Agenda - Council - 09/22/2020 - Laserfiche WebLink

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Staff estimated construction costs for this project at $58,000 based on the attached plans. On August 25, 2020, the City Council authorized Staff to solicit quotes for this work. Staff submitted Requests for Quotes to three local contractors. Two of the contractors indicated they were too busy to complete the work this year. Only one contractor, Dryden Excavating, Inc., submitted a quote, which was in the amount of $53,058.77. Staff believes this is a reasonable quote and recommends that the City accept it and construct the improvements in 2020 to avoid another winter during which the culvert under Inverness Lane could freeze again on one or more occasions, requiring Public Works crews to open it up to prevent runoff from backing up into the rear yard of 9591 Inverness Lane. City Staff will administer and inspect construction of these improvements. Construction staking is proposed to be provided by Bolton & Menk at a cost not -to -exceed $1,520. Project costs are proposed to be funded using a combination of Stormwater Management and Stormwater Utility Funds. Once the contractor begins work, the improvements are anticipated to take 5 to 10 days to complete, with completion specified by October 23, 2020. Final payment will be issued in 2021 after turf is established and all work is approved. Recommendation: Staff Recommendations Staff recommends adopting Resolution #20-215 accepting the quote of and awarding a construction contract to Dryden Excavating, Inc. in the amount of $53,058.77 for 9591 Inverness Lane Drainage Improvements, Improvement Project #20-08, and authorizing Bolton & Menk to stake construction at a cost not -to -exceed $1,600. Public Works Committee Recommendations On August 18, 2020, the Public Works Committee unanimously recommended City Council authorization to solicit Requests for Quotes for 9591 Inverness Lane Drainage Improvements, Improvement Project #20-08. The Committee also asked if Staff had explored the option of extending a culvert under Jarvis Street to discharge the stormwater runoff from the ditch east of Jarvis Street into the ditch west of Jarvis Street, which is located in the City of Elk River. Staff indicated they would review this option and report their findings back to the Committee on September 15th. Below is a summary of Staff's findings for this option. Commercial lots exist on the west side of Jarvis Street, which currently have 12-inch concrete driveway culverts. The driveway culverts west of Jarvis Street are approximately 0.7-feet or 8-inches higher than the culverts east of Jarvis Street, therefore the ditch and culverts west of Jarvis Street would need to be lowered more than 1-foot. The driveway culverts would all need to be upsized to accommodate the additional drainage from the east side of Jarvis Street. In summary, this option would require an 18-inch concrete culvert, approximately 50-feet in length, to be installed under Jarvis Street, either by directional drilling or open trenching. Directional drilling is generally much more costly, but considering the required pavement removal and replacement costs it may be the more cost-effective method. Approximately 100-feet of the ditch west of Jarvis Street would then need to be re -graded at elevations over 1-foot lower, or 100-feet of 18-inch storm sewer could be installed. Then, about 144-feet of 12-inch concrete culvert would need to be removed and replaced with an 18-inch concrete culvert at least 1-foot lower under the commercial driveway west of Inverness Lane. Four (4) commercial driveway aprons would also need to be removed and replaced. The existing drainage ditches between the driveways would need to be re -graded at lower elevations. Several ponds exist south of the commercial lots which accept all drainage from the west side of Jarvis Street. These ponds would need to be analyzed to determine if they have enough capacity to accommodate the additional drainage. If the ponds don't have enough capacity, they would need to be re -graded, along with the swale between Jarvis Street and the ponds. This option would be more expensive than the design currently proposed in the attached plans. In addition, the