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HomeMy WebLinkAbout2010-10-20 PACKET 12.A.REQUEST OF CITY COUNCIL ACTION COUNCIL AGENDA MEETING ITEM # DATE 10/20/201 PREPARED BY Engineering Jennifer Levitt ORIGINATING DEPARTMENT DEPARTMENT HEAD COUNCIL ACTION REQUEST Workshop: 2011 Pavement Management Project. SUPPORTING DOCUMENTS ❑ MEMO /LETTER: ❑ RESOLUTION: ❑ ORDINANCE: ❑ ENGINEERING RECOMMENDATION: ❑ LEGAL RECOMMENDATION: ® OTHER: Report. ADMINISTRATORS COMMENTS �i /o City Administrator Date COUNCIL ACTION TAKEN: ❑ APPROVED ❑ DENIED OTHER Document5 E= 2335 Highway 36 w St. Paul, PIN 55113 Tel 651- 636 -4600 Fax 651- 636 -1311 www.borestroo.com November 3, 2010 Bonestroo Honorable Mayor and City Council City of Cottage Grove 7516 80th Street South Cottage Grove, MN 55016 Re: West Point Douglas Frontage Road Extension & 2011 Pavement Management Project Client Project No.: 10 -284 & 10 -289 Bonestroo File No.: 000048 - 10284 -0 & 000048 -10 -289 -0 Honorable Mayor and City Council Members: Enclosed for your review is the 2011 Pavement Management project Feasibility Report. The project scope includes street rehabilitation and storm sewer improvements in the Pine Coulee /Countrywood (District I) and Howard's Addition (District A) neighborhoods, as identified in this report. This report describes the improvements necessary to improve the streets and storm sewer within the project area. Cost estimates for the proposed improvements are presented in the appendices of the Report. We would be happy to discuss this report at your convenience. Please contact me at 651- 604 -4917 if you have any questions or concerns. Sincerely, BONESTROO Mike Boex, PE 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. Michael I Boex Date: November 3, 2010 Registration No.: 44576 SECTION TITLE Tableof Contents ................................................................................ ............................... I Introduction........................................................................................ ..............................2 Existing Conditions - Pine Coulee /Countrywood ....................................... ..............................2 Streets............................................................................................ ............................... 2 Sanitary Sewer and Water Main .......................................................... ..............................3 StormSewer ........ ................................................... .............. ........ .......... :....... ......... ... .. 3 Existing Conditions - Howard's Addition .................................................. ..:•.r........................3 Streets............................................................................................ ............................... 3 Sanitary Sewer and Water Main ...................... .................. .................. ..............................4 StormSewer .................................................................................... ..............................4 Proposed Improvements - Pine Coulee/ Countrywood ................................ ..............................4 Streets..................................................................... ............................... , ...................... 4 Sanitary Sewer and Water Main .......................... ............................... ..............................4 StormSewer .................................................................................... ..............................5 StormWater Quality . ................................................................. ............................... 5 Proposed Improvements - Howard's Addition „ ...................................... ............................... 5 Streets............................................................................................ ............................... 5 Sanitary Sewer and Water Main .......................................................... ..............................6 StormSewer......' .............................................................................. ..............................6 StormWater Quality... ................................. ...... ............................. -- ..................... 6 EstimatedCosts .....' ............................................................................. ............................... 6 CostSummary .................................................................................. ..............................6 CostAllocation ................................................................................. ............................... 6 Financing........................................................................................ ............................... 7 ProjectSchedule ................................................................................. ............................... 8 Conclusions and Recommendations ........................................................ ..............................8 City of Cottage Grove, MN Page 1 2011 Pavement Management Project Bonestro0 000048 - 10289 -0 2011 PAVEMENT MANAGEMENT PROJECT Introduction The Pine Coulee, Countrywood, and Howard's Addition residential neighborhoods have been identified as candidates for rehabilitation during the 2011 construction season as a part of the City of Cottage Grove's ongoing roadway rehabilitation program. The City Council authorized preparation of this Report to determine the feasibility of rehabilitating those streets as a part of the 2011 Pavement Management Project. Pine Coulee and Countrywood are located in the Southeast corner of the City and are part of Pavement Management District I, as shown on Figure 1 located in Appendix A. There are seven residential streets within these neighborhoods totaling approximately 11,860 lineal feet. The Countrywood neighborhood consists of Lofton Avenue and Lockridge Avenue, with Pine Coulee being the remainder. Howard's Addition is located South of 70th Street and East of the Acorn Ridge development. It's part of Pavement Management District A as shown on Figure .2 located in Appendix A. There are two residential streets within Howard's Addition totaling approximately 1,600 lineal feet. The purpose of this report is to further evaluate the work actually required for this street rehabilitation project, to provide an estimate of cost, and to establish a method of cost allocation or assessment in order to determine the physical and economic feasibility. Existing Conditions - Pine Coulee /Countrywood STREETS The streets within Pine Coulee and Countrywood are rural residential and were originally constructed in the early 1970's. Generally, the streets are 21 -24 feet wide with no concrete curb and gutter. Gravel shoulders, although once present, have been either overlayed with new bituminous or have been covered with vegetation over the years. The Pavement Condition Index (PCI) of these streets range from 22 -40 as identified in the 1994 Pavement Management Plan. Per that plan, PCI's in those range are classified as "Poor" and "Very Poor" and are beyond the point of performing seal coats or overlays to maintain the streets. Test pits were performed to determine the thickness of the existing street section. This information will be used to design a recommended pavement section. Caty of Cottage Grove, MN Page 2 2011 Pavement Management Project Bonestroo 000048- 10289 -0 Existing Street Sections - Pine Coulee /Countrywood No. Location Materials 1 11880 Lofton Ave 3" Bituminous, 3.5" Gravel, 10" Lean Clay, Sand 2 11821 Lockridge Ave 4" Bituminous, 6" Gravel, 6" Sand with Silt 3 11701 Lockridge Ave 3" Bituminous, 3" Gravel, 4.5" Sand 4 11600 Lockridge Ave 3" Bituminous, 4" Gravel, 2" Sand, 6" Sand with Silt 5 11566 Leeward Ave 2.5" Bituminous, 3" Gravel, 5.5" Sand, Mixed Soils & Organics 6 11660 Lehigh Ave 2.5" Bituminous, 7" Mixed Soils, Clean Sand 7 11700 Lehigh Ave 3" Bituminous, 2" Gravel, Mixed Soils 8 11827 Leeward Ct 3" Bituminous, 3" Gravel, 3" Sand, Clay & Organics 9 11680 Leeward Ave 1.5" Bituminous, 1" Gravel, 5" Mixed Soils, Clay & Organics 10 11760 Layton Ave 4" Bituminous, 3" Gravel, Clean Sand 11 11680 Layton Ave 4" Bituminous, 2" Gravel, 7" Sand with Silt 12 11570 Layton Ave 3.5" Bituminous, 3" Gravel, 4" Mixed Soils, 7 Sand with Silt From the existing test pits, it can be seen that the average section consists of 3 inches of bituminous over 2.75 inches of gravel. SANITARY SEWER AND WATER MAIN Currently, there is no public sanitary sewer or watermain within these neighborhoods. STORM SEWER There's a very small amount of existing storm sewer within Pine Coulee and Countrywood. The storm sewer appears to be pieced together over time to address specific drainage needs. Product materials and construction methods do not follow typical City standards. Generally speaking, Lofton Avenue is the only street that consistently has culverts at driveways. Other streets -in the neighborhood have little to no ditch definition and yards are typically graded out to the edge of the street. Existing: drainage follows the street and must cross over the driveways. Leeward Avenue currently has three parallel 60" CMP culverts that convey runoff through a major drainage way. Adjacent to the cross culverts is a street section with bituminous curb and gutter. Existing Conditions - STREETS The streets within Howard's Addition were originally constructed in 1974. The streets are approximately 34 feet wide from back of curb to back of curb. The Pavement Condition Index (PCI) of these streets range from 35 -63 as identified in the 1994 Pavement Management Plan, A PCI of 35 is identified as "Poor" and is beyond the point of performing seal coats or overlays to maintain the streets. There are sections of existing 6618 curb and gutter that have settled, cracked, or have other defects that will require replacement. Test pits were performed to determine the thickness of the existing street section. This information will be used to design a recommended pavement section. City of Cottage Grove, MN Page 3 2011 Pavement Management Project Bonestroo 000048 - 10289 -0 Existing Street Sections - Howards Addition No. Location Materials 1 6588 71st Street 3" Bituminous, 11" Gravel, Clay /Sand 2 7123 Granada Ave 2.75" Bituminous, 4.5" Gravel, Dirty Gravel and Sand 3 7128 Granada Ave 2.75" Bituminous, 6" Gravel, 12" Sand SANITARY SEWER AND WATER MAIN Currently, there is no public sanitary sewer or watermain within the Howard's Addition neighborhood. STORM SEWER There is virtually no existing storm sewer within Howard's Addition. Drainage generally flows from 70th Street to the South along the existing curb and gutter. No catch basins and street storm pipe are present within the project area. There is one cross culvert at the very south end of the project limits that drains towards the Acorn Ridge development. Proposed Improvements - Pine Coulee /Countrywood STREETS Due to the thin and highly variable pavement sections and materials present, reclamation of the existing section could contaminate the redaimed base if additional gravel (add -rock) is not placed prior to the reclamation process. For the majority of the neighborhood, it's proposed to add 2 -4 inches of add -rock over the existing pavement. Then the add -rock, pavement, and existing gravel base would be reclaimed to a depth of approximately 8 inches. The resultant reclaimed material would then be shaped and graded to allow for placement of 3.5 inches of new bituminous pavement. The resulting street section would be much more consistent, comprising of 3.5 inches of bituminous over 7 -8 Inches of reclaimed aggregate base. This method would raise the road 5 -8 inches, which would help improve the depth of adjacent shallow ditches and bring a uniformity to the pavement section not currently present. Due to the existing pavement section, the section of Leeward Avenue between the Layton Avenue loop will require ,a different method of rehabilitation. In this area, subgrade excavation would be performed, followed by placement of an aggregate backfill, construction of aggregate base, and paving. It is proposed that all street widths remain the same as the existing condition. The single exception to this is the cul -de -sac at Leeward Court. The existing pavement at the turnaround is 13 feet in width. Minimum access width per Fire Code is 20 feet so it is proposed that the turnaround be widened meet that requirement. Each driveway would receive an apron as a part of the street reconstruction process. Gravel driveways would receive a bituminous apron, and bituminous or concrete driveways would receive an apron to match the existing material. A bituminous bump -out for each mailbox will also be constructed. This will help reduce wheel rutting occurring adjacent to the edge of road. SANITARY SEWER AND WATER MAIN No public improvements are proposed as a part of this project. City of Cottage Grove, MN Page 4 2011 Pavement Management Project Bonestroo 000048- 10289 -0 FA017S& Allyi4 7 It's proposed that the existing storm sewer systems be replaced with materials conforming to City standards. In doing so, the longevity and reliability of the system will be increased and maintenance should be reduced. The existing bituminous curb along the culverts at Leeward Avenue will be replaced with concrete curb and gutter. A catch basin and short section of storm sewer is proposed to collect street drainage near the culverts and direct runoff into the drainage way. STORM WATER QUALITY Approximately 7 proposed infiltration features will be located along the project corridor to provide water quality treatment and runoff volume reduction within the project area. These small scale surface infiltration features will be located adjacent to the street and within the City owned right - of -way. While the standard restoration option for these features will be a wet - tolerant turf grass, the City offers residents the option to substitute the turf grass with native rain garden plantings within the context of the project. It should be noted however that the turf grass option provides a more economical upfront materials costs and reduces longterm maintenance costs. Figure X identifies the most suitable locations for infiltration features. This preliminary assessment of suitable locations is based on a field inspection that identified locations where no conflicts with significant trees or steep slopes were present, available right -of -way appeared to be sufficient, and the relative elevation of the location was suitable. The infiltration feature locations identified on Figure X should be considered 'preliminary at this time. It will be necessary to perform soil borings in some of the proposed infiltration feature locations to confirm that the existing soils are conducive to infiltration. If the borings indicate that infiltration is not a feasible option, alternative methods such as biofiltration basins or filtration swages will be evaluated to provide water quality treatment within the project area. In the past, the City has partnered with the SWWD to fund storm water quality improvements within the context of their Pavement Management Program. It is anticipated that the South Washington Watershed District (SWWD) will have cost share funds available for the infiltration features and associated storm water improvements included in the 2011 Pavement Management Project. This cost -share opportunity as well as other funding opportunities will be investigated as a part of the final design. Although these funding opportunities vary year to year, the City will continue to monitor solicitations as they become available. Proposed Improvements - Howard's Addition STREETS At Howard's Addition, it's proposed to reclaim the existing pavement and gravel base to a depth of 6 -9 inches. Because Howard's Addition is an urban section with concrete curb and gutter, the top 3.5 inches of reclaimed material would need to be hauled off -site to allow for 3.5 inches of new bituminous pavement. The existing 8618 concrete curb and gutter will be evaluated prior to construction. Based on a preliminary evaluation, it is estimated that approximately 15% is in poor condition and would need to be replaced. City of Cottage Grove, MN Page 5 2011 Pavement Management Project Bonestroo 000048- 10289 -0 SANITARY SEWER AND WATER MAIN No public improvements are proposed as a part of this project. STORM SEWER As a part of this project the existing cross culvert at the south end of the project will be evaluated for replacement. STORM WATER QUALITY Storm water quality improvements are not required in this neighborhood due to no increase of impervious surfacing. Permits and Easements This project will require the following permits: • Phase II General Storm Water Permit from the MPCA No easements are anticipated in the Howard's Addition. In the Pine Coulee and Countrywood neighborhoods, the proposed rain gardens may require additional drainage and utility easements if they cannot be contained within the existing right -of- way. This will be evaluated during the final design (phase of the project. Estimated Costs COST SUMMARY Cost estimates for the improvements have been prepared and are included in the Appendix of this report. All costs for items to be constructed are based on anticipated unit prices for the 2011 construction season. All costs include a thirty (30) percent allowance for indirect costs associated with the project (engineering, administrative, financing, and legal) as well as a ten (10) percent contingency. No costs are included for capitalized interest during the construction period or before assessments are levied. An overall summary of the estimated cost is shown below: Estimated Cost Summary Location Estimated Project Cost Pine Coulee / Countrywood $1,323,000 Howard's Addition $164,000 Countrywood Park Improvements $152,000 Total Estimated Project Cost: $1,639 Assessments for this project will be based upon the "Infrastructure Maintenance Task Force Special Assessment Policy For Public Improvements," dated September 30, 2005. All adjacent benefiting properties are proposed to be assessed. Per the Rural Residential policy, 45% of the project cost would be assigned to each individual residential lot on a unit basis. The intent of the City of Cottage Grove, MN Page 6 2011 Pavement Management Project Bonestroo 000048- 10289 -0 City's policy is to treat all properties within a residential development as similar individual units regardless of lot frontage. City funds would pick up the remaining 55% of the project costs. In the Pine Coulee neighborhood, it should be noted that two (2) "sliver" parcels were not included in the total unit count. It is assumed that one will be turned over to the City and one will be combined into and existing lot prior to the project. The large parcel north of Leeder Avenue that's zoned agricultural was also counted as one unit. In addition, the City Park was counted as 2 equivalent units for the purposes of calculating assessments. The total estimated project assessments are as follows: Estimated Cost Allocation Location City Funds (55% of Total) Assessed Amount (45% of Total) <Estimated Project I Cost Pine Coulee / Countrywood $727,650 $595,350 $1,323,000 Howard's Addition $90,200 $73,800 $164,000 Subtotal $817,850 $669,150 $1,487,000 Howard's Addition 12 $73,800 $6,150 City Funds (100% of Total) Countrywood Park $152,000 - $152,000 Totals: $969,850 $669,150 ,' $1,639,000 Estimated Cost Per Unit FINANCING Assessments are proposed to be levied based on the City's current assessment policy. The remainder of the project would be financed through a combination of City funds such as the General Tax Levy and Enterprise funds for items such as storm sewer improvements. General Levy funds will be utilized for the proposed park improvements. ® p =� Because the properties within the Pavement Management project benefit from the proposed improvements, and the project will be partially funded through assessment, it will be necessary for the City to hold a public improvement hearing to receive comment on the proposed project and to determine the further action to be taken. City of Cottage Grove, MN Page 7 2011 Pavement Management Project Bonestroo 000048 - 10289 -0 Assessable Assessed Amount Location Assessed Cost Per Unit Units (45% of Total) Pine Coulee / Countrywood 86 $595,350 $6,923 Howard's Addition 12 $73,800 $6,150 FINANCING Assessments are proposed to be levied based on the City's current assessment policy. The remainder of the project would be financed through a combination of City funds such as the General Tax Levy and Enterprise funds for items such as storm sewer improvements. General Levy funds will be utilized for the proposed park improvements. ® p =� Because the properties within the Pavement Management project benefit from the proposed improvements, and the project will be partially funded through assessment, it will be necessary for the City to hold a public improvement hearing to receive comment on the proposed project and to determine the further action to be taken. City of Cottage Grove, MN Page 7 2011 Pavement Management Project Bonestroo 000048 - 10289 -0 Project Schedule Below is the proposed schedule assuming a 2011 construction season: • 11/03/2010 • v • February 2011 • Spring 2011 • Spring 2011 • Fall 2011 Council Orders Feasibility Report Council Receives Feasibility Report Council Orders the preparation of the Plans and Specifications Approve Plans and Specifications and set Bid Date Project Bid Date Contract Award Begin Construction Final Completion Conclusions and Recommendations It is recommended that this report be used as a guide for the layout, design, and cost allocation for the public improvements. It is further recommended that the owners of properties within the project limits be notified of the proposed improvements in order to provide comment. 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