1e. City Code Amendment re: Erosion Control0
CITY OF
CNANHASSEN
7700 Market Boulevard
PO Box 147
Chanhassen. MN 55317
Administration
Phone: 952.227.1100
Fax: 952.227.1110
Building Inspections
Phone: 952.227.1180
Fax: 952.227.1190
Engineering
Phone: 952.227.1160
Fax: 952.227.1170
Finance
Phone: 952.227.1140
Fax: 952.227.1110
Park & Recreation
Phone: 952.227.1120
Fax: 952.227.1110
Recreation Center
2310 Coulter Boulevard
Phone: 952.227.1400
Fax: 952.227.1404
Planning &
Natural Resources
Phone: 952.227.1130
Fax: 952.227.1110
MEMORANDUM
TO: Todd Gerhardt, City Manager
FROM: Terry Jeffery, Water Resources Coordinator
DATE: June 27, 2011
t
SUBJ: City Code Amendment — Erosion Control
�
PROPOSED MOTION
"The City Council approves the attached ordinance amending Chapters 7, 18 and
19 of the Chanhassen City Code pertaining to guidance for erosion and sediment
control, and approval of the attached summary ordinance for publication purposes."
City Council approval requires a simple majority vote of the City Council present.
City Council approval of the summary ordinance requires a 4/5 vote of the City
Council.
BACKGROUND
Recent changes to local, state and federal regulations as well as recent erosion and
sediment deposition issues within the City of Chanhassen have prompted staff to
evaluate our existing code. Further impetus for this evaluation was found in the
erosion and sediment issues seen on parcels that may not meet the 50 cubic yard
threshold but have otherwise disturbed enough area such that sediment is being
delivered off the site and causing downstream damage. This review has found not
only inconsistencies between our current code and industry standards but
inconsistencies within the different sections of the code.
Based upon this review, staff is proposing amendments to Chapters 7, 18 and 19
of City Code. Staff recommends approval of the proposed ordinance
amendments.
Public Works
7901 Park Place ANAYLSIS
Phone: 952.227.1300
Fax: 952.227.1310
Section 7 -22: Grading and Erosion Control
Senior Center
Phone: 952.227.1125 Issue: Currently, Section 7 -22 references only the Surface Water Management
Fax:952.227.1110 Plan (SWMP). Chapter 19 will contain all information pertinent to the creation
Web Site and implementation of an erosion and sediment control plan. Chapter 19 will be
www.ci.chanhassen.mn.us incorporated into the SWMP at a later date. However, it is not currently within
the SWMP.
Chanhassen is a Community for Life - Providing for Today and Planning for Tomorrow
Todd Gerhardt, City Manager
City Code Amendment — Erosion Control
June 27, 2011
Page 2
Issue: Currently, Section 7 -22(a) states that "A satisfactory erosion and sediment control
plan .... must be approved .... if the construction will result in disturbing the soil ". There is no
minimum threshold that must be crossed prior to requiring a plan. This has the potential to be far
too onerous to the applicant as it requires a plan anytime there is a land disturbance. Further, this
is inconsistent with §7- 22(e).
Issue: Section 7 -22(b) would be better accomplished through the City's Surface Water
Management Plan and Stormwater Ordinance. To be consistent with the approved grading plan
will not necessarily always mean proper drainage and protection. In many older developments,
an approved grading plan may not even exist or site conditions may have changed substantially
and the existing plan is no longer appropriate to the site conditions.
Issue: Currently, Section 7 -22(e) states that "erosion control shall be installed on all exposed
soils.... consistent with conditions of the NPDES construction permit ". The threshold for the
NPDES is one (1) acre or more of disturbance except in special circumstances. This indicates
that erosion control measures would not need to be installed until there was a land disturbance
totaling at least one (1) acre in area. This is inconsistent with §7 -22(a) and §19 -145. This
amount of land disturbance is also too large to adequately protect our water resources, existing
infrastructure and adjoining property owners.
Issue: Several items within Section 7 -22 are redundant to Chapter 19 or are better located in
Chapter 19.
PROPOSED CHANGE: Amend Section 7 -22 to read as follows:
Sec. 7 -22 — Grading and erosion control.
(a) A satisfactory erosion and sediment control plan and grading plan consistent with the city's
surface water management plan and Chapter 19 Section 145 of Chanhassen City Code
must be approved by the city engineer or designee, before a building permit is issued for
construction, if the construction will require an erosion and sediment control plan under
§19 -145. will r so The e ros i on .,a sedi ,. n t- F ,l plan sh be
illustr-a4ed and �7u the shall be listed in the sur-faee vvfftef management plan and en the eity website. To guafal4e-e
E�.r+��`2L the p p lan a $$00. eas a er erlet4er of er -edi ' n a fisf e t e fy t th e it y ,
'
greater- than $500.00 7 site
gr e ater- eem The iiszz�zrrr'mirc�• , "' ,ll .. :.,l.lo e is
• �P�TF �
$5,000.00 pef aer-e. Th „;t y m e the e ser-ew r ,l,•aw upen the letter of er-e
plan ef in implementing the plan. if the eity dFaws en the eser-ewed f�nds, no addifiena4
biailding pefmits shall be issued tmfil the pr-e draw eserew balanee has been r-ester-ed. The eity
shall endeavor- te give nefiee to the owner- or- develeper- befer-e pr-eeeediag, btA sueh notiee
sh a4l net be required in an o 0
Todd Gerhardt, City Manager
City Code Amendment — Erosion Control
June 27, 2011
Page 3
(b) The gr-ading and erosion eentfel plan ffmst be eensistent v�� the appr-eved grading plan
the plat in whieh the pr-epeft-y is leeated, if any.
(d) Every effort shall be made during the building permit application process to determine the
full extent of erosion control required. However, the city engineer may require additional
controls to correct specific site related problems as normal inspections are performed.
(f) All construction activity that results in disturbance of the ground shall comply with the city's
surface water management plan and Section 19 -145 of the Chanhassen City Code.
(g) if the erosion and sedimea� eentfol measufes have net been installed er- maintained pr-oper4y
the e it y . s the r ight t stop f,,. her- work
•■_
�� ■
Section 18 -62: GradinLy and Erosion Control
Issue: Currently, Section 18 -62 references only the Surface Water Management Plan (SWMP).
Chapter 19 will contain all pertinent information and will be incorporated into the SWMP at a
later date. However, it is not currently within the SWMP.
PROPOSED CHANGE: Amend Section 18 -62 to read as follows:
Sec. 18 -62 — Erosion and sediment control.
(1) The development shall conform to the topography and soils to create the least potential
for soil erosion.
(2) The smallest practical increment of land shall be exposed at any one time during
development.
(3) Detailed requirements for each plat shall be set forth in the development agreement.
(4) Subdivision development shall conform to the city's surface water management plan and
Section 19 -145 of the Chanhassen City Code.
Todd Gerhardt, City Manager
City Code Amendment — Erosion Control
June 27, 2011
Page 4
This proposed change was brought before the Chanhassen Planning Commission on June 7,
2011. The Planning Commission recommended that the City Council adopt the proposed change
to Chapter 18. The June 7, 2011 Planning Commission minutes are item 1 a. of the City Council
Packet.
Section 19 -145: Erosion and Sediment Control
Issue: Currently, §19- 145(a)1 Reads "An erosion and sediment control plan shall be created for
any land disturbing activity." This threshold is far too low and poses numerous issues. Chapter
19 shall be revised to itemize when an erosion and sediment control plan shall be required. This
will be consistent with other local, state and federal regulations and shall be sufficient to protect
surface water features, infrastructure and private land owners.
Issue: Currently, § 19- 145(a)2 references the NPDES construction stormwater permit as the
guidance for developing erosion and sediment control plans. As discussed previously, the
threshold would be one acre of land disturbance. Further, this is inconsistent with §19- 145(a)l
and with Chapter 7.
Issue: Currently, §19- 145(a)2 references the NPDES construction stormwater permit as the
guidance for developing erosion and sediment control plans. By removing this language there no
longer exists any guidance for what is required in the erosion and sediment control plan. The
required elements are therefore now incorporated into Chapter 19. The City Attorney indicated
that it would be preferable to itemize the requirements rather than reference the federal rules.
Issue: Currently, our minimum financial assurance is $500.00. In many instances this might be
excessive for what is required in sediment and erosion control elements. Therefore, it is
proposed to lower the minimum financial assurance to $250.00. Conversely, on some sites
where there are sensitive resources requiring additional protections such as wetlands, lakes,
bluffs, etc., the current maximum of $5,000.00 per acre may be significantly inadequate to cover
temporary and permanent stabilization needs as well as street clean up and other maintenance.
Therefore, it is proposed to increase the maximum financial assurance to $7,500.00 per acre.
PROPOSED CHANGE: Section 19 -145 is amended in its entirety to read as follows:
Sec. 19 -145. — Erosion and sediment control.
(a) Erosion and Sediment Control Plans.
(1) An erosion and sediment control plan shall be required for any land disturbing
activity that meets any of the following conditions:
a. Disturbs 5,000 square feet or more of land area, or
b. Requires the excavation, placement or stockpiling of 50 cubic yards or more
of material, or
Todd Gerhardt, City Manager
City Code Amendment — Erosion Control
June 27, 2011
Page 5
c. Any disturbance that is upgradient of and tributary to a water of the State as
defined in Minnesota Statute 115.01, Subd. 22, or
d. Any disturbance of land that is considered "highly erodible" as identified by
the U.S. Dept. of Agriculture Natural Resources Conservation Service's Web
Soil Survey application or equivalent, or
e. Any land disturbance within the Bluff Creek Overlay District, or
f. Any time an earthwork permit is issued, or
g. An erosion and sediment control plan may be required after the fact if it is
determined that sediment has migrated off of a construction site.
(2) This shall be a standalone document that shall include the following:
a. Site plans for existing and proposed conditions drawn to an appropriate scale.
The plans shall include the following:
1. Site location in relation to surrounding roads, steep slopes and/or bluff
areas, other significant geographic features, buildings and other significant
structures.
2. Site property lines.
3. Area of disturbance.
4. Drainage boundaries and direction of drainage pre- and post - development.
5. Location of surface water features as defined in MN Statute 115.01, Subd.
22 including but not limited to storm sewer inlet structures, wetlands,
ponds, streams, lakes, on or immediately adjacent to the site, and all
appropriate setbacks from these features.
6. Identification of all receiving waterbodies and/or stormwater conveyance
systems to which the site discharges. Notation of an Impaired or Special
Management waters status of waterbodies.
7. Location of all trees and vegetation on the site with identification of what
is to be saved. Installation of protective fencing, or other adequate
measure, so as to exclude all fill and equipment from the drip line or
critical root zone of the vegetation to be protected.
8. Existing easements and utilities.
9. Ingress and Egress for equipment and materials
Todd Gerhardt, City Manager
City Code Amendment — Erosion Control
June 27, 2011
Page 6
10. Location of stockpiled materials
11. Locations of proposed runoff control, erosion prevention, sediment control
and temporary and permanent soil stabilization measures, including, but
not limited to: inlet protection, perimeter control, temporary and
permanent soil stabilization, concrete wash areas, slope breaks, energy
dissipation, rock construction entrance, silt curtains.
b. Dewatering Plan, if necessary, shall be provided to the City for review. The
City must be noticed 24 hours prior to the commencement of any dewatering
activities.
c. As site and/or climatic conditions change additional best management
practices may be needed. These changes must be implemented on the site and
incorporated into the erosion and sediment control plan.
d. Where inadequate natural vegetation exists or where it becomes necessary to
remove existing natural vegetation, both temporary vegetative and permanent
vegetative cover shall be addressed in the plans and specifications.
e. Six (6 ") of topsoil shall be incorporated into the final grading or 4" of 60%
sand and 40% compost mix must be ripped into existing soil materials to a
depth of 10" on the site.
(3) Stream bank stabilization and stream bed control structures shall be designed
based on the unique site conditions present including soil conditions, flow rate,
slope and flow velocity and shall be consistent with Part 654 of the National
Engineering Handbook: Stream Restoration Design [H_210_NEH_654 - May
2008 or most recent revision].
(4) If the disturbance exceeds the minimum threshold for the NPDES permit, Erosion
and Sediment Control Plans shall be compliant with NPDES General Stormwater
Permit for Construction Activity (MN R100001). The applicant shall prepare or
cause to be prepared a Storm Water Pollution Prevention Plan (SWPPP) and
provide this plan to the City.
(5) Every effort shall be made to minimize disturbance of existing groundcover.
(6) All erosion control noted on the approved plan shall be installed prior to the
initiation of any site grading. Noncompliance with the grading and erosion control
plan shall constitute grounds for an order from the City Engineer to halt all
earthwork and related construction on the site.
Todd Gerhardt, City Manager
City Code Amendment — Erosion Control
June 27, 2011
Page 7
(b) Maintenance: The land owner, or permittee shall be responsible at all times for the
maintenance and proper operation of all erosion and sediment control management
practices. Specific maintenance requirements are as follows:
(1) All exposed soil areas must be stabilized as soon as possible to eliminate soil
erosion but in no case later than 14 days after construction activity in that portion
of the site had temporarily or permanently ceased.
(2) The normal wetted perimeter of any temporary or permanent drainage ditch or
swale that drains water from the site, or diverts water around a site must be
stabilized. Stabilization must be completed within 24 hours of connecting to a
surface water. Portions of the ditch that are under construction must be stabilized
within 24 hours after the construction activity in that portion has ceased.
(3) Sediment control practices must minimize sediment from entering surface waters,
including curb and gutter systems and storm sewer inlets.
(4) Sediment control practices must be established on all down- gradient perimeters
before any up- gradient land disturbing activities begin. These practices shall
remain in place until the City has determined that the site soils have been
permanently stabilized.
(5) All storm drain inlets must be protected by Best Management Practices as shown
in the most current edition of City of Chanhassen Standard Specifications &
Detail Plates during construction until all sources with potential for discharging to
the inlet have been stabilized.
(6) Pipe outlets must be provided with temporary or permanent energy dissipation
within 24 hours of connection to a surface water.
(7) In order to maintain sheet flow and minimize rills and gullies, there shall be no
unbroken slope length of greater than 30 feet for slopes with a grade of 3:1 or
steeper.
(8) Temporary stockpiles must have effective sediment controls in place to prevent
discharge to surface waters including stormwater conveyances such as curb and
gutter.
(9) Site access roads (entrances to construction sites) shall be graded or otherwise
protected with silt fences, diversion channels or dikes and pipes to prevent
sediment from exiting the site via the access road. Primary site access roads shall
be surfaced with crushed rock or wood chips. The rock entrance shall extend for
a minimum distance of 75 feet (150 for wood chips) beginning at existing paved
surface; length may be reduced or lengthened at the discretion of the City
Engineer based upon site considerations. All construction traffic shall utilize the
entire length of the rock entrance.
Todd Gerhardt, City Manager
City Code Amendment — Erosion Control
June 27, 2011
Page 8
(10) Soil tracked from the site by motor vehicles shall be cleaned from paved roadway
surfaces at least daily or as needed throughout the duration of construction.
Roadway cleaning shall be the responsibility of the party or parties having a
permit with the City. If the tracked soil is not cleaned in a timely manner, the
City may elect to clean the surface and invoice the responsible party.
(11) During construction of an infiltration or biofiltration system, rigorous prevention
and sediment controls must be used to prevent the discharge of sediment into the
infiltration/biofiltration area. Infiltration/biofiltration areas must not be excavated
to final grade until the contributing drainage area(s) has been constructed and
finally stabilized. Infiltration/biofiltration areas shall be protected from heavy
equipment operation.
(12) Dewatering or basin draining (e.g. pumped discharges, trench/ditch cuts for
drainage) related to the construction activity that may have turbid or sediment
laden discharge water must be discharged to a temporary or permanent
sedimentation basin on the site whenever possible. If water cannot be discharged
to a sedimentation basin prior to entering the surface water, it must be treated with
the appropriate BMPs, such that the discharge does not adversely affect the
receiving water or downstream landowners.
(13) Inlet protection devices and all perimeter control shall be maintained once
sediment accumulates to a depth 1/3 of the designed capacity.
(14) Detention basins may be used as temporary sediment retention during the
construction phase. Upon final stabilization and before final approval,
accumulated sediment must be removed to restore the required permanent pool
volume in the detention area and an as -built survey showing this must be provided
to the City.
(c) Inspections and Notifications
(1) Work sites must be inspected once every seven days and within 24 hours of a 1.0
inch rainfall event to assure that all sediment and erosion control elements are
working effectively.
(2) Inspection and maintenance records must be maintained and retained with the
erosion control plan. Upon request, the inspection records must be made
available to the City within 24 hours.
(3) The City may contract inspections out to the Carver County Soil and Water
Conservation District or other entities. The City may pass the costs on to the
applicant.
Todd Gerhardt, City Manager
City Code Amendment — Erosion Control
June 27, 2011
Page 9
(4) The applicant or its authorized agent shall notify the City in writing at the
following points:
a. On completing installation of perimeter erosion and sedimentation controls.
b. On completing land- disturbing activities and putting into place measures for
final soil stabilization and revegetation.
c. Whenever any site dewatering is proposed to take place.
d. When the site has been permanently stabilized and re- vegetated.
e. When all temporary erosion and sedimentation controls have been removed
from the site.
(d) Financial Assurance
(1) To guarantee compliance with the plan, and related remedial work, a cash escrow
or letter of credit, satisfactory to the City, shall be furnished to the City before a
building permit is issued. The escrow amount shall be not less than $250.00 but
may be greater than $250.00 if, after review of the site, the City deems it
necessary to require a greater amount to guarantee compliance. The maximum
escrow allowable per parcel is $7,500.00 per acre. The City may use the escrow
or draw upon the letter of credit to reimburse the City for any labor or material
costs it incurs in securing compliance with the plan or in implementing the plan.
If the City draws on the escrowed funds, no additional building permits shall be
issued until the pre -draw escrow balance has been restored. The City shall
endeavor to give notice to the owner or developer before proceeding, but such
notice shall not be required in an emergency as determined by the City. The
assurance shall be maintained until final stabilization and removal of erosion and
sediment controls.
ATTACHMENTS
1. City Code Amendment.
2. Summary Ordinance for Publication Purposes.
3. Planning Commission Staff Report dated June 7, 2011.
4. Email correspondence from Steve Christopher of the MCWD.
g: \plan \city code\2011\2011 -07 chapters 18 & 20 erosion control \cc memo 6 -27 -1 Ldoc
CITY OF CHANHASSEN
CARVER AND HENNEPIN COUNTIES, MINNESOTA
ORDINANCE NO.
AN ORDINANCE AMENDING CHAPTERS 7,18 and 19
CHANHASSEN CITY CODE
CONCERNING EROSION CONTROL
THE CITY COUNCIL OF THE CITY OF CHANHASSEN, MINNESOTA ORDAINS:
Section 1. Section 7 -22 of the City Code, City of Chanhassen, Minnesota, is hereby
amended to read as follows:
Grading and erosion control.
(a) A satisfactory erosion and sediment control plan and grading plan consistent with the
city's surface water management plan and Chapter 19 Section 145 of Chanhassen City
Code must be approved by the city engineer or designee, before a building permit is
issued for construction, if the construction will require an erosion and sediment
control plan under §19 -145. will in distwbing the soil. The erosion sedimen4
eontfel plan shall be illustrated and suflunar-ized, by the appliearA at the time e
appheation. Guidanee doeuments shall be listed in the suffaee water management plan
pen:nit is issued. The eserew amount may be greater- than $500.00 if-, after- review of t
site, the eity deems it neeessar-y to require a greater- ameupA to guar-ai4ee eemplianee.
maximum eser-ow allowable per- par-eel is $5,000 * 00 per aer-e. The eity may use the
°r,.,.,,,,, draw u th l°++ °r of er -° ,li+ + . r-e i mb-- +b ,.i+ for „ labor- ma t erial
city dr-aws e ftmds, no additionW building permits shall be issued until the
owner- E)r- developer- befoFe � J
7 r- in
(b) The grading and erosion eentrel plan must be eensistent with the appr-oved grading pl—an
for- the plat in whieh the pr-opefty is 7
(d) (b) Every effort shall be made during the building permit application process to
determine the full extent of erosion control required. However, the city engineer may
require additional controls to correct specific site related problems as normal inspections
are performed.
(f) (c) All construction activity that results in disturbance of the ground shall comply with
the city's surface water management plan and Section 19 -145 of the Chanhassen City
Code.
(g) if the erosion and sediment eent-r-el measufes have not been installed or- maintained
pr erly the eit reserve the r ight t stop fi ,° wo rk .
FA
Ta
•�
■.
Section 2. Section 18 -62 of the City Code, City of Chanhassen, Minnesota, is hereby
amended to read as follows:
Erosion and sediment control
(1) The development shall conform to the topography and soils to create the least potential
for soil erosion.
(2) The smallest practical increment of land shall be exposed at any one time during
development.
(3) Detailed requirements for each plat shall be set forth in the development agreement.
(4) Subdivision development shall conform to the city's surface water management plan and
Section 19 -145 of the Chanhassen City Code.
Section 3. Section 19 -145 of the City Code, City of Chanhassen, Minnesota, is hereby
amended to read as follows:
Erosion and sediment control.
(a) Erosion and Sediment Control Plans.
(1) An erosion and sediment control plan shall be required for any land disturbing
activity that meets any of the following conditions:
a. Disturbs 5,000 square feet or more of land area, or
V
b. Requires the excavation, placement or stockpiling of 50 cubic yards or
more of material, or
C. Any disturbance that is upgradient of and tributary to a water of the State
as defined in Minnesota Statute 115.01, Subd. 22, or
d. Any disturbance of land that is considered "highly erodible" as identified
by the U.S. Dept. of Agriculture Natural Resources Conservation
Service's Web Soil Survey application or equivalent, or
Any land disturbance within the Bluff Creek Overlay District, or
f. Any time an earthwork permit is issued, or
g. An erosion and sediment control plan may be required after the fact if it is
determined that sediment has migrated off of a construction site.
(2) This shall be a standalone document that shall include the following:
a. Site plans for existing and proposed conditions drawn to an appropriate
scale. The plans shall include the following:
Site location in relation to surrounding roads, steep slopes and/or
bluff areas, other significant geographic features, buildings and
other significant structures.
2. Site property lines.
3. Area of disturbance.
4. Drainage boundaries and direction of drainage pre- and post -
development.
5. Location of surface water features as defined in MN Statute
115.0 1, Subd. 22 including but not limited to storm sewer inlet
structures, wetlands, ponds, streams, lakes, on or immediately
adjacent to the site, and all appropriate setbacks from these
features.
6. Identification of all receiving waterbodies and /or stormwater
conveyance systems to which the site discharges. Notation of an
Impaired or Special Management waters status of waterbodies.
7. Location of all trees and vegetation on the site with identification
of what is to be saved. Installation of protective fencing, or other
adequate measure, so as to exclude all fill and equipment from the
drip line or critical root zone of the vegetation to be protected.
3
8. Existing easements and utilities.
9. Ingress and Egress for equipment and materials
10. Location of stockpiled materials
11. Locations of proposed runoff control, erosion prevention, sediment
control and temporary and permanent soil stabilization measures,
including, but not limited to: inlet protection, perimeter control,
temporary and permanent soil stabilization, concrete wash areas,
slope breaks, energy dissipation, rock construction entrance, silt
curtains.
b. Dewatering Plan, if necessary, shall be provided to the City for review.
The City must be noticed 24 hours prior to the commencement of any
dewatering activities.
C. As site and /or climatic conditions change additional best management
practices may be needed. These changes must be implemented on the site
and incorporated into the erosion and sediment control plan.
d. Where inadequate natural vegetation exists or where it becomes necessary
to remove existing natural vegetation, both temporary vegetative and
permanent vegetative cover shall be addressed in the plans and
specifications.
e. Six (6 ") of topsoil shall be incorporated into the final grading or 4" of 60%
sand and 40% compost mix must be ripped into existing soil materials to a
depth of 10" on the site.
(3) Stream bank stabilization and stream bed control structures shall be designed
based on the unique site conditions present including soil conditions, flow rate,
slope and flow velocity and shall be consistent with Part 654 of the National
Engineering Handbook: Stream Restoration Design [H_210 NEH_654 - May
2008 or most recent revision].
(4) If the disturbance exceeds the minimum threshold for the NPDES permit, Erosion
and Sediment Control Plans shall be compliant with NPDES General Stormwater
Permit for Construction Activity (MN R100001). The applicant shall prepare or
cause to be prepared a Storm Water Pollution Prevention Plan (SWPPP) and
provide this plan to the City.
(5) Every effort shall be made to minimize disturbance of existing groundcover.
(6) All erosion control noted on the approved plan shall be installed prior to the
initiation of any site grading. Noncompliance with the grading and erosion control
plan shall constitute grounds for an order from the City Engineer to halt all
earthwork and related construction on the site.
0
(b) Maintenance: The land owner, or permittee shall be responsible at all times for the
maintenance and proper operation of all erosion and sediment control management
practices. Specific maintenance requirements are as follows:
(1) All exposed soil areas must be stabilized as soon as possible to eliminate soil
erosion but in no case later than 14 days after construction activity in that portion
of the site had temporarily or permanently ceased.
(2) The normal wetted perimeter of any temporary or permanent drainage ditch or
Swale that drains water from the site, or diverts water around a site must be
stabilized. Stabilization must be completed within 24 hours of connecting to a
surface water. Portions of the ditch that are under construction must be stabilized
within 24 hours after the construction activity in that portion has ceased.
(3) Sediment control practices must minimize sediment from entering surface waters,
including curb and gutter systems and storm sewer inlets.
(4) Sediment control practices must be established on all down- gradient perimeters
before any up- gradient land disturbing activities begin. These practices shall
remain in place until the City has determined that the site soils have been
permanently stabilized.
(5) All storm drain inlets must be protected by Best Management Practices as shown
in the most current edition of City of Chanhassen Standard Specifications & Detail
Plates during construction until all sources with potential for discharging to the
inlet have been stabilized.
(6) Pipe outlets must be provided with temporary or permanent energy dissipation
within 24 hours of connection to a surface water.
(7) In order to maintain sheet flow and minimize rills and gullies, there shall be no
unbroken slope length of greater than 30 feet for slopes with a grade of 3:1 or
steeper.
(8) Temporary stockpiles must have effective sediment controls in place to prevent
discharge to surface waters including stormwater conveyances such as curb and
gutter.
(9) Site access roads (entrances to construction sites) shall be graded or otherwise
protected with silt fences, diversion channels or dikes and pipes to prevent
sediment from exiting the site via the access road. Primary site access roads shall
be surfaced with crushed rock or wood chips. The rock entrance shall extend for a
minimum distance of 75 feet (150 for wood chips) beginning at existing paved
surface; length may be reduced or lengthened at the discretion of the City Engineer
based upon site considerations. All construction traffic shall utilize the entire
length of the rock entrance.
5
(10) Soil tracked from the site by motor vehicles shall be cleaned from paved roadway
surfaces at least daily or as needed throughout the duration of construction.
Roadway cleaning shall be the responsibility of the party or parties having a permit
with the City. If the tracked soil is not cleaned in a timely manner, the City may
elect to clean the surface and invoice the responsible party.
(11) During construction of an infiltration or biofiltration system, rigorous prevention
and sediment controls must be used to prevent the discharge of sediment into the
infiltration/biofiltration area. Infiltration/biofiltration areas must not be excavated
to final grade until the contributing drainage area(s) has been constructed and
finally stabilized. Infiltration/biofiltration areas shall be protected from heavy
equipment operation.
(12) Dewatering or basin draining (e.g. pumped discharges, trench/ditch cuts for
drainage) related to the construction activity that may have turbid or sediment
laden discharge water must be discharged to a temporary or permanent
sedimentation basin on the site whenever possible. If water cannot be discharged
to a sedimentation basin prior to entering the surface water, it must be treated with
the appropriate BMPs, such that the discharge does not adversely affect the
receiving water or downstream landowners.
(13) Inlet protection devices and all perimeter control shall be maintained once
sediment accumulates to a depth 1/3 of the designed capacity.
(14) Detention basins may be used as temporary sediment retention during the
construction phase. Upon final stabilization and before final approval,
accumulated sediment must be removed to restore the required permanent pool
volume in the detention area and an as -built survey showing this must be provided
to the City.
(c) Inspections and Notifications
(1) Work sites must be inspected once every seven days and within 24 hours of a 1.0
inch rainfall event to assure that all sediment and erosion control elements are
working effectively.
(2) Inspection and maintenance records must be maintained and retained with the
erosion control plan. Upon request, the inspection records must be made
available to the City within 24 hours.
(3) The City may contract inspections out to the Carver County Soil and Water
Conservation District or other entities. The City may pass the costs on to the
applicant.
(4) The applicant or its authorized agent shall notify the City in writing at the
following points:
0
a. On completing installation of perimeter erosion and sedimentation
controls.
b. On completing land- disturbing activities and putting into place measures
for final soil stabilization and revegetation.
C. Whenever any site dewatering is proposed to take place.
d. When the site has been permanently stabilized and re- vegetated.
C. When all temporary erosion and sedimentation controls have been
removed from the site.
(d) Financial Assurance
(1) To guarantee compliance with the plan, and related remedial work, a cash escrow
or letter of credit, satisfactory to the City, shall be furnished to the City before a
building permit is issued. The escrow amount shall be not less than $250.00 but
may be greater than $250.00 if, after review of the site, the City deems it
necessary to require a greater amount to guarantee compliance. The maximum
escrow allowable per parcel is $7,500.00 per acre. The City may use the escrow
or draw upon the letter of credit to reimburse the City for any labor or material
costs it incurs in securing compliance with the plan or in implementing the plan.
If the City draws on the escrowed funds, no additional building permits shall be
issued until the pre -draw escrow balance has been restored. The City shall
endeavor to give notice to the owner or developer before proceeding, but such
notice shall not be required in an emergency as determined by the City. The
assurance shall be maintained until final stabilization and removal of erosion and
sediment controls.
Section 4. This ordinance shall be effective immediately upon its passage and
publication.
PASSED AND ADOPTED this 27 day of June, 2011, 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\2011\2011 -07 chapters 18 & 20 erosion control \amendment ordinance ch 7, 18 and 19 erosion control.doc
7
CITY OF CHANHASSEN
CARVER AND HENNEPIN COUNTIES, MINNESOTA
SUMMARY OF ORDINANCE NO. ,
CHAPTERS 7,18 AND 19
CONCERNING EROSION CONTROL
The code amendment to Chapters 7 and 18 reference Chapter 19 as the requirements for
grading, erosion and sediment control plans. The Amendment to Chapter 19, section 19 -145,
provides the standards and requirements for erosion and sediment control plans.
A printed copy of Ordinance No. is available for inspection by any person during
regular office hours at the office of the City Manager /Clerk.
PASSED, ADOPTED, AND APPROVED FOR PUBLICATION this 27 day of June,
2011, by the City Council of the City of Chanhassen.
CITY OF CHANHASSEN
M.
Thomas A. Furlong, Mayor
W
Todd Gerhardt, City Manager /Clerk
(Published in the Chanhassen Villager on
g: \plan\city code \2011 \2011 -07 chapters 18 & 20 erosion control \summary ordinance ch 7, 18 & 19.doc
0
CITY OF
CBANHASSEN
7700 Market Boulevard
PO Box 147
Chanhassen, MN 55317
Administration
Phone: 952.227.1100
Fax: 952.227.1110
Building Inspections
Phone: 952.227.1180
Fax: 952.227.1190
Engineering
Phone: 952.227.1160
Fax: 952.227.1170
Finance
Phone: 952.227.1140
Fax: 952.227.1110
Park & Recreation
Phone: 952.227.1120
Fax: 952.227.1110
Recreation Center
2310 Coulter Boulevard
Phone: 952.227.1400
Fax: 952.227.1404
Planning &
Natural Resources
Phone: 952.227.1130
Fax: 952.227.1110
MEMORANDUM
TO: Planning Commission
FROM: Terry Jeffery, Water Resources Coordinator
DATE: June 7, 2011 �Q
SUBJ: City Code Amendment
Chapter 18, Subdivisions
PROPOSED MOTION:
"The Chanhassen Planning Commission recommends that City Council adopt
the attached ordinance amending Chapter 18 of the Chanhassen City Code."
BACKGROUND
Staff has reviewed the new Minnehaha Creek Watershed District rules, the new
National Pollution Discharge Elimination System ( NPDES) General Stormwater
Permit for Construction and compared that with the existing City Code. During
this review it was discovered that discrepancies existed within City Code and
that current code was inadequate to address issues with erosion control and
sediment deposition as well as meeting the requirements of the NPDES and
MCWD rules. The proposed amendment changes what the subdivision chapter
references for guidance.
Staff recommends approval of the proposed ordinance amendments.
ANAYLSIS
Changes to guidance reference.
Public Works
Issue: Chapter 19 of the Chanhassen City Code is to be modified to include all
7901 Park Place
erosion and sediment control management practices required by the City. This
Phone: 952.227.1300
change to Chapter 19 will assist in protecting water resources, preventing the
Fax: 952.227.1310
deposition of sediment onto public streets and private property, and comply with
Senior Center
other applicable rules.
Phone: 952.227.1125
Fax: 952.227.1110
Issue: Currently Section 18 -62 references only the Surface Water Management
Plan (SWMP). Chapter 19 will contain all pertinent information and will be
Web Site
incorporated into the SWMP at a later date. However, it is not currently within
www.ci.chanhassen.mn.us
the SWMP.
SCANNED
Chanhassen is a Community for Life - Providing for Today and Planning for Tomorrow
Planning Commission
June 7, 2011
Page 2
PROPOSED CHANGE: Amend Section 18 -62 to read as follows:
Sec. 18 -62 — Erosion and sediment control.
(1) The development shall conform to the topography and soils to create the
least potential for soil erosion.
(2) The smallest practical increment of land shall be exposed at any one time
during development.
(3) Detailed requirements for each plat shall be set forth in the development
agreement.
(4) Subdivision development shall conform to the city's surface water
management plan and Section 19 -1.45 of the Chanhassen City Code.
RECOMMENDATION
Staff recommends that the Planning Commission recommend approval of the
attached ordinance amending Chapter 18 of the Chanhassen City Code
pertaining to guidance for erosion and sediment control.
ATTACHMENTS
1. Ordinance Amending Chapter 18, Subdivision.
2. Chapter 19 Revision.
g: \eng \terry\code ammendments \mcwd rule changes \erosion \pc memo 6 -7 -1 l.doc
CITY OF CHANHASSEN
CARVER AND HENNEPIN COUNTIES, MINNESOTA
ORDINANCE NO.
AN ORDINANCE AMENDING CHAPTER 18
CHANHASSEN CITY CODE
SUBDIVISION
THE CITY COUNCIL OF THE CITY OF CHANHASSEN, MINNESOTA ORDAINS:
Section 1. Section 18 -62 of the City Code, City of Chanhassen, Minnesota, is hereby
amended to read as follows:
(1) The development shall conform to the topography and soils to create the least potential
for soil erosion.
(2) The smallest practical increment of land shall be exposed at any one time during
development.
(3) Detailed requirements for each plat shall be set forth in the development agreement.
(4) Subdivision development shall conform to the city's surface water management plan and
Section 19 -145 of the Chanhassen City Code.
Section 2. This ordinance shall be effective immediately upon its passage and
publication.
PASSED AND ADOPTED this day of
the City of Chanhassen, Minnesota.
Todd Gerhardt, City Manager
(Published in the Chanhassen Villager on
2011, by the City Council of
Thomas A. Furlong, Mayor
g: \plan \city code\2011\2011 -07 chapters 18 & 20 erosion control \amendment ordinance ch 18 subdivisions. doc
Meuwissen, Kim
From: Jeffery, Terry
Sent: Monday, June 20, 2011 3:14 PM
To: Meuwissen, Kim
Subject: FW: Erosion Rewrite.docx
From: Steve Christopher [mai Ito: SChristopher @m innehahacreek.orgl
Sent: Thursday, June 02, 2011 11:16 AM
To: Jeffery, Terry
Cc: Becky Houdek
Subject: RE: Erosion Rewrite.docx
Terry,
Looks good and I would be willing to recommend approval for continuance of rule authority.
Thanks
Steve Christopher
Regulatory Program Manager
18202 Minnetonka Blvd.
Deephaven, MN 55391
Direct: 952 - 641 -4506
Office: 952 - 471 -0590
Fax: 952- 471 -0682
www.minnehahacreek.org