HomeMy WebLinkAboutFile Documents.1320 Mountain View Dr.0291.2018 (2).ARBK P.O. Box 3901 YARNELL CONSULTING & 229 Midland Ave.
Eagle, Colorado 81631 Basalt, Colorado 81621
CIVIL DESIGN, LLC
(970) 323-7008 • 5/3/2019
Jack Danneberg
City of Aspen Engineering Department
201 N. Mill Street,Suite 101
Aspen, Colorado 81611
Jack.Danneberg@CityOfAspen.com
Subject: Engineering1_0023.2019.arbk_1320 Mountain View
Comment Responses
Jack:
Thank you for your thorough review of our project.Please find your comments and the associated
responses listed below for the above-referenced project.
1. Sheet C2 "Existing Conditions&Demo Plan". Call out abandonment of existing water service
per city of Aspen standards.
YCCD Response:The label has been revised.
2. Sheet C4.1 "Stormwater Mgmt. Plan". Provide a drainage swale detail.
YCCD Response:A swale cross section would not be appropriate on this sheet.Alternatively,
sections A and B are on Sheet C5.1 "Drainage Plan"where the section cuts are shown.
Furthermore Note 6 on Sheet C5.1 continues to reference the drainage report for analysis of
the cross sections.
3. Sheet C4.1 "Stormwater Mgmt. Plan". Provide an overflow detail for bioretention pond.
YCCD Response: The overflow detail would not be appropriate on this sheet.Alternatively,
we designated an overflow location and dimensions on Sheet C5 "Grading Plan."A detail has
been provided on Sheet C9.1 "Details."
4. Sheet C4.1 "Stormwater Mgmt. Plan". Provide bioretention detail. See URMP for
specifications.
YCCD Response: Note 8 on Sheet C5.1 "Drainage Plan"was included for this purpose. But per
the comment,a detail has been added to Sheet C9.1 "Details."This would not be appropriate
on Sheet C4.1 "Stormwater Mgmt. Plan."
5. Sheet C5 "Grading Plan".Show curb stop for water service line on property line.
YCCD Response:The curb stop is shown on the water line.It is labeled on Sheet C6.1 "Utility
Plan"as that seems most appropriate.
6. Sheet C5 "Grading Plan".Water service directly under proposed evergreen tree.Water line
and evergreen tree need to be installed so they can be maintained.
YCCD Response: The evergreen tree has been relocated off the proposed water service.
RECEIVED
Engineering1_0023.2019.Arbk_1320 Mountain View Pagedg� 212019
ASPEN
BUILDING DEPARTMENT
P.O. Box 3901 YARNELL CONSULTING & 229 Midland Ave.
Eagle, Colorado 81631 Basalt, Colorado 81621
CIVIL DESIGN, LLC
(970) 323-7008 • 5/3/2019
7. Sheet C7"Foundation Drain Plan". Is the sump discharged somewhere?
YCCD Response:Yes,it will discharge out the west wall of the residence and into the
vegetated swale for conveyance to the pond.A note has been added to the sheet
accordingly.The geotechnical investigation did not identify the presence of groundwater;
therefore,the foundation drain and pump are not anticipated to receive water. Refer to
Sheet P-200 "Plumbing Plan-Foundation Level."
8. Sheet C7"Foundation Drain Plan". Drainage report calls out for 990 sqft of bioretention area.
This seems to suggest only 176 sqft. Show clearly extent of bioretention area.
YCCD Response:All the drainage calculations have been revised as the buyer for the project
would like the flexibility of adding approximately 1,000 square feet of additional
impervious area without needing to update the drainage calculations again.Also,we added
a steel edger to gain additional volume while reducing the footprint. But to respond to your
comment: as shown on the stage-storage curve for the pond,approximately 212 (previously
176) square feet of bioretention area is required.The 690 (previously 990) square feet
refers to the footprint of the detention pond when it is full during the 100-year storm event.
The infiltration calculation accounts for the maximum footprint of the full pond since
infiltration will be occurring beneath all the water during the 100-year storm event-not
just at the bioretention area.
9. Sheet P-202.00 "Plumbing Plan - Upper Level".Where are the roof drains routed to?
YCCD Response: Due to insufficient available elevation on the site,below-grade piping is not
viable.Alternatively,roof drains are proposed to splash onto grade where they are routed
overland via vegetated swales to the bioretention area.A label has been added to Sheet C5.1
"Drainage Plan"to indicate the locations where roof drains discharge onto grade.
10. "Drainage Package"[Page 4]. Sign and stamp in final submittal.
YCCD Response:We provided an unsecured,unstamped version for you to markup but also
a secured,stamped version for the original submittal.We are taking a similar approach with
the resubmittal.
11. "Drainage Package"[Page 15].The soils report calls out as stated that the perc rate is
between 2 and 5 inches per minute. It started at 2 and ended at 5.The stable perc rate must
be used for the calculations, 5 min/inch.
YCCD Response: The calculations (and associated pond footprint) have been revised to
reflect 5 minutes/inch.We added a steel edger to gain additional volume while reducing the
footprint.
12. "Drainage Package"[Page 15].Where is [990 square feet of stormwater detention]
provided? Is this all in the bioretention bed?
YCCD Response: No,the WQCV calculations and associated grading only necessitate
approximately 212 (previously 176) square feet of bioretention area.The approximately
690 (previously 990) square feet refers to the footprint of the detention pond when it is full
during the 100-year storm event.The infiltration calculation accounts for the maxinRECEIVED
Engineering1_0023.2019.Arbk_1320 Mountain View Pagedg� 212019
ASPEN
BUILDING DEPARTMENT
P.O. Box 3901 YARNELL CONSULTING & 229 Midland Ave.
Eagle, Colorado 81631 Basalt, Colorado 81621
CIVIL DESIGN, LLC
(970) 323-7008 • 5/3/2019
footprint of the full pond since infiltration will be occurring beneath all the water-not just
at the bioretention area.
13. "Drainage Package"[Page 15]. [In Section 6.5] give a brief description of how the design is
intended to operate.
YCCD Response:The requested description has been added.
Sincerely,
\V
Justin J.Yarnell, PE
Colorado PE Number 47241
RECEIVED
Engineering1_0023.2019.Arbk_1320 Mountain View Page �5 212019
ASPEN
BUILDING DEPARTMENT