HomeMy WebLinkAboutWPO202100034 Correspondence 2022-02-14I® COLLINS ENGINEERING
February 8, 2022
David James
Department of Community Development
401 McIntire Road
Charlottesville, VA 22902
RE: Victorian Heights (WPO 202100034)
200 GARRETT ST, SUITE K CHARLOTTESVILLE VA 22902
��434.293.3719 PH 434.293.2813 FX
www.coll ns-eng ineeri ng.com
Thank you for your comments dated January 26, 2022 on the above referenced project. Below are our responses to
the remaining comments on the road plans.
A. Stormwater Pollution Prevention Plan
1. Addressed
2. Sections 4 & 5 will be updated with approved plans.
B. Pollution Prevention Plan
1. Addressed.
C. Stormwater Management Plan
1. Addressed.
2. Addressed.
3. This comment is acknowledged.
4. Addressed
a. As discussed and decided upon on Thursday February 3, the outfalls have been further
broken out for the analysis. The sheetfow areas have been broken out into drainage areas
to individual inlets. Please see sheet 8. Individual drainage areas to the existing inlets
analyzed are shown on sheets 12 & 13. In the existing condition, as a result to the change of
drainage areas of sheetflow, the drainage areas concentrated onsite have also changed and
the channel and flood protection analysis has been adjusted to match these areas.
b.As discussed, Subarea D (Renamed Subarea J as multiple drainage areas have been added) is
routed through the site. For the purposes as channel protection, this means no
improvement factor is applied to the offsite upland area (per DEQ requirements). For flood
protection, the onsite 10 yr flow of Drainage Area A + Upland Offsite Drainage Area J is less
than the existing onsite 10 yr flow+ Upland Drainage Area J. Storm sewer computations
provided in the SWM calculations packet shows the pipe under Berkmar Dr adequately
conveys the post development flow. The Narrative on Sheet 8 has been updated accordingly.
c. Tc flowpaths:
1. Post dev flow path has been altered as suggested. As the existing site is steep, the
resulting Tc was still below the minimum 0.10 hours and the Tc was rounded up to
the minimum Tc of 0.10 hours.
2. Post dev Tc path has always been shown as well as the description of it since the V
submission. Most of the path is channel flow through proposed underground storm
sewer. Perhaps that makes it harder to see, so the line has been made bolder.
5. Addressed.
6. Sheet 9—
a. Addressed.
b. Addressed.
c. Addressed.
d. Addressed.
7. As discussed, drainage structure profiles are not required for WPO approval. This comment is to be
removed.
8. Acknowledged.
9. Acknowledged.
10. Addressed.
11. As discussed, drainage design tables/worksheets are not required for WPO approval. This comment is
to be removed.
12. Addressed.
13. Agreed.
14. Acknowledged.
15. The offsite drainage area has been taken into consideration in both Channel Protection and Flood
Protection analyses as discussed in response to comment 4b above.
16. Addressed.
17. Addressed.
18. As discussed the highlighted portion to the left has been taken out of Subarea A. The highlighted
portion to the right has been defined further to show how drainage reaches the yard inlet.
19. UGD facility labels have been adjusted to show the facility as HDPE. A note has been added to the
UGD detail on sheet 9 indicating all connections to the UGD shall be water -tight.
20. The "&" symbol has been added. Please see sheet 11.
21. Calculations packet has been revised per comments.
22. The calculations packet has been signed and sealed.
D. Erosion and Sediment Control Plan
1. Addressed.
2. Sheet 5-
a. Stone weir for ST5 has been shown on Sheets 6 & 7.
b. Addressed.
c. B/M has been shown outside sediment trap. Label has been moved to outside the trap for
clarity. Please see sheet 6.
d. Addressed.
e. Addressed.
f. Addressed.
g. Addressed.
3. Sheet 6/7-
a. Addressed.
b. Addressed.
c. Addressed.
d. Addressed.
e. A note has been added to Sheets 6 and 7 as discussed that silt fence and safety fence shall
be installed at the back of the sidewalk.
f. Addressed.
g. Addressed.
h. Addressed.
i. Addressed.
j. Addressed.
4. Addressed.
5. Addressed.
6. Acknowledged.
7. Addressed.
8. Addressed.
9. Addressed.
10. Addressed.
11. Acknowledged.
12. Addressed.
13. Addressed.
14. Addressed.
E. Additional Meeting Items
1. Please see sheet 11 for updated grading plan showing Swale drainage to yard drain inlets behind
retaining walls as discussed in the meeting.
2. Please see sheets 11 and 12 for additional yard drains where roof drains will tie into around the
various units. The drainage map has been adjusted.
Should you have any questions, please feel free to contact Scott Collins at Scott@collins-eneineerine.com.
Sincerely,
Scott Collins, PE