Does paving a dirt street in the floodway require an engineer's "no-rise" certification?

In the context of floodplain management and floodway regulations, paving a dirt street may impact water flow and flood conveyance. A "no-rise" certification is needed when any alteration in a floodway could increase the base flood elevation, thereby risking higher flood levels downstream.

When the street is paved, if the grade remains unchanged, it means there will be no alteration to the existing elevation or the flow of water. Since the physical characteristics of the floodway are preserved, the paving itself does not create additional challenges concerning water displacement or flooding risk. As such, a certification is not necessary in this scenario, making the answer accurate in stating that no certification is required if the elevation of the street does not change.

Changes in paving materials or street widening could potentially affect water flow, but if only the surface is altered without changing the ground's elevation or drainage characteristics, a "no-rise" certification isn't warranted.