OAK MARSH PHASE II FEASIBILITY REPORT CITY OF MANKATO MINNEOSTA. January 20, 2015 Project No

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1 PHASE II FEASIBILITY REPORT CITY MINNEOSTA January 20, 20 Project No. 14

2 I. INTRODUCTION Oak Marsh Phase II is a residential development on a parcel of land located in the Southern portion of the City of Mankato, west of Pohl Road, south of Stadium Road, and north of Timberwolf Drive. The proposed development will consist of 35 single family residential lots, extend one city street, and utilize the City s utility infrastructure to serve the proposed development. The developer proposes to develop and construct this project utilizing public funding. The following report discusses, among other topics, the nature and extent of the proposed improvements, potential environmental impacts, and potential construction difficulties. The preliminary plans are attached to this report in Appendix A. II. EXISTING CONDITIONS The proposed property is currently undeveloped and located south of previously developed residential lots and north of an existing multifamily development. The proposed development will consist of 35 single family residential lots. The City of Mankato presently operates and maintains a potable water distribution system, and wastewater and stormwater collection systems along Pohl Road at the intersection of Pohl Road and Timberwolf Drive. This infrastructure is currently stubbed into the property and will be utilized to serve the proposed development. III. STREET IMPROVEMENTS It is proposed that Oak Marsh Drive will be extended from its current termination location south and east to Pohl Road. The new street will be constructed with a 50foot right of way and a 32foot wide driving surface of bituminous pavement with curb and gutter. The proposed typical street sections for bituminous streets are provided in Appendix A. The proposed sections will provide the development with a 7ton minimum road design to accommodate traffic associated with a residential development. The proposed new street will be constructed to meet City of Mankato standards. IV. SITE GRADING The area to the north was previously developed into residential lots; therefore, the grading of the proposed new residential lots will correspond with the grading of the previously developed area. Erosion control measures will be implemented during construction of the project. A Stormwater Pollution Prevention Plan (SWPPP) will be completed which meets current MPCA requirements for erosion control V. SANITARY SEWER IMPROVEMENTS A proposed 8inch sanitary main will be installed and connected to the existing sanitary sewer stub present within Oak Marsh Drive and extend a short distance south to an existing utility easement. A proposed 8inch sanitary main will also be installed and constructed to run south and east from the existing utility easement and connect into the existing sanitary stub provided from Pohl Road. Manholes will be utilized to serve the new main line connections. In addition to the installation of new sanitary main lines, a proposed 4inch sanitary line will be installed at each stubbed connection to serve all 35 of the single family lots within the proposed new development. 14 Oak Marsh Phase II Feasibility Report 1

3 VI. WATERMAIN IMPROVEMENTS A proposed 8inch watermain will be installed in Oak Marsh Drive and loop through the development via the existing watermain stub and connect to an existing stub provided within Pohl Road. Hydrants will also be installed throughout the development to adequately serve all 35 single family lots. A 1inch service connection will be provided to each single family lot via the proposed new 8 inch watermain. The utility layout is included in Appendix A as part of the preliminary plans along with corresponding utility easements. VII. STORM DRAINAGE IMPROVEMENTS A storm drainage system will be constructed under the proposed city street which will convey a majority of the drainage to the existing storm sewer that was previously constructed to serve the Phase I of the Oak Marsh Drive development. The storm drainage is treated in an existing stormwater pond located west of the proposed development before it outlets to the storm sewer located within Timberwolf Drive. Catch basins will be connected to the proposed storm lines to drain designated low points within the street. VIII. STORMWATER MANAGEMENT Stormwater management was previously established with the construction of two stormwater ponds to serve Phase I of the Oak Marsh development. The north pond serves as the primary treatment for Oak Marsh Phase I drainage which is then directed to the west pond. The west pond will serve as the primary drainage and treatment infrastructure for the proposed area included within Phase II of the development. Both ponds are connected to storm sewer and ultimately outlet via the existing storm sewer located within Timberwolf Drive. Although the ponds were designed prior to the most current MPCA stormwater management requirements, the west basin still meets the requirements for the proposed development. IX. COST ESTIMATE The estimated cost of the improvement is projected to be $1,060, A breakdown of the preliminary cost estimates are provided in Appendix B. The project will be publically funded and all project costs will be assessed to the developer. X. SCHEDULE The following is a possible schedule for the proposed Oak Marsh Phase II development. 01/26/20 Determination of Sufficiency of Petition (Council Meeting) 02/09/20 Ad for Bids 02/09/20 Project Feasibility/Assessment Hearing (Council Meeting) 03/13/20 Open Bids 03/23/20 Award Bids (Council Meeting) 04//20 Begin Construction 07/03/20 Final Completion 14 Oak Marsh Phase II Feasibility Report 2

4 XI. RECOMMENDATIONS To properly service the proposed development, the proposed improvements are necessary, cost effective, and feasible. This can best be accomplished through soliciting competitive bids for the work. It is recommended that the council accept this project feasibility report and schedule a preliminary assessment hearing for the proposed improvements. I hereby certify that this plan, specification, or report was prepared by me or under my direct supervision and that I am a duly licensed Professional Engineer under the laws of the State of Minnesota. Charles J. Brandel, PE Date: January 20, 20 Reg. No Oak Marsh Phase II Feasibility Report 3

5 Appendix A: Preliminary Plans 14 Oak Marsh Phase II Feasibility Report Appendix A

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7 BIOROLL MULCH LOG N.T.S NOTES: PREASSEMBLED SILT FENCE N.T.S NO. SCHEDDETAIL CLIENT NO. WOOD MULCH BERM N.T.S CONCRETE WASHOUT AREA N.T.S ESTIMATED QUANTITIES & STANDARD PLATES 2

8 NO. SCHEDDETAIL CLIENT NO. UTILITY SCHEDULES 3

9 POHL ROAD N.T.S. DRIVE NO. SCHEDDETAIL CLIENT NO. TYPICAL STREET SECTION 1"=10' 4

10 NO. UTILITY CLIENT NO. EXISTING SITE & REMOVAL PLAN B.M. ELEVATION=

11 NO. GRADING CLIENT NO. GRADING PLAN B.M. ELEVATION=

12 NO. SCHEDDETAIL CLIENT NO. GRADING DETAILS 7

13 SWPPP QUANTITIES B.M. ELEVATION= NO. SWPPP CLIENT NO. STORM WATER POLLUTION PREVENTION PLAN 8

14 NO. SWPPP CLIENT NO. STORM WATER POLLUTION PREVENTION NOTES 9

15 NO. UTILITY CLIENT NO. OVERALL UTILITY PLAN B.M. ELEVATION=

16 NO. UTILITY CLIENT NO. HYDRANT COVERAGE PLAN B.M. ELEVATION=

17 1 PARK BLOCK 4 BLOCK 3 BLOCK 2 B.M. ELEVATION= NO. PRILES CLIENT NO. DRIVE PLAN & PRILE 12

18 BLOCK 1 14 BLOCK B.M. ELEVATION= NO. PRILES CLIENT NO. DRIVE PLAN & PRILE 13

19 B.M. ELEVATION= BLOCK 1 BLOCK NO. PRILES CLIENT NO. DRIVE PLAN & PRILE 14

20 1 BLOCK 1 BLOCK B.M. ELEVATION= NO. PRILES CLIENT NO. DRIVE PLAN & PRILE

21 Appendix B: Cost Estimates Cougar Estates East Feasibility Report Appendix B

22 Cost Estimate January 20th, 20 ITEM NO. DESCRIPTION UNITS QUANTITY UNIT PRICE AMOUNT STREETS, GENERAL & GRADING MOBILIZATION (5%) LS 1 $ 39, $ 39, CLEARING AND GRUBBING LS 1 $ 2, $ 2, REMOVE EXISTING CONCRETE CURB LF 82 $ 4.00 $ REMOVE EXISTING CONCRETE AND BIT SY 198 $ $ 1, SAWCUT BITUMINOUS OR CONCRETE PAVEMENT LF 172 $ 4.00 $ TOPSOIL STRIP (EV) CY 6,6 $ 8.00 $ 49, COMMON EXCAVATION (EV) CY 185 $ 8.50 $ 1, COMMON BORROW (CV) CY 4,432 $ 8.50 $ 37, " SUBGRADE PREPARATION (CV) (P) STA 17 $ $ 3, " AGGREGATE BASE, CL. 3 (CV) CY 1,125 $ $ 23, " AGGREGATE BASE, CL. 5 (CV) CY 1,500 $ $ 42, TYPE SP 12.5 WEARING COURSE MIXTURE (2,C), 1.5" THICKNESS (P) (PUBLIC) SY 5,512 $ $ 71, TYPE SP 19 NONWEARING COURSE MIXTURE (2,B), 2.5" THICKNESS (P) (PUBLIC) SY 5,512 $ $ 77, GEOTEXTILE FILTER, MNDOT TYPE V SY 6,752 $ 1.50 $ 10, ' CONCRETE WALK W/ 4" CL. 5 AGGREGATE BASE SF 8380 $ 5.00 $ 41, CONCRETE CURB & GUTTER, S418 LF 3353 $ $ 46, 'x2' TRUNCATED DOME DETECTABLE WARNING PANELS SF 16 $ $ SIGNAGE LS 1 $ 3, $ 3, STREETS SUBTOTAL $ 454, STORM SEWER / TREATMENT GRANULAR PIPE FOUNDATION CY 500 $ $ 17, " PERF PVC LF 3263 $ 8.00 $ 26, " PVC CLEANOUT EA 4 $ $ " PVC SUBDRAIN STUB LF 341 $ 8.00 $ 2, " PVC CAP EA 33 $.00 $ " HDPE STORM SEWER PIPE LF 136 $ $ 2, " HDPE STORM SEWER PIPE LF 166 $ $ 3, " RCP STORM SEWER PIPE LF 210 $ $ 5, " RCP STORM SEWER PIPE LF 338 $ $ 10, " RCP STORM SEWER PIPE LF 439 $ $ 14, CONSTRUCT DRAINAGE STRUCTURE TYPE 3 CATCH BASIN LF 40 $ $ 14, CONSTRUCT DRAINAGE STRUCTURE MnDOT DESIGN LF 40 $ $ 12, CONSTRUCT DRAINAGE STRUCTURE MnDOT DESIGN G LF 5 $ $ 1, CONSTRUCT 10" INLINE DRAIN LF 4 $ $ CONSTRUCT " INLINE DRAIN LF 3 $ $ NEENAH R1733 CASTING EA 5 $ $ 3, NEENAH R3067 CASTING EA 10 $ $ 6, NYLOPLAST 10" CASTING STANDARD EA 1 $ $ NYLOPLAST " CASTING STANDARD EA 1 $ $ CONNECT TO INPLACE STORM EA 2 $ $ 1, STORM SEWER / TREATMENT SUBTOTAL $ 123, SANITARY SEWER GRANULAR PIPE FOUNDATION CY 500 $ $ 10, CONNECT TO INPLACE SANITARY STUB EA 2 $ $ "x4" PVC WYE, HEAVY WALL EA 32 $ $ 4, " PVC CAP EA 32 $ $ " PVC SEWER, SDR 35 LF 1465 $ $ 32, " PVC SANITARY SERVICE LF 1241 $ $ 22, NEENAH CASTING, R W/HEAVY LID & CONCEALED PICK HOLES EA 9 $ $ 6, CHIMNEY SEALS EA 9 $ $ 2, CONSTRUCT MANHOLE, DSGN 4007C w/mech JOINT LF 109 $ $ 27, SANITARY SEWER SUBTOTAL $ 106, WATERMAIN GRANULAR PIPE FOUNDATION CY 500 $ $ 10, CONNECT TO INPLACE WATERMAIN EA 2 $ $ 1, " WATERMAIN LF 1688 $ $ 38, " WATERMAIN LF 61 $ $ 1, " GATE VALVE & BOX EA 1 $ 1, $ 1, WATERMAIN FITTINGS LBS 805 $ 6.00 $ 4, HYDRANT EA 4 $ 2, $ 10, " GATE VALVE & BOX EA 4 $ 1, $ 5, " WATER SERVICE LF 1184 $ $ 21, " CORPORATION STOP EA 32 $ 5.00 $ 4, " CURB STOP & BOX EA 32 $ $ 5, " POLYSTYRENE INSULATION LF 24 $ $ WATERMAIN SUBTOTAL $ 106, EROSION CONTROL AND BOULEVARD TREES SILT FENCE, TYPE MACHINE SLICED LF 3009 $ 1.50 $ 4, TEMPORARY ROCK CONSTRUCTION ENTRANCE EA 2 $ $ 1, STORM DRAIN INLET PROTECTION EA 16 $ 0.00 $ 2, SOD SY 3550 $ 4.50 $, BOULEVARD TREES EA 68.0 $ $, EROSION CONTROL SUBTOTAL $ 39, SUBTOTAL $ 831, % CONTINGENCY $ 83, % ADDITIVE TOTAL ESTIMATED COST $ 146, $ 1,060,428.31