36.15.801 ALLOWED USES WHERE FLOODWAY NOT DESIGNATED OR NO FLOOD ELEVATIONS
(1) For those watercourses or
drainways in which there is a designated floodplain but not a designated
floodway or where no flood elevations are available, all uses allowed in a
designated floodway under ARM 36.15.601 without a permit shall also be allowed
without a permit in such designated floodplain.
(2) All other uses within the designated
floodplain shall require permits from the permit issuing authority. The
following conditions insofar as each is applicable shall be attached to each
(a) If the elevation of the base flood is
available, residential structures must be built on compacted fill as specified
in ARM 36.15.702(1) . If such elevation is not available, the highest known
historical flood elevation may be used to establish fill heights;
(b) If the elevation of the base flood is
available, commercial and industrial structures must meet the flood proofing
requirements set forth in ARM 36.15.702(2) . If such elevation is not available,
the highest known historical flood elevation may be used to establish flood
(c) Proposed structures must be anchored to
prevent flotation or collapse and must be located as far from stream channels
as is practicable; and
(d) Sanitary sewage systems must be allowed
and approved under laws and standards administered by the department of health
and environmental sciences or the local health board.
(3) Where a proposed development within
such designated floodplain may significantly increase flood velocities or
depths, the permit issuing authority may require a permit applicant to furnish
additional hydraulic and survey information before acting upon the permit
application. This information may include, but is not limited to, any of the
(a) valley cross sections of the
watercourse and adjoining floodplain;
(b) certification by a qualified
professional engineer that floodproofing measures are reasonably adequate to
protect against major flood damages; or
(c) a hydrologic study documenting probable
effect on upstream or downstream property owners.
(4) Permits for such proposed developments
may be modified or denied if the additional information shows that proposals
would increase flood damages to other properties or would cause a threat to the
health or safety of its occupants.
History: Sec. 76-5-208, MCA; IMP, Sec. 76-5-402, 76-5-404 through 76 -5-406, MCA; NEW, Eff. 9/4/74; AMD, 1989 MAR p. 1665, Eff. 10/27/89.