3b. City Code Amendment - Chapter 20 - Bluff Protection
CITY OF
CHANIlASSEN
7700 Market Boulevard
PO Box 147
Chanhassen, MN 55317
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Fax: 952.227.1110
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MEMORANDUM
TO: Planning Commission
FROM:
Sharrneen Al-laff, Senior Planner
DATE:
of{!
October 6,2009
SUBJ:
City Code Amendment
Chapter 20, Zoning, Bluff Protection
PROPOSED MOTION:
"The Chanhassen Planning Commission recommends that City Council
adopt the proposed amendments to Chapter 20 of the Chanhassen City Code
as outlined in the staff report."
BACKGROUND
~
On September 15,2009, staff presented an issue paper to the Planning Commission
regarding the Bluff Ordinance. This same issue paper was then forwarded to the City
Council on September 28,2009. The ordinance was initially adopted by the City on
October 14, 1991. The intent of the Bluff Protection Ordinance was to regulate activities
that may cause erosion.
The area that is most critical in protecting a bluff is immediately adjacent to the top of the
bluff and is part of the "Bluff Impact Zone".
This area measures 20 feet in width and acts as a buffer between erosion-causing
activities and the bluff. It must always be protected. When vegetation is removed,
protection of the bluff is compromised. This results in a significant increase in the
likelihood that severe erosion will occur. The impacts of such alterations include:
. Erosion of developable land
. Increased impairment to area
surface waters
. Elimination of native species
and replacement by invasive
species such as buckthorn
. City-borne costs of
stabilization of slopes
. Compromise of structures in
the immediate vicinity
Bluff Impact Zone
Means the bluff and the land located
within 20 feet from the top of the bluff.
BlutTImpact Z<>ne
20 ft. Bluff(Slope-30% (I" Greater)
Chanhassen is a Community for Life. Providing for Today and Planning for Tomorrow
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Planning Commission
October 6, 2009
Page 2 of4
Examples of eroded bluffs due to alterations within the bluff impact zone
There are sections within the ordinance that contradict the intent. They allow grading within the
bluff impact zone if an earthwork permit is obtained.
Staff is recommending these sections be amended to provide consistency within the ordinance
and to protect the integrity of the bluffs.
ANALYSIS
The intent of the bluff protection ordinance is to limit alteration of the bluff impact zone to
prevent erosion of the bluff. This is a separate ordinance from the Bluff Creek Overlay district
which is more restrictive in preserving the natural state. The bluff ordinance is embedded into
the Bluff Creek Overlay Ordinance.
Since the adoption of the bluff ordinance, staff has reviewed subdivisions containing bluffs. For
example, the Settlers West Subdivision, which is highly visible and is located on one of the
steepest slopes within the City ofChanhassen, required a 30-foot setback from the top of the
bluff and protection of the 20 feet immediately adjacent to the top of the bluff.
The purpose of this amendment is to clarify the intent of how to protect the slopes and prevent
eroSIOn.
Sec. 20-1400. Statement of intent, contains an error. The intent of the ordinance is to preserve
the bluff by protecting the bluff impact zone which includes the bluff and the 20-foot strip
immediately adjacent to the bluff. Staff is recommending the ordinance be amended to read as
follows:
Sec. 20-1400. Statement of intent.
Development, excavation, clearcutting and other activities within the bluff impact zone
may result in increased dangers of erosion, increased visibility to surrounding properties
and thereby endanger the natural character of the land and jeopardize the health, safety,
and welfare of the citizens of the city. To preserve the character of the bluff impact zone
within the city, alteration to land or vegetation within the bluffimp.act zone _ will not
be permitted except as regulated by this ordinance and by the regulations of the
underlying zoning district where the property is located.
Planning Commission
October 6, 2009
Page 3 of 4
Sec. 20-1402. Regulates and sets standards for the construction of stairways, paths, landings and
lifts. It prohibits major topographic alterations and requires an earthwork permit prior to
commencement of work.
Sec. 20-1403 addresses the removal and alteration of vegetation within a bluff impact zone.
Such activity is prohibited except for limited clearing of trees and shrubs and cutting, pruning
and trimming of trees to provide a view from the principal dwelling site and to accommodate the
placement of stairways and landings and access paths. Staff recommends permitting limited
clearing of trees to accommodate stairways and paths. Alterations to create views will be limited
to pruning and trimming of trees and shrubs in order to retain bluff stability. Trees and shrubs
slow run-off, provide protection from raindrops which carry soil downhill, and stabilize the bluff
with their root structure. The amended ordinance reads as follows:
Sec. 20-1403. Removal or alteration of vegetation.
Removal or alteration of ve etation within a bluff impact zone is prohibited except for
limited , pruning and trimming of trees.
_ to provide a view from the principal dwelling site. accommodate the
placement of stairwa sand landin s and access aths,
Removal or alteration of vegetation must receive prior approval of the community
development director or designee. An on-site review will be made to determine if the
removal or alteration of vegetation will require new ground cover. In no case shall
clearcutting be permitted. City staff will work with the property owner to develop a
means of creating a view while minimizing disturbance to the bluff impact zone.
Sec. 20-1404 requires an earthwork permit for the movement of more than 10 cubic yards. The
intent of the ordinance is to limit the activity to the construction of paths, stairways and landings.
This section is inconsistent with the intent of the bluff protection ordinance as it does not specify
the limitation of the type of alteration that may be permitted. Staff recommends this section of
the ordinance be amended to read as follows:
Planning Commission
October 6,2009
Page 4 of 4
Topographic alterations/grading and
permitted to increase the rate of drainage
__ The drainage from property within the bluff impact zone may
not be redirected without a permit from the city. Fill or excavated material shall not be
placed in bluff impact zones.
RECOMMENDA TION
"The Chanhassen Planning Commission recommends that City Council adopt the proposed
amendments to Chapter 20 of the Chanhassen City Code as outlined in the staff report."
ATTACHMENTS
1. Ordinance Amendment pertaining to Bluff Protection.
2. Existing Bluff Protection Ordinance.
g:\plan\city code\2009 code amendments\bluff ordinance\bluff ordinance cover memo pc.doc
CITY OF CHANHASSEN
CARVER AND HENNEPIN COUNTIES, MINNESOTA
ORDINANCE NO.
AN ORDINANCE AMENDING CHAPTER 20
CHANHASSEN CITY CODE,
ZONING
THE CITY COUNCIL OF THE CITY OF CHANHASSEN, MINNESOTA ORDAINS:
Section 1. Section 20-1400 of the City Code, City of Chanhassen, Minnesota, is hereby
amended to read as follows:
Sec. 20-1400. Statement of intent.
Development, excavation, clearcutting and other activities within the bluff impact zone
may result in increased dangers of erosion, increased visibility to surrounding properties
and thereby endanger the natural character of the land and jeopardize the health, safety,
and welfare ofthe citizens ofthe city. To preserve the characteroft~e ?ltlr.fiI!l~act zone
within the city, alteration to land or vegetation within the bluff inl.P~~~~9Jle'af~9: will not
be permitted except as regulated by this ordinance and by the regulations of the
underlying zoning district where the property is located.
Section 2. Section 20-1403 of the City Code, City of Chanhassen, Minnesota, is hereby
amended to read as follows:
Sec. 20-1403. Removal or alteration of vegetation.
Removal or alteration of vegetation within a bluff impact zone is prohibited except for
'i" T",,'~"< 5"7' p,"" ,,',.;ry'5C...':..'C'i'::.'....,. ":...",...",.'....::"..".,.,.,',.,' .....,.", ,....
l~iI!l!,~~~ ~~~g!(jfff@~~.~~;:~~;~tt;;~~!~, pruning anetri~i~g of trees~*<l
~~~qJ!~ to provide a view from the principal dwelling site. M'd"~~~:9 accommodate the
placement of stairwa sand landin s and access aths,~':'~"; . '''.' . ....iil~
-. 'J(~~Q~
wtif
Removal or alteration of vegetation must receive prior approval of the community
development director or designee. An on-site review will be made to determine if the
removal or alteration of vegetation will require new ground cover. In no case shall
clearcutting be permitted. City staff will work with the property owner to develop a
means of creating a view while minimizing disturbance to the bluff impact zone.
Section 3. Section 20-1404 of the City Code, City ofChanhassen, Minnesota, is hereby
amended to read as follows:
Sec. 20-1404. Topographic alterations/grading and filling.
1
An earthwork permit will be required for the movementof~nYB1pr~that t0l:1el:1hieiyatd,f;
(ff material within bluff impact zones. The permit sftall.may be granted only if the
-- ~ -" ... .. - ..'.-.... .. -.-.... -, .....- --
prop?sed alteration does l10t adversely affect the bluff impactzoIle or other property.
..p. .... e...........IDI..,......t.s. ..... m... ..ay. b...e. ......g. r.,.an. t.e. d....l..C. .......t...h... e. ....p. r.. oP.. os.....e.d.....alteration complieswitb, Sec.20-1402an~
tl.t~<(()1l9lV<ing..con:4iti9nsarell()t..presen!:
. .', A moderate to severe erosion hazard classification as dermed and mapped by the
, . ~atural Resourc,es Conservation Service . " .. . . .
.. EXisting gullieSftildlor escarpmentSa..e present on the subject property or in an
ar~a which the subject property is tributary to.
Topographic alterations/grading and filling ",ithinthebluffitnpact zone shall not be
p~itted .to incre~~~ th.e. rate of drainage all<l.noconcentrated.flow.' conditiolls sb,all
J:es~ltff()D:l the alteratioll. The drainage from property within the bluff impact zone may
not be redirected without a permit from the city. Fill or excavated material shall not be
placed in bluff impact zones.
Section 4. This ordinance shall be effective immediately upon its passage and
publication.
PASSED AND ADOPTED this _ day of , 2009, by the City Council of
the City of Chanhassen, Minnesota.
Todd Gerhardt, City Manager Thomas A. Furlong, Mayor
(Published in the Chanhassen Villager on )
g:\plan\city code\2009 code amendments\bluff ordinance\ordinance.doc
2
ARTICLE XXVIII. BLUFF PROTECTION
Bluff impact zone means a bluff and land located within 20 feet from the top of a bluff. (20)
Bluff means a natural topographic feature such as a hill, cliff, or embankment having the following
characteristics:
(1) The slope rises at least 25 feet above the toe ofthe bluff; and
(2) The grade of the slope from the toe of the bluff to a point 25 feet or more above the toe of
the bluff averages 30 percent or greater; and
(3) An area with an average slope of less than 18 percent over a distance for 50 feet or more
shall not be considered part of the bluff. (20)
Bluff, side of means a point at which both conditions for a "bluff" no longer exist. The side of the bluff is
delineated by a line connecting the top and toe of a bluff at a location in which the slope of the bluff is
less than 30 percent or the change in elevation becomes smaller than 25 feet. (20)
Bluff, toe of means the point on a bluff where there is, as visually observed, a clearly identifiable break
in the slope, from flatter to steeper slope above. If no break in the slope is apparent, the toe of the bluff
shall be determined to be the lower end of a 50-foot segment, measured on the ground, with an
average slope exceeding 18 percent. (20)
Bluff, top of means the point on a bluff where there is, as visually observed, a clearly identifiable break
in the slope, from steeper to gentler slope above. If no break in the slope is apparent, the top of the
bluff shall be determined to be the upper end of a 50-foot segment, measured on the ground, with an
average slope exceeding 18 percent. (20)
Sec. 20-1400. Statement of intent.
Development, excavation, c1earcutting and other activities within the bluff impact zone may result in
increased dangers of erosion, increased visibility to surrounding properties and thereby endanger the
natural character of the land and jeopardize the health, safety, and welfare of the citizens of the city. To
preserve the character of the bluff impact zone within the city, alteration to land or vegetation within
the bluff area will not be permitted except as regulated by this ordinance and by the regulations of the
underlying zoning district where the property is located.
(Ord. No. 152, ~ 2,10-14-91; Ord. No. 249, ~ 2,4-8-96)
Sec. 20-1401. Structure setbacks.
(a) Structures, including, but not limited to, principal buildings, decks, and accessory buildings, except
stairways and landings, are prohibited on the bluff and must be set back from the top of the bluff, the
toe of the bluff, and the side of a bluff at least 30 feet.
(b) On parcels of land on which a building has already been constructed on June I, 1991, the setback
from the top of the bluff is five feet or existing setback, whichever is more, for additions to an existing
building. Any new buildings will have to meet the 3D-foot setback.
(Ord. No. 152,92,10-14-91; Ord. No. 249,93,4-8-96)
Sec. 20-1402. Stairways, lifts and landings.
Stairways, paths and lifts may be permitted in suitable sites where construction will not redirect water
flow direction and/or increase drainage velocity. Major topographic alterations are prohibited.
Stairways, paths and lifts must receive an earthwork permit and must meet the following design
requirements:
(1) Stairways, paths and lifts may not exceed four feet in width on residential lots. Wider stairways may
be used for commercial properties, public open space recreational properties, and planned unit
developments.
(2) Reserved.
(3) Canopies or roofs are not allowed on stairways, lifts, or landings.
(4) Stairways, paths, lifts and landings may be either constructed above the ground on posts or placed
into the ground, provided they are designed and built in a manner that ensures control of soil erosion.
(5) Stairways, paths, lifts and landings must be located in the most visually inconspicuous portions of
lots.
(6) Facilities such as ramps, lifts, or mobility paths for physically handicapped persons are also allowed,
provided that the dimensional and performance standards complied with of subsections (1) to (5).
(Ord. No. 152,92,10-14-91; Ord. No. 218, 9 1,8-22-94; Ord. No. 377,9148,5-24-04)
Sec. 20-1403. Removal or alteration of vegetation.
Removal or alteration of vegetation within a bluff impact zone is prohibited except for limited clearing of
trees and shrubs and cutting, pruning and trimming of trees to provide a view from the principal
dwelling site and to accommodate the placement of stairways and landings and access paths.
Removal or alteration of vegetation must receive prior approval of the community development director
or designee. An on-site review will be made to determine if the removal or alteration of vegetation will
require new ground cover. In no case shall c1earcutting be permitted. City staff will work with the
property owner to develop a means of creating a view while minimizing disturbance to the bluff impact
zone.
(Ord. No. 152, ~ 2, 10-14-91; Ord. No. 377, ~ 149,5-24-04)
Sec. 20-1404. Topographic alterations/grading and filling.
An earthwork permit will be required for the movement of more that ten cubic yards of material within
bluff impact zones. The permit shall be granted if the proposed alteration does not adversely affect the
bluff impact zone or other property. Topographic alterations/grading and filling within the bluff impact
zone shall not be permitted to increase the rate of drainage. The drainage from property within the bluff
impact zone may not be redirected without a permit from the city. Fill or excavated material shall not be
placed in bluff impact zones.
(Ord. No. 152, ~ 2,10-14-91)
Sec. 20-1405. Roads, driveways and parking areas.
Roads, driveways, and parking areas must meet structure setbacks and must not be placed within bluff
impact zones when other reasonable and feasible placement alternatives exists. If no alternatives exist,
they may be placed within these areas, and must be designed to not cause adverse impacts.
(Ord. No. 152, ~ 2, 10-14-91)