Adopt Resolution #20-215 Accepting Quotes and Awarding Contract for 9591 Inverness Lane Drainage Improvements, Improvement Project #20-08

Purpose:
The purpose of this case is to adopt Resolution #20-215 accepting the quote of and awarding a construction contract to Dryden Excavating, Inc. for 9591 Inverness Lane Drainage Improvements, Improvement Project #20-08. 

Background:
In December of 2015, the property owner at 9591 Inverness Lane first contacted Staff to discuss some drainage concerns regarding the operation of the drainage ditch east of Jarvis Street on both sides of Inverness Lane, which had just been improved that summer as part of the Jarvis Street Reconstruction project.  After numerous conversations with Elk River Staff, who led this street reconstruction project, and with Staff from Bolton & Menk, who designed the project, prepared plans and specifications, and inspected construction, some grading modifications were made as part of the project punch list work. On June 12, 2016, the property owner at 9591 Inverness Lane reached out again to let us know the ditch appeared to be flowing well and that his concerns had been addressed.
 
In early 2019, the property owner contacted Staff again to report that the swale traversing their back yard, which conveys stormwater runoff from several properties upstream, was full of water and was roughly 10 feet from the back of their house and encroaching under the rear edge of their deck.  The property owner said the swale had never been this full of water before.  That spring, Staff began working on plans to improve drainage in the ditch east of Jarvis Street, including collecting survey shots and investigating options for improving drainage in the ditch east of Jarvis Street to prevent water from backing up into the rear yard of this property.
 
During late winter and early spring, snow and ice in the ditches and the culvert under Inverness Lane prevents stormwater runoff from flowing properly, causing stormwater to back up into the swale in the rear yard of 9591 Inverness Lane.  Staff confirmed the ditch to the south of Inverness does not have proper slope for drainage. Staff originally looked at re-grading the ditch east of Jarvis Street to the existing pond one lot south of Inverness Lane. Due to existing private utilities, poles, impacts to existing mature trees, and to avoid steep ditch side slopes, Staff determined piping the runoff through this stretch to be the most feasible approach.
 
This project proposes to remove the two existing bituminous flumes on either side of Inverness Lane, along with the 12-inch concrete culvert under Inverness Lane.  Instead, 18-inch concrete storm sewer pipe will be placed between two 48-inch diameter concrete catch basins with 2-foot deep sumps in the bottom to capture sand and other debris that would otherwise end up in the bottom of the City’s stormwater ponds, where it is more costly to remove.  Then, 18-inch high-density polyethylene (HDPE) storm sewer pipe will be extended south within City right-of-way east of Jarvis Street to the south edge of the property immediately south of Inverness Lane.  The HDPE pipe will then tie into the existing ditch that routes runoff to the east to the existing stormwater pond by the golf course.  Fill will be placed over the storm sewer pipe, and a shallow swale will be graded above the pipe to direct runoff from the street and adjacent properties to the existing ditch and stormwater pond.  The attached plans show the proposed improvements and have been shared with the property owner.
 
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.   

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 required design analysis would likely prevent this project from being completed this year.  For these reasons, Staff does not recommend this option.  
 
On September 15, 2020, the Public Works Committee reviewed the quote submitted by Dryden Excavating, Inc. and unanimously recommended that the City Council accept the quote and award 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 to authorize Bolton & Menk to stake construction at a cost not-to-exceed $1,600.   

Adopt 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 $1,520.