The City of Bonney Lake, Washington, publishes separate 2026 impact-fee and utility system-development-charge (SDC) examples for ADUs. The figures below are local schedule values, not a total project quote or rates for other Washington cities.
Published 2026 examples
| Charge | Published amount | Applicability note |
|---|---|---|
| Park impact fee | $2,613.53 per ADU | Confirm current City schedule and project classification. |
| School impact fee | $2,297.50 per ADU | Both Sumner-Bonney Lake and White River School Districts currently publish this rate through January 31, 2027. Confirm which district applies and its payment-receipt procedure. |
| Transportation impact fee | $1,877.50 per ADU | Confirm current schedule and project classification. |
| Sewer SDC | $9,183.79 per ADU | A single ADU may qualify for deferral under Bonney Lake Municipal Code 13.12.100.E; approval is not automatic. |
| Stormwater SDC | $1,282.05 per ADU | Other site and service conditions may affect the project. |
| Water SDC | $4,439.82 per ADU | A single ADU may qualify for deferral under Bonney Lake Municipal Code 13.04.070.D.2.c; approval is not automatic. |
The City page states that impact fees and SDCs must be paid in full before a building permit can be issued, subject to any approved deferral or exception. It also says bedroom-based school-fee calculations begin February 1, 2027; it does not establish the future bedroom-based amount.
What to confirm for an address
Ask Bonney Lake to confirm the applicable permit classification, number of units, school district, current fee schedule, payment timing, and documents for any ADU deferral request. Confirm the water and sewer service configuration with the relevant provider. The City page lists rates and code references; it does not determine whether a particular parcel qualifies for a deferral or what its final bill will be.
Impact fees and utility SDCs are separate from ordinary permit fees, private construction costs, and potential service upgrades. Payment or deferral does not establish zoning eligibility, building-code compliance, utility capacity, or permission to occupy.