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HomeMy WebLinkAboutFile Documents.232 E Main St.0078-2020-BCHO (74)November 3, 2020 502 Main Street • Suite A3 • Carbondale, CO 81623 • (970) 704 -0311 • Fax (970) 704 -0313 S OPRIS E NGINEERING • LLC civil consultants Jack Danneberg, PE Civil Engineer Engineering Department 201 N Mill Street 970-429-2750 RE: Supplemental Information: 232 East Main Street SE Job # 16016 Dear Jack, This letter summarizes the various civil engineering related revisions included in the requested change order dated November 3, 2020.  The proposed water service along Main Street has shifted approximately 8’ south to provide a more direct entry alignment to the proposed Mechanical Room. The proposed 4” gate valve for the corresponding hot tap would have fallen directly within the proposed Bioretention Cell #2. To avoid this conflict, we have eliminated the central bioretention cell and increased the depth and bottom treatment area for the northernmost bioretention cell. A landscape swale collects runoff from the tributary impervious area and routes the collected runoff to the northernmost cell for water quality treatment. The northernmost cell has been renamed to Bioretention Cell #2 to provide a sequential naming structure. Please refer to the water quality treatment summary table below and the revised plan set for the water quality treatment design and corresponding tributary imperviousness.  The proposed transformer vault in the northwest corner of the property has been adjusted approximately 2-ft east to provide additional circulation clearance at the bottom of the stairs associated with the adjacent Cortina Lodge. The proposed protective bollards have also been adjusted accordingly.  Grading for the sidewalk, curb, gutter and associated limits of disturbed asphalt within the right-of-way have been updated to reflect the as-constructed foundation conditions.  Snowmelt has been eliminated from the project and therefore plans and details have been revised accordingly.  The south entrance has shifted to the west and minor revisions to south patio delineation. Please don’t hesitate contacting our office with any questions and thanks in advance for your review and consideration of this information. Sincerely, Jesse K. Swann, PE Principal Sopris Engineering, LLC WQ SUB-BASIN AREA IMPERV %MDCIA EFF. IMPERV WQCV REQ.FOOTPRINT DEPTH PROVIDED I.D.I.D.S.F.S.F.IMPERV LEVEL %(in)WQCV (cf)(sf)(ft)WQCV (cf) BRC-1 OS2.2, 4.1 760 453 60%1 56%0.110 7.0 45.5 0.25 11.4 BRC-2 OS2.3, OS2.4, 4.2 810 298 37%1 40%0.075 5.1 20 0.42 8.3 11/09/2020