HomeMy WebLinkAboutCarmel Engineering Waiver Request 12.11.19
December 11, 2019
Alex Jordan
Department of Engineering
One Civic Square, 1st Floor
Carmel, IN 46032
RE: Bear Creek South – Updated Drainage Waiver Request
Docket Number: 17040018 SP Amend
Mr. Jordan:
A previous waiver request was submitted July 7, 2017. Since then, the project has been updated for an
adjusted storm outfall configuration which required raising Lake#1 normal pool. I’m following up with a
waiver request to the City of Carmel Stormwater Technical Standards Manual as listed below:
Waiver Request to the City of Carmel Stormwater Technical Standard Section 501.01 which requires
there should be no less than 2.5 feet of cover along any part of the pipe from final pavement elevation or
final ground surface elevation to the top of the pipe. This variance request is to cover proposed Structures
663, 658, 659, 662, 628, 629, 630, 635, 622, 621, 620, 612, 611, 676 and 675 all of which fall outside of
the pavement.
663: Roughly 1.58 ft of cover located in a rear yard swale. Cover increases along pipe in both directions.
Not anticipated to be exposed to vehicle loading. Shallower design driven by overall outfall elevation
restriction and/or crossing conflict with shallow gravity sanitary sewer.
658: Roughly 1.75 ft of cover located in a rear yard swale. Cover increases along pipe in both directions.
Not anticipated to be exposed to vehicle loading. Shallower design driven by overall outfall elevation
restriction and/or crossing conflict with shallow gravity sanitary sewer.
659: Roughly 1.72 ft of cover located in a rear yard swale. Cover increases along pipe in both directions.
Not anticipated to be exposed to vehicle loading. Shallower design driven by overall outfall elevation
restriction and/or crossing conflict with shallow gravity sanitary sewer.
662: Roughly 2.06 ft of cover located in a rear yard swale. Cover increases along pipe in both directions.
Not anticipated to be exposed to vehicle loading. Shallower design driven by overall outfall elevation
restriction and/or crossing conflict with shallow gravity sanitary sewer.
628: Roughly 1.66 ft of cover located in a rear yard swale. Cover increases along pipe in both directions.
Not anticipated to be exposed to vehicle loading. Shallower design driven by overall outfall elevation
restriction and/or crossing conflict with shallow gravity sanitary sewer.
629: Roughly 1.56 ft of cover located in a rear yard swale. Cover increases along pipe in both directions.
Not anticipated to be exposed to vehicle loading. Shallower design driven by overall outfall elevation
restriction and/or crossing conflict with shallow gravity sanitary sewer.
630: Roughly 1.83 ft of cover located in a rear yard swale. Cover increases along pipe in both directions.
Not anticipated to be exposed to vehicle loading. Shallower design driven by overall outfall elevation
restriction and/or crossing conflict with shallow gravity sanitary sewer.
635: Roughly 2.06 ft of cover located in a rear yard swale. Cover increases along pipe in both directions.
Not anticipated to be exposed to vehicle loading. Shallower design driven by overall outfall elevation
restriction and/or crossing conflict with shallow gravity sanitary sewer.
622: Roughly 1.58 ft of cover located in a rear yard swale/pond outlet control structure. Not anticipated to
be exposed to vehicle loading. Shallower design driven by overall outfall elevation restriction and/or
crossing conflict with shallow gravity sanitary sewer.
621: Roughly 1.93 ft of cover located in a rear yard swale. Not anticipated to be exposed to vehicle
loading. Shallower design driven by overall outfall elevation restriction and/or crossing conflict with
shallow gravity sanitary sewer.
620: Roughly 1.71 ft of cover located in a rear yard swale. Cover increases along pipe in both directions.
Not anticipated to be exposed to vehicle loading. Shallower design driven by overall outfall elevation
restriction and/or crossing conflict with shallow gravity sanitary sewer.
612: Roughly 2.10 ft of cover located in a rear yard swale. Cover increases along pipe in both directions.
Not anticipated to be exposed to vehicle loading. Shallower design driven by overall outfall elevation
restriction and/or crossing conflict with shallow gravity sanitary sewer.
611: Roughly 2.3 ft of cover located in a rear yard swale. Cover increases along pipe in both directions.
Not anticipated to be exposed to vehicle loading. Shallower design driven by overall outfall elevation
restriction and/or crossing conflict with shallow gravity sanitary sewer.
677: Roughly 2.33 ft of cover located in a rear yard swale. Cover increases along pipe in both directions.
Not anticipated to be exposed to vehicle loading. Shallower design driven by overall outfall elevation
restriction and/or crossing conflict with shallow gravity sanitary sewer.
676: Roughly 2.34 ft of cover located in a rear yard swale. Cover increases along pipe in both directions.
Not anticipated to be exposed to vehicle loading. Shallower design driven by overall outfall elevation
restriction and/or crossing conflict with shallow gravity sanitary sewer.
Lake #1 Outfall: Str#604,603,602,601: Varies, not less than 1 ft. Pipe material changed to Class V
RCP. Outfall elevation restrictions.
Waiver Request to the City of Carmel Stormwater Technical Standard Section 501.03 which requires a
minimum drop of 0.1 foot through manholes and inlet structures. This variance request is to cover
proposed Structures 611 and offsite Lake Outfall.
611: Str. #611 also does not provide a 0.1 ft drop in order to create a 0.2 foot drop at diversion manhole
#610. This drop at #610 provides positive flow to/from the Aqua-Swirl structure #WQ1. Due to elevation
challenges and desire to combine a substantial amount of the projects storm network to be routed
through a mechanical unit this was needed.
Lake #1 Outfall: Str#604,603,602,601: Outfall elevation restrictions.
657 & 658: Outfall elevation restrictions. Upstream structure reduced cover, inclusion of the 0.1’ drops
would further reduce cover upstream.
621: 0.1’ drop removed to contend with outfall elevation restrictions and raising of Lake#1 normal pool.
In the interim, if you should have any questions, or are in need of additional information, please feel free
to contact me at your convenience.
Sincerely,
Brandon T. Burke, P.E.
Senior Project Manager