3. Minnehaha Creek Watershed District Plan Amendment and Rule Changes0
CITY OF
CHANHASSEN
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
MEMORANDUM
TO: Planning Commission
FROM: Terry Jeffery, Water Resources Coordinator
DATE: May 3, 2011
SUBJ: Minnehaha Creek Watershed District Plan Amendment and Rule
Changes
This item is being presented for information purposes. Staff will bring back
necessary code amendments for review and public hearing. No action is
currently required.
Engineering
BACKGROUND
Phone: 952.227.1160
• March 29, 2006: The City of Chanhassen submitted their Second
Fax: 952.227.1170
Minnesota Rules Chapter 10313.231 requires that "A watershed management plan
Fax: 952.227.1310
is required for all minor watershed units wholly or partly within the metropolitan
Finance
area." Subdivision 3 of the same section states that "Where a watershed
Phone: 952.227.1140
management organization exists, the plan for the watershed must be prepared and
Fax: 952.227.1110
adopted by the organization."
Park & Recreation
and plan revisions.
Phone: 952.227.1120
Minnesota Rules Chapter 10313.235 states that "After a watershed plan is
Fax: 952.227.1110
approved and adopted ... the local government units having land use planning and
regulatory responsibility for territory within the watershed shall prepare or cause
Recreation Center
to be prepared a local water management plan, capital improvement plan, and
2310 Coulter Boulevard
Phone: 952.227.1400
official controls as necessary to bring local water management into conformance
Fax: 952.227.1404
with the watershed plan within the time period prescribed in the implementation
program of the watershed plan and, as necessary, shall prepare or cause to be
Planning &
prepared amendments to the local comprehensive plan."
Natural Resources
Phone: 952.227.1130
The following timeline describes the coincidence of the City's plan with the
Fax: 952.227.1110
District's plan:
Public Works
7901 Park Place
• March 29, 2006: The City of Chanhassen submitted their Second
Phone: 952.227.1300
Generation Local Surface Water Management Plan (SWMP) for
Fax: 952.227.1310
review to all review agencies including the Minnehaha Creek
Watershed District (MCWD).
Senior Center
Phone: 952.227.1125
Fax: 952.227.1110
May 12, 2006: MCWD submits requests for additional information
and plan revisions.
Web Site
www.ci.chanhassen.mn.us
. May 18, 2006: MCWD approves sixty -day extension request from
City for review process.
Chanhassen is a Community for Life - Providing for Today and Planning for Tomorrow
Planning Commission
May 3, 2011
Page 2 of 5
• July 12, 2006: Chanhassen submits requested information for approval.
• July 20, 2006: MCWD approves the SWMP with the following conditions:
➢ Execute a Memorandum of Understanding (MOU) with the MCWD establishing
implementation responsibilities as between the two bodies.
➢ Incorporate prioritized list of capital improvements in the Chanhassen SWMP
within 120 days.
➢ Adoption of wetland ordinance the District determines to be at least as protective
as the MCWD Rule D within 6 months of execution of the MOU.
• July 5, 2007: MCWD Board votes to approve their Comprehensive Water Resources
Management Plan (WRMP).
• January 28, 2009: Minnesota Board of Soil and Water Resources (BWSR) approves
MCWD Comprehensive WRMP Amendment.
• September 1, 2010: MCWD implements new rules including Erosion Control and
Wetland Protection.
• October 14, 2010: MCWD amended their 2007 Comprehensive Water Resources
Management Plan incorporating their new Erosion and Wetland rules.
Municipalities have one year from the date of adoption to update their local controls. The city
will be reviewing Erosion Control and Wetland Protection in upcoming meetings. MCWD will
soon adopt their new stormwater rules. We have one year from their adoption to change our
stormwater rule.
DISCUSSION
The current city agreement with the MCWD is that the MCWD regulates shoreline and
streambank stabilization, waterbody crossings and structures, and dredging. The City maintains
regulatory authority over erosion control, wetland protection and stormwater management. This
report is intended to address the erosion control and wetland protection rules in anticipation of
changes to the pertinent sections of Chanhassen City Code.
Erosion Control Rule
The 1972 Federal Clean Water Act (CWA) has led to the creation of the National Pollution
Discharge Elimination System (NPDES). There are three permits under the NPDES, two of
which apply directly to the City: the Municipal Separate Storm Sewer System (MS4) permit and
the General Construction Permit. Both of these permits have very specific requirements for
Planning Commission
May 3, 2011
Page 3 of 5
sediment and erosion control best management practices; during construction and after final
stabilization.
To a large extent, the City of Chanhassen erosion and sediment control local controls mirror the
NPDES General Construction Permit. A review of the new MCWD rules indicates that they
have done so as well. It is anticipated that the changes to content will be relatively minor. This
will include what will trigger the need for preparing an erosion control plan and what items are
required on that plan in order to ensure consistency between all agencies.
Other factors in this code amendment will be looking at impaired waters and our MS4 permit and
making certain that they are consistent and that we are proactively addressing emerging
Minnesota Pollution Control Agency directives and goals. This amendment will also provide an
opportunity to create a cleaner code regarding erosion and sediment control by consolidating our
controls and regulations. Currently erosion and sediment control standards and practices can be
found within Sections 7 -22, 7 -33, 18 -62, 19 -144 & 145, 20 -518 and 20 -1183 of the City Code.
Wetland Protection Rule
Chanhassen has had a wetland protection rule since before the 1991 MN Wetland Conservation
Act. This rule has gone through several iterations over the past two decades; most recently when
we adopted our Second Generation Surface Water Management Plan in August of 2006.
There are two facets to wetland protection. First, how do we plan land use changes so that we
avoid, minimize and /or mitigate for wetland impacts — a process referred to as "sequencing ".
Second, how do we prevent land use changes from permanently altering a wetland plant
community, hydrology or water quality?
Under the sequencing facet, most organizations model their rules after the MN Wetland
Conservation Act, MN Rules Chapter 8420. This is the case with Chanhassen and with MCWD.
As such, the changes to sequencing are primarily within what an applicant must submit to the
review agency and how different wetland types are treated.
The larger and potentially farther reaching change comes in the long term protection of wetlands:
the use of buffers and setbacks. Currently the City of Chanhassen requires a buffer of varying
width depending upon the wetland classification. From this buffer, the City of Chanhassen also
requires a setback for all structures. This width also varies depending upon the wetland
classification. The MCWD requires buffers of varying widths based upon wetland classification
but does not require any setback from the buffer.
The following table illustrates the requirements of each entity.
r
Planning Commission
May 3, 2011
Page 4of5
Staff is meeting with District staff to review our current ordinance and compare it with their rule
changes. Staff will proffer that our buffer combined with our setback is substantially equivalent
to their rules. Also to be discussed at this meeting is how they classify their wetlands. It is
possible that our outstanding is equivalent to their preserve in which case our buffer widths are
more analogous to theirs.
In the event that the District does not agree that our code is materially equivalent, staff is
evaluating ways to meet the District rules while not increasing the encumbrance on privately
owned land. For instance, it may be possible to reduce the setback and match the District
buffers.
Two other changes have potential to be problematic. Staff is evaluating this and will be
discussing these issues with the District staff. The first is how buffers will be addressed for
linear projects such as roadways and trails. The District rule requires buffers with new road
projects but limits the buffer to the extent of right -of -way. The other concern pertains to
crossings of water bodies. The District rule requires that a buffer is established for all crossings
of waters or wetlands. The City does not enforce water crossings. Further, it is unclear if these
would pertain to such crossings as docks and boardwalks. City staff is awaiting clarification
from District staff.
Other potential issues staff is evaluating concern the administration of the rule. What items are
required with the application? What activities are exempt? Another area to be addressed
includes providing the reductions for soil types and slope that the District has written into their
rule.
Stormwater Management Rule
As with erosion control, the 1972 Clean Water Act (CWA) is the driver behind most water
quality rules. The CWA trickles down to local controls through the two National Pollution
MCWD WETLAND
CHANHASSEN CITY CODE CH. 20; SEC. 20 -411
PROTECTION RULE: 6.
BUFFER WIDTH
'COMBINED
'PRINCIPAL
'ACCESSORY
`PERMANENT
PRINCIPAL
% OF BUFFER
'BASE
'MIN
WETLAND
STRUCTURE
STRUCTURE
BUFFER STRIP
STRUCTURE
REO. FOR
BUFFER
APPLIED
CLASSIFICATION
SETBACK
SETBACK
(MIN WIDTH)
SETBACK & BUFFER
NATIVE VEG. .
IDTH
BUFFER
WIDTH FROM
WIDTH
DELINEATED BNDRY
OUTSTANDING
50
50
50
100
100
N/A
N/A
PRESERVE
40
20
40
80
100
75
67
MANAGE 1
30
15
25
55
100
40
34
MANAGE 2
30
15
20
50
OVER 50
30
24
MANAGE 3
30
15
16.5
46.5
OVER 50
20
16
Staff is meeting with District staff to review our current ordinance and compare it with their rule
changes. Staff will proffer that our buffer combined with our setback is substantially equivalent
to their rules. Also to be discussed at this meeting is how they classify their wetlands. It is
possible that our outstanding is equivalent to their preserve in which case our buffer widths are
more analogous to theirs.
In the event that the District does not agree that our code is materially equivalent, staff is
evaluating ways to meet the District rules while not increasing the encumbrance on privately
owned land. For instance, it may be possible to reduce the setback and match the District
buffers.
Two other changes have potential to be problematic. Staff is evaluating this and will be
discussing these issues with the District staff. The first is how buffers will be addressed for
linear projects such as roadways and trails. The District rule requires buffers with new road
projects but limits the buffer to the extent of right -of -way. The other concern pertains to
crossings of water bodies. The District rule requires that a buffer is established for all crossings
of waters or wetlands. The City does not enforce water crossings. Further, it is unclear if these
would pertain to such crossings as docks and boardwalks. City staff is awaiting clarification
from District staff.
Other potential issues staff is evaluating concern the administration of the rule. What items are
required with the application? What activities are exempt? Another area to be addressed
includes providing the reductions for soil types and slope that the District has written into their
rule.
Stormwater Management Rule
As with erosion control, the 1972 Clean Water Act (CWA) is the driver behind most water
quality rules. The CWA trickles down to local controls through the two National Pollution
Planning Commission
May 3, 2011
Page 5 of 5
Discharge Elimination System ( NPDES) permits mentioned earlier. As part of Chanhassen's
Municipal Separate Storm Sewer System (MS4) permit, we were selected with 29 other cities to
complete a pollutant loading assessment and Nondegradation Plan. These nondegradation cities,
as they are referred to, were required to model pollutant loading for three parameters for 1988,
2010, and 2030. If they exceeded the 1988 level for any of the three parameters, they are
required to amend their MS4 permit to include Best Management Practices (BMPs) geared
towards how they will return to the 1988 loading levels. As with each of the 30 cities, we
exceeded total volume of runoff for every watershed in Chanhassen.
In addition to the soon -to -be adopted MCWD stormwater rule, the new NPDES MS4 permit is
scheduled to be issued in January of 2012. It is anticipated that the nondegradation cities will
need to amend their MS4 permits at this time to address loading. We will need to evaluate
methods to minimize the amount of stormwater running off the land into our lakes and streams.
This can be done through infiltration — percolating water through the soils into shallow, or deep,
aquifers — or abstraction — capturing water at the source.
MCWD's new rule is intended to pollutant loading with an emphasis on capturing water on site
rather than sending it downstream. Currently they are looking for the abstraction and/or
infiltration of the first inch of rainfall unless it can be shown that is not possible, but in no case
shall it be less than the first one -half inch. This is consistent with the NPDES General
Construction permit requirements.
Also involved with this rule are requirements for phosphorous reduction and reduced sediment
loading. Except in very rare cases, these requirements will only apply to new impervious
surfaces greater than 10,000 square feet.
This rule will have the final public hearing on May 5 and will likely be adopted the last regular
MCWD Board Meeting in May. By state law we will have one year to update our local controls
to be compliant with theirs.
RECOMMENDATION
Staff intends to bring proposed Erosion Control code changes before the planning commission
within the next six to eight weeks and then begin discussion on the wetland rules. Staff would
prefer to wait until the new MS4 permit is issued prior to putting forward any proposed code
amendments pertaining to stormwater. Is there specific information the Planning Commission
would like in reviewing these proposed changes?
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