HomeMy WebLinkAbout2528 Phy. & Env. ConstraintsOrdinance No. 2528
An ordinance adopting a new Chapter 18.62 of the Ashland
Municipal Code relative to Physical and Environmental
Constraints, and repealing the existing Chapter 18.62.
The people of the City of Ashland do ordain as follows:
Section 1: Chapter 18.62 of the Ashland Municipal Code is hereby repealed
in its entirety.
Section 2: The following section is hereby adopted as Chapter 18.62, and
shall read as follows:
Chapter 18.62
PHYSICAL & ENVIRONMENTAL CONSTRAINTS
Sections:
18.62.010
18.62.020
18.62.030
18.62.040
18.62.050
18.62.060
18.62.070
18.62.075
18.62.080
Purpose and Intent.
Regulations.
Definitions.
Approval and Permit Required.
Land Classifications.
Official Maps.
Development Standards for Floodplain Corridor Lands.
Devel.opment Standards for Riparian Preserve Lands.
Development Standards for Erosive and Slope
Failure Lands.
18.62.090 Development Standards for Wildfire Lands.
18.62.100 Development Standards for Severe Constraint Lands.
18.62.010 Purpose and Intent. The purpose of this Chapter is to provide for
safe, orderly and beneficial development of districts characterized by diversity
of physiographic conditions; to limit alteration of topography and reduce
encroachment upon, or alteration of, any natural environment and; to provide
for sensitive development in areas that are constrained by various natural
features. Physiographic conditions can be considered to include, but are not
limited to: slope of the land, natural drainage ways, wetlands, soil
characteristics, potential landslide areas, and natural and wildlife habitats.
18.62.020 Regulations. The type of regulation applicable to the land depends
upon the classification in which the land is placed, as provided in Section
18.62.050. If those regulations conflict with other regulations of the City of
Ashland's Municipal Code, the more stringent of the two regulations shall
govern.
18.62,030 Definitions. The following terms are hereby defined as they apply
to this Chapter:
A. Architect - An architect licensed by the State of Oregon.
B. Buildable area That portion of an existing or proposed lot that
is free of building restrictions. For the purpose of this ordinance, a
buildable area cannot contain any setback areas, easements, and
similar building restrictions, and cannot contain any land that is
identified as Floodplain Corridor Lands, or any land that is greater
than 40% slope.
C. Cohesive Soils - Residual or transported soils, usually originating
from parent rock which contains significant quantities of minerals
which weather to clay. Cohesive soils have a Plasticity Index of 10 or
more, based on laboratory testing by AASHTO, or a site-specific
scientific analysis of a particular soil material.
D. Development - Alteration of the land surface by: 1) grading, filling,
cutting or other earth-moving activity involving more than 50 cubic
yards on any lot; 2) the 'removal of three or more living trees of over
six inches diameter at breast height (DBH), or the removal of 5% of
the total number of living (or dead trees) over 6" DBH, whichever is
greater, on any lot within any one calendar year, or any form of
commercial logging; 3) construction of a building, road, driveway,
parking area, or other structure, 4) culverting of any stream.
E. Engineer - A registered professional engineer licensed by the State
of Oregon.
F. Engineering Geologist - A registered professional engineering
geologist licensed by the State of Oregon.
G. Floodway Channel - The floodway channel as defined in the Flood
Insurance Study for Ashland, Oregon, published by the Federal
Emergency Management Agency on December 1, 1980.
H. Gully - A drainage incision, commonly caused by erosion, which
does not experience regular or seasonal stream flow, but does act as
a channel for runoff during periods of high rainfall.
I. Non-cohesive Soils - Residual or transported soils containing no or
very little clay, usually from crystalline granitic parent rock.
Non-cohesive soils have a Plasticity Index of less than 10, based on
laboratory testing by AASHTO, or a published scientific analysis of a
particular soil type.
J. Riparian That area associated with a natural water course
including its wildlife and vegetation.
K. Wildfire - Fire caused by combustion of native vegetation,
commonly referred to as forest fire or brush fire.
18.62.040 Approval and Permit Required.
A. A Type I Physical Constraints Review Permit is required for any
development, as defined in 18.62.030 (C), in areas identified as
Floodplain Corridor Land, Riparian Preserve, Erosive and Slope
Failure land, or Severe Constraint land.
B. If a development is part of a Site Review, Performance Standards
Development, Conditional Use Permit, Subdivision, Partition, or other
Planning Action, then the Review shall be conducted simultaneously
with the Planning Action and no additional fee shall be charged.
C. If a development is exclusive of any other Planning Action, as noted
in Subsection B, then the Physical Constraints Review shall be
processed as a Staff Permit.
D .Plans Required. The following plans shall be required for any
development requiring a Physical Constraints Review:
1. A site plan containing the following:
a) Project name.
b) Vicinity map.
c) Scale (the scale shall be at least one inch equals 50
'feet or larger).
d) North arrow.
e) Date.
f) Street names and locations of all existing and proposed
streets within or on the boundary of the proposed
development.
g) Lot layout with dimensions for all lot lines.
h) Location and use of all proposed and existing buildings,
fences and structures within the proposed development.
Indicate which buildings are to remain and which are to be
removed.
i) Location and size of all public utilities affected by the proposed development.
Location of drainage ways or public utility easements
in and adjacent to the proposed development.
k) A topographic map of the site at a contour interval of 5 feet
J)
or less.
1) Location of all parking areas and spaces, ingress and egress
on the site, and on-site circulation.
m)Locations of all existing natural features including, but not limited to, all trees of a caliper greater than
6 inches DBH, natural drainages or creeks on the site, and
outcroppings of rocks, boulders, etc. In forested areas, it is
necessary to identify only those trees which will be affected
or removed by the proposed development. Indicate any
contemplated modifications to a natural feature.
n) The proposed method of-erosion control, water runoff
control, and tree protection for the development.
o) Building envelopes for all existing and proposed new parcels
that contain only buildable area, as defined by this Chapter.
2. Additional plans and studies as required in Sections 18.62.070,
18.62.080,.18.62.090, 18.62.100 of this Chapter.
E. Criteria for Approval. A Physical Constraints Review Permit shall be
issued by the Hearings Officer when the Applicant demonstrates the
following:
1.That the development will not cause damage or hazard to persons
or property upon or adjacent to the area of development.
2. That the applicant has considered the potential hazards that the
development may create and implemented reasonable measures to
mitigate the potential hazards caused by the development.
3. That the applicant has taken all reasonable steps to reduce the
adverse impact on the environment. Irreversible actions shall be
considered more seriously than reversible actions. The Staff Advisor
or Planning Commission shall consider the existing development of the
surrounding area, and the maximum permitted development permitted
by the Land Use Ordinance.
4. That the development is in compliance with the requirements of
this chapter and all other applicable City Ordinances and Codes.
F. The Staff Advisor or Planning Commission has the power to amend plans
to include any or all of the following conditions if it is deemed necessary to
mitigate any potential negative impact caused by the development:
1. Require the retention of trees, rocks, ponds, water courses and
other natural features.
2. Require plan revision or modification to mitigate possible negative
or irreversible effect upon the topography or natural features that the
proposed development may cause.
G. The Staff Advisor or Planning Commission may deny the Physical and
Environmental Constraints Review Permit if, in its opinion:
1. The proposed development will have a detrimental effect on the
lands regulated and protected by this Chapter, or if inconsistent with
the Comprehensive Plan.
2. Where it appears that the proposal is part of a more extensive
development that would require a master site plan, or other Planning
Action. In this case, approval is to be postponed until a complete
planning application has been processed.
18.62.050 Land Classifications. The following factors shall be used to
determine the classifications of various lands and their constraints to building
and development on them:
A. Floodplain Corridor Lands - Lands with potential stream flow and flood
hazard. The following lands are classified as Floodplain Corridor lands:
1. All land contained within the 100 year floodplain as defined by the
Federal Emergency Management Agency, in maps adopted by Chapter
15.10 of the Ashland Municipal Code.
2. All land within the area defined as Floodplain Corridor land in
maps adopted by the Council as provided for in section 18.62.060.
3. All lands which have physical or historical evidence of flooding in
the historical past.
4. All ai'eas within 20 feet (horizontal distance) of any creek
designated for Riparian Preservation in 18.62.050 (B) and depicted as
such on maps adopted by the Council as provided for in section
18.62.060."
5. All areas within 10 feet (horizontal distance) of any drainage
channel depicted on maps adopted by the Council but not designated
as Riparian Preservation.
B. Riparian Preservation - The following Floodplain Corridor Lands are
also designated for Riparian Preservation for the purposes of this Section and
as listed on the Physical and Environmental Constraints Overlay Maps:
Tolman, Hamilton, Clay, Bear, Kitchen, Ashland, Nell, and Wrights Creeks.
C. Erosive and Slope Failure Lands - I~nds with potential erosion hazards.
Erosive Lands and Slope Failure Lands are lands which are subject to
damage from erosion and slope failure. The following lands are classified as
Erosive and Slope Failure Lands:
1. All areas defined as erosion and slope failure lands on the Physical
Constraints Overlay map and which have a slope of 40% or greater.
D. Wildfire Lands - Lands with potential of wildfire. The following lands
are classified as Wildfire Lands:
1. All areas defined as wildfire lands on the Physical Constraints
Overlay map.
E. Severe Constraint Lands - Lands with severe development characteristics
which generally limit normal development. The following lands are classified
as Severe Constraint Lands:
1. All areas which are within the floodway channels, as defined in the
City's Flood Protection Ordinance, Chapter 15.10.
2. All lands with a slope greater than 50%.
F. Classifications Cumulative. The above classifications are cumulative in
their effect and, if a parcel of land falls under two or more classifications, it
shall be subject to the regulations of each classification. Those restrictions
applied shall pertain only to those portions of the land being developed and
not necessarily to the whole parcel.
18.62,060 Official Maps.
A. The City Council shall adopt official maps denoting the above identified
areas. Substantial amendments of these maps shall be a Type 3 procedure.
B. Minor amendments of the maps to correct mapping errors when the
amendments are intended to more accurately reflect the mapping criteria
contained in this ordinance or in the findings of the Council in adopting a
official map may be processed as a Type 1 procedure.
18.62.070 Development Standards for Floodplain Corridor Lands
For all land use actions which could result in development of the Floodplain
Corridor, the following is required in addition to any requirements of Chapter
15.10:
A. Standards for fill in Floodplain Corridor lands:
1. Fill shall be designed as required by the Uniform Building Code,
Chapter 70, where applicable.
2. The toe of the fill shall be kept at least 10 feet outside of floodway
channels, as defined in section 15.10.
3. The amount of fill in the Floodplain Corridor shall be kept to a
minimum. Fill and other material imported from off the lot that could
displace floodwater shall be limited to the following:
a. Poured concrete and other materials necessary to
build permitted structures on the lot.
b. Aggregate base and paving materials.
c. Plants and other landscaping material.
d. A total of 50 cubic yards of other imported fill material, or
300 cubic yards per acre, whichever is greater. These amounts
are the maximum cumulative fill that can be imported onto the
site, regardless of the number of permits issued.
e. The above limits on fill shall be measured from April, 1989,
and shall not exceed the above amounts.
4. If additional fill is necessary beyond the permitted amounts in (3)
above, then fill materials must be obtained on the lot from cutting or
excavation only to the extent necessary to create an elevated site for
permitted development. All additional fill material shall be obtained
from the portion of the lot in the Floodplain Corridor.
5. Adequate drainage shall be provided for the stability of the fill
6. Fill to raise elevations for a building site shall be located as close
to the outside edge of the Floodplain Corridor as feasible.
B. Culverting or bridging of any waterway or creek identified on the official
maps adopted ptirsuant to section 18.62.060 must be designed by an engineer.
Stream crossings shall be designed to the standards of Chapter 15.10, or
where no floodway has been identified, to pass a 100 year flood without any
increase in the upstream flood height elevation. The engineer shall consider
in his/her design the probability that the culvert will be blocked by debris
in a severe flood, and accommodate expected overflow. Fill for culverting
and bridging shall be kept to the minimum necessary, but is exempt from the
limitations in section (A) above. Culverting or bridging of streams identified
as Riparian Preservation are subject to the requirements of 18.62.075.
C. Non-residential structures shall be flood-proofed to the standards in
Chapter 15.10 to one foot above the elevation contained in the maps adopted
by chapter 15.10, or up to the elevation contained in the official maps
adopted by section 18.62.060, whichever height is greater. Where no specific
elevations exist, then they must be elevated to an elevation of 10 feet above
the creek channel on Ashland, Bear, or Neil Creek; to 5 feet above the creek
channel on all other Riparian Preserve creeks defined in section 18.62.050
(B); and 3 feet above the stream channel on all other drainage ways
identified on the official maps.
D. All residential structures shall be elevated so that the lowest habitable
floor shall be raised to one foot above the elevation contained in the maps
adopted in chapter 15.10, or to the elevation contained in the official maps
adopted by section 18.62.060, whiever height is greater. Where no specific
elevations exist, then they must be elevated to an elevation of 10 feet above
the creek channel on Ashland, Bear, or Neil Creek; to 5 feet above the creek
channel on all other Riparian Preserve creeks defined in section 18.62.050
(B); and 3 feet above the stream channel on all other drainage ways
identified on the official maps. The elevation of the finished lowest habitable
floor shall be certified to the city by an engineer or surveyor prior to issuance
of a certificate of occupancy for the structure.
E. To the maximum extent feasible, structures shall be placed on other than
Floodplain Corridor Lands. In the case where development is permitted in
the Floodplain corridor area, then development shall be limited to that area
which would have the shallowest flooding.
F. Existing lots with buildable land outside the Floodplain Corridor shall
locate all residential structures outside the Corridor land, unless 50% or
more of the of the lot is within the Floodplain Corridor. For residential uses
proposed for existing lots that have more than 50% of the lot in Corridor
land, structures may be located on that portion of the floodplain corridor
that is 2 feet or less below the flood elevations on the official maps, but in
no case closer than 20 feet to the channel of a Riparian Preservation Creek.
Construction shall be subject to the requirements in paragraph D above.
G. New non-residential uses may be located on that portion of Floodplain
Corridor lands that are two feet or less below the flood elevations on the
official maps adopted in section 18.62.060. Second story construction may be
cantilevered over the floodplain corridor for a distance of 20 feet if the
clearance from finished grade is at least 10 feet in height, and is supported
by pillars that will have minimal impact on the flow of floodwaters. The
finished floor elevation may not be more than two feet below the flood
corridor elevations.
H. All lots modified by lot line adjustments, or new lots created from lots
which contain Floodplain Corridor land must contain a building envelope on
all lot(s) which contain(s) buildable area of a sufficient size to accommodate
the uses permitted in the underling zone, unless the action is for open space
or conservation purposes. This section shall apply even if the effect is to
prohibit further division of lots that are larger than the minimum size
permitted in the zoning ordinance.
I. Basements
1) Habitable basements are not permitted for new residential
structures or additions located within the Floodplain Corridor.
2) Non-habitable basements, used for storage, parking, and similar
uses, are permitted for residential structures but must be flood-proofed
to the standards of Chapter 15.10.
3) Development of habitable basements of existing non-residential
structures that are at or below the flood elevations contained in the
official maps shall be permitted in the Ashland Historic Interest Area,
as defined in the Ashland Comprehensive Plan.
4) No new habitable basements lower than two feet below the
floodplain corridor elevations shall be permitted on any existing or
new non-residential structure outside the historic interest area.
5) Habitable basements shall not be used for sleeping quarters.
J. Storage of petroleum products, pesticides, or other hazardous or toxic
chemicals is not permitted in Floodplain Corridor lands.
K. Fences constructed within 20 feet of any Riparian Preservation Creek
designated by this ordinance shall be limited to wire or electric fence, or
similar fence that would not collect debris or obstruct flood waters, but not
including wire mesh or chain link fencing.
L. Decks and structures other than buildings, if constructed on Floodplain
Corridor Lands and at or below the levels specified in paragraph (C) and
(D) of the section, shall be flood-proofed to the standards contained in
Chapter 15.10.
M. Local streets and utility connections to developments in and adjacent to
the Floodplain Corridor shall be located outside of the Floodplain Corridor,
except for crossing the Corridor in the shortest possible distance.
18.62,075 Development Standards for Riparian Preservation lands.
A. All development in areas indicated for Riparian Preservation, as defined
in 18.62.050 (B), shall comply with the following standards:
1. Development shall be subject to all Development Standards for
Floodplain Corridor Lands (18.62.070).
2. Any species of pine, oak, fir, madrone, yew, or Douglas Fir
over 6 inches DBH shall be retained to the greatest extent feasible.
3. Fill and Culverting shall be permitted only for streets, access, or
utilities. The crossing shall be at right angles to the creek channel to
the greatest extent possible. Fill shall be kept to a minimum.
4. The general topography of Riparian Preservation lands shall be
retained.
18.62,080 Development Standards for Erosive and Slope Failure Lands.
A. All development which removes vegetation or disturbs topsoil and leaves
the disturbed soil at a slope of 50% or more shall comply with the following
standards:
1. Any exposed soil shall be revegetated in a manner to reestablish
a vegetative community within a one-year period from issuance of a
Certificate of Occupancy. If irrigation is not provided, then the
exposed soil must be planted with species which can survive without
irrigation.
2. Vegetative cover, rock, dry or conventional masonry, or other
permanent cover must be maintained in perpetuity on areas which
have been' disturbed.
3. These restrictions shall not apply to areas of exposed bedrock
which exhibit no erosion potential.
B. Any development which increases the natural runoff by decreasing the
infiltration of the soil shall conform to the following standards:
1. All roof drainage must be collected, controlled and directed either
by underground pipe or concrete or asphalt gutter to a City street or
storm drain or a natural water course.
2. All drainage from driveways, parking areas and other impervious
surfaces must be collected, controlled and directed to a City street or
storm dr/iin by underground pipe or concrete or asphalt gutter.
3. Other alternate methods of storm water disposal, such as a
leachfield, must be approved by the City's Public Works Department.
C. Cuts and Fills.
1. All cuts, grading or fills shall conform to Chapter 70 of the
Uniform Building Code.
2. In addition, any cuts and/or fills greater than 250 cubic yards must
be designed by an engineer to comply with UBC Chapter 70. Such
cuts and/or fills shall be designed in such a manner that they will be
stable for the use intended.
3. If the excavation is not a City street or a public right-of-way, the
engineer shall declare to the City, after the cut and/or fill is
completed, that it was constructed to plans and meets all standards set
forth in the plans approved.
4. Nothing in this Section shall abridge the City's right to inspect work
in progress or in its completed state, to make appropriate
measurements and tests to determine if the cut and fill was made
according to plan, and to require alterations prior to final approval
of the cut and/or fill.
D. Any development or partitioning which is proposed in Erosive and Slope
Failure Lands must be shown on a master plan at the time the final plan or
plat is filed. All development must comply with the master plan. Any
improvements necessary for the implementation of the master plan (e.g.,
storm drains, gutters, etc.) which involve two or more parcels of land must be
constructed by the applicant prior to any development occurring on the
parcels.
E. All structures' in Erosive and Slope Failure Lands shall have foundations
which have been designed by an engineer or architect.
F. All newly created lots or lots modified by a lot line adjustment must
include a building envelope on all lots that contains a buildable area of
sufficient size to accommodate the uses permitted in the underlying zone,
unless the division or lot line adjustment is for open space or conservation
purposes.
18.62.090 Development Standards for Wildfire Lands.
A. A 30 foot "shaded fuel break" shall be installed and maintained around
each dwelling unit or structure. Such fuel break shall be increased by 5 feet
for each 10% increase in slope over 10%.
B. A "shaded fui~l break" is defined as an area which is free of dead or dying
vegetation, and has native, fast-burning species sufficiently thinned so that
there is no interlocking canopy of this type of vegetation. Where necessary
for erosion control or aesthetic purposes, the fuel break may be planted in
slow-burning species. Fuel breaks do not involve stripping the ground of all
native vegetation.
C. No structure shall be constructed or re-roofed with wooden shingles,
shakes or other combustible roofing material, as defined in the City's building
code.
D. Fuel breaks in areas which are also Erosive or Slope Failure Lands shall
be included in the erosion control measures outlined in Section 18.62.080.
E. In subdivisions or Performance Standards Developments, provisions for
the maintenance of fuel breaks shall be included in the Covenants,
Conditions and Restrictions for the development.
18.62.100 Development Standards for Severe Constraint Lands.
A. Severe Constraint Lands are extremely sensitive to development, grading,
filling, or vegetation removal and, whenever possible, alternative development
should be considered.
B. Development of floodways is not permitted except for bridges and road
crossings. Such crossings shall be designed to pass the 100-year flood without
raising the upstream flood height more that 6 inches.
C. Development of land or approval for a planning action shall be allowed
only when the following study has been accomplished. An engineering
geologic study approved by the City's Public Works Director and Planning
Director establishes that the site is stable for the proposed use and
development. The study shall include the following:
1. Index map.
2. Project description to include location, topography,
vegetation, discussion of previous work and discussion
exploration methods.
drainage,
of field
3. Site geology, based on a surficial survey, to include site geologic
maps, description of bedrock and surficial materials, including artificial
fill, locations of any faults, folds, etc., and structural data including
bedding, jointing and shear zones, soil depth and soil structure.
4. Discussion of any off-site geologic conditions that may pose a
potential hazard to the site, or that may be affected by on-site
development.
5. Suitability of site for proposed development from a geologic
standpoint.
6. Specific recommendations for cut slope stability, seepage and
drainage control or other design criteria to mitigate geologic hazards.
7. If deemed necessary by the engineer or geologist to establish
whether an area to be affected by the proposed development is stable,
additional studies and supportive data shall include cross-sections
showing subsurface structure, graphic logs with subsurface exploration,
results of laboratory test and references.
8. Signature and registration number of the engineer and/or geologist.
9. Additional information or analyses as necessary to evaluate the site.
18.62.110 Density Transfer
Density may be transferred out of unbuildable areas to buildable areas of a
lot provided the following standards are met:
A. Partitions and subdivisions involving density transfer shall be processed
under Performance Standards, Chapter 18.88 of the Ashland Municipal Code.
B. A map shall be submitted showing the net buildable area to which the
density will be transferred.
C. A covenant shall be recorded limiting development on the area from
which density is transferred.
D. Density may not be transferred from one ownership to another, but only
within the lot(s) owned by the same person.
E. Density may be transferred only on contiguous lots under common
ownership.
F. The density of the buildable area may not be increased to more than two
(2) times the permitted density of the underlying zone. Fractional units are
to be rounded down to the next whole number."
Section 3. Section 18.68.100 is hereby repealed in its entirety.
Section 4. The maps attached hereto and by this reference made a part of
this ordinance are hereby adopted as the official maps referenced by Section
18.62.060 of the above adopted chapter.
Section 5. The' filing fee for a minor amendment as defined in Section
18.62.060(B) of the maps adopted by Section 4 above is hereby waived for a
period for 6 months from the effective date of this ordinance.
Section 6. The Floodplain Corridor for Bear Creek is specifically excluded
from this ordinance, and the Bear Creek Floodplain Area will continue under
the moratorium adopted by the Council until a floodplain corridor is adopted
for Bear Creek through Section 18.60.060.
The foregoing ordinance was first read by title only in accordance
with Article X, Section 2(C) of the City Charter on the 20th day of
June, 1989, and duly PASSED and ADOPTED this 5th day of July, 1989.
Nan E. Franklin
City Recorder
SIGNED and APPROVED this
day of July, 1989.
Catherine M. Golden
Mayor