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HomeMy WebLinkAboutFile Documents.433 W Bleeker St.0170.2017.ARBKMarkup Summary Page: 11 Author: jackd File Name: 06.28.2017.433Bleeker.DrainageReport.pdf Provide drain down calculations for drywell. 06.28.2017.433Bleeker.DrainageReport.pdf (2) Page: 11 Author: jackd File Name: 06.28.2017.433Bleeker.DrainageReport.pdf Drywell is not shown as 10ft away from foundation on the plan set. Rectify. Page: SURVEY Author: jackd File Name: 45349B.pdf Show water line associated with the water valve shown on the property. 45349B.pdf (1) Page: [4] C3 GRADING AND UTILITIES Author: jackd File Name: civil plans - 433 W Bleeker.pdf The survey shows a water valve here. What is associated with this water valve? How will the existing water valve be abandoned? civil plans - 433 W Bleeker.pdf (7) Page: [5] C4 LAYOUT Author: jackd File Name: civil plans - 433 W Bleeker.pdf 5'-1 1/16" 11 7.0 Operation and Maintenance 7.1 Drywell Drywells must be inspected and maintained quarterly to remove sediment and debris that has washed into them. A maintenance plan shall be submitted to the City in the Drainage Report describing the maintenance schedule that will be undertaken by the owners of the new residence or building. Minimum inspection and maintenance requirements include the following:  Inspect drywells at least four times a year and after every storm exceeding 0.5 inches.  Dispose of sediment, debris/trash, and any other waste material removed from a drywell at suitable disposal sites and in compliance with local, State, and Federal waste regulations.  Routinely evaluate the drain-down time of the drywell to ensure the maximum time of 24 hours is not being exceeded. If drain-down times are exceeding the maximum, drain the drywell via (Name)(#)D (ft)H (ft)π*H*(D/2)2) (ft3)0.3*π*H*((D/2)+1.5)2 - (D/2)2) (ft3)(ft3)(ft3) DRYWELL 1 6 9 254 95 350 327 Provide drain down calculations for drywell. 6.0 Proposed Facilities 6.1 Drywell The proposed drywell collects all runoff from the site and is designed to have capacity for full detention. The drywell is 6’ in diameter and 13’ deep, with 9’ of storage capacity. It is 10’ away from the structure and will not affect the foundation. Given the extra 3’ within the drywell, although the system will back up, it has a much higher capacity and will not overflow. 7.0 Operation and Maintenance 7.1 Drywell Drywells must be inspected and maintained quarterly to remove sediment and debris that has washed into them. A maintenance plan shall be submitted to the City in the Drainage Report describing the maintenance schedule that will be undertaken by the owners of the new residence or building. Pipe Design Flow Rate Proposed Pipe Diameter Slope d/D Manning Coefficient Rh/D Hydraulic Radius Exit Velocity (ID)Qdes (ft3/sec) Dpro(in)(%)(from Chart)n (from Chart)Rh (ft) = (Rh/D) Dpro V (ft/sec) = [1.49/n] Rh2/3 √S A1 0.068 4.0 1.50%0.35 0.01 0.19 0.19 6.11 A2 0.156 4.0 1.50%0.57 0.01 0.27 0.27 7.63 A3 0.178 4.0 1.50%0.62 0.01 0.28 0.28 7.80 A4 0.220 4.0 1.50%0.70 0.01 0.30 0.30 8.11 A5 0.248 4.0 1.50%0.75 0.01 0.30 0.30 8.21 A6 0.267 4.0 2.00%0.73 0.01 0.30 0.30 9.41 B1 0.051 4.0 1.50%0.31 0.01 0.18 0.18 5.72 B2 0.062 4.0 1.50%0.35 0.01 0.19 0.19 6.11 B3 0.074 4.0 1.50%0.37 0.01 0.20 0.20 6.20 B4 0.180 4.0 1.50%0.62 0.01 0.28 0.28 7.80 Drywell Storage Drywell Basins Diameter Storage Depth Internal Volume External (18" of Screened Rock) Volume Total Capacity Required Capacity (Name)(#)D (ft)H (ft)π*H*(D/2)2) (ft3)0.3*π*H*((D/2)+1.5)2 - (D/2)2) (ft3)(ft3)(ft3) DRYWELL 1 6 9 254 95 350 327 Drywell is not shown as 10ft away from foundation on the plan set. Rectify. Show water line associated with the water valve shown on the property. The survey shows a water valve here. What is associated with this water valve? How will the existing water valve be abandoned? 5'-1 1 / 1 6 " 1/15/18 Page: [5] C4 LAYOUT Author: jackd File Name: civil plans - 433 W Bleeker.pdf 8'-1 11/32" Page: [5] C4 LAYOUT Author: jackd File Name: civil plans - 433 W Bleeker.pdf No variance will be granted for a drywell within 10ft of the neighboring property line. Page: [5] C4 LAYOUT Author: jackd File Name: civil plans - 433 W Bleeker.pdf Drywell is shown within 10ft of foundation which will require a variance. Page: [6] C5 FOUNDATION DRAINS Author: jackd File Name: civil plans - 433 W Bleeker.pdf Surface drainage can not be routed to foundation drywell. Page: [7] C6 DETAILS Author: jackd File Name: civil plans - 433 W Bleeker.pdf Show pervious paver underdrain on plans. 8' - 1 1 1 / 3 2 " CK 37 No variance will be granted for a drywell within 10ft of the neighboring property line. ALLEY B L O C K 3 7 Drywell is shown within 10ft of foundation which will require a variance. Surface drainage can not be routed to foundation drywell. Show pervious paver underdrain on plans. 1/15/18 From: Jay Engstrom Roaring Fork Engineering 592 Highway 133 Carbondale, CO 81623 Jaye@rfeng.biz (970) 404-1144 Richard Goulding Roaring Fork Engineering 592 Highway 133 Carbondale, CO 81623 richardg@rfeng.biz (970) 948-7474 To: Jack Danneberg Civil Engineer City of Aspen Engineering Department 130 S. Galena Street 970-429-2776 (Office) 970-920-5081 (Fax) 433 West Bleeker Comment Responses Permit Number: 0170. 2017.ARBK January 10th, 2018 Included in this document are the comments and corrections made by the City of Aspen’s Engineering Department. In green, below each comment, is a written response to the comment from Roaring Fork Engineering. These responses explain the alterations to the proposed design for conformance to the state and local codes. Adjustments to the plans, calculations, and drainage report are all described in the responses. All alterations done in the drainage report are highlighted. --------------------------------------------------------------------------------------------------------------------- ENGINEERING REVIEW COMMENTS AND CORRECTIONS Drainage Report and Plan The drainage report and plan set is not in compliance with the City of Aspen Grading and Drainage Requirements for Major Design. The following items from the Checklist for Grading and Drainage Requirements for Major Design need to be included, addressed or discussed: DRAINAGE PLANS SHALL INCLUDE: 1. The survey shows a water valve here. What is associated with this water valve? How will the existing valve be abandoned? The valve shown on the survey is an irrigation valve. An existing water line appears to run onto the property and has been installed for irrigation purposes. Water service will be 1/15/18 433 W Bleeker Comment Responses January 10th, 2018 Page 2 of 3 abandoned as per City of Aspen Water Department Specifications and irrigation and water lines will be removed. Notes have been added to the utilities design on page C3. 2. Revise dimensions of the distance between the drywell and the foundations and property line. The proposed drywell size and location has been revised. A smaller diameter and deeper drywell was used to infiltrate the groundwater below the foundation. The edge of the drywell is now 10’ from the neighboring property and 5’ from the Alley Block 37 Right of Way. A variance has been submitted to have the drywell within the 10’ setback from the alley and the structure foundations. This design was approved by HP Kumar, and a description of the agreed drywell is included in the attached letter. See Sheet C2 for updated calculations and C4 for layout and information within the plan set, along with updates in the drainage report. 3. No variance will be granted for a drywell within 10ft of the neighboring property line. See previous comment response. The drywell is now 10’ away from the neighboring property line, but 5’ away from the alley right-of-way. A variance to allow a drywell within the 10’ Right-of-Way setback from the Alley Block 37 has been submitted to approve the new location of the drywell. 4. Drywell is shown within 10ft of foundation which will require a variance. A detailed cross section has been provided to show the feasibility of a drywell within 10 feet of the foundation without affecting the foundation. The foundation of the lightwell is within 5 feet of the drywell, however the footer from the main foundation wall is almost 12 feet away. A variance has been submitted to allow the placement of a drywell within 10 feet of the structure. This design was approved by HP Kumar, and a description of the agreed drywell is included in the attached letter. See Sheet C4 of the plan set. 5. Surface drainage cannot be routed to foundation drywell A lightwell detail has been included on page C5 of the civil set. Lightwells have snowmelted concrete, where a center drain conveys runoff into a screened rock bed beneath the concrete base. 6. Show pervious paver underdrain on plans. The location of the underdrains of the pervious paver patios and tie in locations have been shown on Sheets C3 & C4 of the plan set. DRAINAGE REPORT SHALL INCLUDE: 1. Provide drain down calculation for drywell. A percolation test was performed on December 19th, 2017. Draw down time has been calculated using the determined rate of 6 inches per hour. See page 11 of Drainage Report. HP Kumar approval of drywell location must be included in the variance request. 1/15/18 433 W Bleeker Comment Responses January 10th, 2018 Page 3 of 3 2. Drywell is not shown as 10ft away from foundation on the plan set. Rectify. Drywell location has been updated in Drainage Report with explanation of placement and feasibility. See page 11 of Drainage Report. --------------------------------------------------------------------------------------------------------------------- Feel free to contact me if you have any questions about the responses to your comments. Sincerely, Jay Engstrom Design Engineer Roaring Fork Engineering (970) 404 – 1144 jaye@rfeng.biz 1/15/18