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HomeMy WebLinkAboutFile Documents.219 N Monarch St.0179.2017 (24).ARBK An Employee-Owned Company Date: November 16, 2017 To: Jack Danneberg Civil Engineer, City of Aspen Phone 970/429-2750 jack.danneberg @cityofaspen.com From: Daniel Dennison High Country Engineering 1517 Blake Ave Glenwood Springs, CO 81601 ddennison@hceng.com | 970-945-8676 Permit No. 0179.2017.ARBK, 219 North Monarch Street On August 31, 2017, High Country Engineering, Inc. (HCE) received comments from the City of Aspen Engineering Department relating to the constructions documents and drainage study for the site located at 219 North Monarch Street. A copy of the original comments is attached with responses. All addressed comments by High Country Engineering shown in red below the City comment. Land Surveying Civil Engineering 12/26/2017 Markup Summary Page: 1 Author: jackd File Name: 2171613 ISP-TOPO 24X36 04-18-17 (1).pdf Surveyor's certificate must state that the error of closure is less that 1/15,000. 2171613 ISP-TOPO 24X36 04-18-17 (1).pdf (2) Page: 1 Author: jackd File Name: 2171613 ISP-TOPO 24X36 04-18-17 (1).pdf Survey: 1. Survey must be tied to two COA monuments. 2. Provide vicinity map. Page: 11 Author: jackd File Name: 219 N Monarch Drainage Study.pdf Provide volume calculations for each bioretention pond. 219 N Monarch Drainage Study.pdf (2) Page: 11 Author: jackd File Name: 219 N Monarch Drainage Study.pdf Include pipes and trench drains in Operation and maintenance section of the drainage study. Page: 1 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf Show all roof drains and downspout locations on the plans. CIVIL PERMIT SET_STAMPED 07-24-17.pdf (19) Surveyor's certificate must state that the error of closure is less that 1/15,000. Survey: 1. Survey must be tied to two COA monuments. 2. Provide vicinity map. BASIN BIORETENTION AREA WQCV (Watershed inches) WQCV (CF) PR-1 NORTHWEST 0.082 28.3 PR-2 NORTHEAST 0.088 12.4 PR-3 SOUTHEAST 0.080 21.2 TOTAL 0.082 61.9 If the bioretention facilities surpass the WQCV, the system will allow runoff to overflow the pond weirs before entering the City of Aspen curb and gutter system, as it did historically. Calculations for the proposed drainage facilities are included in the appendices of this report under the Facility Calculations section. F. Operation and Maintenance The proposed drainage facilities are to be constructed in conformance with the City of Aspen Urban Runoff Management Plan, dated April 2010 and revised thereafter. The bio-retention basins will need to be inspected and maintained quarterly to make sure that the reservoirs have not become clogged and that the reservoirs are functioning properly. Debris and liter removal shall occur routinely. The owners of the property will be responsible for the maintenance and upkeep of the drainage facilities. The property owner shall dispose of sediment and any other waste material removed from a reservoir at suitable disposal sites and in compliance with local, state, and federal waste regulations. This project includes “Low Impact Site Design” to mimic the natural pre-development hydraulic pattern. Storm water runoff is to be in contact with soils and plants prior to reaching Provide volume calculations for each bioretention pond. BASIN BIORETENTION AREA WQCV (Watershed inches) WQCV (CF) PR-1 NORTHWEST 0.082 28.3 PR-2 NORTHEAST 0.088 12.4 PR-3 SOUTHEAST 0.080 21.2 TOTAL 0.082 61.9 If the bioretention facilities surpass the WQCV, the system will allow runoff to overflow the pond weirs before entering the City of Aspen curb and gutter system, as it did historically. Calculations for the proposed drainage facilities are included in the appendices of this report under the Facility Calculations section. F. Operation and Maintenance The proposed drainage facilities are to be constructed in conformance with the City of Aspen Urban Runoff Management Plan, dated April 2010 and revised thereafter. The bio-retention basins will need to be inspected and maintained quarterly to make sure that the reservoirs have not become clogged and that the reservoirs are functioning properly. Debris and liter removal shall occur routinely. The owners of the property will be responsible for the maintenance and upkeep of the drainage facilities. The property owner shall dispose of sediment and any other waste material removed from a reservoir at suitable disposal sites and in compliance with local, state, and federal waste regulations. This project includes “Low Impact Site Design” to mimic the natural pre-development hydraulic pattern. Storm water runoff is to be in contact with soils and plants prior to reaching the City of Aspen curb and gutter system. The plants and soil are to act as filters to remove pollutants. The proposed plants and soils are present along the lengths of proposed graded swales and within the proposed bio-retention basins. Include pipes and trench drains in Operation and maintenance section of the drainage study. Show all roof drains and downspout locations on the plans. Surveyor's certificate has been modified as requested. Surveyor's certificate has been modified as requested. The calculations used in bioretention pond design have been added to the pdf of the drainage report The maintenace portions of the drainage study now include the pipes and trench drains. The roof drain downspout locations are now clearly labeled on sheet C4 of the civil set. 12/26/2017 Page: 3 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf Move Utility pedistals onto private property. Page: 3 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf The utility pedistals on the SE corner of the lot need to be moved onto private property out of the alley. Page: 3 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf Maintain 30" seperation between gas and electric. Page: 4 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf This access walkway will require approval by the City of Aspen Parks Department due to tree conflicts. Page: 4 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf Show all roof drains. Move Utility pedistals onto private property. The utility pedistals on the SE corner of the lot need to be moved onto private property out of the alley. Maintain 30" seperation between gas and electric. This access walkway will require approval by the City of Aspen Parks Department due to tree conflicts. Show all roof drains. The utility pedastals have been relocated into the property as requested on sheet C3. The utility pedastals have been relocated into the property as requested on sheet C3. Gas and electric line layout has been updated to provide a minimum 30" separation. Understood. We did the best we could to stay beyond the tree drip lines on both sides of the path. Roof downspouts were shown, but have been revised to be more visible and called out in grading plan. 12/26/2017 Page: 4 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf Call out all inverts of perforated pipes. Page: 5 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf Widen alley way to 16ft. Page: 5 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf Design ADA ramps at 2% to minimize water in ramp. Page: 5 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf When measured by point elevations these Eastern ADA ramps exceed 8.3% slope. Please correct. Try to design slope less than 8.3% slope to help field install. Page: 6 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf Point elevations don't match cross sections. Please correct. Call out all inverts of perforated pipes. Widen alley way to 16ft. Design ADA ramps at 2% to minimize water in ramp. When measured by point elevations these Eastern ADA ramps exceed 8.3% slope. Please correct. Try to design slope less than 8.3% slope to help field install. Point elevations don't match cross sections. Please correct. The plans reflect a 16' driveway with handicap ramps that narrows to the existing alley width behind the sidewalk. This would be installed if the City requires the alley intersection improvements made during this permitting process must be removed. The cross-sections have been revised to reflect the corrsesponding spot elevations. The ramp slopes have been adjusted. The ramp lengths have been increased to reduce slope to 8.3% max slope where necessary. We have added call outs along the swale perforated pipes. 12/26/2017 Page: 6 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf Design positive drainage out of the ADA ramp to prevent ponding. Page: 7 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf What is the turning radius of this modeled fire truck? Page: 8 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf Details: 1. Provide asphalt patching detail. 2. Provide sidewalk detail. 3. Provide curb and gutter detail. Page: 8 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf The City of Aspen bioretention spec calls for 70% sand and 30% organics. Page: 8 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf An impermeable liner is not required for this swale. Design positive drainage out of the ADA ramp to prevent ponding. What is the turning radius of this modeled fire truck? Details: 1. Provide asphalt patching detail. 2. Provide sidewalk detail. 3. Provide curb and gutter detail. The City of Aspen bioretention spec calls for 70% sand and 30% organics. An impermeable liner is not required for this swale. Updated the Station 1+50 cross- section. We have added the Aspen Fire Proptection District fire truck specs to the exhibits of the turning movements around the narrowed Hallam/Monarch curve. We have added these details to the draings set. Revised soils media in detail per City of Aspen specifications. Impermeable liner is included for swales with underdrain due to the proximity of house. This was going to be allowed based on our conversations with City of Aspen Engineering Stafff. 12/26/2017 Page: 8 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf How will the pipe entering bioretention pond B be maintained? Page: 8 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf These values for swale B(2) seem inconsistent with the rest of the drainage calculations. Page: 8 Author: jackd File Name: CIVIL PERMIT SET_STAMPED 07-24-17.pdf A bioretention system that has an impermeable liner requires an underdrain. This liner is not required. How will the pipe entering bioretention pond B be maintained? These values for swale B(2) seem inconsistent with the rest of the drainage calculations. A bioretention system that has an impermeable liner requires an underdrain. This liner is not required. Added maitenance description/ note to detail and drainage report narrative The calcuations and detail are now matching. Changed impermeable liner to filter fabric within the bioretention ponds.12/26/2017