Agenda - Council - 02/14/2023 - Laserfiche WebLink

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No man-made materials were observed. The DNR provided information on their records for the normal water level of the wetland. This information was used to guide the design of the outlet. Observations/Alternatives: Staff met with Wes Saunders -Pearce, DNR North Metro Area Hydrologist, on October 25 and discussed the plans. He liked the plans and that the City is moving towards providing a permanent outlet structure for Wetland 114P. He asked for some additional information to be provided with the plans. The DNR normal water level for the wetland was recorded using the NGVD29 datum. The current elevation datum is NAVD88. Staff contacted a surveyor that has done work for the City and asked what the correction factor is to convert from NGVD29 to NAVD88. The NAVD88 is 0.34 ft higher than NGVD 29. THe DNR provided a normal water level of 858.1. Staff is proposing using this elevation based on NAVD88 which will result in the water level of the wetland being 0.34 ft higher than when the DNR recorded the elevation. The DNR also asked for the hydrology model for the wetland and drainage basin. The 2-year elevation is 856.8 ft, 0.5 ft above the normal elevation. The 10-year elevation is 859.8 ft, 0.8 ft above normal elevation. The 100-year elevation is 859.6 ft, 1.5 ft above normal elevation. The rims of the existing sanitary manholes in the project area will be set at 860.6 ft, 1 foot above the 100-year elevation. We also discussed timing for the DNR permit that is required to modify the outlet elevation. The DNR Permit can take up to 60 days from submittal of the application to receipt of the permit. Raising the sanitary sewer manholes is planned for late January/early February to take advantage of frozen conditions to allow access to the structures. Staff applied for the DNR permit in December 2022 and is working out the final details requested by the DNR. The City Council approved Resolution #23-038 at the January 24, 2023 meeting authorizing advertisement for quotes for the Wetland 114P outlet improvement project. Staff solicited quotes from four (4) contractors. Quotes were received from three (3) contractors. Tabulation of the quotes is attached to this case. Proposals Received Project a Dryden Excavating, One Call Contracting, Perkins Contracting, Inc. Inc. Inc. IP 2019-07 Wetland 114P Outlet $ 55,910.79 $104,945.00 $1081658.00 1 Improvements Dryden Excavating, Inc. submitted the lowest responsible quote. Based on the submitted quotes, Staff recommends accepting the proposal for Wetland 114P Outlet Improvements from Dryden Excavating, Inc. The contactor is expected to complete raising the sanitary manholes in February- March, with the outlet control structure installed after spring thaw. Motion to adopt Resolution #23-041 Accepting Proposals and Awarding Contract for Improvement Funding Source: Funding for this project is proposed to come from the Stormwater Utility Fund. The Engineers Estimate for this project is $90,875,. Recommendation: