HomeMy WebLinkAboutSDP202000031 Review Comments Final Site Plan and Comps. 2020-06-03 (2)Phone (434) 296-5832
Project:
Plan preparer:
Owner or rep.:
Plan received date:
(Rev. 1)
Date of comments:
(Rev. 1)
Reviewer:
Project Coordinator:
COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road, Room 227
Charlottesville, Virginia 22902-4596
Site Plan review
Boys and Girls Club, Northside — Final Site Plan
Craig Kotarski, PE, Timmons Group — 608 Preston Ave, Suite 200,
Charlottesville, VA 22903 [craig.kotarski(iDtimmons.com ]
Boys and Girls Club, 1000 Cherry Ave., Charlottesville, VA 22903
[ jpierceLbeclubva.org ]
26 Mar 2020
8 May 2020
20 Apr 2020
3 Jun 2020
John Anderson
Tori Kanellopoulos
Fax (434) 972-4126
SDP2020-00031 (Also, see SDP2020-00011. Initial site plan comments below are basis of Engineering review
comments for the Final site plan.)
If text grayscale, comment is addressed.
Follow-up at items 11, 14, 16, 47, only. .PDF preview prior to re -submittal is welcome.
* Engineering deems Initial Site Plan detail adequate for approval of the ISP. For Final Site Plan Approval:
1. VSMP /WPO plan approval is required prior to Final Site Plan approval. WP0202000005 is under review.
Note: Applicant made critical slopes waiver request; based on information submitted, including Applicant
email, 2/27/2020 4:05 PM, Engineering supports critical slopes waiver request. (FSP) Persists. April 20,
2020 9:41 AM email (A�plicant): `...asked Megan to pull it from the 4/15 BOS agenda, as we knew it
would increase based on this latest set of plans. Once you've been able to review and give your support, we
will update and get it back to the County as quickly as possible.' Also, email to Applicant, April 20, 2020
1:09 PM. (Rev. 1) FSP revision, None. Engineering will comment on revised WPO Plan, 4-Jun, if
possible. Albemarle board approved critical slopes waiver request on 6/3/20 (consent agenda item).
2. Stream buffers exist on parcel. Requirements listed at Ch. 17, Article VI, Stream Buffers, apply.
C1.1
3. Flush curb detail indicates —10" base. Please confirm depth of base and identify base material (asphalt,
asphalt type; stone, stone type).
4. Similarly, VDOT Std. CG-3 /CG-2 details indicate —10" base, each typ. section. Identify base material and
depth of each layer if base is a mixed stone /asphalt composite.
5. C1.2: Include VDOT SL-1 detail (safety slab).
6. C2.0: Show and label stream buffers.
C4.0:
7. This plan sheet appears twice; please label 2°d occurrence C4.3.
8. Revise CG-2 to CG-6 along south side of heavy-duty asphalt access, S side of building. Gutter is required
to convey drive aisle /access /parking area storm runoff. Curb alone is insufficient. (18-4.12.15.g.)
9. Label Jouett MS main building, to orient project.
Engineering Review Comments
Page 2 of 4
10. Label Ivy Creek School main building.
C4.1
11. Since proposed 8' (Max. ht.) retaining wall N of main parking area supports infrastructure (parking), sealed
geotechnical retaining wall plans are required prior to FSP approval. Please ref. retaining wall checklist for
plan reviewers (Attached). (FSP, Rev. 1) Persists. Applicant response (3/23/20; 5/5/20): 'Acknowledged.
Sealed retaining wall plans will be submitted with future submission.'
12. Label typical narrowest width dimension of 19 proposed curvilinear parking spaces.
13. Provide bollard at double -doors opening to 5' sidewalk and flush mount curb on south side of building to
protect occupants exiting blindly to sidewalk without visibility east, of approaching vehicles. Place left of
door, on exiting. Recommend bollards both right and left. At a minimum, provide bollard to left on exiting.
14. Provide evidence of coordination and approval from ACSA concerning design approval of sanitary sewer
pump station connecting via 6" new force main to Ex. pump station alongside Jouett Middle School. (FS)
Persists. Applicant: `Sanitary sewer pump station and force main plans have been submitted to ACSA with
this submission. See Sheets C8.0-C8.3.' (Rev. 1) Applicant is coordinating sanitary utility plan with
ACSA. Applicant response: `Sanitary sewer pump station and force main plans were once again submitted
to ACSA with this submission.' As follow-up: Engineering reminds to coordinate pump station plans,
reliability classification form /VDH review, as needed. Please ensure pump station /2" FM design receive
VDH approval.
15. Consider sequence and pedestrian safety needed during force main construction. Provide narrative and
details to protect visitors to Jouett MS (parents, teachers, students, etc.). (FSP) Addressed. Applicant:
`Sequencing and safety will be at the forefront of construction. Force main construction adjacent to Jouett
will most likely take place during the summer, when parents, teachers, and students are not present.
Additional notes have been provided on Sheets C8.0-C8.3.'
16. (C4.1, C5.0, C5.2): Label proposed storm lines downstream of 70-1f and 700-1f x 96" DIA CMP
underground detention systems public drainage easements. Provide easement plat, showing SWM facility,
facility access, and public drainage easements. Public drainage easement must extend to a natural drainage
feature, or to the property line. (FSP) Persists. Applicant: `...An easement plat will be provided with a
future submission.'
17. For both detention systems, provide overland relief to protect improvements against flooding, and critical
slopes against erosion in event of weir plate obstruction. Design overland relief to convey 10-yr event.
Assume complete bypass of systems, should one or both become non -operational. (FSP) Addressed.
Applicant `SWM1 would overflow to structure 202 if the weir plate was obstructed. In this case, the
overflow drainage would make its way south and end up in Ditch C, which would then convey it to SWM2.
If the weir plate in SWM2 became obstructed as well, the drainage would overflow to structure 402. This
structure is more than 1' below the adjacent building FFE, so no impact to the building is anticipated.
Ultimately, this drainage would overtop the curb and sheet flow south down the slope. Due to the proposed
grading, this overflow drainage would not channelize. While it is important to consider all possible
outcomes, it is very unlikely that this situation would occur; Boys & Girls Club will enter into a
Stormwater Maintenance Agreement with the County to ensure that the underground detention systems are
maintained and monitored so that the weir plates never become fully obstructed. For this reason, and those
listed above, we believe adequate protection is provide d for both site improvements and critical slopes.'
18. C4.1, C5.0, C5.1: Revise CG-2 to CG-6 at all locations where storm runoff collects against a curb. CG-2
alone is insufficient. (18-4.12.15.g.)
19. Recommend revise parking drive aisle grade slightly, provide DI at pipe 209 intersection with CG-6 (rev.
CG-2) in front of N side of building. Proposed grade requires exact construction to bend drive aisle runoff
between contours 543 and Str. 206. A more reliable design (a recommendation) is to direct runoff to a new
DI at pipe 209 (rev. CG-2 to CG-6 between Str. 234 and new DI, then CG-2 after new DI); then, after new
DI, provide grade directing runoff to Str. 206. Water flowing across a paved surface tends to travel
straight. A likely better long-term drainage design that more nearly meets expectations for pavement
/drainage performance is to collect runoff traveling west at a new DI, then collect runoff traveling north in
parking aisle /areas N of the building. Collection of concentrated flow at main entrance to facility avoids
Engineering Review Comments
Page 3 of 4
ice which is likely consequence of sheet flow over this distance, west then north, if proposed pavement
grade is constructed. At entrance to the building, pipe 209 is immediately below, and for slight expense, a
DI may greatly reduce risk to patrons, including children unaware of risk or hazard of black ice in winter.
(FSP) Addressed. Applicant: `Ditch F has been added to ensure that additional drainage does not make its
way to the drive aisle directly in front of the building. Additionally, CG-6 has been added to the entirety of
the eastern internal parking island to more effectively convey the water coming down the sloped drive aisle
to structure 206. As a result of these improvements, we do not believe an additional structure is needed in
front of the building.'
C4.1, C4.2
20. Label underground detention systems. If Mfr. system, include name of Mfr. in plan or profile view. (If
Mfr. system, for VSMP/WPO plan, include recommended installation guidelines, maintenance, and
periodic inspection guidelines.) (FSP) Persists only at WPO202000005. (SWMP review item 6, follow-up:
Technical installation notes provided. Please furnish periodic inspection and Lane mfr.-recommended
maintenance procedures on the [WPO] plans).
21. For VSMP and final site plan, ensure manway entries to underground facilities permit visual check of weirs
without entry. Manways should provide check of SWM facility operation, especially weirs. Do not place
SWM facility manways in a designated parking or loading space.
22. Add FM (force main) size descriptor (6" DIA).
23. Ensure Nyloplast ® pipes and risers are identified and labeled. Provide Nyloplast typical construction
installation and periodic maintenance and inspection guidelines.
24. Provide drainage calculations (LD-229, LD-204) for all storm pipes and inlets. (FSP) Addressed —See
4/20/20 WPO2020-00005 submittal Design Calculations & Narrative booklet, rev. April 17, 2020, p. 4-7.
25. Provide, show, label basketball court fencing.
26. C4.3: Label loading area/s, if any.
C5.0
27. Revise proposed contours, consistent with grading required to install Ditch B.
28. C5.0, C5.2, proposed 2:1 slopes on critical slopes do not, for the moment, appear to include reverse slope
benches. Ensure contours and labels guide construction of reverse slope benches. (FSP) Persists. Transfer
fill slope benching detail from WPO202000005, C5.2, to final site plan, C5.2. (Rev. 1) Addressed.
29. Provide EC-3, pipe or concrete channel section at proposed 90-degree change in direction of runoff
proposed for Ditch D.
30. (C5.0, C5.1, C5.2): Provide guardrail WDOT GR-1) with typ. details along south side of heavy-duty
asphalt access located on south side of building. Although CG-2 is proposed, proposed grading is an
unrecoverable slope. Guardrail is required. (FSP) Partially addressed. As follow-up: Provide VDOT GR-
4-2 detail on the plans. (Rev. 1) Addressed.
31. C5.2: Revise aisle grade on south side of building between contour elevations 534 and 516 to concentrate
flow against CG-6 curb (revise CG-2 to CG-6) for reasons of practicality and safety stated elsewhere.
Proposed grade assumes sheet flow over 18-ft vertical interval when effort should be made to eliminate
runoff from this drive aisle (place against curb) rather than design to spread runoff across entire width of
the drive aisle.
32. C5.0, C5.2: Label proposed slopes (3:1, 2:1) south and west of building. Slopes steeper than 2:1 are
impermissible.
33. Engineering recommendation to approve waiver to impact critical slopes (south and west of building)
requires design incorporate construction standards at 18-30.7.5, including reverse slope benches. (FSP)
Persists. Also, item 28, above. Transfer WPO202000005, C5.21 fill slope benching detail to FSP, C5.2.
(Rev. 1) Addressed.
34. Increase separation between pipe 303 and back face of retaining wall, especially at NW end of wall; see
ifnage [image removed with FSP comments].
35. Provide and define ditches /channels formed by proposed /existing contours N of playfield, and elsewhere
(blue arrows, images below [image removed]). Note presence of critical slopes immediately downslope of
many locations.
Engineering Review Comments
Page 4 of 4
C5.1, C5.2
36. Provide channel design for ditches formed by existing /proposed grade. Ref. images, b ,,. [images
removed]. (FSP) Addressed. Applicant: `Grading has been revised to limit channelization of water where
proposed grade meets existing grade. In the case shown below (Sheet C5.2), an existing channel exists in
this area. Proposed grading mimics existing grade to the largest extent practical, while reducing
channelization in the proposed condition.'
37. Show full extent of proposed grade, south of SE corner of basketball court. Grade =?
C5.4
38. 18-4.12.19.b. (Drainage Plan checklist, drainage item 7): Revise contours to prevent storm runoff running
through dumpster enclosure. Recommend direct pad to drain to a surface stone (French) drain to right of
pad, then exit surface drain via curb cut to drive aisle surface. Minimize contamination of stormwater
runoff due to contact with solid waste.
39. Consider highlight section downslope runoff without, in most cases, defined grade to intercept runoff prior
to curb, or sidewalk. Provide capture /conveyance in locations with 7', 10' or 15' vertical interval leading
to sidewalk, curb, basketball court, or heavy-duty concrete.
40. Provide curb or hardscape edging between earth slopes and heavy-duty concrete east of main building
(image, above).
C7.0, C7.1
41. Recommend plan note emphasize compaction requirements beneath pipes or MHs entirely in fill section;
prior VDOT specification would be appropriate. (Str. 402, 404, 501, RD3, nearly all Str. 412 — SWM2A)
CONTRACTOR SHALL PLACE FILL UNDER INLET(S) AT 95%
COMPACTION & EMBANKMENT MATERIAL SHALL
CONSIST PREDOMINANTLY OF SOIL AND BE PLACED IN
SUCCESSIVE UNIFORM LAYERS NOT MORE THAN 8' IN
THICKNESS BEFORE COMPACTION IN ACCORDANCE
WITH VDOT 2007 ROAD AND BRIDGE SPECIFICATION
303.04. AFTER T VERTICAL PLACEMENT OF FILL,
CONTRACTOR SHALL EXCAVATE RECENTLY LAID FILL
AND INSTALL COMPACTED VDOT STD. 21A STONE IN AN
8'x8' O.C. COMPACTED 21A AREA CENTERED ON THE
INLET(S). CONTRACTOR SHALL REPEAT THIS OPERATION
UNTIL AN 8'x8' O.C. 21A STONE BASE IN INSTALLED
BETWEEN THE EXISTING GROUND AND THE PROPOSED
INLET(S) BASE IN EFFORTS TO REDUCE THE RISK OF
SETTLING, CONTRACTOR SHALL PROVIDE VDOT WITH
COMPACTION RESULTS PRIOR TO ROAD ACCEPTANCE.
42. Include safety slab label in storm profiles for MH ht. >12-ft. Str. 102, 108, for example.
43. Recommend VDOT anchoring of storm pipe that approaches 16% grade. Conservative design, care, and
precautionary measures for storm pipe installed at steep grade on critical slopes are appropriate.
VDOT drainage manual, p. 9-37 (FSP) Addressed. Applicant: `The proposed outfall pipe layout has been
revised so that the slope does not exceed 4-1-OA [15%] at any point. As a result, VDOT anchoring is not
required.'
44. SWM1 — Str 100: Label reverse slope bench. (FSP) Comment revised to request ditches be labeled in
storm profiles. Reverse (fill slope) benching does not intersect storm lines, so will not appear in storm
profiles. (Rev. 1) Addressed.
45. Label SWM1 and SWM2 in plan view (C5.0).
46. Show /label riprap in profile at outfall Str. 100.
47. New: Please provide whips (canopy tree) planting plan /see Engr. email to Applicant, 6/3/2020 3:02 PM.
Please feel free to call if any questions: 434.296-5832-0069. Thank you
SDP2020-00031 Boys and Girls Club FSP 060320revl