Methodology

What we cover

ImpactFeeAtlas normalizes three families of one-time charges on new residential development:

• Development / impact fees — transportation, parks, schools, fire, police, drainage, general government, library, open space, and affordable-housing fees.
• Water & sewer connection fees — tap fees, capacity charges, and system development charges (SDCs).
• Mitigation fees — habitat, environmental, and agricultural mitigation where charged per unit.

We exclude building-permit and plan-review fees — they are a different, well-served category. Our focus is the capital charges that move a development pro forma.

Source hierarchy

For every figure we prefer sources in this order:

1. The jurisdiction’s adopted master fee schedule or fee resolution/ordinance.
2. The official impact-fee study or nexus study the schedule is based on.
3. The jurisdiction’s fee web page or hosted municipal code (Municode / American Legal).
4. An authoritative government report citing the adopted figure.

Every fee row stores the exact source URL and a short quote lifted from that source. If a figure cannot be tied to a real source, we leave it out rather than estimate. Partial coverage is normal; invented numbers are not.

Normalization

Jurisdictions publish fees in wildly different formats — per door, per fixture unit, per trip, per 1,000 sq ft, by meter size. We map each into one schema: jurisdiction × category × land use × unit basis × amount × effective date. For comparison we express residential fees per dwelling unit; water and sewer connection fees use the base residential meter (typically 5/8″ or 3/4″) when priced by meter size.

Verification & confidence

Each figure is gathered and then independently re-checked against its cited source; rows that don’t confirm are dropped. Every row carries a confidence rating:

• High — current official schedule, exact quote confirmed.
• Medium — official but older or summarized.
• Low — a secondary government/industry source citing the figure.

Freshness

Fees change — most jurisdictions escalate annually (often by a construction cost index), with occasional mid-year updates. Each jurisdiction page shows a last-verified date. We currently track 60 jurisdictions across 8 states and re-check on a rolling basis.