CR 01-16 Accept Feasability Report Order Public Hearing Knollwood Pond Improvements
C\TY OF
m
HOPKINS
February 1, 2001
Council Report 2001-16
Accept Feasibility Report
Order Public Hearing
Knollwood Pond Improvements
Proposed Action.
Staff recommends adoption of the following motion: Move that Council adopt
Resolution 2001-10. Resolution Orderina Public Hearina. Knollwood stormwater
detention pond improvements. Proiect 00-14.
This action continues an assessable project for pond improvements.
Overview.
Council at its January 2,2001 meeting authorized the preparation of a feasibility study
concerning improvements to the Knollwood stormwater detention pond. The report is
complete and is now submitted to City Council for review and continued action.
Primary Issues to Consider.
. Scope of improvements
Project Schedule
Staff recommendation
Supportina information.
Analysis of Issues
Feasibility Report
Resolution 0 -10
Steven J. Stadler, Public Works Director
Financial Impact: $ 75.000 Budgeted: Y/N Y Source: Storm Sewer utilitv. SA
Related Documents (CIP, ERP, etc.):
Notes: SS Utilitv Funds: $22.500: Special Assessment: $52.500
.
Council Report 2001-16
Page 2
Analvsis of Issues
. Scope of Improvements
The proposed improvements will provide erosion control along the perimeter of the pond
and island and help control the goose population. Details of the improvements are
described and shown in the attached feasibility report
Project Schedule
Receive Report, Order Public Hearing.................. '.' ... ... ......... .Feb 6,2001
Public Hearing, Approve Plans and Order Bids... ...... ... ... ... ... .....Mar 6,2001
Accept Bids and Order Assessment Hearing...... ... ...... ............. April 3, 2001
Assessment Hearing... ... . .. .. . . .. ... ... ... ... ... ... .. . . . . ... ... ... ... .. . . .. ... . May 1, 2001
Award Contract and Construction... ........ ... ... ... ... ... ... ... ... ... ... ... May/June, 2001
Staff Recommendation
Staff recommends accepting the feasibility report and ordering a public hearing for
March 6,2001.
CITY OF HOPKINS
H nnepin County, Minne ota
RESOLUTION NO. 2001-10
RESOLUTION ORDERING PUBLIC HEARING
KNOLLWOOD POND IMPROVEMENTS
PROJECT # 00-14
WHEREAS, the City Council authorized and directed the City Engineer to
prepare a report with reference to the aforesaid improvement, and
WHEREAS, the City Engineer has caused to be prepared the aforesaid report for
improvements to the Knollwood neighborhood storm water detention pond.
NOW THEREFORE BE IT RESOLVED, by the City Council of the City of
Hopkins, Minnesota:
1. The Council will consider the aforesaid improvements in accordance with
the report and the assessment of benefiting property for all or a portion of
the cost of the pond improvements pursuant to Minnesota Statutes
Chapter 429 at an estimated total cost of $75,000.
2. A public hearing will be held in the Council Chambers of the City Hall at
1010 First Street South on Tuesday, the 6th day of March 2001, to
consider said improvements. The hearing time is 7:30 P.M.
The City Clerk shall give mailed and published notice of said hearing and improvements
as required by law.
Adopted by the City Council of the City of Hopkins this 6th Day of February 2001.
BY
Eugene J. Maxwell, Mayor
ATTEST:
Terry Obermaier, City Clerk
Feasibility Report
Knollwood Pond Improvements
City Project No. 00-14
Prepared for
City of Hopkins
January 2001
4700 West 77th Street
Minneapolis, MN 55435
Phone: (952) 832-2600
Fax: (952) 832-2601
BARR
FEASIBILITY REPORT
KNOLLWOOD POND IMPROVEMENTS
CITY PROJECT NO. 00-14
Introduction
The residents of the Knollwood neighborhood in Hopkins, along with the City of
Hopkins have determined that Knollwood pond is in need of shoreline improvements and
stabilization. Knollwood Pond is locat~d north ofT.H. 7 and east of Oak Ridge Road.
The pond is encircled by V alley Way, Park Terrace, and Bridle Lane. The city, in 1992,
completed a street and utility project in the area, City Project #90-01.
Background
Knollwood pond is a stormwater detention pond that receives surface runoff from
approximately 22 acres of the Knollwood neighborhood. The existing banks of the pond
are steep and are experiencing erosion control problems. Existing grouted rip-rap that
was installed around storm sewer inlets and outfalls and along portions of the pond
perimeter is failing and not providing bank protection due to its poor condition. The
center island is also experiencing erosion problems along its banks, especially adjacent to
the foot bridge. During the summer months, there is a significant over population of
geese in the area. The geese have eaten the majority of the vegetation along the
shoreline. The geese have limited public use of the area and have decreased the water
quality of the pond.
Proposed Improvements
The proposed improvements are presented in the attached figures. These improvements
will provide 1) erosion control along the perimeter of the pond and island and 2) a
proposal to control the goose problem.
The grouted rip-rap at the existing stOllI! sewer inlets and along the pond banks will be
removed. All inlets will have a geotextile filter fabric and 12 to 18 inches of Class II 6 to
12 inch diameter rip-rap installed. The banks adjacent to the inlets will be re-graded to a
maximum slope of 2: 1. The rip-rap along approximately 100 feet of the northeast bank
will also be replaced with a geotextile filter fabric and 12 to 18 inches of rip-rap. Where
necessary, sediment at the storm sewer outfall( s) will be removed.
F or the areas of the pond perimeter which do not have rip-rap or sod on the banks, it is
proposed that a three to five foot buffer strip consisting of tall grass and wildflower be
planted to restore these areas and deter geese from occupying the banks. The remaining
area between the buffer strip and the road will be sodded.
The island banks adjacent to the foot bridge are to be re-graded to a flatter slope. New
shrubs are to be planted on the west side of the bridge. Class II rip-rap with a geotextile
#223149 vI - Knollwood Pond Feasibility Report
filter fabric will be placed for a distance of approximately 20 feet along the east side of
the bridge. The remainder of the island perimeter will be restored with a buffer strip to
serve as a geese deterrent. The interior of the island is to be sodded.
Agency Review
This project will be submitted to the Minnehaha Creek Watershed District, Minnesota
Department of Natural Resources, and the U.S. Army Corps of Engineers for review,
comment, and approval of permits. The documentation will be submitted to these
agencies by February 1, 2001 and it is 3;nticipated that the review process will be
completed within 60 to 90 days.
Proposed Funding
It is proposed that the Knollwood pond project be assessed, wherein 70% of the cost is
assessed to the Knollwood neighborhood, and 30% to be funded as a City cost. It is
further proposed that the City's portion of the costs be paid entirely from the storm sewer
utility fund.
It has been determined that the fairest method to assess this project is on a unit
assessment basis, where each Knollwood neighborhood property is assessed equally.
Project Costs
Construction Costs
Engineering Costs (including field inspection
$60,000
$15,000
$75,000
Total Project Costs
Proposed Funding
70% of Total project cost per Knollwood neighborhood
$52,500
$22,500
30% of Total project cost per City
Recommendations
The proposed improvements will improve both the aesthetics and the function of the
pond. The improvements will provide bank stability which will help improve the water
quality of the pond, protect the stability of the adjacent public streets, and deter geese
from using the area. The project is cost effective because it will reduce future
maintenance and repair of the pond and adj acent roads.
#223149 vI - Knollwood Pond Feasibility Report
It is recommended that the City Council accepts the project engineer's feasibility report
as outlined herein, and order the improvements made, subsequent to holding a public
hearing. Addended to the end of this report is a summary of the estimated construction
costs and a preliminary proj ect schedule for the City Council's consideration.
Respectfully submitted,
#223149 vI - Knollwood Pond Feasibility Report
Preliminary Project Schedule
Knollwood Pond Improvements
City Project Number 00-14
Council Accept Petition, Order Feasibility Report
Receive Report, Order Public Hearing.
Public Hearing, Order Improvements, Approve Design, Order Bids
City Council Accepts, Order Assessment Hearing
Assessment Hearing, Award Contract
Construction
#223149 vI - Knollwood Pond Feasibility Report
January 2, 2001
February 6, 2001
March 6, 2001
April 3, 2001
May 1,2001
June/July, 2001
Knollwood Pond Slope Stabilization
Estimate for City's Work
Engineer's Estimate
Estimated
Area Description Length Width Depth Unit Quantity Unit Price Extension
(ft) (ft) (ft)
1 Remove and Haul Existing Grouted Rip-Rap 100 5 1 CY 19 20.00 370.37
Install 100' 12"-18" Class II Rip-Rap with Geotextile Fabric 100 9 1.5 CY 50 40.00 2,000.00
2 Install 12"-18" Class II Rip-Rap with Geotextile Fabric around inlet 10 4 1.5 CY 2 40.00 88.89
3 Clean Outlet Each 1 500.00 500.00
4 Install 12"-18" Class II Rip-Rap with Geotextile Fabric around inlet 10 2 1.5 CY 1 40.00 44.44
6" Topsoil 19 10 0.5 CY 4 10.00 35.19
b) Sod 19 10 SY 21 4.00 84.44
5 Remove and Haul Existing Grouted Rip-Rap 15 6 1 CY 3 20.00 66.67
Install 12"-18" Class II Rip-Rap with Geotextile Fabric around inlet 10 7 1.5 CY 4 40.00 155.56
6" Topsoil 10 6 0.5 CY 1 10.00 11.11
b) Sod 10 6 SY 7 4.00 26.67
8 Install 12".18" Class II Rip-Rap with Geotextile Fabric around inlet 10 4 1.5 CY 2 40.00 88.89
Plant Tall Grass - seed Acre 0.01 2,000.00 13.09
Straw Fiber Blanket for Tall Grass SY 32 2.50 79.17
Plugs. 9" o.c. Each 321 2.00 641.45
6" Topsoil \ CY 7 10.00 74.07
b) Sod SY 44 4.00 177.78
Regrade Slope - 2 days LS 1 2,400.00 2,400.00
Total 6,857.78
Knollwood Pond Slope Stabilization
Estimate for Total Work Opti n SA
Engineer's Estimate
Estimated
Area Description length Width Depth Unit Quantity Unit Price Extension
(ft) (ft) (ft)
Estimate for City Funded Portion - 1B (sod) 6,857.78
2 Plant Tall Grass - seed 200 4 Acre 0.02 2,000.00 36.73
Plugs, 9" o.C. 200 4 Each 712 2.00 1,424.00
Straw Fiber Blanket for Tall Grass 200 4 SY 88.89 2.50 222.22
6" topsoil for grass seed CY 48 10.00 483.33
b) Sod SY 290 4.00 1,160.00
6 Plugs, 9" 0 c. 50 4 Each 178 2.00 356.00
Tall grass seed 50 4 Acre 0.005 2,000.00 9.18
Straw Fiber Blanket for Tall Grass 50 4 SY 22 2.50 55.56
6" Topsoil 50 8 0.50 CY 7.41 10.00 74.07
b) Sod 50 4 SY 22 4.00 88.89
7 Plugs, 9" o.C. 45 4 Each 160 2.00 320.00
Tall grass seed 45 4 Acre 0.006 2,000.00 12.26
Straw Fiber Blanket for Tall Grass 45 4 SY 20 2.50 50.00
Install 12"-18" Class II Rip-Rap with Geotextile Fabric 10 7 1.5 CY 4 40.00 155.56
6" Topsoil 45 8 0.5 CY 8 10.00 76.67
b) Sod 45 4 SY 20 4.00 80.00
9A Regrade Slope lS 1 300.00 300.00
6" Topsoil 0.5 CY 3 10.00 25.93
Fill Material CY 4 15.00 60.00
Tall grass seed Acre 0.003 2,000.00 6.43
Install 12"-18" Class II Rip-Rap with Geotextile Fabric 20 7 1.5 CY 8 40.00 311.11
9B Regrade Slope lS 1 300.00 300.00
and Plant Shrubs, 4' o.C. 80 4 Each 29 20.00 580.00
Fill Material CY 6 15.00 90.00
4" Shredded Hardwood Mulch 80 4 0.33 CY 4 40.00 160.00
Erosion Control Netting 80 4 SY 36 2.50 90.00
9C Seed and Mulch 80 4 Acre 0.01 2,000.00 14.69
Fill Material CY 6 15.00 90.00
6" Topsoil 80 4 0.5 CY 6 10.00 59.26
I Buffer Strip
Tall grass seed 750 4 Acre 0.069 2,000.00 137.74
Straw Fiber Blanket for Tall Grass 750 4 SY 333 2.50 833.33
Plugs, 9" o.C. 750 4 Each 2,666 2.00 5,332.00
6" topsoil for grass 0.5 CY 243 10.00 2,433.33
b) Sod SY 1,460 4.00 5,840.00
II Island Buffer Strip
Tall grass seed 390 4 Acre 0.036 2,000.00 71.63
Straw Fiber Blanket for Tall Grass 390 4 SY 173 2.50 433.33
Plugs, 9" o.C. 390 4 Each 1,386 2.00 2,772.00
6" topsoil for grass 0.5 CY 193.33 10.00 1,933.33
Coconut "Biolog" IF 470.00 20.00 9,400.00
b) Sod SY 1,160 4.00 4,640.00
Silt Fence 1345 2 l.F. 2,690 2.50 6,725.00
subtotal 54,101.37
Mobilzation/Demobilization 5% 2,705.07
Total 56,806.44
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