reuse and redistribution are permitted with attribution to Municorn.us and a link to this URL.

A stormwater charge has no meter. The link between a property and its bill has to be established some other way, usually measured impervious area. We review an existing fee and the basis underneath it.

Water and sewer charges have a meter behind them. A stormwater charge does not. Whatever connects a particular parcel to a particular bill has to be constructed, published and defended, and it is almost always measured impervious area expressed in equivalent residential units.

That construction is where the charge gets challenged, which is why stormwater charges are litigated more often than metered ones: the leading case on the fee-versus-tax question in Michigan was a challenge to a stormwater charge, and the leading case upholding one was too.

## The four questions

We take the fee ordinance, the current rate schedule, the parcel and impervious area data the charge is billed from, and the stormwater program budget, and we work back from the bill to the cost.

What does the program cost, by activity, and which of those costs is the fee recovering. How was one equivalent residential unit defined, from what measurement of what population of parcels. How is each parcel's impervious area measured, when was that measurement last refreshed, and what happens when a property owner says it is wrong. And what credits exist for on-site detention or treatment, on what basis, and who has actually claimed them.

Where the answers are documented we point at the document. Where they are not, the review says so.

## What arrives

A written review of the fee against its own basis, with each element sourced to the ordinance, the budget or the parcel data. The impervious area and ERU calculation as a spreadsheet you keep. A list of the places where the current basis is not evidenced, ranked by how exposed each one is. Where the review supports a change, the revised schedule and the bill impact by property type. Slides for the council or board, and us at the meeting.

```exhibit invented
What the parcel record actually supports, before any rate is set

| Parcel class | Parcels | Median impervious area | Billing units | Share of fee base |
| --- | --- | --- | --- | --- |
| Single family | 7,910 | 2,640 sq ft | 1.00 ERU each | 44.1% |
| Multifamily | 412 | 18,300 sq ft | Measured | 12.7% |
| Commercial | 690 | 31,100 sq ft | Measured | 29.6% |
| Institutional | 88 | 44,800 sq ft | Measured | 9.4% |
| Tax exempt, currently unbilled | 143 | 39,200 sq ft | Not billed | 4.2% |

City of Ellery, parcels as of FY2028. One ERU is the median single-family impervious area.
```

Churches, schools and the city's own buildings generate runoff and generally do not pay for it. Whether they should is a council decision, and this row is the number that decision needs.

## Where this stops

Whether the fee is legally defensible is an opinion about your jurisdiction's law applied to your ordinance, and it belongs to your attorney. What we produce is the factual record that opinion would be written from.

If the ERU definition was never documented, the finding is that it was never documented. The fix is to adopt one going forward, not to construct one now and present it as the basis the fee was adopted on.

Impervious area measured off aerial imagery is not a survey and this review will not call it one. Where the parcel data is the source, the review inherits its accuracy and says so.

## Who this is for

Best fit: a city, county or district with an adopted stormwater fee, a parcel-level impervious area dataset of some kind, and either a rate increase coming or a dispute already open.

Also a fit before a program expands. A fee adopted for street sweeping and inlet cleaning, now funding capital work under a permit obligation, is recovering a different cost than the one it was adopted for, and that is a basis question whether or not anyone has raised it.

Poor fit: if there is no impervious area data at all, the first project is building it from parcel records or imagery, which is a larger piece of work we are happy to scope separately.

## The fee

Flat. The scope is the four questions above and the deliverables listed under them, priced by the number of parcels and by how much of the ordinance and budget record is already published.

_Municorn.us · https://municorn.us/services/stormwater-fee-review/ · CC BY 4.0 https://creativecommons.org/licenses/by/4.0/ · updated 2026-09-03_

---