(1) The delineations of a designated floodway shall be based on the channel of the
water course or drainway and those portions of the adjoining floodplain which
are reasonably required to carry the discharge of the base flood without
cumulatively increasing the water surface more than one half foot.
(2) In
areas having appreciable urban development on the floodplain, the outer
boundary lines of the floodway may generally follow the riverward limits of
development provided that:
(a) The calculated
elevation of the base flood would not be increased more than 0.5 of a foot as a
result of any adjustment to the floodway;
(b) Floodway lines are compatible with local land use plans; and,
(c) The
flood fringe does not contain appreciable areas with flood velocities greater
than 3 feet per second or flood depths greater than 3 feet.
(3) After
delineation of a suggested designated floodway and prior to the public hearing
to consider the floodway delineation, the department shall meet with local planning
officials to consider possible adjustments due to land use considerations. No
adjustments in floodway width or location may be made if the theoretical
increase in flood heights would exceed 0.5 foot or if adjustments affect
private property rights.