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VII.1. Resolution Ordering Public Improvement Hearing Central Avenues Improvements, City Project 2024-10; Klingbeil CITY OF HOPKINS City Council Report 2024-131 To: Honorable Mayor and Council Members Mike Mornson, City Manager From: Eric Klingbeil, PE, City Engineer Date: October 15, 2024 Subject: Order Public Improvement Hearing – Central Avenues Improvements, City Project 2024-10 _____________________________________________________________________ RECOMMENDED ACTION MOTION TO adopt Resolution 2024-063, Resolution Ordering Public Improvement Hearing, Central Avenues Improvements OVERVIEW At its September 3, 2024 meeting the Central Avenues Phase 2 Scoping Study Report, ordered by Council at the April 16, 2024 City Council Meeting, was presented At its September 10, 2024 meeting, a feasibility report concerning street and utility improvements along 9th Avenue N from 1st Street N to 3rd Street N, 10th Avenue N from 1st Street N to 4th Street N, 11th Avenue N from 1st Street N to Minnetonka Mills Road, 12th Avenue N from 1st Street N to Minnetonka Mills Road, 13th Avenue N from the regional trail N to Minnetonka Mills Road, 2nd Street N from 8th Avenue N to 12th Avenue N, 3rd Street N from 9th Avenue N to 15th Avenue N, and 4th Street N from 9th Avenue N to 10th Avenue N and 11th Avenue N to 12th Avenue N ordered by the City Council. This report is now complete. In accordance with state statutes, the City Council needs to conduct a public hearing and authorize final design to continue the project process. SUPPORTING INFORMATION Feasibility Report, select pages – full report available upon request Resolution 2024-063 ANALYSIS OF ISSUES Scope of Improvements This project includes the following improvements: Full reconstruction of the following streets: o 9th Avenue N from 1st Street N to 3rd Street N o 10th Avenue N from 1st Street N to 4th Street N o 11th Avenue N from 1st Street N to Minnetonka Mills Road o 12th Avenue N from 1st Street to Highway 7 o 13th Avenue N from Maetzold Field to South Service Drive Public Works Dept. o 3rd Street N from 9th Avenue N to 11th Avenue N o 4th Street N from 9th Avenue N to 10th Avenue N o 4th Street N from 11th Avenue N to 12th Avenue N Reclamation and resurfacing of the following Streets: o 3rd Street N from 11th Avenue N to 15th Avenue N Mill and Overlay of the following streets: o 2nd Street N from 8th Avenue N to 12th Avenue N The pavement condition index for most of the project area is below 40, which indicates failed pavement and warrants reconstruction. Maintenance procedures such as seal coating, mill and overlay, or reclamation are no longer effective strategies. Proposed street improvements include full reconstruction of streets and new curb and gutter. Water main is proposed to be replaced in the entire reconstruction area. Most of the existing main is in excess of 60 years old, undersized, and made from cast iron. New main will be ductile iron, which has better reliability and when properly installed a longer lifecycle than cast iron. All water services will be replaced from the main to the property line. Sanitary sewer improvements consist of replacing old and outdated material mains. The existing sanitary sewer mains are in excess of 60 years old and are made of an outdated material, clay. Proposed storm sewer improvements include new curb and gutter, removal and replacement of the existing storm sewer mains, upsizing mains in select areas to better handle larger storm events, and addition of storm sewer inlets to reduce water ponding in the street. Pedestrian and Bicycle facilities include: Replacement of existing sidewalk and pedestrian ramps in the reconstruction area Improved pedestrian crossings on 12th Avenue N Improved regional trail crossings at 10th, 11th, and 12th Avenues N During the scoping for this project, it was determined that there was other work that should be included in the project. Traditionally this work was bid as a separate, standalone project but in recent years it has been bid with the street and utility improvement project and the City has received very favorable bid prices as a result. This additional work will be funded by separate items in the CIP and Budget and includes the following: Sanitary Sewer Lining in areas across the City as identified by Public Works Citywide sidewalk repairs Pedestrian crossing improvements on 11th Avenue South Public Input A Public informational meetings regarding the improvements was held on October 2nd. The meeting formats consisted of a presentation of the overall project scope, with an open house style question and answer session. An additional public meeting is scheduled for November 6th with a similar format. A questionnaire was sent to all properties in the project area in spring 2024 in advance of the neighborhood meetings. Drainage concerns, pedestrian facility concerns, desire for improved street surface, and property specific concerns were the most common responses. Assessments The proposed street assessments are based on the City’s assessment policy, whereby 70% of the street reconstruction cost and 50% of the water and sewer service replacement are assessed to benefiting properties. The policy also allows for assessments to be capped should assessments exceed previous year assessments by 20%; the costs for this project will trigger the assessment cap. A preliminary assessment roll has been calculated and can be found in the appendix of the attached Feasibility Report. As with the 2023 and 2024 Street and Utility Improvement Project staff has identified properties that were assessed in previous adjacent projects to determine if the assessment cap would have been in a factor if the projects had been assessed as one project. The assessment cap for residential properties is $109.32 per front foot, following the typical 3% increase per year. Without the cap assessments could be more than double the capped rate. This cap amount is assuming starting work in 2025. Starting work at a later date will result in a higher assessment amount. Project Budget and Costs The estimate for this project which includes contingency, and costs for legal, administrative, and engineering costs for all the work, including 15% contingency, totals to $17,754,000. These costs are assuming a 2025 work start date. Starting at a later date will result in higher prices as outlined at the September 3, 2024 Council meeting. Project costs and funding sources are as follows: Funding Source CIP Budget Street Reconstruction, Rehabilitation, Additional Work Estimated Cost PI-PIR/General Obligation Bonds $7,111,000 $6,626,000 Assessments 2,092,000 2,248,000 Storm Sewer Fund 1,305,000 2,264,000 Sanitary Sewer Fund 3,316,000 3,104,000 Water Fund 3,170,000 3,512,000 Total $16,994,000 $17,754,000 As design has progressed, costs have come down as anticipated. Design modifications, value engineering, and reduced contingencies have brought the estimated cost down almost $2,000,000 from the estimated costs shown at the September 3rd City Council Meeting. It is anticipated the estimated project cost will continue to be reduced as design progresses and will be within the CIP budget. Project Schedule At previous City Council meetings, there was discussion of starting the project in 2025 or 2026. Ording a Public Improvement Hearing does not commit the project to a specific timeline. Future Council action items will be required to continue the project timeline. Per state statute, if the project is to being in 2026, an additional public hearing MAY be required depending on Council action. Public hearing/order final design November 12, 2024 Approve final plans/order bids Jan/Feb 2025 Order Assessment Hearing Feb/Mar 2024 Public Informational Neighborhood Meeting March 20245 Conduct Public Assessment Hearing April 2025 Adopt Assessment Roll/Award Contract April 2025 Begin Construction Spring 2025 Complete Construction Fall 2026 Staff Recommendation Staff recommends ordering the Public Improvement Hearing with adoption of Resolution 2024-063. CITY OF HOPKINS HENNEPIN COUNTY, MINNESOTA RESOLUTION 2024-063 RESOLUTION ORDERING PUBLIC IMPROVEMENT HEARING FOR CENTRAL AVENUES IMPROVEMENTS CITY PROJECT 2024-10 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 on 9th Avenue N from 1st Street N to 3rd Street N, 10th Avenue N from 1st Street N to 4th Street N, 11th Avenue N from 1st Street N to Minnetonka Mills Road, 12th Avenue N from 1st Street N to Minnetonka Mills Road, 13th Avenue N from the regional trail N to Minnetonka Mills Road, 2nd Street N from 8th Avenue N to 12th Avenue N, 3rd Street N from 9th Avenue N to 15th Avenue N, and 4th Street N from 9th Avenue N to 10th Avenue N and 11th Avenue N to 12th Avenue N; and WHEREAS, the report provides information regarding whether the proposed improvement is necessary, cost-effective, and feasible; whether it should best be made as proposed or in connection with some other improvement; the estimated cost of the improvement as recommended; and a description of the methodology used to calculate individual assessments for affected parcels, NOW THEREFORE, BE IT RESOLVED, that the City Council of the City of Hopkins will consider the improvement of such streets and utilities in accordance with the report and the assessment of benefitting properties for all or a portion of the cost of the improvement pursuant to Minnesota Statues Chapter 429 at an estimated total cost of $17,754,000 and that a public hearing shall be held on such proposed improvement on Tuesday, the 12th day of November in the Council Chambers at 1010 1st Street South at 6:30 P.M. and the City Clerk shall give mailed and published notice of said hearing and improvements as required by law. Adopted by the City Council this 15th day of October, 2024. _________________________ Patrick Hanlon, Mayor __________________________ Amy Domeier, City Clerk H:\HOPK\24X134763000\2_Preliminary\C_Reports\Feasibility\Central Avenues Phase 2 Feasibility Cover Letter.docx October 8, 2024 Honorable Mayor and City Council City of Hopkins 1010 1st St S Hopkins, MN 55343 RE: Central Avenues Improvements Phase 2 – Feasibility Report City Project No. 2024-10 BMI Project No. 24X.134763.000 Mayor and Council Members: In accordance with your direction, the following Feasibility Report has been prepared for the Central Avenues Improvements Phase 2 project. This report is an extension of the Project Scoping Study Report completed this past summer. As a part of the feasibility study, the various public utilities, pedestrian facilities, and associated impacts of improvement have been reviewed. Necessary improvements have then been recommended where appropriate. Estimated project costs and preliminary assessments have been calculated and included with these findings. During the process of studying the existing conditions within the project areas, meetings were held, and input was received from area residents, City staff, and permitting partners. We would like to acknowledge the cooperation and information received and thank all parties for their support in helping us better understand the problems and concerns within the project area. Respectfully submitted, Bolton & Menk, Inc. Nicholas J. Amatuccio, P.E. Senior Associate Project Manager Submitted by: Nicholas J. Amatuccio, P.E. Senior Associate Project Manager nicholas.amatuccio@bolton-menk.com Bolton & Menk, Inc. 12224 Nicollet Avenue Burnsville, MN 55337 P: 952-890-0509 Central Avenues Improvements Phase 2 Feasibility Report City of Hopkins City Project No. 2024-10 BMI Project No. 24X.134763.000 Prepared by: Bolton & Menk, Inc. Certification Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Certification Feasibility Report for Central Avenues Improvements Phase 2 City of Hopkins October 2024 PROFESSIONAL ENGINEER 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. Signature: Typed or Printed Name: Nicholas J. Amatuccio, PE Date: 10/8/2024 License Number: 53639 Prepared by: Bolton & Menk, Inc. Table of Contents Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Table of Contents I. Executive Summary .............................................................................................................................. 1 Background Information ............................................................................................................... 1 Proposed Improvements .............................................................................................................. 1 Estimated Costs and Proposed Funding ....................................................................................... 2 II. Scoping Study Introduction .................................................................................................................. 3 III. Background........................................................................................................................................... 3 IV. Existing Conditions ............................................................................................................................... 4 Streets ........................................................................................................................................... 4 Storm Sewer ................................................................................................................................. 6 Sanitary Sewer .............................................................................................................................. 6 Watermain .................................................................................................................................... 7 V. Proposed Improvements ...................................................................................................................... 8 Streets ........................................................................................................................................... 8 Storm Sewer ............................................................................................................................... 11 Stormwater Management .......................................................................................................... 11 Sanitary Sewer ............................................................................................................................ 13 Watermain .................................................................................................................................. 14 Pedestrian Facilities .................................................................................................................... 15 Driveways ................................................................................................................................... 16 Lawn Irrigation Systems .............................................................................................................. 17 Street Signing and Striping ......................................................................................................... 17 Turf and Landscaping Restoration .............................................................................................. 17 Boulevard Trees .......................................................................................................................... 17 VI. Neighborhood Meetings and Public Engagement ............................................................................. 18 VII. Estimated Costs and Funding ............................................................................................................. 19 VIII. Special Assessments .......................................................................................................................... 21 IX. Right-of-Way/Easements/Permits ..................................................................................................... 22 X. Project Schedule ................................................................................................................................. 23 XI. Feasibility and Recommendation ....................................................................................................... 23 Prepared by: Bolton & Menk, Inc. Table of Contents Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Tables Table ES-1 – Estimated Cost of Proposed Central Avenues Improvements Phase 2 .................................... 2 Table 1: Summary of Existing Corridor Conditions ...................................................................................... 5 Table 2: Summary of Geotechnical Evaluation ............................................................................................ 5 Table 3: Proposed Sanitary Sewer Improvements ..................................................................................... 14 Table 4: Proposed Watermain Improvements ........................................................................................... 15 Table 5: Resident Questionnaire Response Summary ................................................................................ 19 Table 6: Estimated Cost of Proposed Central Avenues Phase 2 Improvements ........................................ 20 Appendix Appendix A: Preliminary Cost Estimates Appendix B: Figures Appendix C: Preliminary Assessment Roll Appendix D: Resident Questionnaires & Neighborhood Meetings Appendix E: Geotechnical Evaluation Prepared by: Bolton & Menk, Inc. Executive Summary Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 1 I. Executive Summary Background Information The Hopkins City Council ordered the preparation of this feasibility report at its September 10, 2024 meeting. This report is an extension of the scoping study that was completed in the Summer of 2024 to better identify the infrastructure improvements that are needed within the Central Avenues neighborhood. In general, the goal of the project is to preserve the investments Hopkins has made in its infrastructure with proper upkeep through the City’s Pavement Management Program. The feasibility report has been completed to confirm the appropriate improvements needed based on the project scoping study report, as well as the associated project costs and preliminary estimated assessments. Proposed Improvements This report examines potential street and utility construction of several streets in the Central Avenues Neighborhood in the City of Hopkins. These areas are depicted in Figure 1 of Appendix B. The proposed improvements are described in the body of this report and are graphically illustrated in Appendix B. In brief, the proposed improvements consist of: • Full reconstruction of the following street sections in the Central Avenues Neighborhood with replacement of concrete curb and gutter and concrete sidewalk, and replacement or rehabilitation of watermain, sanitary sewer, and storm sewer utilities. o 9th Ave N from 1st St N to 3rd St N o 10th Ave N from 1st St N to 4th St N o 11th Ave N from 1st St N to Minnetonka Mills Rd o 12th Ave N from 1st St N to Highway 7 o 13th Ave N from the dead-end north of Maetzold Field to South Service Dr o 3rd St N from 9th Ave N to 11th Ave N o 4th St N from 9th Ave N to 10th Ave N and from 11th Ave N to 12th Ave N • Reclamation and resurfacing of 3rd St N from 11th Ave N to 15th Ave N. • Mill and overlay of 2nd St N from 8th Ave N to 12th Ave N. Prepared by: Bolton & Menk, Inc. Executive Summary Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 2 Estimated Costs and Proposed Funding Cost estimates have been prepared to address the varying needs of all areas reviewed. Detailed cost estimates are provided in Appendix A and summarized below in Table 1. Table ES-1 – Estimated Cost of Proposed Central Avenues Improvements Phase 2 Proposed Street Improvements $5,253,000 Proposed Pedestrian Facility Improvements $1,285,000 Proposed Sanitary Sewer Improvements $2,288,000 Proposed Watermain Improvements $2,588,000 Proposed Storm Sewer Improvements $1,669,000 Construction Cost Subtotal $13,083,000 Contingencies (15%) $1,963,000 Construction Cost with Contingencies (15%) $15,046,000 Engineering & Administration (18%) $2,708,000 Total Estimated Project Costs $17,754,000 These improvements would be funded with general obligation bonds, utility funds, and assessments to individual properties. The chart below illustrates proposed funding sources inclusive of contingencies, engineering, and administration. PIR (BONDS, GENERAL TAX LEVY), $6,625,585 , 37% SPECIAL ASSESSMENTS, $2,247,496 , 13% WATER FUND, $3,512,316 , 20% SANITARY SEWER FUND, $3,104,294 , 17% STORM SEWER FUND, $2,264,431 , 13% FUNDING SOURCES Prepared by: Bolton & Menk, Inc. Scoping Study Introduction Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 3 II. Scoping Study Introduction This report examines the proposed street and utility improvements including storm sewer replacement, water main replacement, sanitary sewer replacement, and street reconstruction or resurfacing throughout the Central Avenues Neighborhood. The following streets that will be included in this study are shown on Figure 1 in Appendix B and listed below: • 9th Ave N from 1st St N to 3rd St N • 10th Ave N from 1st St N to 4th St N • 11th Ave N from 1st St N to Minnetonka Mills Rd • 12th Ave N from 1st St N to Highway 7 • 13th Ave N from the dead-end north of Maetzold Field to South Service Dr • 2nd St N from 8th Ave N to 12th Ave N • 3rd St N from 9th Ave N to 15th Ave N • 4th St N from 9th Ave N to 10th Ave N and from 11th Ave N to 12th Ave N The improvements on these streets will include some or all of the following proposed work: • Addition/replacement of storm sewer • Watermain replacement • Water service replacement • Sanitary sewer replacement • Sanitary sewer rehabilitation • Sanitary sewer service replacement • Concrete curb & gutter replacement • Bituminous street removal and reconstruction • Bituminous street resurfacing • Concrete sidewalk replacement III. Background The Central Avenues Neighborhood has been included in the City’s Capital Improvement Plan in some capacity for the several years. The Hopkins City Council ordered the preparation of this feasibility report at its September 10, 2024 meeting after the completion of the scoping study report which determined the scope and size of the project. It was also determined that this project will be constructed over two construction seasons and under one construction contract to be more efficient and cost effective with the proposed improvements. Preliminary construction phasing can be seen on Figure 1 in Appendix B, which displays how the project will be broken up into two construction seasons. Based upon direction by Council, construction for these project improvements is proposed to begin in either the Spring of 2025 or 2026. The feasibility study and report has been completed to better identify the infrastructure improvements needed within the Central Avenues neighborhood and to better define costs associated with the improvements. This report will be used as the basis for final design and is also a required step in the State’s Chapter 429 process for special assessments. Prepared by: Bolton & Menk, Inc. Existing Conditions Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 4 IV. Existing Conditions Streets The bituminous streets within the project areas are aged and exhibit various levels of wear and distress. This is evident on the surface by transverse, block, and alligator cracking. There is evidence of previous additional street repairs and maintenance throughout the project area including numerous street patches. Examples of the existing pavement conditions are shown below (pictures were taken on 12th Ave N between 1st St N and 2nd St N). Consistent with observations of the existing pavements made during preparation of this report, the City of Hopkins’ Pavement Management System also indicates that the “Pavement Condition Index” (PCI) for several streets in the neighborhood are in fair or poor condition and beyond the pavement’s life cycle. The streets within the project area have varying widths (measured curb face to curb face). Table 1 below summarizes these and other existing conditions. Parking is typically allowed on both sides of the streets throughout the neighborhood. Large, mature trees can be found throughout the project within the City’s ROW and near the back of curb. Prepared by: Bolton & Menk, Inc. Existing Conditions Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 5 Table 1: Summary of Existing Corridor Conditions Roadway Existing Street Width Existing Curb Type Existing ROW Width 9th Ave N 35 feet Concrete B618 Curb & Gutter 66 feet 10th Ave N 36 feet Concrete B618 Curb & Gutter north of the regional trail; some Curb w/ no gutter south of the regional trail 66 feet 11th Ave N 31 feet – 35 feet Concrete B618 Curb & Gutter 66 feet 12th Ave N 36 feet Concrete B618 Curb & Gutter north of the regional trail; mostly Curb w/ no gutter south of the regional trail 66 feet 13th Ave N 36 feet Concrete B618 Curb & Gutter south of 4th St N; Curb w/ no gutter north of 4th St 66 feet 2nd St N 36 feet Concrete B618 Curb & Gutter 66 feet 3rd St N 30 feet Concrete B618 Curb & Gutter west of 11th Ave N; mixture of Concrete B618 Curb & Gutter and Curb w/ no gutter between 11th Ave N and 9th Ave N 60 feet 4th St N 36 feet Curb w/ no gutter 66 feet Subgrade soil sampling was completed throughout the neighborhood by Braun Intertec in the Summer of 2024. A copy of Braun Intertec’s Geotechnical Evaluation Report is included in Appendix E of this report. Twenty-two soil borings and five pavement cores were taken throughout the area and summarized in Table 2 below. Table 2: Summary of Geotechnical Evaluation Street Bituminous Thickness Subgrade Material 9th Ave N 4 inches – 5.5 inches Mixture of silty and clayey sand 10th Ave N 4 inches – 9 inches Mixture of silty, clayey, and poorly graded sand 11th Ave N 4.5 inches – 8 inches Mixture of silty, clayey, and poorly graded sand; gravel with silt; sandy silt; and sandy lean clay 12th Ave N 4.5 inches – 6.5 inches Mixture of silty, clayey, and poorly graded sand; and sandy lean clay 13th Ave N 4 inches – 6.5 inches Mixture of silty, clayey, and poorly graded sand with silt; and lean and sandy lean clay Prepared by: Bolton & Menk, Inc. Existing Conditions Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 6 2nd St N 3.5 inches – 5.5 inches Aggregate base material 3rd St N 2 inches – 6.5 inches Mixture of silty, clayey, and poorly graded sand with silt; lean clay; sandy silt; and possible buried asphalt 4th St N 4.5 inches to 6.5 inches Mixture of silty, clayey, and poorly graded sand; and sandy lean clay The soils found just beneath pavements in the neighborhood were most commonly fill soils classified as poorly graded sand, silty sand, clayey sand, sandy silt, or lean clay. At least one of the borings in the neighborhood found slightly organic clay (buried topsoil). Buried topsoil is an undesirable material for roadway construction as it’s unable to adequately support heavy vehicles, leading to earlier failure of overlying pavements. Storm Sewer The existing storm sewer systems serving the neighborhood are mostly comprised of reinforced concrete pipe (RCP), varying in size from 12-inch diameter to 60-inch diameter, with some 12-inch diameter clay pipes as well. The storm sewer catch basins and manholes are a mixture of precast concrete and block structures. The neighborhood generally drains south through an existing 60-inch trunk storm sewer main along the alley between 11th Ave N and 10th Ave N, south of 3rd St N, then turns down 11th Ave N, west on Mainstreet over to 13th Ave S ultimately discharging to Nine Mile Creek near south of Excelsior Blvd. Some of the neighborhood drains to the east and south before turning west south of Mainstreet, but ultimately connects to the same trunk storm sewer system as the rest of the neighborhood that discharges to Nine Mile Creek south of Excelsior Blvd. Drainage issues have been identified throughout the neighborhood through evaluation of site grades and elevations by the project team and visual inspections from site visits. These drainage issues can be generalized as: 1. Due to the flat grades of some of the streets, especially from 2nd St N to 3rd St N on 9th Ave N, 10th Ave N, and 11th Ave N, localized drainage problems are prevalent. 2. There is a lack of catch basin inlets at a few of the intersections and alley entrances in the project area, and these limited catch basins can be overloaded during heavier rain events which causes ponding in the street. 3. There is a lack of gutters along several of the streets to adequately direct water through areas of flat topography to drainage inlets. 4. Many of the sidewalks throughout the neighborhood have isolated low spots and do not drain well after rain events or during snow melt. Proposed storm sewer improvements are discussed later in this report. Sanitary Sewer The existing sanitary sewer system throughout the neighborhood primarily consists of 8-inch diameter clay pipe, except for the following blocks that differ in either material or size: • 11th Ave N from 2nd St N to 3rd St N and 2nd St N from 10th Ave N to 11th Ave N consists of 12-inch diameter clay sewer pipe. Prepared by: Bolton & Menk, Inc. Existing Conditions Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 7 • 11th Ave N from 1st St N to 2nd St N consists of 15-inch diameter clay sewer pipe. o The sewer pipe on this block is also deeper than the rest of the sanitary sewer system in the neighborhood at over 20 feet in depth with tall risers off the main for each sanitary sewer service. • 2nd St N from 8th Ave N to 10th Ave N consists of 10-inch diameter clay sewer pipe. • An 8-inch PVC (plastic) sewer pipe runs up the alley between 9th Ave N and 10th Ave N from 2nd St N to 4th St N, which serves Alice Smith Elementary School and Eisenhower Elementary School across Highway 7. o While this pipe consists of newer material than the rest of the neighborhood, the pipe is in somewhat poor condition with sags, deflections, and dents in the interior of the pipe based on televising in the last 10 years. o It is also not ideal to have a sanitary sewer with a larger flow run down an alley with limited right-of-way for access, maintenance, and repairs. Clay pipe is susceptible to infiltration and root intrusion over time due to the large number of joints and the deterioration of the gasket material originally used to seal the joints. The project’s sanitary manholes are made of a mixture of brick, concrete block, and precast concrete structures. Brick and block structures were typically built around the 1950’s/1960’s or earlier, whereas precast structures indicate these structures were replaced at some point after initial construction of the other infrastructure, likely in response to some deficiency with the original structure while some were replaced as part of an adjacent reconstruction project in the past 15 years. Brick and block manholes are susceptible to infiltration over time due to cracks and deterioration of the mortared joints. Precast concrete manholes continue to be used in modern construction and are generally acceptable provided proper gaskets were provided with the initial construction and remain in good working order. Service lines in the neighborhood are typically 4-inch or 6-inch and their material may be clay, cast iron, orangeburg, transite, or PVC. Clay and orangeburg sanitary sewer pipes are highly susceptible to infiltration by groundwater, causing groundwater to be treated by the Met Council at its treatment facilities downstream at a cost to the public. The vast majority of sanitary sewer mains and service lines in the neighborhood are made of clay material. Based on observations of sewer service replacements to individual properties performed recently in nearby neighborhoods, potential exists for encountering orangeburg sewer service pipes during construction of the project. Orangeburg pipe, which can generally be described as layered tar paper wrapped in a round manner to create a pipe, was commonly installed around the time several neighborhoods in Hopkins originally developed. Orangeburg pipe is widely known to ‘rot’ where exposed to water, generally on the bottom of the pipe, and ultimately collapse as it ages and is unable to support the surrounding soil. Proposed sanitary sewer improvements are discussed later in this report. Watermain The water main throughout the neighborhood is primarily 6-inch cast iron pipe (CIP). CIP is a common watermain material, however upon reaching its useful life tends to fail. Because it is so brittle, as the soils around the pipe move slowly over decades, CIP cannot support shearing forces and ultimately breaks. These portions of the watermain system were installed in the 1950s and 1960s. CIP installed around this time period was also occasionally installed with lead-packed fittings. Prepared by: Bolton & Menk, Inc. Proposed Improvements Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 8 Service lines for single family homes in the project area are typically ¾-inch or 1-inch and their material may be copper, galvanized steel, or lead. However, lead service material (outside of fittings) have not been found on recent reconstruction projects on adjacent streets in the Central Avenues neighborhood. Proposed watermain improvements are discussed later in this report. V. Proposed Improvements Streets Several of the streets within the neighborhood have reached a point where maintenance procedures such as seal coating or milling and overlaying are no longer cost-effective strategies. In addition, the age and material of the underground sewer and water throughout the neighborhood requires that most of the streets are fully reconstructed after the replacement of these utility mains and services nearing the end of their life expectancy. The streets that would be recommended for full reconstruction include: • 9th Ave N from 1st St N to 3rd St N • 10th Ave N from 1st St N to 4th St N • 11th Ave N from 1st St N to Minnetonka Mills Rd • 12th Ave N from 1st St N to Highway 7 • 13th Ave N from the dead-end north of Maetzold Field to South Service Dr • 3rd St N from 9th Ave N to 11th Ave N • 4th St N from 9th Ave N to 10th Ave N and from 11th Ave N to 12th Ave N Proposed reconstruction improvements include replacement of concrete curb and gutter and replacement of the full depth of the pavement section with underlying aggregate base. It is also recommended to install a sand section under the aggregate base for additional roadway stability and pavement longevity. Concrete curb will be replaced per City Policy 8.02 with B618 concrete curb and gutter, which will help extend the life of the pavement by keeping water out of the subgrade and will provide a solid edge for the asphalt pavement. Some of the streets within the neighborhood, including blocks of 10th Ave N, 12th Ave N, 13th Ave N, 3rd St N, and 4th St N, do not have an existing concrete gutter, just a curb back which does not convey stormwater effectively. Existing drainage patterns will be maintained and the elevation of the existing roadways at their edge is proposed to approximate the existing elevations. Attempts at lowering the road will be made (during final design) where appropriate to improve drainage within and toward the street where beneficial and practical. Proposed street widths from face of curb to face of curb will vary from street to street throughout the neighborhood but will generally be narrowed on reconstructed streets to the City’s standard width for residential streets (28 feet wide from curb face to face) where feasible. Using a proposed street width of 28 feet will provide a consistent street width along each roadway’s length, reduce impervious area to reduce costs and stormwater management needs, and create a wider turf boulevard for healthier trees, additional snow storage, and increased pedestrian safety. The following specific improvements are proposed for each unique roadway corridor: Prepared by: Bolton & Menk, Inc. Proposed Improvements Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 9 • 9th Ave N is proposed to be reconstructed, including the replacement of concrete curb and gutter, at 28 feet wide from curb face to face. This will narrow the road by approximately 7 feet. Parking regulations will remain consistent with existing conditions throughout this area. The City and project team will continue to evaluate the proposed roadway width along 9th Ave N based on comments and feedback from residents at the first neighborhood meeting (see Appendix D). • 10th Ave N is proposed to be reconstructed, including the replacement of concrete curb and gutter, at 28 feet wide from curb face to face. This will narrow the road by approximately 8 feet. Parking regulations will remain consistent with existing conditions throughout this area. • 11th Ave N is proposed to be reconstructed, including the replacement of concrete curb and gutter, at 28 feet wide from curb face to face. This will narrow the road by approximately 3 feet on the north end of 11th Ave, and up to 7 feet near 1st St N. Parking regulations will remain consistent with existing conditions throughout this area. • 12th Ave N is proposed to be reconstructed, including the replacement of concrete curb and gutter, at 36 feet wide from curb face to face. This road is proposed to remain the same width at 36 feet due to it being a state aid route, truck route, and corridor that is used for additional parking, especially along Maetzold Field south of 2nd St N. Parking regulations will remain consistent with existing conditions throughout this area. • 13th Ave N is proposed to be reconstructed, including the replacement of concrete curb and gutter, at 28 feet wide from curb face to face. This will narrow the road by approximately 8 feet. Parking regulations will remain consistent with existing conditions throughout this area. • 3rd St N from 9th Ave N to 11th Ave N is proposed to be reconstructed, including the replacement of concrete curb and gutter, at 28 feet wide from curb face to face. This will narrow the road by approximately 2 feet. Parking regulations will be consistent with existing conditions throughout this area. • 4th St N is proposed to be reconstructed, including the replacement of concrete curb and gutter, at 34 feet wide from curb face to face. This will narrow the road by approximately 2 feet. This road is proposed to be similar to the existing street width at approximately 36 feet because the adjacent blocks along the 4th St N corridor that are outside the scope of the project are currently around 35’ wide from curb face to curb face. Narrowing 4th St N down to 28 feet wide like some of the other streets is not proposed since this would result in street width inconsistency along the corridor. Parking regulations will remain consistent with existing conditions throughout this area. The minimum proposed street grade is 0.50% consistent with City standards. Street grades flatter than 0.50% are undesirable for drainage. In some areas, new low points with adequate storm sewer will need to be created to increase roadway longitudinal slope for Prepared by: Bolton & Menk, Inc. Proposed Improvements Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 10 proper drainage. These locations will be confirmed during the final design process, but a few locations have been identified based on a review of the existing topography and site conditions including 9th Ave N, 10th Ave N, and 11th Ave N between 2nd St N and 3rd St N. Overall drainage patterns/directions throughout the project area are not proposed to change. The preliminary proposed typical pavement section for all reconstructed streets consists of 2-inches wearing course bituminous pavement, 2-inches non-wear course bituminous pavement, 8-inches aggregate base class 5, 12-inches select granular, and spot subgrade soil corrections. The exception to this pavement section is on 12th Ave N, where a 3-inch non- wear course bituminous pavement section would be proposed due to the higher traffic levels, including truck traffic. Pavement maintenance is proposed for the following streets in the project area: • 2nd St N from 8th Ave N to 12th Ave N o A 2-inch mill and overlay is recommended based on the PCI rating and a geotechnical investigation of the existing pavement conditions, confirming this to be a feasible maintenance operation for the pavement. This will extend the life of the pavement at a significantly lower cost than full reconstruction. o The existing B618 curb and gutter is in relatively good condition, requiring minimal spot concrete repairs. o The original underground sanitary sewer from 8th Ave N to 11th Ave N can be rehabilitated without excavation using a CIPP (cured in place pipe) liner since there are no confirmed sewer services to replace along the corridor. This is discussed further in the proposed sanitary sewer improvements section later in this report. o There is no watermain along 2nd St N and the storm sewer is not in need of replacement except for the catch basin inlets at the intersections, which would be reconstructed with the improvements to 9th Ave N, 10th Ave N, 11th Ave N, and 12th Ave N. • 3rd St N from 11th Ave N to 15th Ave N o Reclamation and resurfacing with 2-inches wearing course and 2-inches non- wearing course bituminous pavement is recommended based on the PCI rating and a geotechnical investigation of the existing pavement conditions, confirming this to be a feasible maintenance operation for the pavement. While the pavement is not in good enough condition for a cheaper mill and overlay operation, reclaiming the existing bituminous pavement and underlying aggregate base to pave a new bituminous pavement section overtop will extend the life of the pavement longer than a mill and overlay and still at a significantly lower cost than full reconstruction. o The existing B618 curb and gutter is in relatively good condition, requiring only spot concrete repairs. Prepared by: Bolton & Menk, Inc. Proposed Improvements Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 11 o The original underground sanitary sewer can be rehabilitated without excavation using a CIPP (cured in place pipe) liner since there are no confirmed sewer services to replace along the corridor. This is discussed further in the proposed sanitary sewer improvements section later in this report. o The original watermain from 11th Ave N and 13th Ave N has no confirmed services and is not needed for the water distribution system, so this watermain does not need to be replaced and can be abandoned without excavation. This is discussed further in the proposed watermain improvements section later in this report. o The storm sewer is not in need of replacement except for the catch basin inlets at some of the intersections, which would be reconstructed with the improvements to 13th Ave N, 12th Ave N, 11th Ave N, and 10th Ave N. Storm Sewer Most of the smaller 12-inch diameter storm sewer in the neighborhood would be reconstructed for constructability of other utilities, changing curb alignment, replacing aging materials, or increasing the storm water pipe capacities to meet City standards for a 10-year rainfall event. Storm sewer will generally be replaced in the same location as the existing system, other than some additional catch basin inlets and storm sewer pipe as needed for drainage and stormwater capacity. Most of the larger diameter storm sewer (27-inches and larger) is in good condition and would not be replaced as part of the proposed improvements. However, some of the existing manholes are in poor condition (constructed from old block material) and are proposed to be replaced as part of the project improvements. The following is a summary of the most significant improvements proposed to the storm sewer system, and proposed stormwater improvements are also shown in Appendix B. • 12-inch diameter storm sewer along 12th Ave N (south of 3rd St N), 11th Ave N (north of 4th St N), and 4th St N would be replaced with 15-inch or 18-inch diameter storm sewer. • Storm sewer along 12th Ave N (north of 1st St N) would be replaced with a minimum pipe size of 24-inch diameter storm sewer. • Storm sewer will be extended down 9th Ave N, 10th Ave N, and 11th Ave N between 2nd St N and 3rd St N to mid-block, with additional catch basin inlets to create a new low point on this block with flat grades. This will improve drainage on this block by providing a location for the water to flow in the curb line. While other blocks in the project area are not as flat as these 3 blocks, they will also be evaluated further during final design to determine if additional storm sewer pipe and catch basins will be necessary for proper drainage. • Storm sewer catch basin inlets will be added and reconfigured at intersections to improve the efficiency of stormwater runoff collection during larger rain events, and to provide appropriate pedestrian ramp access. • Storm sewer catch basin inlets will be added at and near alley entrances to improve the efficiency of stormwater runoff collection during larger rain events and to minimize the spread of stormwater into the street during such events. Stormwater Management Prepared by: Bolton & Menk, Inc. Proposed Improvements Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 12 The proposed improvements will result in more than 1 acre of impervious pavement reconstruction; therefore, stormwater management will be required by the Municipal Separate Storm Sewer System (MS4) General Permit and Nine Mile Creek Watershed District (NMCWD) with their updated rules to align with MS4 permit requirements. The water quality volume was calculated as one-half (0.5) inch times the sum of the new and fully reconstructed impervious surface (estimated to be 10.2 acres), equaling approximately 18,500 cubic feet of required water quality volume to be treated with the improvements for Central Avenues Phase 2. During final design, the actual treatment volume will be verified, but feasible treatment options have been investigated to maximize the treatment of the water quality volume prior to discharge from the MS4: 1. Reduction in Impervious Surface o The reduction in impervious surface from narrowing the roads (a reduction of 1.4 acres) will not count towards any water quality volume treatment, but it does reduce the amount of volume that needs to be treated for the project improvements. o This comes at no additional cost to the project since it is already planned to be included in the improvements and is a cost savings due to the reduction in pavement area. 2. Infiltration Pipes along the west side of 12th Ave N by Maetzold Field o The soil types along the 12th Ave N boulevard are not favorable for infiltration so this option is no longer being considered. o However, there is a low green space area near the Maetzold Field bullpens to the west of 12th Ave N that has sandy soils for infiltration just 5 feet below the surface. An infiltration basin could be considered here if the top 5 feet of soil is removed and replaced with sandy soils and would provide some stormwater treatment for the surrounding area. 3. Underground Chambers in the Parking Lot at 10th Ave N & 1st St N o This option was previously considered as part of the project scoping study, however, the City is putting together an RFP to sell this parking lot to a developer which would most likely result in a new structure with an underground foundation. Therefore, this option is no longer being considered. 4. Stormwater Wet Pond at Valley Park o This was a regional treatment option that was considered as part of the project scoping study, but this option is no longer being considered at this time due to it being outside the scope of the project improvements and creating potential conflicts with the City’s Park System Master Plan. A stormwater treatment pond at Valley Park may be considered in the future when Valley Park improvements are implemented based on the Park System Master Plan. Bolton & Menk and City staff have had preliminary discussions with representatives from Nine Mile Creek Watershed District and the Watershed recognizes the challenges involved in meeting the required treatment volume of a reconstruction project within a fully developed and densely populated neighborhood with limited space for treatment options, such as the Central Avenues neighborhood. Therefore, the Watershed representatives will Prepared by: Bolton & Menk, Inc. Proposed Improvements Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 13 work with the project team during final design and the permitting process to go through the steps of ensuring that stormwater treatment is maximized throughout the project area to the extents feasible, knowing the limitations of the neighborhood and space available for stormwater management. The costs for stormwater management that are shown in Appendix A is what the project team anticipates will be feasible based on preliminary site investigations and discussions with Nine Mile Creek Watershed District. Sanitary Sewer As summarized in the existing conditions section of this report discussing sanitary sewer, most of the existing system in the reconstruction area is relatively old, made of an outdated (clay) material, and in poor condition. Given these conditions, the opportunity to excavate to this utility given removal of overlying roadway pavement for street reconstruction, and the City of Hopkins policy to replace clay sewers during street projects, the existing clay gravity sanitary sewer system throughout the neighborhood is proposed to be replaced with PVC pipe or rehabilitated with a trenchless CIPP liner. An 8-inch PVC pipe was installed underneath the alley between 9th Ave N and 10th Ave N from 2nd St N to 4th St N to service the Alice Smith and Eisenhower Elementary schools. While this sewer is made from a current and acceptable pipe material, it has several significant defects and is located in an undesirable location (narrow alley right-of-way) for maintenance or future repairs. The proposed reconstruction of 10th Ave N and its sanitary sewer main provides an opportunity to replace and relocate the existing PVC sewer pipe beneath the alley. The 8-inch PVC pipe is proposed to be extended down 4th St N from 9th Ave N and connect to the existing sewer on 10th Ave N instead of turning down the alley between 9th Ave N and 10th Ave N. The sanitary sewer main along 10th Ave N between 4th St N and 2nd St N would be upsized to at least a 10-inch PVC sewer pipe to accommodate the additional flow from the elementary schools before connecting to the larger 12-inch sewer main along 2nd St N. After this sewer main in the alley is redirected to 10th Ave N, the deficient pipe in the alley can be abandoned in place with a grout or sand material without any excavation outside of the roadway. The clay sanitary sewer along 2nd St N and 3rd St N can be rehabilitated with a trenchless CIPP liner since there are no confirmed services that need to be replaced along these corridors and the sewer can remain its existing location. While most of the clay sewer mains along the avenues will be excavated and replaced with 8-inch to 12-inch diameter PVC pipe, the deep 15-inch diameter clay sewer main along 15th Ave N between 1st St N and 2nd St N would be proposed for rehabilitation using a CIPP liner. While this rehabilitation method is not typically used on streets designated for reconstruction with many service laterals, the overly deep sewer main (20-feet below ground) makes open cut excavation costly and infeasible on a residential street. Not only would replacing a 20-foot-deep sanitary sewer main be expensive, but it would also be nearly impossible to maintain daily access to residents with slower progress and larger trenches. Due to the additional complexity and cost of full replacement of the sewer on this block, trenchless CIPP rehabilitation would be proposed. Existing sewer service laterals may also be lined from inside the main and/or from the right-of-way (ROW) line if found to be feasible and cost effective during the final design and bidding process. At a minimum, the sewer service tap connections at the sanitary sewer main would be lined approximately 2 feet into the service pipe from the main to ensure a secure and watertight connection. Where gravity mains are to be excavated and replaced, new service wyes will be provided to each home. Per City policy, sanitary services which are not PVC are proposed to be replaced Prepared by: Bolton & Menk, Inc. Proposed Improvements Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 14 with PVC pipe to the ROW line. New precast concrete manholes will be installed and will incorporate the City standard 27-inch diameter cover utilizing concealed pick-holes to minimize inflow and infiltration. The proposed sanitary sewer mainline improvements are summarized in Table 3 below and shown in Appendix B. The exact age of the existing pipes listed in Table 3 could not be verified. Ages were reasonably estimated based on the existing pipe material and the known age of other utilities in the area. Table 3: Proposed Sanitary Sewer Improvements Roadway From/To Existing Pipe Proposed Improvements Dia. Matl. Age 9th Ave N 1st St N to 3rd St N 8” VCP (Clay) 1950 8” PVC 10th Ave N 1st St N to 2nd St N 8” VCP 1950 8” PVC 10th Ave N 2nd St N to 4th St N 8” VCP 1950 10” PVC 11th Ave N 1st St N to 2nd St N 15” VCP 1950 15” CIPP Liner 11th Ave N 2nd St N to 3rd St N 12” VCP 1950 12” PVC 11th Ave N 3rd St N to Minnetonka Mills Rd 8” VCP 1950 8” PVC 12th Ave N 1st St N to Highway 7 8” VCP 1950 8” PVC 13th Ave N Dead-End by Maetzold Field to South Service Dr 8” VCP 1950 8” PVC 2nd St N 8th Ave N to 10th Ave N 10” VCP 1950 10” CIPP Liner 2nd St N 10th Ave N to 11th Ave N 12” VCP 1950 12” CIPP Liner 2nd St N 11th Ave N to 12th Ave N N/A N/A N/A None/No Sewer 3rd St N 9th Ave N to 11th Ave N N/A N/A N/A None/No Sewer 3rd St N 11th Ave N to 15th Ave N 8” VCP 1950 8” CIPP Liner 4th St N 9th Ave N to 10th Ave N 8” PVC 1970 8” PVC Extension 4th St N 11th Ave N to 12th Ave N N/A N/A N/A None/No Sewer Alley b/w 9th Ave N & 10th Ave N 2nd St N to 4th St N 8” PVC 1970 Abandon Sewer Watermain All existing cast iron pipe (CIP) watermain along the Avenues in the neighborhood is proposed to be replaced with new ductile iron pipe (DIP). An 8-inch pipe is proposed on all the roadways to most cost effectively achieve adequate fire flows and water distribution. Fire Hydrants will also be replaced along the new watermain, and gate valves will be added at each intersection for more efficient operations and maintenance. The only east-west street in the project area with existing watermain is 3rd St N from 11th Ave N to 13th Ave N. This watermain has no confirmed services and is not necessary to achieve adequate fire flows and water distribution in the area. Due to the redundancy of this watermain, and to avoid additional costs from excavation and full street reconstruction on these two blocks of 3rd St N, it is recommended that this watermain along 3rd St N is abandoned in place with grout or sand material. The City’s standard flushing station would be installed at the dead-end of 13th Ave N to ensure water quality in the system. There is another east-west cast iron pipe watermain that runs along the south side of Trunk Highway 7 between 11th Ave N and 13th Ave N, mostly in the highway ditch between Minnetonka Mills Rd on the east side of 12th Ave N and South Service Dr on the west side of Prepared by: Bolton & Menk, Inc. Proposed Improvements Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 15 12th Ave N. While this is outside the scope of the project area improvements, there was recently a break along this segment of watermain which required a closure of northbound 12th Ave N near Highway 7 to complete the necessary repairs. To avoid costly repairs and community service interruptions in the future, it is proposed that this watermain be replaced with a new 8-inch directionally drilled high density polyethylene (HDPE) pipe from the connection at 11th Ave N to the connection at 13th Ave N. This method of replacement is trenchless and will only require excavations at each end where the watermain is already proposed to be replaced on 11th Ave N and 13th Ave N, and in the middle under green space near Highway 7 and 12th Ave N to connect to the relatively new watermain installed under Highway 7 as park of the 2022 Trunk Watermain Improvements project. Due to no additional pavement replacement and no service connections on this segment of watermain, the benefits of this proposed watermain improvement will significantly outweigh the costs. The old existing watermain will be filled and abandoned in place, again requiring no additional excavation or restoration costs. Per City policy all water service lines to single family homes are proposed to be replaced to the right-of-way with a new 1” diameter copper service line. A new curb stop valve and box will be provided on each service, approximately on the right-of-way line. Multi-family residential properties and commercial properties will receive a new 6” service line or a service line matching their existing service diameter, whichever is greater. The proposed watermain mainline improvements are summarized in Table 4 below and shown in Appendix B. The exact age of the existing pipes listed in Table 4 could not be verified. Ages were reasonably estimated based on the existing pipe material and the known age of other utilities in the area. Table 4: Proposed Watermain Improvements Roadway From/To Existing Pipe Proposed Improvements Dia. Matl. Age 9th Ave N 1st St N to 3rd St N 6” CIP 1950 8” DIP 10th Ave N 1st St N to 4th St N 6” CIP 1950 8” DIP 11th Ave N 1st St N to Minnetonka Mills Rd 6” CIP 1950 8” DIP 12th Ave N 1st St N to Highway 7 6” CIP 1950 8” DIP 13th Ave N Dead-End to South Service Dr 6” CIP 1950 8” DIP 2nd St N 8th Ave N to 12th Ave N N/A N/A N/A None/No Watermain 3rd St N 9th Ave N to 11th Ave N N/A N/A N/A None/No Watermain 3rd St N 11th Ave N to 13th Ave N 6” CIP 1950 Abandon Watermain 3rd St N 13th Ave N to 15th Ave N N/A N/A N/A None/No Watermain 4th St N 9th to 10th Ave; 11th to 12th Ave N N/A N/A N/A None/No Watermain TH 7 Service Dr 11th Ave N to 13th Ave N 6” CIP 1950 8” HDPE (Trenchless) Pedestrian Facilities Replacement of existing concrete sidewalks is proposed on all Avenues to be fully reconstructed. This will be necessary due to the proposed street and utility construction and because the existing sidewalks are in poor condition and/or do not drain properly. The sidewalks are proposed to be constructed at 6 feet width, and the proposed turf boulevard width will vary but will be somewhat consistent and generally wider than existing since most roadways are being narrowed. The preliminary proposed typical sidewalk section consists of 4” concrete, 4” aggregate base class 5, and spot subgrade soil corrections. Prepared by: Bolton & Menk, Inc. Proposed Improvements Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 16 The existing concrete sidewalk on 13th Ave N from 4th St N to South Service Dr will need to be removed due to the proposed street and utility construction. However, the sidewalk on both sides of this block does not connect to any existing pedestrian facilities to the north, south, east, or west. Due to the lack of existing pedestrian connectivity and lower pedestrian use, it will be considered to not replace this sidewalk and instead replace the area with additional turf (sod). The project team will reach out to the residents on this block to determine if they would prefer to replace the existing sidewalk with new concrete walk or turf to have no sidewalks along 13th Ave N. If the majority (greater than 50%) of the residents on this block respond in favor of not reinstalling the sidewalk, the proposed improvement would reflect that in the final plans with turf restoration in the place of sidewalk. Currently, the proposed preliminary improvements show the sidewalk being replaced on this block until coordination occurs with the adjacent residents. Not replacing the sidewalk would be a cost saving measure if desired by the residents/property owners on this block. There are no sidewalks along 13th Ave N south of 4th St N, and it would not be proposed to add sidewalks along these blocks unless desired by Council and the residents/property owners due to the lack of other pedestrian facilities to connect to in the area and the relatively lower pedestrian use with 13th Ave N being a dead-end to the south of 3rd St N. Spot sidewalk replacements are proposed along 2nd St N and 4th St N as determined by the engineer in the field for areas with poor drainage, cracked sidewalk, or settled sidewalk which could become a tripping hazard. There are no sidewalks along 3rd St N, and it would not be proposed to add sidewalks along these blocks unless desired by Council and the adjacent residents/property owners. There are no existing sidewalks along 3rd St to the east of the proposed street improvements (9th Ave N) or to the west of the proposed street improvements (15th Ave N), and there are existing east-west sidewalks along 1st St N, 2nd St N, 4th St N, and Minnetonka Mills Rd. There is also neighborhood access to the Lake Minnetonka Regional Trail at the intersection of 3rd St N & 15th Ave N and every other Avenue within the neighborhood. The City and project team are working with Three Rivers Park District to improve the Regional Trail crossings within the proposed improvement areas at 12th Ave N, 11th Ave N, and 10th Ave N. Possible improvements may include, but are not limited to: • Curb bump outs at the intersection of 12th Ave N and 2nd St N to shorten the crossing distance, slow vehicular traffic, and improve stopping compliance. o Curb bump outs will also be considered by the project team to improve both pedestrian and vehicular safety at other intersections within the project area including 12th Ave N and 4th St N, and 10th Ave N and 4th St N. • The proposed narrowed street widths along 10th Ave N and 11th Ave N will shorten the distance of the trail crossings mid-block and provide better sight lines. • Improved crosswalk pavement markings and signage. • Possible trail realignment at the street crossings if feasible within the existing public right of way. The proposed improvements to pedestrian facilities are shown in Appendix B. Driveways All single-family residential driveways that conform with current City codes within the reconstruction project area receiving new concrete curb and gutter, will receive a new 5- Prepared by: Bolton & Menk, Inc. Proposed Improvements Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 17 foot-wide concrete apron adjacent to the concrete curb. The new concrete aprons will be constructed accordance with City standards in terms of depth and shape. In addition to the 5-foot driveway apron, additional driveway pavement disturbed as a part of the project will be replaced in-kind to match the existing driveway with the street improvements. Non-conforming driveway aprons may be removed and not replaced during the construction of the new curb and gutter on reconstructed streets. Non-residential and multi-family residential properties will receive the City’s standard concrete commercial driveway entrance apron. Alley entrances will also be replaced with the City’s standard concrete alley entrance. Lawn Irrigation Systems There may be existing sprinkler systems encountered in construction of the project. Adjacent property owners will need to assist in locating and identifying the type of sprinkler systems that are in place prior to and during construction if these facilities are to be protected. The contractor will be required to make efforts to preserve the in-place systems during construction. Where this is found to be unfeasible, the contractor will be required to remove and replace or salvage and reinstall the existing sprinkler system. Street Signing and Striping The existing street name signs will be replaced by the contractor to update the signs to the new City standards. Regulatory signs such as stop and parking enforcement signs will be replaced to conform to retroreflectivity requirements. All intersections are proposed to keep their current traffic control layout, i.e., stop signs are not proposed to be removed or added at any of the intersections within the project area. Crash history data was evaluated within the project area and the number of crashes that have been reported in the past 5 years are relatively minimal, especially outside of 12th Ave N which is a truck route with higher traffic volumes than the rest of the project area streets. Existing crosswalk blocks are proposed to be repainted in approximately the same locations in both the reconstruction and street maintenance areas, with the potential for additional and improved crosswalk blocks at the Regional Trail crossings. Existing centerline striping will be restriped after final paving is completed. Turf and Landscaping Restoration Boulevards will be graded as necessary to facilitate drainage from the existing yards to the streets. Turf areas disturbed by construction, either due to boulevard grading or utility service construction, will be graded to match the new street grades and restored with sod in residential yards. In parks or other areas maintained by the City, and sometimes larger commercial properties, areas will be restored with seed and mulch (hydroseed). Landscaping within the project area will be protected where feasible. Landscaping that is within the right-of-way and/or cannot be protected will either be salvaged and reinstalled by the contractor or will be the owner’s responsibility. Items including, but not limited to walls, fences, and pavers, will be salvaged and reinstalled by the contractor. The engineer will coordinate with individual homeowners on landscape impacts to items including, but not limited to plantings, decorative rock, and decorative pavers for removal and relocation by the homeowner. Boulevard Trees As with all street and utility improvements being considered by the City of Hopkins, it is a goal of this project to protect healthy boulevard trees and/or make improvements to the Prepared by: Bolton & Menk, Inc. Neighborhood Meetings and Public Engagement Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 18 urban tree canopy where feasible. Design and construction of improvements, including appropriate selection of street widths and utility main placement, are proposed to be completed in a manner to achieve the City’s goals to save healthy trees. An evaluation of boulevard tree species and condition throughout the neighborhood will be completed with City Staff in consideration of the adjacent street and utility improvements to facilitate design and construction and meet these criteria. Due to their susceptibility to the emerald ash borer, green ash trees are generally considered undesirable trees. Similarly, silver maple trees are more susceptible to storm damage than other species, create more litter because of their soft wood and weak, brittle branches, and thus are not desirable trees to Public Works staff and local residents. Silver maples are also known to have an intrusive root system that can damage sidewalks and curbs and penetrate sewer joints. Finally, American Elm are still susceptible to Dutch Elm disease. These three undesirable species, as well as other trees that are either dead or in poor health, should either be removed or otherwise not protected through the design/construction process. An inventory of the trees located in the right of way was performed in September 2024 by the City Forester and Bolton & Menk staff. Consistent with all City of Hopkins annual street and utility improvement projects, trees that are dead or in very poor condition, and “undesirable” species in fair or poor condition, are proposed for removal and replacement. Proposed tree removals are shown on the figures in Appendix B. Some of the tree removals identified due to conflicts with utilities or street grading and may be further evaluated during final design to see if reasonable measures can be taken to preserve them. Options to preserve highly desirable trees in harm’s way include small retaining walls or moving service lines around trees but these practices are not always feasible. Unfortunately, there is always the possibility that additional trees will need to be removed and replaced during the construction process that were not planned for removal during design due to various unforeseen circumstances. The project team and field representatives would communicate and coordinate tree replacement with the property owner for each of these occurrences. This project provides an opportunity to increase the health of the neighborhood forest by replacing some of the undesirable species with trees better suited for boulevard areas. One tree is proposed to be installed per each tree removed. New 2-inch diameter trees are typically planted in replacement of those removed. The City will communicate with the property owners to replace trees as part of the project in the event tree removal is necessary. The species of trees to be planted will be a wide variety and coordinated with the City’s public works staff. Properties located adjacent to boulevard tree removals will be contacted and allowed to provide input on their desire for a particular tree species to be planted based on the list provided. VI. Neighborhood Meetings and Public Engagement A neighborhood meeting occurred on October 2, 2024 with residents and property owners that are affected by the improvements in the reconstruction area. The City Engineer and Bolton & Menk Project Manager presented the scope of the project with a discussion of existing and proposed street and utility conditions, preliminary assessment policies, other City policies, and project schedule. Additional information on the neighborhood meeting is documented in Appendix D of this report. There were approximately 40 property owners/residents who participated in the event in-person at City Hall. Some of the most Prepared by: Bolton & Menk, Inc. Estimated Costs and Funding Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 19 common questions or comments received from residents at the neighborhood meeting are summarized in Appendix D. A second neighborhood meeting has been scheduled for November 6, 2024 to review preliminary special assessments and proposed improvements. This meeting will be held in- person again at City Hall and the presentation will also be broadcasted and recorded over Zoom online. The materials from the first meeting and the recorded presentation of the second meeting will be available on the project website (www.HopkinsAvenuesProject.com) for residents to view at their convenience. Residents within the reconstruction project area were also mailed questionnaires in September 2024 as shown in Appendix D. The questionnaire focused on drainage issues, utilities, pedestrian facilities, landscaping, and other concerns the residents may have. Seventy-three (73) questionnaires, which is roughly 25% of the affected properties, were returned with comments. The most common questionnaire responses related to: 1. Specific drainage problems in the roadway and on the sidewalk 2. Desire for sidewalk and trail crossing improvements 3. Speeding and intersection safety 4. Sewer or water service issues 5. Concerns about existing landscaping and trees in the boulevard A summary of the responses to the resident questionnaire are provided in the Table below. Table 5: Resident Questionnaire Response Summary Yes No or N/A Total # of Responses Drainage Issue 27 46 73 Sanitary Issue 23 50 73 Water Issue 17 56 73 Pedestrian Facility Issue 35 38 73 Irrigation 13 60 73 Invisible Fence 0 73 73 Tree Concerns 41 32 73 Landscaping Concerns 14 59 42 VII. Estimated Costs and Funding Estimated construction costs presented in this report are based on anticipated 2025 unit bid prices for a two-year construction contract and include a 15 percent contingency factor. Overhead costs, estimated at 18 percent, include legal, engineering, administrative and fiscal costs. Final costs and any assessments would be determined by using low-bid construction costs of the proposed work. Proposed construction costs for the Central Avenues Improvements Phase 2 (including curb and gutter, bituminous street, pedestrian facilities, storm sewer, sanitary sewer, water main, and turf restoration) are itemized in Appendix A and are summarized in Table 6 below. Prepared by: Bolton & Menk, Inc. Estimated Costs and Funding Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 20 These cost estimates are based upon public construction cost information. Because the consultant has no control over the cost of labor, materials, competitive bidding process, weather conditions and other factors affecting the cost of construction, all cost estimates are opinions for general information of the client and no warranty or guarantee as to the accuracy of construction cost estimates is made. It is recommended that costs for project financing should be based upon actual, competitive bid prices with reasonable contingencies. Table 6: Estimated Cost of Proposed Central Avenues Phase 2 Improvements Proposed Street Improvements $5,254,000 Proposed Pedestrian Facility Improvements $1,285,000 Proposed Sanitary Sewer Improvements $2,288,000 Proposed Watermain Improvements $2,588,000 Proposed Storm Sewer Improvements $1,669,000 Construction Cost Subtotal $13,083,000 Contingencies (15%) $1,963,000 Construction Cost with Contingencies (15%) $15,046,000 Engineering & Administration (18%) $2,708,000 Total Estimated Project Costs $17,754,000 The improvements would be funded using the following sources: PIR (BONDS, GENERAL TAX LEVY), $6,625,585 , 37% SPECIAL ASSESSMENTS, $2,247,496 , 13% WATER FUND, $3,512,316 , 20% SANITARY SEWER FUND, $3,104,294 , 17% STORM SEWER FUND, $2,264,431 , 13% FUNDING SOURCES Prepared by: Bolton & Menk, Inc. Special Assessments Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 21 VIII. Special Assessments Street improvements throughout the reconstruction project area (9th Ave N, 10th Ave N, 11th Ave N, 12th Ave N, 13th Ave N, 3rd St N from 9th Ave N to 11th Ave N, and 4th St N) will be assessed to adjacent and benefitting properties according to the City of Hopkins’ assessment policy. Street improvement work includes pavement removals, grading, subgrade correction, aggregate base, driveways, pavement construction, and restoration. There are no assessments for maintenance work, including milling or reclaiming and street resurfacing, per City policy. According to the City’s assessment policy, residential street improvement costs are assessed to the benefitting properties. In summary, assessments to benefitting properties are determined based on the following criteria: • Properties are assessed based on 70% of the actual street improvement costs. This is referred to as a “Street Assessment”. • North/South Avenue improvements are typically assessed to properties with direct frontage based on a front foot basis (length) along the Avenue. • East/West Street improvements are typically assessed to properties located within one block north/south of the Street on a unit basis (per each property). • “Street Assessments” to any individual property are capped at front foot rate increase annually by 3% over the prior year’s amount. An assessment cap for residential properties of $109.32 per front foot has been established by adding 3% to the 2024 assessment cap according to City policy. This assumes that the project will go out for bids and a construction contract will be awarded in 2025 to begin construction that same year. If construction does not begin until 2026, the assessment cap would be increased by another 3% which would amount to $112.60 per front foot. The same assessment cap would be applied to all residential properties in the project area at the time of final assessment roll adoption by Council, regardless of which year their street is reconstructed. • The assessment cap is applied to residential properties in the project area and is not applicable to commercial properties which will receive a benefit appraisal in preparation of the assessment roll. For properties receiving a benefit appraisal, the lesser of the ‘per policy’ calculation and the benefit amount per the appraisal will be used. The benefit appraisals for these properties are expected to be available in December 2024, which will be after the Public Improvement Hearing but prior to the Public Assessment Hearing. For this report, the ‘per policy’ calculation was used to determine the assessment amount for these properties, but this amount could be reduced if the benefit appraisal amount is lower. • Several properties in the project area were previously assessed during the 2012 Street & Utility Improvements project for the reconstruction of Minnetonka Mills Rd, 4th St N from 10th Ave N to 11th Ave N, and 3rd St N from 8th Ave N to 9th Ave N, or during the 2011 Street & Utility Improvements for the reconstruction of South Service Dr and 4th St N west of 12th Ave N. These previous assessment amounts were considered when calculating preliminary assessments for this project, and properties that were assessed in 2011 or 2012 will either be assessed at a lower amount or will not be assessed for the 2024 project depending on what they were Prepared by: Bolton & Menk, Inc. Right-of-Way/Easements/Permits Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 22 assessed for in 2011 or 2012 for the improvements at that time. This same policy was applied to several of the properties in the 2024 Central Avenues project because they were adjacent to or part of the 2012 Street & Utility project and assessed in 2012 for improvements to those streets. • Several properties in the project area are adjacent to the Lake Minnetonka Regional Trail’s Hennepin County Regional Railroad Authority right of away, resulting in irregularly shaped (non-rectangular) parcels. These irregularly shaped parcels have either larger or smaller frontages than what they would have if they were rectangularly shaped parcels. To address this, the front footage for these parcels was calculated by dividing the area of the parcel by the depth of the parcel, which was then used in the assessment calculation per City policy. • Utility (sanitary sewer, storm sewer, water) main improvements are 100% paid by the respective utility funds. No assessment for utility mains is proposed and their costs do not contribute to either the “Street Assessments” or “Utility Assessments”. • Utility service lines are owned by the individual property per City Code. As a result, the City assesses for the cost of the individual service line replacements. This is referred to as a “Utility Assessment”. The City participates in a share of these costs for residential properties because the replacement is mandatory where mains are reconstructed, and therefore properties are assessed for only 50% of the cost of the service replacement based on actual bid prices received. Commercial properties are assessed for 100% of the cost of the service replacement. • The estimated cost of the water service replacement from the main to property line is $2,850. With the proposed 50/50 “Utility Assessment” split, $1,425 will be assessed to each property where water services are replaced. The estimated cost of the sewer service replacement from the main to the property line is $2,475. With the proposed 50/50 “Utility Assessment” split, $1,237.50 will be assessed to each property where sewer services are replaced. Thus, a property proposed to receive both a new water service and sewer service would have a proposed “Utility Assessment” of $2,662.50, which is an estimated amount until bids prices are known. In the case that sanitary sewer services are made of Orangeburg, or are in disrepair, replacement or lining of the entire line will also be required from the property line to the house. On past projects, the property owner has been given one year to address the necessary repairs and the City will provide contact information for contractors that have performed this work within the City. A preliminary assessment roll is included in Appendix C of this report. Total estimated assessments are $2,247,495.67. IX. Right-of-Way/Easements/Permits The majority of the proposed improvements will be limited to the existing street ROW along all corridors. Temporary construction easements may be needed for work outside the street ROW such as driveway apron replacement, grading and turf restoration, but is not anticipated. It is also Prepared by: Bolton & Menk, Inc. Project Schedule Central Avenues Improvements Phase 2 ǀ BMI 24X.134763.000 Page 23 not anticipated that any permanent easements would be required for the proposed improvements. Therefore, there are no anticipated costs for easement acquisition. Permits would be required from the Minnesota Pollution Control Agency for grading (National Pollutant Discharge Elimination System permit), Minnesota Department of Health for Water Main Replacement, Nine Mile Creek Watershed District for Erosion Control and Stormwater Management, and MnDOT for work within trunk highway right of way. X. Project Schedule The following tentative schedule is proposed and assumes construction will start in 2025. If construction doesn’t start until 2026, the following schedule would need to be modified. Neighborhood Meeting 1 .............................................................................. October 2, 2024 Council Set Public Hearing Date / Present Feasibility Report ..................... October 15, 2024 Neighborhood Meeting 2 .......................................................................... November 6, 2024 Present Feasibility Report / Conduct Public Hearing / Order Final Plans/Specifications ................................................. November 12, 2024 Preparation of Final Plans & Specifications ............ November 13, 2024 – Late January 2025 Approve Final Plans & Specifications / Authorize Advertisement for Bids ........................ Late January/Early February 2025 Bid Opening ......................................................................... Late February/Early March 2025 Council Sets Public Assessment Hearing Date ..................................................... March 2025 Neighborhood Meeting 3 ............................................................ Late March/Early April 2025 Council Accepts Bids / Conduct Public Assessment Hearing / Adopt Assessment Roll / Award Bid ...........................................................April 2025 Start of Construction ............................................................................................... May 2025 Finish Year 1 Construction Phases .................................................. October/November 2025 Start Year 2 Construction Phases ................................................................... April/May 2026 Substantial Project Completion ...................................................... October/November 2026 Finish Punch List and Project Closeout ................................................................. Spring 2027 XI. Feasibility and Recommendation From an engineering standpoint, this project is feasible, cost effective, and necessary and can best be accomplished by letting competitive bids for the work. It is recommended that the work be done under one contract over two construction seasons, for all project areas, to complete the work in an orderly and efficient manner. The City, its financial consultant, and the persons assessed will have to determine the economic feasibility of the proposed improvements.