HomeMy WebLinkAboutResponse to CrossRoad Engineer 01-9-2014 LetterFebruary 3, 2014
Mr. Gregory J. Ilko, P.E.
Senior Project Manager
CrossRoad Engineers, P.C.
3417 South Sherman Drive
Beech Grove, Indiana 46107
Re: Health and Wellness Suites of Carmel – Drainage Review
Project No. 2013.00569
Dear Mr. Ilko:
This is a response to the January 9, 2014 letter regarding the review of the construction plans and
drainage calculations. Below are the original comments from the letter and the responses for
each comment.
1) Per Section 302.11, please provide calculations demonstrating the proposed pond
emergency spillway detailed on plan sheet C.414 provides for 1.25 times the peak
inflow discharge and peak flow velocity resulting from the 100-year design storm
event runoff from the entire contributing watershed draining to the
detention/retention facility.
Please refer to the Emergency Spillway Calculations located in Appendix C of the
Drainage Report.
2) Per Section 302.12, where the outfall from the stormwater drainage system of any
development flows through real estate owned by others prior to reaching a regulated
drain or watercourse, no acceptance shall be granted for such drainage system until
all owners of real estate and/or tenants crossed by the outfall consent in writing to the
use of their real estate through a recorded easement or are notified of such proposal
and their rights to appeal any approval of the design. Proof of this notification must
be submitted to the jurisdiction entity. The emergency overflow path for this site
appears to cross through private property east of the retention pond to the Fertig
Regulated Drain. Please review and revise, and see item 3 below.
After discussing the easement requirement with the City of Carmel
Engineering Department, it has been decided that due to the
overflow path following the existing drainage route to the legal
drain, no such easement will be needed.
201300569
Mr. Gregory Ilko, P.E.
February 3, 2014
Page 2
3) Per Section 306.02.C. emergency overflow paths associated with detention ponds shall be
contained within a minimum of 30 feet width (15 feet from centerline on each side) of the
drainage easement. Please see item 2 above.
After discussing the easement requirement with the City of Carmel Engineering Department,
it has been decided that due to the overflow path following the existing drainage route to the
legal drain, no such easement will be needed.
4) Per Section 501.01, 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.
Please review and revise accordingly.
We have updated the storm sewer profiles and have met the 2.5’ minimum cover
requirement. Please refer to the revised Storm Sewer Plan and Profile sheet C403-C409
and the revised Storm Sewer Design Table – Rational Method located in Appendix D of the
Drainage Report.
5) Per Section 501.03, a minimum drop of 0.1 foot through manholes and inlet structures
should be provided. Please review and revise accordingly.
A variance is being requested from the Section 501.03, requiring 0.1 foot drop through
manhole and inlet structures, of the Stormwater Technical Standards. A copy of the
variance request is provided and the response will be sent once the outcome has been
provided.
6) Per your response letter dated December 12, 2013, with regards to Section 104.02, a copy of
the variance request and response to this request should be provided to our office.
Copies of both variance requests are provided. Variances include the 0.1 foot drop through
structures and the FFE being 15 inches above adjacent roadway elevations. Copies of the
outcome of the requests will be provided at a later date.
If you have any questions or need clarification on any of these comments, please feel free to contact me
at our office (317) 547-5580.
Very truly yours,
American Structurepoint, Inc.
Ross L. Nixon, PE, LEED AP
Project Manager
RLN:
201300569