Ordinance No. 79-46 FI1( APPROVED COPY
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CITY OF TIGARD, OREGON
ORDINANCE NO. 79-_AL
AN ORDINANCE AMENDING CHAPTERS 18.57, RELATING TO FLOODPLAINS AND OTHER SENSITIVE
LANDS.
THE CITY OF TIGARD ORDAINS AS FOLLOWS:
Section 1. Chapter 18.57 of the Tigard Municipal Code is amended to read as follows:
CHAPTER 18.57
SENSITIVE LANDS
18.57.010 Statement of Intent: Sensitive lands are lands potentially
unsuitable for development because of location within the 100-year floodplain,
within a natural drainageway, or on steep slopes. Sensitive land areas are designated
as such in order to give recognition to the need to protect the public health,
safety and welfare of the community through the regulation and control of lands
within floodplains, drainageways, and steeply-sloping land areas, and to thereby
mitigate potential financial burdens arising from flood damage loss and to preserve
natural drainageways from encroaching uses which threaten to affect adversely the
property rights of the citizenry of the community, public safety, and the public health
by natural conditions arising from upstream or downstream flood levels. City
actions under this ordinance will recognize the rights of riparian owners to be free
from invasion of flood or water intrusion and damage caused by acts or omissions
to act on the part of the City, its Commissions, representatives and agents, and
landowners and occupiers.
The floodplain district has for its purpose the preservation of natural
_water storage areas within the floodplain district by discouraging or prohibiting
incompatible uses.
18.57.020 Definitions: (a) In this chapter the following words and
phrases shall be construed to have the specific meanings assigned to them as
follows:
(1) "Drainageways" are defined as those areas_which convey significant
seasonal concentrations of water over the surface of the land.
(2) "Excavation" means mechanical removal of earth material.
(3) "Fill" means any act by which earth, sand, gravel, rock or any
other similar material is deposited, placed, pulled or transported,
and includes the conditions resulting therefrom.
(4) "Flood" means a temporary rise in stream flow or stage that results
in water overtopping stream banks and inundating land adjacent to
the normal flow of water through the stream channel.
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ORDINANCE No. 79-
(5) "Flood hazard" means a danger to property or health as the result
of inundation of the floodplain.
(6) "Floodplain" means the relatively flat area or lowlands adjoining
the channel of a river, stream, watercourse or other body of water
which has been or may be covered by floodwaters within the area of
applicability defined by the floodplain district.
(7) "Floodplain district" means those areas within the City of Tigard
inundated by the 100-year regulatory flood.
(8) "Grading" means any excavation or filling or combination thereof.
(9) "Obstruction" means any dam, wall, embankment, levee, dike, pile,
abutment, projection, excavation, channel modification, bridge,
conduit, culvert, building, gravel, refuse, fill, structure, matter
or things of a similar nature in, along, or across or projecting
into any channel, watercourse, or floodplain drainageway areas
which may impede, retard or change the direction of the flow of
water, either by itself or by catching or collecting debris carried
by such water, or that is placed where the flow of water might carry
the same downstream to the damage of health or property.
(10) "Regulatory flood" means the flood used to define the outer boundary
lines of the floodplain district. The maximum flood predicted to
occur within 100 years.
(11) "Steeply sloping lands" are portions of the ground surface which
have a slope of 12 percent (127) or greater.
(12) "Structure" means constructed edifice, barrier or building of
any kind, or any artificial build-up or composition of physical
parts adjoined together.
19.57.0.30 Permitted uses: Except as provided by Section 18.57.040,
the following uses shall be permitted within sensitive lands;
(1) Floodplain District and Drainageways:
a) Accessory uses such as lawns, gardens or unpaved play areas.
b) Agricultural uses conducted without locating a structure in the
floodplain district.
c) Community recreational uses such as bicycle and pedestrian
paths, archery ranges, or unpaved athletic fields or parks.
d) Public and private conservation areas for water, soil, open
space, forest or wildlife resources.
e) Removal of poison oak, tansy ragwort, blackberry or any other
noxious vegetation.
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ORDINANCE No. 79-4,6
(2) Drainageways:
a) Fences.
b) Removal of poison oak, tansy ragwort, blackberry or any other
noxious vegetation.
(3) Steeply sloping lands:
a) Low-intensity recreational uses such as bicycle and pedestrian
paths.
b) Landscaping or gardens which provide substantial vegetative
cover.
c) Public and private conservation areas for water, soil, open
space, forest or wildlife resources.
d) Removal of poison oak, tansy ragwort, blackberry or any other
noxious vegetation.
(4) Except as explicity authorized by other provisions of this chapter,
all other uses are prohibited on sensitive lands.
(5) Modification by grading shall not alter the character of lands for
the purposes of this chapter. Land which in its natural state lay
within the floodplain, or was steeply sloping shall continue to have
that legal character, though grading may have altered the surface
condition.
18.57.040 Uses and activities allowed with a Special Use Permit: The
following uses and activities are allowed only by Special Use Permit granted by the
Planning Commission and based on the standards set forth in Section 18.57.060.
t
(1) Within floodplains, drainageways and steeply sloping lands:
a) Fill, grading, excavating.
b) Structures.
C) Off-street parking and maneuvering areas, accessways and service
drives located on the ground surface.
d) Roadways, bridges or utility facilities.
e) Removing any live vegetation other than poison oak, tansy
ragwort, blackberry or any other noxious vegetation. '
(2) Within the floodplain only:
a) Any temporary structure which by its nature cannot be readily a
removed from the floodplain area during periods of flooding,
and which would impede or interfere with the flow of floodwaters
within the distruct.
b) Any change in the topography or terrain which would change the
flow of waters during flooding periods, or which would increase ,
the flood hazard or alter the direction or velocity of the
floodwater flow.
18.57.050 Nonconforming uses: A use established prior to June 1, 1979„
which would be prohibited by this'chapter or which would be subject to the limitations
and controls imposed by this chapter shall have nonconforming use status, and be sub-- r
ject to the provisions of Chapter 18.68 of this Code. _ The benefits of non-conforming
use status shall not, however, be available to uses or conditions established or creat-
ed in violation of any statutes ordinance, or law in effect at the time of establishment
or creation.
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ORDINANCE NO. 79-. 4
1$.57.060 S ecial ter 18Use Permits: In accordance with the roe-or a ySpes a
requirements set forth in Chapn18.84this Code, an application
or denied by the
Use Permit" filed as by said thapter stated
ed may be app
Planning Commission following a public hearing.
l be
rted by the
All applications for "Speciating Commissionstoldetermine whether the
following information to enable the Plannlain or drainage district and if so, whether
proposed use is located in the floodplain purposes and guidelines as set forth
the proposal, if approved, will conform to the perp
in this chapter.
A. Floodplain:
submitted in triplicate as prepared by
1) plans drawn to scale, th experience in hydraulic
a registered professional engineer rocesses, showing the
and geohydrologic engineering P rah of ne
nature, location, dime nsions, elevapro osedtions dstructuresylocated
site; the location of existingan
areas to be filled or
upon the site, existing and proposed
otherwise modified, and the relationship of these to the location
of the stream channel, and proposed methods for controlling
erosion.
2) Any documentation, photographs, water marks, and similar evidence
offered in support of the claim that the site or area in question
lies above high water as defined by the regulatory flood.
B. Drainageways:
1) plans drawn to scale, submitted in triplicate as prepared by a
registered professional engineer with experience in hydraulic
and hydrologic engineering and processes, showing
ofthe
naiteep
location, dimensions, elevations and topography upo
the location of existing and fillaorposetexcavatedlareas�, andn
the site; existing and proposed
the relationship of these to the location of the stream channel
(if any), and the proposed methods of controlling erosion.
C. Steep slopes:
1) Plans drawn to scale, submitted in triplicate as prepared by
a qualified registered professional engineer showing the
_ nature, location, dimensions, elevations, and topography of
the site; the location of existing and proposed structures
located upon the site, existing and proposed fill or excavated r
areas and proposed methods of controlling erosion.
18.57.070 Standards:
Permdplain
as shall
l) Application for a SPeCiaaccuUse
rdancelwith thet in �following�standards:
be granted or denied in `
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ORDINANCE No. 79-
a) No structure, fill, excavation, storage or other use shall be
permitted which alone or in combination with existing or
proposed uses would reduce the capacity of the floodplain
area or raise either the flood surface elevation or flow
rates, or adversely affect flow direction cn upstream or
downstream properties, or create a preiq.tt or foreseeable
hazard to public health, safety and general welfare.
b) The applicant must obtain the permit required by the State
of Oregon under ORS chapter 541 for removal or filling of
waterways, or demonstrate that the provisions of this statute
do not apply.
(2) Application for a Special Use Permit in a drainageway area
shall be granted or denied in accordance with the following
standard:
a) The proposed action must not adversely impact runoff, erosion,
ground stability, water quality, ground water level, flow
rates or flooding.
(3) Application for a Special Use Permit in a steeply sloping land area
shall be granted or denied in accordance with the following
standard:
a) Applicant must supply affirmative documentation that the
proposed action will not adversely impact runoff, erosion,
ground stability, water quality, groundwater level, or
flooding; and that the site can support the proposed mod-
ification or structure as designed.
This ordinance shall take effect on the 31st day following its passage
and signing.
PASSED: By the City Council by &AA&lyn0 Svote of all Council members present,
after being read two times by number and title only, thisS-'
day of /Ls��__- --, 1979.
City Recorder-City Tigard
SIGNED: By the Mayor, this /r day of _A1 , 1979.
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`Mayor, City of Tigard
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ORDINANCE No. 79-A
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Page 1.
SPECIAL USE PERMIT-
APPLICANT_;
Fill Type of fill:_
Cubic yards of fill:
Area of site to be occupied by fill: _ sq. ft.
(Sq.F't. (Fill)/Sq.Ft. (Site)) x 100 = of -site to be
filled.
Distance of fill from stream's edge: Horizontal Distance Ft.
Vertical Drop: Ft,
Type of bank to be installed:
Net change in storage capacity of floodplain resulting fro,m, fill
CU.Ft.
Will the fill increase the flood crest or modify the flow of floodwaters?
Yes No If so, what will the quantitative
effects be? (Attach a sheet for explanation) .
Structures Existing structure(s) in floodplain:
"t Height Ft. Width ft_
Distance from stream' s edge:. Horizontal Distance Ft,
' Vertical Drop Ft,
Proposed structures) in floodplain
Height Ft. Width Ft.
Distance from stream's edger Horizontal Distance Ft
Vertical Drop Ft.
Distance between existing and proposed structure (nearest Point)
Ft.
Will the structure increase the flood crest or modify the f lora
of flood waters? Yes No If so, what will the
quantitative effects be? (Attach a sheet for explanation) .
Will the proposed structure be designed to withstand the destructive
effects of a flood without significant damage? (Attach a sheet to
i
explain specifics)
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SPECIAL USE PERMIT
Storage What type of materials are to be stored?
Volume/quantity of material(s)
Distance of storage from stream's edge: Horizontal Ft,
Vertical Drop Ft,
Distance of storage from nearest building gt_
Will the material be anchored to prevent movement in the eventof a
Flood? Yes How? No Why Not:
(Attach a sheet for explanation)
Type of scree ting for storage M
APPLICANT:
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ADDRESS
TELEPHONE
PROJECT;
' SITE LOCATION
TAX MAP TAX LOT