1c WAP to Expand Minnewashta Regional Beach
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*This item is being reviewed by
the Planning Commission on
11/18/98. An update will be
given to you prior to the meeting.
CITY OF
CHANHASSEN
MEMORANDUM
690 City Center Drive, PO Box 147 TO:
Chanhassen, Minnesota 55317
Phone 612.937.1900 FROM:
General Fax 612.937.5739
Engineering Fax 612.937.9152 DATE:
Public Safety Fax 6] 2.934,2524
Web www.ci.chanhassell.lIJn.lIS SUBJ:
Planning Commission
Phillip Elkin, Water Resources Coordinator
November 9, 1998
Wetland Alteration Permit (#98-4) for Lake Minnewashta Regional
Park
BACKGROUND
This project proposes to expand the existing beach lot at Lake Minnewashta
Regional Park by 200 linear feet. This expansion is in response to the increasing
demand, and the projected future demands on the park's beach. Most ofthe work in
this project will involve excavating below the ordinary high water (OHW) level,
which is under the Minnesota Department of Natural Resources jurisdiction.
However, creating a larger beach area will involve filling wetlands along the
shoreline above the OHW, which the City ofChanhassen regulates (see attachment
A). In an effort to underline the need for this expansion, the park has included
information about current user demand, future population growth and information
comparing this beach (see attachments).
WETLAND
The wetland that is proposed to be impacted is not identified on the Chanhassen
wetland inventory. This area meets the requirements of soil, vegetation and
hydrological saturation to be classified as a wetland. Most likely the hydrology for
this wetland comes from Lake Minnewashta during periods when lake levels are
higher than normal such as spring thaw. The wetland averages approximately 30
feet shoreward from the OHW of the lake and extends along the shoreline at about
the 945.5 contour line. This area supports both a herbaceous and woody vegetation
such as lake bank sedge, elms, dogwoods and purple loosestrife. Because of the
location and size of this section of the wetland, it is considered to provide lower
functions and low in wetland quality.
The City ofChallhasse1l. A growillg COlllmulliry with clean lakes, qutllity schools, a clhli7lling dOlUntoll'll, thrilling busillesses, and beautiful parks. A great pIa(/' to /i1'C, work, .md play.
Planning Commission
Wetland Alteration Permit
November 9, 1998
Page 2
MITIGATION
Wetland ordinances require that wetland impacts must be mitigated at a ratio of 2: 1, that is, for
every acre of wetland filled or destroyed, two acres of new wetland must be created to
compensate for the loss. The first acre, or first unit of wetland replacement is called the NWC or
new wetland credit. The second acre or unit created is called PVC, or public value credit. While
NWC must be a new wetland or NWC from a wetland bank, PVC may be new wetlands, restored
wetlands, increased buffer areas a percentage of storm water ponds or any combination.
The applicant has submitted a mitigation plan to compensate for wetland impacts in two areas.
First, a replacement wetland area of 0.14 acres will be created to compensate for the wetland
loses. This mitigation area is located within the park (see mitigation site photo). This mitigation
fulfills the NWC portion of their mitigation requirement. The PVC of this project is proposed to
be a vegetativelbuffer restoration near the public access landing. (see mitigation photo) This
vegetative restoration will be in conjunction with a larger restoration project to fulfill the
MnDNR's mitigation requirement for impacts this project has below the OHW. This restoration
plan will replace a large area of reed canary grass to establish a more desirable native vegetation
which is designed promote wildlife and water quality.
RECOMMENDATION
Staff recommends that the Planning Commission recommend the City Council approve Wetland
Alteration Permit #98-4 to allow a larger beach area for Lake Minnewashta Regional Park. The
applicant has provided an innovative mitigation plan and has retained competent professionals to
implement the plan. Approval is subject to the following conditions:
1. All areas disturbed as a result of construction activities shall be immediately restored with seed and
disc-mulched or wood-fiber blanket or sod within two weeks of completion of each activity in
accordance with the City's Best Management Practice Handbook.
2. The applicant will meet wetland rules and regulations as stated in Corps of Engineers section 404
permit, the State Wetland Conservation Act, and the City's Wetland Ordinance. Mitigation work
shall be implemented prior to or concurrent with wetland fill activity in all phases of the project.
3. -The applicant shall apply for and obtain permits from the appropriate regulatory agencies, i.e.
Minnesota Pollution Control Agency, Minnesota Department of Natural Resources, Army Corps of
Engineers and comply with their conditions of approval.
4. The applicant will need to develop a sediment and erosion control plan in accordance with
the City's Best Management Practice Handbook and the Surface Water Management Plan
requirements for new developments. The plan shall be submitted to the city for review and
formal approval.
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Permit A lication for Lake Minnewashta Beach Ex ansion
October 26, 1998
Attachment "8"
lake Minnewashta Beach Expansion Project
Carver County Parks
The following relate to the various sections of the local - State _ Federal Application Form.
Part IV - Volume of FiJI or Excavation
The wettand area impacted by this project lies both above and below the ordina'Y high water line
(OHWL) of Lake Minnewashta. The beach expansion is approximately 200 lineal feet directly adjacent to
the existing beach area.
The area above the OHWL involves a total of 224 cubic yards of topsoil and subsoil excavation and
backfilling with sand for the new beach area. The area below the OHWL involves a total of B 15 cubic
yards of muck excavation and backfilling with sand to provide a sandblanket in fhe main swimming area.
No changes 10 existing grades lines and elevalions are anticipated due to this work once the sand is
placed in lieu of excavated material. Attachments" N, "A-1", "A-2" and "C" illustrate Ihe areas impacted
by the beach expansion.
Part V - Work Description
The project focuses on expanding the existing beach at Lake Minnewashta Regional Park by
approximately 200 lineal feet to meet anlicipated future demand. Drawings are attached (Attachment
"e") that detail the construction of the beach expansion.
Mitigation for impacts to wetland areas fall under two plans: 1) mitigation for impacted areas below the
OHWL and 2) mitigalion for areas above the OHWL. The repOri entitled "Mitigation Report for
Mlnnewashte Beach Expansion" attached to this exhibit provides discussion on the mitigation plans
proposed for this project. The following provides a brief overview of these two plans:
· For impacted areas below the OHWl (0.65 acres of wetland vegetation), the plan calls for
restoration of 1.5 acres of poor quality wetlands within the park. This strategy was discussed in the
tield with representatives from the Minnesota Deparimenl of Natural Resources during the summer
of 1998.
· For impacted areas above the OHWl (0.14 acres between the OHWl and the wetland delineation
line), the plan calls for mitigation by creating a new wetland within the park.
Attachments "A', "A-1", and "A-2" graphically illustrate the impacted areas as they relate to the existing
beach.
The actual construction of Ihe beach expansion will involve mucking and excavation above and below
the water to an anticipated depth of 12". These excavations will be backfilled with sand to fa,," a sand
blanket above and below the OHWL. Attachment "C" provides the construction documents for this work.
It Is anticipated that the mucking and excavation will be completed by a backhoe or dragllne. Erosion
control measures will be undertaken as defined on Ihe plans. This includes erosion control fencing and a
floaling silt curtain. The contractor will be responsible for maintaining Ihe erosion control measures for
the duration of the projecl. Other erosion control measures would be taken if requested by pe,,"itting
agencies.
Attachment "C" also provides Supportive exhibits Ihat detine Ihe project and associated wetland impacts.
Carver County Parks
Permit Application for Lake Minnewashta Beach Expansion
October 26, 1998
Part VI - Project Purpose
The request to expand the Lake Minnewashta Regional Park is based on three primary factors:
· Increase In User Demand
· Future Population Growth
· Comparison With Similar Park Beach Facilities
.
Increase In user Demand
The beach count records from 1987 to present show a large increase in the number of people attending
the beach area. Lake Minnewashta Park had approximately 3,107 user visits in 1987. In 1998 the user
count numbers had increase to 11, 002 or a 354 percent increase in people using the beach facility.
(See Attached Bar Graph)
Another change in demand is the user type. While most of our visits are family type outings, Lake
Minnewashta has experienced large group activities associated with daycare centers, church groups and
other organizations. Routinely organizations request space for groups of children ranging in numbers
from 50 to 150 children. Accommodating space for traditional users as well as larger groups has become
a challenge at the beach area.
The frequency that the number of users at the beach has reached between 100 and 400 users at a time
continues to increase. It is during these times that providing space in terms of safety and user enjoyment
that the need to expand the beach area is evident. In 1987 only four times were recorded that the beach
use exceeded 1 OOpersons at a time. The 1998 beach count information recorded 47 different occasions
that 100 or more people were at the beach at a given time.
Future Population Growth
CaNer County is expected to increase its population from approximately 60,000 people today to over
100,000 by the year 2020. The additional growth will place more demand on beach facilities. It is
projected that the majority of growth in the CaNer County will occur in the eastern portion of the county.
Lake Minnewashta seNes the eastern area of CaNer County. The County is not aware of any new
facilities being planned that might help to satisfy user demand. (See Attached Demographic Chart)
Comparison with similar park and beach facilities
The beach at Lake Minnewashta is 200 lineal feet in size and comprises of approximately 10,000 square
feet of beach area. Listed below are the sizes of other regional type park beaches.
Regional Park Length of beach Size of beach area
Lake Rebecca Regional Park 400 lineal feet 24,000 square feet
Fish Lake Regional Park 550 lineal feet 41,250 square feet
French Regional Park 500 Lineal feet 50,000 square feet
Bryant Lake Regional Park 450 Lineal feet 45,000 square feet
Lake Independence 2,500 lineal feet 250,000 square feet
Lebanon Hill Regional Park 300 lineal feet not available
Lake George Regional Park 300 lineal feet 15,000 square feet
Square Lake Regional Park 900 lineal feet 27,000 square feet
Carver County Parks
2
Permit A lication for Lake Minnewashta Beach Ex ansion
October 26. 1998
Environmental Impacts
The environmental impacts are limited, with the total impact on wetland areas above and below the
OHWL being 0.79 acres. The wetlands being impacted are highly degraded, with monocultures of reed
canary grass, cattails, and buckthorn dominating the plant life. It is anticipated that the mitigation plans
presented here will result in higher quality wetland areas than those currently exhibited along the
impacted shoreline.
Part VII - Alternates
No other practical alternative exists for expanding beach services at Lake Minnewashta Regional Park.
The existing infrastructure would support expanded use of beach type activities at the present beach
location. Support facilities of parking lots, picnic area, bathhouse/restrooms exist in the area proposed
for beach expansion. No other area within the park would serve the public as well as the proposed
location.
The Master Plan created for Lake Minnewashta Regional Park identifies the proposed beach expansion
area. Creating another beach facility within the park would be inconsistent with the approved Master
Plan and adversely effect other components of the Master Plan.
Part IX - Adjoining Property Owners
Given its location in the regional park, there are no other property owners directly adjacent to the beach I
development area. As part of the City of Chanhassen's review process, all land owners surrounding
Lake Minnewashta will be notified of a public hearing on the beach expansion project. Property owners
will be allowed to express their point of view and ask questions during the public hearing. A list of
property owners can be submitted, if requested.
Carver County Parks
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LAKE MINNEWASHTA BEACH USER COUNTS
# PEOPLE
#
PEOPLE
12000
10000
8000
6000
4000
2000
o
1987 1992 1994 1997 1998
3107 4171 7607 9533 11002
11002
1987 1992 1994 1997 1998
YEAR
MITIGATION PLAN AND IMPLEMENTATION SCHEDULE