1n. Autumn Rodge/Frontage Road - Wetland Alteration Permit 95-4G
r
l
MEMORANDUM
CITY OF �u
CHANHASSEN
690 COULTER DRIVE • P.O. BOX 147 • CHANHASSEN, MINNESOTA 55317
(612) 937 -1900 • FAX (612) 937 -5739
TO: Don Ashworth, City Manager
FROM: Diane Desotelle, Water Resources Coordinator
DATE: August 8, 1995
SUBJ: Autumn Ridge/Frontage Road - Wetland Alteration Permit 95 -4
BACKGROUND
Aet n by Ck / fir
i`.i)dDlS2'� Y �Gt
MOdiAe�
D* Submitted to commission
DOC `WIMdtod to Council
F - t I -i !�7. _
The total parcel is 89.59 acres. There is a wetland which is 43.8 acres through the center of
the site. The property that is suitable for development will be split by the extension of the
collector road that will eventually connect Audubon Road with Highway 41. This road is part
of the City Comprehensive Plan and the alignment was refined in the Highway 5 Corridor
Plan. The connection will also serve as an access to the open space park proposed on the
west side of the large DNR wetland. The extension of the collector road must cross a portion
of DNR protected Wetland 10 -210W, however, the road will not be below the ordinary high
water mark eliminating the need for a DNR permit. The collector road has been moved to
the south to accommodate the school site east of the project. The final alignment on the west
end must be determined in conjunction with the development of the Opus site.
The City and Betty O "Shaughnessy, property owner of the Autumn Ridge development, have
combined the Autumn Ridge development and Highway 5 frontage road construction into one
project for the wetland alteration permit. Since a large area of open space was dedicated as
' park and half of the wetland impacts are the City's responsibility, the City agreed to process
the wetland alteration permit.
Wetland Impacts
The attached figure shows the site with the proposed wetland impact areas. The Autumn
Ridge developer will be filling a 0.3 acre ag /urban wetland (wetland 3) as a result of the
construction of multi- family units. The extension of the southern alignment for the Highway
5 frontage road will be performed by the city in conjunction with the Autumn Ridge
development. As a result, approximately 0.06 acre of a 0.3 acre ag /urban wetland (wetland 2)
Don Ashworth, City Manager
August 8, 1995
Page 2
and approximately 0.3 acre of the large DNR natural wetland (wetland 1) will be filled by the
city. All of the supportive documentation on avoidance, minimization of impacts, and
replacement are in the file for review.
The mitigation for the project will come from the bank of wetland restoration and creation
credits that the City is building this summer. One project is the wetland south of Lake Susan
and the other is on the Jerome Carlson property just south of the new Lake Lucy Road
extension.
ANALYSIS
Staff has reviewed the project carefully and replacement of wetland loss will be provided at a
ratio of 2:1 as required under the Wetland Conservation Act (WCA). All the necessary
parties have been notified of the project in accordance with the WCA, and the City permit
will reflect those conditions. The wetland in the Autumn Ridge development cannot be saved
as a result of the development since the drainage patterns will be altered. The impacts
occurring along the frontage road were reduced to the maximum extent possible by designing
the road location at the narrowest crossing of the large DNR wetland. The DNR wetland has
been drained and altered as a result of years of agricultural practices, and therefore, there is
potential for designing some wetland enhancement and restoration on this wetland as well.
PLANNING COMMISSION UPDATE
On July 19, 1995, the planning commission recommended approval of the wetland alteration
permit. The commission requested the council examine the fill for the entire road alignment
Staff realizes that additional wetland fill may be required when the road is continued to the
west and every effort will be made to design the road to minimize wetland impacts.
RECOMMENDATION
Staff recommends the City Council adopt the following motion:
"The City Council approves Wetland Alteration Permit 95 -4 and staff pursue the possibilities
for wetland enhancement to the large DNR wetland subject to the following conditions:
1. Wetland Conservation Act conditions are met.
2. General Permit 17 under the Army Corps of Engineers is applicable and should be
completed by the City.
3. The city shall develop a sediment and erosion control plan in accordance with the
City's Best Management Practice Handbook (BMPH). Type III erosion control fencing
Don Ashworth, City Manager
August 8, 1995
Page 3
will be required around the wetlands. Additional erosion control may be necessary
around the DNR wetland.
4. Verification of permit exemption shall be received from the DNR.
5. Wetland bank necessary for the project is completed in accordance with the WCA.
6. A feasibility study and design is included to enhance the DNR wetland if the plan
proves to be efficient and acceptable.
Attachment
1. Reduced plan.
c: Charles Folch, City Engineer
g: \eng \diane \wetlands \permits \autumn.cc
1 '1
I(
If
11
If
z(
1 (�
((
(
i (i
11(
.
I rk; ;
f s�:
I'
I
I � \
I
I I
. 0 • Z,
1
°mr`aM,i r1�`
._ NOLLYNDINCI ONrMU NNQ
Milo �N
a.Iagn S, 6uISSo�� pa
z'isb � MHO
la LaA *oy s'
1
• 1.
I II
ONI 'NOSOVYf v T130HOS \ .
&a ([MIS slin I QNV'I.LaK
� 1
aNI 'Nosam v TIaOHOS
/) as a3xv.LS SL'ym axvLL /
a
r
.o
� Q M
I
,r
\ \ v
� \ o
f
_2
� � N
V - G
Z /%