HomeMy WebLinkAboutFile Documents.1010 E Hyman Ave.0025-2022-BCHO (18) RIVERCITY
CONULTANT
MEMORANDUM
Re: 1010 E. Hyman Avenue,Aspen: Drywell Setback Variance Request
To: Carly McGowan, E.I.T., Project Manager II, City of Aspen Engineering Department
From: Paul Southworth, P.E. River City Consultants
Date: January 11, 2023
Below is a response to each Engineering Comment made on the 1010 E. Hyman Civil Set. City of Aspen
comments are dated 11/18/2022. City of Aspen comments are transposed in black font. River city
Consultant's responses to the City's comments are provided in red font.
1) Call out distance from each drywell to property line with neighboring property and distance
between dry well and property line and ROW. Stormwater drywell must be located 10' away
from all property lines and building foundations
Distance callouts have been added to Sheet C2. A variance request memo with justification is
provided along with this resubmittal.
2) Provide detail for drywell in civil plans
Detail added as Sheet C4.
3) Is this a solid or grated lid? Please include in detail.
The surface runoff drywell is a grated lid.The foundation drain dry well is a solid lid. Both are
now noted on Sheet C2.
4) Please clearly denote if this is already existing or proposed. If it is proposed, all disturbance area
related to installation is included in disturbance area calcs. It appears that the electric secondary
service. Please submit updated load calcs and show trenching all the way to the transformer.
Confirm with utility dept.that there is adequate space/load in the transformer.
The electrical line is a replacement. Load calcs and communication with utility department are
included with this resubmission.
5) Please submit updated drainage narrative that includes drywell. In particular, please discuss:
a. Drainage basin that is collected in drywell
b. Purpose of drywell (WQCV or detention)
c. Show calculations for drywell capacity
d. Overflow path of drywell. Narrative must that any overflow drainage will reach the ROW
and not negatively impact neighboring properties RECEIVED
01/17/2023
ASPEN
BUILDING DEPARTMENT
RIVERCITY
u O f,l :3 U L 1_. A N I
Updated drainage report has been submitted addressing the drainage basin that is collected in
dry well, purpose of drywell (WCQV and Detention), calculations for drywell capacity, and
overflow path.All cross-lot drainage is removed in the proposed condition.
6) Provide Invert and sump elevations for stormwater drywell, as well as overflow route
Invert and sump elevations as well as overflow route added to Sheet C2.
7) Extensive grading in the ROW (like what is proposed) is not approved. Please revised.
Grading in right-of-way reduced to only what is needed to tie-in walkway connection to existing
sidewalk.
8) STRM line appears to drain to foundation drain drywell. Please clarify plans. All stormwater lines
should connect to storm drywell.
Labeling on which line drains to which drywell has been updated to provide clarity.
9) Please show limit of disturbance on civil set, including in the right-of-way. It appears that over
1,000 sq. ft of exterior area is disturbed, meaning that a major engineering review will be
required.
It was confirmed with Carly McGowan that disturbance in right-ofway is not needed in the limit
of disturbance calculation. Regardless, the on-site limit of disturbance was calculated as 1,088
SF. A note showing the limit of disturbance and amount of square footage has been added to
Sheet C2.
___..P6 vkiL _-- - __
Paul J. Southworth, P.E.
CO Professional Engineer No 60123
RECEIVED
01/17/2023
ASPEN
BUILDING DEPARTMENT