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2b-3. Creekside Addition approve Sanitary Sewer Stub Location to Timberwood Estates AdditionCITY OF ° � 5 = CHANHASSEN I MEMORANDUM 690 COULTER DRIVE • P.O. BOX 147 • CHANHASSEN, MINNESOTA 55317 (612) 937 - 1900 • FAX (612) 937 - 5739 ' TO: Charles Folch, Director of Public Works /City Engineer FROM: Dave Hempel, Assistant City Engineer ' DATE: May 2, 1995 ' SUBJ: Approve Sanitary Sewer Stub Location to Timberwood Estates Project No. 95 -8 r In conjunction with the preliminary plat ar requested staff to explore alternatives for pros Estates. A previous staff report for the prel extending a sewer line along the Bluff Creek 3. Some members of the City Council were to the Bluff Creek corridor. Action by Ctty AdmlftnW Ertdors ✓ DIJA Modifie ...,_ • ___ . _ w Rejeote --_ Date Submitted to Commission - oval for Creekside Addition, the City Council ling future sanitary sewer service to Timberwood iinary plat of Creekside Addition recommended butary through Lots 20, 21, 23, 24 and 25, Block ncerned that this alignment would be detrimental Attached is a letter from Mr. Phil Gravel of Bonestroo and Associates dated May 1, 1995 regarding possible alternatives for future service to Timberwood Estates. In summary, Mr. Gravel recommends either options 1 or 3 to insure that future gravity service is available to Timberwood Estates. From an economical and environmental standpoint, I concur with Mr. Gravel's assessment of at least extending an 8 -inch line from the proposed Creekside Addition, specifically along Lots 19 and 20, Block 3 to the plat boundary. This is the most feasible and flexible alternative for providing future sanitary sewer service to Timberwood Estates. This proposed segment of pipe through Creekside Audition will not remove any trees or impact the creek and will be constructed as a part of the Creekside development at no cost to the City. Option No. 3 is feasible from a construction standpoint; however, it would require the acquisition of additional easements and involve much more tree loss than Option No. 1. The construction plans for Creekside Addition have been designed with ,an 8 -inch sanitary sewer line proposed along Lots 19 and 20, Block 3 to the Timberwood Estates plat line. If the City Council requests a different alternative than Option No. 1, the construction plans would have to be revised accordingly. It is therefore recommended that the City Council approve the sanitary sewer stub location to Timberwood Estates shown on Option No. 1 between Lots 19 and 20, Block 3, . r ,.� e ,.• i Creekside Addition. ktm:: Attachment: L Letter from Phil Gravel dated May 1, 1995. 1 g: \eng\ projects \creeksidlsanitary.cc {'' G- — � -- — -- JA Bonestroo Rosene Anderlik & Associates Engineers & Architects May 1, 1995 Mr. David Hempel Assistant Engineer City of Chanhassen 690 Coulter Drive Chanhassen, MN 55317 Bonestroo, Rosene, Anderlik and Associates, Inc. is an Affirmative Action /Equal Opportunity Employer Otto G. Bonestroo, PE. Robert W Rosene, PE* Joseph C. Anderlik, PE, Marvin L. Sorvala, PE. Richard E. Turner, RE. Glenn R. Cook, PE. Thomas E. Noyes. RE. Robert G. Schunicht, PE Susan M. Eberlin, CPA, Senior Consultant Howard A. Sanford, PE. Keith A. Gordon., PE. Robert R. Pfefferle, PE. Richard W. Foster, PE. David O. Loskota, PE. Robert C. Russek, A.I.A. Jerry A Bourdon, PE. Mark A. Hanson, PE. Michael T Rautmann, PE. Ted K. Field, PE. Thomas R. Anderson, A.I.A. Donald C Burgardt, PE. Thomas A. Syfko, RE. Frederic J. Stenborg, PE, Ismael Martinez, PE. Michael P Rau, PE. Thomas W. Peterson, PE. Michael C. Lynch, PE. James R. Maland, PE. Jerry D. Pertzsch, PE. Scott J. Arganek, PE. Kenneth P Anderson, PE. Mark R. Rolfs, PE. Mark A. Seip, PE. Gary W. Morien, PE. Paul J. Gannon, At A. Daniel J. Edgerton, RE. A. Rick Schmidt, PE. Philip J. Caswell, PE. Mark D. Wallis, PE. Miles B. Jensen, PE. L. Phillip Gravel, PE. Karen L. Wiemeri, PE, Gary D. Kristofitz, PE. Brian K. Gage, PE Keith R. Yapp, PE. Douglas J. Benoit, PE. Shawn D. Gustafson, PE. Cecilio Olivier. PE. Paul G. Heuer, PE. John P Gorder, PE. Dan D. Boyum, PE. Jeffrey J. Ehleringer, PE. Joseph R. Rhein, PE. Lee M. Mann, PE. Charles A. Erickson Leo M. Pawelsky Harlan M. Olson Agnes M. Ring James F Engelhardt Re: Ultimate Sanitary Sewer Service Timberwood Estates, City Project 95 -8 File 393 Gen Dear Dave: As requested, we have again reviewed the ultimate sanitary sewer service options for the Timberwood Estates Area. Five possible options were reviewed as shown on the attached sketch. The design of all five options is governed by the creek crossing and the low point in Timberwood Drive, Option No. 4 is not practical due to the depths necessary. Option No. 2 is not practical due to the environmental concerns, the amount of tree removal, and easements required. Option No. 1 and 3 were evaluated in greater detail and are discussed below: Option No. 1 Option No. 1 for sewer service to the Timberwood Addition consists of an extension from the proposed Creekside Addition westerly to Timberwood. The sewer could follow an alignment on either the north or south side of Bluff Creek. The north alignment of Option No. 1 would begin in the Creekside Addn. cul -de -sac and would follow the creek to Timberwood Drive. The south alignment for Option No. 1 would also begin in the Creekside Addn. cul -de -sac but would cross the creek along a lot line and run through Renaissance Court. This alignment has the advantage of providing lateral benefit to the Renaissance Ct. and not requiring as much easement as the north alignment. The advantages of Option No. 1 are that the depths are less than other options and that the amount of tree removal is less. The southern alignment of Option No. 1 also has the advantage of providing approximately 560 feet of lateral benefit. 2335 West Highway 36 ■ St. Paul, MN 55113 ■ 612 - 636 -4600 Mr Dave Hempel May 1, 1995 v p Y ' City of Chanhassen Page 2 ' The disadvantages of Option No. 1 are that some tree removal is required and that access to the sewer for maintenance may be limited for the segments along easements and lot lines. Option No. 3 : This option routes the future sewer through the proposed Creekside Addn. and along common lot lines to Renaissance Court. The total length is approximately 1,240 feet. The ' total estimated construction cost is $50,400. The benefits of Option No. 3 are a lower construction cost and shallower pipe. This option has ' approximately 560 feet of lateral benefit. The disadvantages of Option No. 3 are that it will require substantial tree removal, it will require ' easement acquisition, and part of the sewer is located on lot lines which can be a maintenance problem. ' Option No. 5 : Option No. 5 consists of a sanitary sewer lift station located near the creek crossing of Timberwood Drive. Effluent from the lift station would be pumped through a forcemain to the existing sewer in Stonecreek. This option is the most expensive of the options ' considered. ' The advantages of this option include little or no tree removal and no easement requirements. The disadvantages of this option include higher initial and long term costs. Lift stations are generally avoided where possible, due to long term operation and maintenance costs. Conclusion There is no simple solution on how to ultimately serve Timberwood Estates. Certainly, if the addition were being platted today, sanitary sewer service would be considered and the layout of the plat would likely be different than it is. However, since we need to deal with the existing plat, either Option No. 1 or Option No. 3 should be implemented to ensure that future service is available. ' From an engineering standpoint, either option will work. From a political and environmental standpoint, I think that the southern alignment of Option No. 1 is the most prudent solution. Please feel free to contact me if you have any questions or require additional information. ' Sincerely, BONESTROO, ROSENE, ANDERLIK & ASSOCIATES ?0�� ' Phil Gravel PG:lk 1 Enclosure 112 SEC 15 10 60 6 / OA �. b 10 OA 12 _ 2 �oF\0 �7vP ` 101 Ibq.3 x . 13 3 (,��sr �t�-11.2' �s� � • °• �� — — — � � I I 12 13 s pPT10N1#5 ( cree0c 14 �g.E`=� O O �--.� ^ / 0 1 o OUR N ,:.:::� / 0Q / 1 RENA To 14 / ti 16 15 - -� / / 0 16 2 /,Cj 0 0 0 0 ,11 ' Posible Sewer Service Options 5 6 Existin ewer Timberwood Estates ,,���' n L 0 J �I FEASIBILITY COST ESTIMATES TIMBERWOOD ESTATES ULTIMATE SANITARY SEWER SERVICE May 1, 1995 O tion No. 1 - South Alignment 5 EA Manholes @ $1,400 /ea $7,000.00 39 LF Manhole overde th @ $75/lf $2,925.00 690 LF 8" PVC, 14'- 16' deep @ $18.00 /lf $12,420.00 300 LF 8" PVC, 16- 18' deep @ $20.00 /lf $6,000.00 270 LF 8" PVC, 18'- 20' deep @ $22.00/lf $5,940.00 Lum Sum Clear and Grub $2,000.00 Lump Sum Restoration $2,700.00 Subtotal $38,985.00 + 10% Contingencies $3,915.00 TOTAL OPTION 1 $42,900.00 Option No. 3 7 EA Manholes @ $1,400 /ea $9,800.00 53 LF Manhole overde th @ $75/lf $3,975.00 460 LF 8" PVC, 14'- 16' deep @ $18.00 /lf $8,280.00 410 LF 8" PVC, 16- 18' deep @ $20.00 /lf $8,200.00 370 LF 8" PVC, 18'- 20' deep @ $22.00/lf $8,140.00 Lum Sum Clear and Grub $4,700.00 Lump Sum Restoration $2,700.00 Subtotal $45,795.00 + 10% Contingencies $4,605.00 TOTAL OPTION 3 $50,400.00 Option No. 5 Lift Station Lump Sum Lift Station in place $55,000.00 800 LF 6" Forcemain @ $10.00/lf $8,000.00 580 LF 8" PVC 14'- 16' deep @ $18 /1f $10,440.00 Lum Sum Restoration $2,000.00 Subtotal $75,440.00 + 10% Contingencies $7,560.00 TOTAL OPTION 5 $83,000.00 I 1:093093- GEMCOST.EST