HomeMy WebLinkAboutCrossRoad Response 12.11.19
December 11, 2019
Willie Hall/ Greg Ilko
CrossRoad Engineers, P.C.
3417 S. Sherman Drive
Beech Grove, IN 46107
RE: Bear Creek South
Docket No. 17040018 SP Amend
Dear Willie,
Please find enclosed 1 set of revised Final Plats (Section 1A & 1B), Construction Plans, O&M Manual,
Update Carmel Engineering Waiver Letter and Drainage Report for Bear Creek South. The plans have
been revised per your comment letter dated August 3, 2017. I have addressed each of your items
individually with a numbering system consistent to your comment letter.
NOTE: Please know this project has been idle since August 2017 while the Developer worked with
adjoiners to south and Hamilton County Surveyor’s Office to secure an offsite easement for the
storm sewer outfall. In addition, as the project moves forward Pulte has split the Section 1 Final
Plat into two (2) phases Section 1A& 1B. The entire project will be built in one construction
season however there is now a 1A and 1B plat, the intent is to complete the initial infrastructure
required for the initial Section 1A 7 lots to allow for building permits to be pulled sooner than
waiting for entirety of infrastructure to be completed.
The revised drainage outfall has been moved to the east, revised to single outfall pipe, inverts and
Lake#1 raised, and an easement is being executed. The change in location raised the outfall and
thus Lake#1. Revisions were made accordingly. Meetings on outfall options were also conducted
with the Hamilton County Surveyors Office and this was deemed the best option and resolution.
1. Per Section 102.02 of the Stormwater Technical Standards Manual (STSM), the current revision
date shall be indicated on all sheets in the construction plans. See comments in bold and
italics below.
Noted. All sheets were updated for the recent revision and resubmittal date.
2. Per Section 102.02.xi.l of the STSM, the grading and drainage plan shall include one or more
typical cross sections of all existing and proposed channels or other open drainage facilities
carried to a point above the 100-year high water and showing the elevation of the existing land
and the proposed changes, together with the high water elevations expected from the 100-year
storm under the controlled conditions called for by the City of Carmel’s Stormwater Management
Ordinance, and the relationship of structures, streets, and other facilities. Open drainage
facilities – see Section 303 of the manual, and revise accordingly. Significant concern are
the rear yard swales proposed that will capture offsite areas.
Noted. The Drainage Report was updated to include a 100yr analysis for rear yard swales
capturing offsite areas. A typical section is noted on the grading and drainage plan for
these locations. A conservative analysis was done for each offsite watershed, the flow is
based on the entire offsite basin entering the typical section verses prorating percentage
of flow or further subdividing offsite basin. Of each condition reviewed, the typical detail
on sheet C8.3 “4’ Wide Bottom Swale Cross Section E-E” the maximum stage is indicated.
3. Per Section 102.02.xi.m of the STSM, the grading and drainage plan shall include a drainage
summary, which summarizes the basic conditions of the drainage design, including site acreage,
off-site/upstream acreage, allowable release rates, post-developed 10-year, and 100-year flows
leaving the site, volume of detention required, volume of detention provided, and any release
rate. Please see comment 5 below.
The drainage summary was updated on sheet C1.5 based on requested revisions below.
4. Per Section 102.02.xiv of the STSM, the Structure Data Table shall include, in addition to the
information provided, any notes related to the structure. Please include in the structure data table
notes for those manholes with snouts, and reference the snout detail on Plan Sheet C8.2, for
Structures 617, 636, 648, 651, 656, 666, 671 and 679. See comment 44 below.
The structure data tables were reviewed for conformance to above comment. The
previous submittal removed some storm structures as part of 141st entrance removal and
snouts were removed if part of the network associated with the added mechanical unit.
We believe this addresses this comment. Comment #44 below correlates to a comment
regarding swale slope labeling and assume does not require data table adjustments.
5. Per Section 102.03.i.a.i of the STSM, the stormwater drainage technical report shall contain pre-
development calculations, to include a pre-development watershed map, including the drainage
area designation corresponding to the designations in the drainage calculations, the area in acres
for each drainage area and any off-site drainage areas that need to be accommodated by the
system, including the fully developed right-of-way per the City of Carmel Thoroughfare
Plan. Please revise accordingly. Please include the area of the full width right of way in the
pre-developed watershed. Please review the northeast corner of the Existing Basin Map. It
appears that Basin “OFF-E1”, a portion of “OFF-E2” and approx. 5 acres of “PRE-BASIN”
drain north to The Preserve at Bear Creek, thus being a second outlet point for this site.
Per Section 302.03 of the manual, the release rate should be computed based on pre-
developed discharge to each outlet point.
Noted. We were previously excluding the full width right of way in the pre-developed
watershed as it did not drain into the site etc, thus not including within allowable release.
We did include within the proposed watershed map/basins to account for the water within
the detention. We updated the pre-developed watershed components as requested.
Prior to the development of Preserve at Bear Creek (by another consultant), the noted
offsite area potentially drained to that location. Bear Creek South development has
addressed the areas that might not be draining well today by accepting/routing through
Bear Creek South. Bear Creek South design does not direct runoff to Preserve of Bear
Creek thus we are not evaluating that release rate/point. Should the offsite property to the
east develop we have provided outfall connection points. We are proposing street inlets
at stub connection and side yard beehives to accept runoff to help drain lower areas along
ex tree line to remain.
6. Per Section 102.03.i.b of the STSM, the stormwater drainage technical report shall contain post-
development calculations, to include the following:
a. Addressed satisfactorily.
b. Addressed satisfactorily.
c. Please see comment 5 above.
The Drainage Report has been updated per #5.
7. Per Section 102.03.i.c of the STSM, the stormwater drainage technical report shall contain
detention calculations. Please see comment 5 above.
The Drainage Report has been updated per #5.
8. Addressed satisfactorily.
Noted.
9. Per Section 302.05 of the STSM, the following:
a. The invert elevation of the secondary outlet for bypassing off-site runoff is determined
according to the 100-year on-site only pond elevation only. From the calculations
provided, it appears the invert elevation of the secondary outlet for bypassing off-site
runoff for Lake #1 should be 866.95. Revised as required; please see comment 5
above.
Noted. In efforts working with the adjoiners for an offsite easement, double pipes
and end sections were not desirable. We revised the outfall to a single pipe and
per ordinance are now bypassing the offsite flow via overflow weir in more intense
storm events
b. The size of the secondary outlet and the 100-year pond elevation is determined by
routing the entire inflow, on-site and off-site, through the pond, and the crest elevation of
the emergency weir noted in Section 302.11 of the STSM is set at the 100-year pond
elevation that is determined. It appears the crest elevation for Lake #1 should be 868.26,
Lake #2 should be 870.39, and Lake #3 should be 869.27. Revised as required; please
see comment 5 above.
Noted. In efforts working with the adjoiners for an offsite easement, double pipes
and end sections were not desirable. We revised the outfall to a single pipe and
per ordinance are now bypassing the offsite flow via overflow weir in more intense
storm events
c. Please see comment 5 above, and revise accordingly.
The Drainage Report has been updated per #5.
10. Addressed satisfactorily.
Noted.
11. Addressed satisfactorily
Noted.
12. Per Section 501.01 of the STSM, 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 Structures 604, 604A, 605, 605A, 620, 621, 628, 629, 630, 638, 639, 646, 663,
658, 659, 676 and 677. Approval subject to favorable review of Drainage Waiver Request
dated July 7, 2017, for Structures 663, 658, 659, 662, 628, 629, 630, and 635, as well as
outlet control structures 606, 605, 604, 603, 602, 606A, 605A, 604A, 603A, and 602A.
Noted. See updated Drainage Waiver Request to Engineering Department. In order to
secure an offsite drainage easement, the location of the outfall pipe was required to be
moved east. The drainage outfall inverts were required to be raised which also raised
Lake#1 normal pool. In meetings with Hamilton County Surveyors Office, it was
concluded this was the best option.
13. Per Section 302.12.7 of the STSM, 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. This applies to the easement for the outlet storm structures across
the “Pegram” property (Plan Sheet C1.6). Discussions with the City of Carmel, the proposed
easement width shall be 15 feet outside each run from the center of each run, plus the width
between the two runs measured from the center of each run. Scaling, it appears an additional 5
feet along the east side of the proposed easement is required. Revisions to the easement
width made as requested; approval of drainage subject to Section 302.12.7 of the STSM.
Noted. It is my understanding in the adjoiner is in agreement with the current location and
meetings have been held with the Surveyors Office. In order to secure an offsite drainage
easement, the location of the outfall pipe was required to be moved east. The drainage
outfall inverts were required to be raised which also raised Lake#1 normal pool. In
meetings with Hamilton County Surveyors Office, it was concluded this was the best
option. I have been directed to move forward now that easement is a viable route.
14. Addressed satisfactorily.
Noted.
15. Per Section 303.05.7 of the STSM, minimum swale slopes are 1.0%, unless designed to act as a
stormwater quality BMP. Unless designed to act as a stormwater quality BMP, swales shall have
tile underdrains to dry the swales (See Hamilton County Surveyor’s Office Standard Details D-
16). Tile lines may be outlet through a drop structure at the ends of the swale or through a
standard tile outlet. Please review the swale behind Lots 16-19, inclusive. Please see comment
44 below.
All swales were reviewed for labeling on grading & drainage plan. Label locations were
adjusted to improve plan clarity, we believe they are all labeled and minimum of 1.0%.
16. Addressed satisfactorily.
Noted.
17. Per Section 501.03 of the STSM, a minimum drop of 0.1 foot through manholes and inlet
structures should be provided. Please review Structures 603, 603A, 604, 604A, 605, 605A, 611
and 612. Approval subject to favorable review of Drainage Waiver Request dated July 7,
2017, for Structure 610, as well as outlet control structures 606, 605, 604, 603, 602, 606A,
605A, 604A, 603A, and 602A.
Noted. An updated Drainage Waiver Request has been provided to both Engineering
Department and CrossRoad Engineers.
18. Addressed satisfactorily.
Noted.
19. Addressed satisfactorily.
Noted.
20. Addressed satisfactorily.
Noted.
21. Addressed satisfactorily.
Noted.
SWPPP
22. Please provide a wetlands delineation. Aerial photography indicates inundated areas within the
limits of the site. Subject to response from the developer.
Pulte Homes has indicated they have provided wetland delineation information to John
Thomas at the City of Carmel in 2017. It is my understanding that the direction is to
provide drainage for the poor drainage issues developed during Preserve at Bear Creek.
Please advise if not the case and I’ll try to follow up with others.
23. Addressed satisfactorily.
Noted.
24. Addressed satisfactorily.
Noted.
25. Please provide an address and list of qualifications for the trained individual responsible for
stormwater pollution prevention for this site. Note that the name provided on Plan Sheet C1.7
(per direction from Item 14 on Plan Sheet C8.0) is not the same individual provided in the
response letter dated July 7, 2017.
Sheets C1.7-C1.12 were revised to update the Person Onsite Responsible for Erosion
Control to match as Michael Morgan with Pulte Homes (currently slated to be Project
Manager during construction and TI)
26. Addressed satisfactorily.
Noted.
27. Addressed satisfactorily.
Noted.
28. Addressed satisfactorily.
Noted.
29. Addressed satisfactorily.
Noted.
30. Addressed satisfactorily.
Noted.
Engineering
31. Please provide an anticipated start construction date. Noted.
Pulte Homes would like to start construction upon final approvals.
32. Until the construction plans are approved, the current revision date shall be indicated on all plan
sheets. See comments in bold and italics above and below.
Noted. All sheets were updated for the recent revision and resubmittal date.
33. Addressed satisfactorily.
Noted.
34. Addressed satisfactorily.
Noted.
35. Addressed satisfactorily.
Noted.
36. Addressed satisfactorily.
Noted.
37. Please include in the notes on Plan Sheet C3.4 to read, “All Signs Are Installed By The City And
Require An Ordinance.”
Sheet C3.4 has been updated to include requested note as Carmel General Note #4.
38. Addressed satisfactorily.
Noted.
39. Addressed satisfactorily.
Noted.
40. Addressed satisfactorily.
Noted.
41. Addressed satisfactorily.
Noted.
42. Addressed satisfactorily.
Noted.
43. Addressed satisfactorily.
Noted.
44. Per Section 102.02.xi.r of the STSM, please label slopes of all drainage swales.
All swales were reviewed for labeling on grading & drainage plan. Label locations were
adjusted to improve plan clarity, we believe they are all labeled and minimum of 1.0%.
If you have any questions or require additional information, please feel free to contact me at your
convenience.
Sincerely,
Brandon T. Burke, P.E.
Senior Project Manager
Enclosure