HomeMy WebLinkAboutSDP202000063 Review Comments Final Site Plan and Comps. 2020-10-27� AI
?"h
�IRGRTF
COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road, Room 227
Charlottesville, Virginia 229024596
Phone (434) 296-5832 Fax (434) 972-4126
Site Plan review
Project: HTC Area C Townhomes —block II and III —Final Site Plan
Plan preparer: Stephanie Paul, Shimp Engineering stephanie(d�shimp-engineering.com
Shimp Engineering P.C., 912 E. High Street, Charlottesville, VA 2290
Owner or rep.: Post Office Land Trust, Charles Wm Hut & Shirley L. Fisher Trustees
P. O. Box 8147 Charlottesville, VA 22906
Plan received date: 8 Oct 2020
Date of comments: 27 Oct 2020
Reviewer: John Anderson
Project Coordinator: Andy Reitelbach
SDP2020-00063
1. Recommend revise FSP title to include ref. to SDP202000063.
2. Submit Road Plan and VSMP /WPO plan applications. Road plan and WPO plan approval is required for
FSP approval.
3. Roads must be built or bonded for final plat approval.
4. Note: On -site SWM (if any) and public /pvt. drainage easements may be recorded with fmal plat.
5. 10/5/20 Shimp Engineering curb and gutter waiver request is addressed via these Engineering site plan
review comments in context of design standards and ordinance (VDOT subdivision design standards,
drainage manual). Engineering does not request additional width with request for CG-6 where CG-2, or
roll-top, or ribbon curb may be proposed (see comments elsewhere). Curb and gutter are required by 14-
410(H) for pavement stability/durability, drainage, and safety reasons. Waiver request statement reading
`Curb and gutter is not needed internally along both sides of Road A and B for the purposes of helping to
frame the street or for the purposes of further defining the pedestrian realm' may express a useful planning
orientation, but this review reflects engineering perspective that includes pavement integrity, safety, and
drainage.
6. Engineering does not object to Planning authorization of Roads A, B, and C as private streets, but requests
pavement design for (C18) Road A, B, C sections. Also, item 78 below. Also, please note: horizontal
road design must meet AASHTO Guideline for Geometric Design of Very Low -Volume Local Roads
(ADT<400).
C5, block II
7. Lot 52, 53: Revise entrance geometry so that vehicle wheel path between street and parking area on lot is
continuous without steering correction after passing the sidewalk. Issues with this type constrictive design
have required post -construction demolition /rebuild on another project (Rivanna Village). Lots 54-60 show
`straight -in' (no steering) continuous entrance -driveway design. On a different project, vehicle wheel path
cut into lawn and entrance apron required widening, and relocation.
8. Show lot entrance design radii for each lot (ref. CG-9 detail, Cam. Certain lots show radii graphically,
Lots 36-52, for example, others do not —Lots 29-35, for example.
9. Eliminate Lot 45 drive entrance -crosswalk design, which places driveway in permanent conflict with a
pedestrian crosswalk. This design should not be shown under this or any circumstance, should be
abandoned, cannot be approved. Overlap (even partial, but total in this instance) between a pedestrian
crosswalk and driveway brings diametrically opposed pedestrian and vehicle facilities into permanent
Engineering Review Comments
Page 2 of 7
conflict, posing extreme risk to pedestrians. A driver reversing from Lot 45, whether under poor visibility,
distracted, or simply unaware, may strike a pedestrian (parent with stroller, etc.) who has every right to
occupy a crosswalk with expectation of safety. Perhaps Lot 45 driveway location can be shown adjacent to
Lot 44 to avoid pedestrian crosswalk conflict.
10. Lot 24,2 issues:
a. Driveway entrance width <12' absolute minimum. Revise to meet absolute min. entrance width.
IT. If approaching from Conner Drive, 12' w entrance maybe insufficient. Provide auto -turn at
entrance to Lot 24, approaching from east/Conner Drive. Revise as needed so that vehicle wheel
path does not leave paved driveway at entrance at revised min. width while at the same time not
requiring drastic maneuver to opposite side of Road A in order to park at Lot 24.
Ref. detail 3/C 16, CG-9 Driveway apron: desirable Min. 16' -Absolute Min. 12'.
RL.H.1KIN AOLIrNLwqQmqr/�xY aSYn/Q tti€FA.i
Lr°!mi`JrLifV-rEa.SKrvSw�EPseDw EpSDemIaREI6a.SK�.raTa`uRE.oNAn N roACCESS
CCESIS
IiSrtYrRrot.O[• e aU. TE.NaE�rtos
DETaA
. � SCC�NELOrSO rM EKLCS4R[ EIEEN bra � }
bl6 @pIgyB7� ip_ U. 'eac�o'Ei.%Nu.r 'ss DLouE"TiEe �i rM+
ea m"B0M AHDI[ ✓(: cne. MeiN FRTx maLD a r. SI
14LESSIN RNLI IWrzYlPS$EE .1r
i .A w.n . Yu ]r tla0 aasE. r
HALF PLAN
MF Dxv x awresirr mswwwm
nr cum rKr
.T.a *D sE Krerm rD wra Lre
YAIfdNE mM Cgi%SaI.iCM Y:
SE
Mme4 4VrtM � �� e l '
•. ..:v} '%i 4E } rAl v•i Li us u naE.ar aNc.
• � G vP1r m ni 1.1R MW4S � e
rw are we artrw NNr • },
F a R i WIyV MI.E.S[ F YDP[ .1 rNYY O FrrINYS
r
SECTION C'C ...
L i WYLN RQ F. MCLELNG IMIM 4 MER MS
9[V GiLw V
•'uE'= STANDARD ENTRANCE GUTTER „K „r
aoa (FOR USE WITH UNPAVED SPACE BETWEEN CURB & SIDEWALK) vmox D.¢
Dvu
"�3VDOT: CG-9 DRIVEWAY APRON
,,,C16 NOT TO SCALE
11. Multiple (perhaps the majority) of driveway entrance widths in block I1 are 9'. Revise entrances and avoid
driveway width <12'. Effect of design is that driveway width < 12' (which does not meet entrance
requirements), similar to constraint experienced in parking lots (especially if in or next to an SUV or
pickup), affords very little room to either side of a sedan, much less to either side of an SUV or pickup, to
enter or exit a vehicle. A 9' wide driveway is far worse than a 9' wide parking space where pavement is
continuous. A 9' w driveway means different surfaces (landscape stone, turf, uneven surface, edge) require
care to navigate. Even then, risk is random; 9' is too narrow for even well-balanced drivers to use without
mishap. Ave. width of a car is around 6 to 6.5 ft.; SUV, 69-79"; pickup, 6'-8"; pickup incl. std. mirrors,
96.8" (google). Compare with 9' (108"). Residents with pickups with std. mirrors will have, if truck is
centered, a strip < 6" to edge around the mirror without stepping off the driveway. Revise to extend width
at entrance onto lots; i.e.: 12' absolute minimum width. Note: Certain lots (3, 4, 5, all <1,275 SF lots) are
provided 16' w driveways, others (-1,367, 1,379 SF) have 9' w driveways. This seems insensible. Please
Engineering Review Comments
Page 3 of 7
consider practical effects and relevant standards. Design that requires residents to enter or exit vehicles in
the narrow permanent confines of a 9' driveway is deficient, given standard vehicle widths, and poses risk.
If ZMA or Planning Div. has approved a 9' w driveway for these HTC Area C block II townhomes, please
notify Engineering. Otherwise, please accept that entrance width for driveways should continue the
absolute minimum entrance width onto lots. To argue the alternative ( <12') ends where, is unclear. 9'?
8'? 6.5'? No paved minimum?
12. Lot 29: Remove road name and stop sign from driveway.
13. (and C18): Revise Road A, Sec. B-B to provide CG-6 where street cross -slope /x-section indicate runoff
concentrates against curb. Also, revise C5.
14. (and C18): Revise Road C, Sec. A -A to provide CG-6 along outer curb edge. See blue highlight, image,
below, near subdivision entrance off Berkmar Drive. Revise C5 plan view ( same comment ).
15. (and C18): Revise Road A, Sec. A -A to provide CG-6 where street cross -slope /x-section indicate runoff
concentrates against curb. Also, revise C5.
16. Provide occasional dimensional width labels for sidewalk fronting Berkmar Dr., widened with this project.
17. Road A and B 70'R (radii) do not meet AASHTO Guidelines for Geometric Design of Very Low -Volume
Local Roads (5400 ADT). Revise design to meet standards.
Note: Roads A, B, C are streets not alleys and must meet VDOT /AASHTO low -volume, local road
standards. (CL R =70' appears less than AASHTO Min.)
18. (With road plan) Submit ADT table values for ease of comparison with VDOT /AASHTO guidelines.
19. Line of sight label on 2,259 SF recreational area is unclear. `All terrace to be limited trees must be pruned
to provide the line of sight' is ambiguous. Revise text for clarity. Line of sight across Lot 28 extending
toward Conner Drive appears to require an easement. Provide and label (this/other) sight line easement/s.
20. Lots 33-35 indicate porch stairs extend across parcel lines on Conner Drive private right-of-way. Revise,
or provide easement with maintenance agreement/s for portions of stairs serving units on these lots that lie
within private right-of-way.
21. Label sidewalk width, Road B.
22. Label trail width in amenity /playset area.
23. Provide /label retaining wall safety railing in amenity /playset area for all retaining walls given risk to
children and proximity to Conner Drive (railing required even for retaining wall <4-ft. In. at this location).
Engineering Review Comments
Page 4 of 7
24. (Cl Provide retaining wall safety railing detail with max. opening between vertical members <_ 4".
25. Retaining wall appears to extend across SE side of amenity /play area. Provide TWBW labels at Lot 35
end of wall to clarify where the wall ends, and that the wall ends. Wall maintenance easement on Lot 35 is
required if wall is proposed to end at lot line.
26. Label amenity /play area trail material type, and width.
C6, block III
27. Label CG-2 (Typ.) between driveways that extends between walk and units on each lot.
28. Provide CG-2 at Lots 1 and 10 (end units), similar to Lots 2-9 to complete curbing at existing gaps,
especially since, in these gaps, vehicle wheel path for vehicles reversing from Lot 1 and 10 driveways will
tend to drift from pavement, degrade turf, and undermine pavement. Ref. HTC block 4 photo below for
29. New `alley name and stop sign' label appears in duplicate. Engineering commends design for emphasis on
pedestrian safety, but is unsure how this will work in practicality. Drivers are not accustomed to a double
stop sign, and may be confused. Block III connects with a public street. Engineering defers to VDOT, yet
recommends pedestrian crosswalk striping to either side of the stamped concrete brick pattern crosswalk,
with stop condition past the crosswalk at intersection with Lockwood Drive.
30. Label radii (typ.) for CG-2 curbing at ribbon curb (CG-2 that extends between alley and units). If <1.5'R,
revise design and provide detail for a gradually sloping concrete ramp to replace CG-2 at radii, such that
vehicle wheels can mount the ramp as vehicles enter driveways, and such that this section of curbing (now
ramp) is more durable and may not deteriorate as rapidly due to wheel strike /multiple wheel crossings.
31. C5C6: Provide intersection sight lines for internal intersections.
C7
32. Remove hydrant from sidewalk near storm Str. A5.
33. Provide pvt. san. easement on Lot 46 for Lot 47 owner since lateral may not be installed or accessed
without easement across a portion of Lot 46.
34. Similarly, provide pvt. san. lateral easement on Lot # /for owner of Lot #:
a. 47/48
b. 51/52
c. 13/14
d. 51/52
e. 53/54
f. 58/57
Engineering Review Comments
Page 5 of 7
g. 59/58
h. 60/59
35. Provide pvt. sanitary lateral for Lots 18, and 36-40.
36. Relocate pvt. san. laterals onto Lots 51 and 50. Two laterals are shown on Lot 52, none on Lot 50.
37. Recommend extend pvt. san. sewer lateral for Lot 52 further onto lot.
38. Recommend extend pvt. water laterals to structure side of sidewalks to minimize and avoid damage to
walks during water line service connections. [ Note: walks must be acceptable prior to street acceptance. ]
39. Note: San. sewer lateral clean -outs appear problematic for attached units with laterals located in pavement,
else clean -outs require traffic rated lids if CO's located in private drives. Examples: Lots 24-27.
Engineering defers to ACSA.
40. Provide private drainage easements across Lots 47-52, 54-59, and 3645, for yard inlet systems.
41. Revise New 20' Storm Sewer Esm't label to read New 20' Private Drainage Easement.
42. Label 8" DIP WLs.
43. Delete concrete shading (in turf area) adjacent to CG-6 on Lot 55, 60.
44. There may be limit on placement of hydrant behind parallel parking near Lot 60, Engineering defers to
ACFR.
45. Shift Str. A7 label to more nearly align with structure location.
46. C7C8: There are two A2 and two Al structures, with same labels used in both block II and IIl. Relabel
block III drainage structures (revise labeling on C 13 profile, as well). Revise labels in Calc. report tables.
47. C7C8: Show linework and provide labels to show roof leader line connection with storm system. Ensure
Lots 1-10, block I1I, roof leader line discharge does not sheet across sidewalk and is not trapped behind
CG-2 curbing, if discharge is to surface.
48. Revise design: spread at inlet A6 (6.27') exceeds half lane width (5'). Also, LD-204, Cale. packet.
C8
49. Label Ex. watermain size in Lockwood Drive.
50. Please use conventional notation for remaining lot size (69,971.6 SF).
51. Recommend extend pvt. water laterals to structure side of sidewalks to minimize and avoid damage to
walks during water line service connections. [ Note: walks must be acceptable prior to street acceptance. ]
C9
52. Revise grading behind lots 53-60 to provide a reasonably -defined channel, ensure low points at yard inlets.
Runoff may not cross more than 2 lots; i.e., must be collected on Yd lot.
53. Lots 12-23: In limited turf space, provide runoff collection on every third lot (yard inlet) unless roof leader
lines connect with new /ex. storm sys. Vertical fall across lots as well as ambiguity concerning roof leader
lines is cause for concern. No runoff collection appears to be proposed on Timberwood Blvd side of these
twelve (12) units.
54. Label retaining wall, Lots 12, 13.
55. Lot 12, 13 retaining wall TW BW elevations are somewhat ambiguous. Additional elevations at either end
(TW/BW at each end) would be helpful.
56. Provide % slope with flow arrow for all driveways.
57. Lots 36-45, and Lots 12-13 retaining walls: Provide evidence of recorded (party) wall maintenance
agreement/s, and provide wall maintenance easement on final subdivision plat.
58. Provide grading or spot shots to ensure there is no nuisance ponding in southmost parallel parking space (of
5 spaces) opposite Lots 4-9, Road A.
59. Wherever storm runoff concentrates against curbing, provide CG-6, for example, 5 parallel spaces
referenced in comment, immediately preceding.
60. Provide labels that more clearly identify proposed retaining walls that extend from block II amenity space
across lots 36-45. Also, if retaining walls:
a. Span lot lines, they require easement and recorded (party) retaining wall maintenance agreement.
Albemarle is not a party to wall maintenance agreements but needs to ensure wall maintenance
agreements are recorded. Also, item 57, above.
b. >3' ht., they require a building permit.
Engineering Review Comments
Page 6 of 7
c. >4' In., they require sealed geotechnical design, and safety railing. Also, item 23 above.
61. Evaluate depth of Q iun event runoff, Road B, where grade indicates runoff concentrates inflow line at
drive entrances to lots 36 thru 45. Ensure runoff does not enter driveways of any lot in the development.
62. Provide storm runoff capture (grate/inlet) in line with CG-6 or at end of CG-6, blue -circles, image below.
1136 10 100
}go -
CIO
63. Replace Alley B CG-2 between entrance on Lockwood Drive and intersection with back alley access to
units. Runoff concentrates against curbing along both edges (entrance alley is crowned). Engineering
consistently requests that design that proposes to concentrate runoff against a curb provide CG-6, not CG-2.
Issue has been raised with /resolved by Albemarle County Engineer.
64. CG-6 label near 82.81' contour is confusing. It is somewhat unclear if gutter pan is to extend across paved
asphalt alley entrance, or not.
65. Provide spot elevations along outer edge of southmost bump out at face of curb to ensure that runoff
internal to development that drains along Alley B to Lockwood Drive, reaches Str. B 1.
66. Label driveway grade, units 1-10.
C11
67. Recent aerial imagery indicates existing landscaping /streetscape trees along Tmberwood Blvd that may
relieve requirement to plant a few of the proposed street trees along Timberwood. Engineering defers to
Planning.
C13
68. Provide B 1 to A 1 storm profile. Although shown partially in detail 51C 13, request profile for Str. B 1 with
complete structural information (INV out, rim, str. type, etc.).
69. Provide label for %:" steel plate in floor of Str. A4, in each profile that shows Str. A4.
70. Show all crossing san. laterals in water profile. 8" DIP WL appears to be located 3.5-4' below proposed
grade, and crossing water laterals may conflict /should be shown.
71. Provide profile, Str. Cl, Berkmar Drive, since Ex. 4' DI-3B is to be replaced with new 10' DI-3B. Provide
rim elevation, replacement DI.
72. C 14: Show all crossing water laterals in san. sewer profile.
73. C 15: Revise sight line captions to read Berkmar Drive (and Road C), rather than Timberwood Blvd.
Engineering Review Comments
Page 7 of 7
C18:
74. Provide ribbon curb detail.
75. Provide CG-6 to ribbon curb transition detail.
76. Road A, Sec. C-C: Label CG-6, for clarity.
77. Provide typ. amenity /play area trail section.
78. Provide pavement design [D,, DP] per 2018 VDOT Pavement Design Guide for Subdivision and Secondary
Roads in Virginia, required to evaluate pavement section depths and for comparison with 10/5/20 Private
Street Request, item 1. [ link:
https://www.virginiadot.org/business/resources/MateriaWPavement Design Guide for Subdivision and
Secondary Roads.pdf]
79. CALCULATIONS (31-pg. packet d. 10/5/20 re: HTC Area C Townhomes: Block II & Block III, SWM Plan):
a. HTC Area C Townhomes Block I1 Inlets Drainage Area Map (p. 5 of Cale. packet)
i. Indicates 11 attached units fronting Berkmar Drive will discharge post -developed runoff
to Str. C 1. It is not apparent how Berkmar Drive portion of rooftop runoff will reach C 1.
Roof leader lines and roof runoff may not discharge to surface and sheet across sidewalk
fronting Berkmar Drive as this represents high risk of fall due to ice in winter weather,
and lesser risk of challenge to permanently stabilize areas along fronts of units, if roofs
discharge to splash blocks. Provide additional plan detail that indicates how development
areas shown draining to C 1 will reach C 1 without crossing sidewalk.
ii. Similarly, provide same level of plan detail showing how roof runoff from attached units
fronting Timberwood Blvd. or Timberwood Blvd. roundabout, will reach inlet structures
DI, D2 without sheeting across sections of broad sidewalk, which is impermissible.
b. Pg. 8, LD-229:
i. Revise pipe DIA, F1 A8 or revise slope since total flow=1.29 which is nearly equal pipe
capacity: 1.30cfs.
ii. Revise pipe, A5-A4, since total flow, 7.50cfs, exceeds pipe capacity: 7.0cfs.
c. HTC Area C Townhomes Block III Inlets Drainage Area Map (p. 12 of Calc. packet)
Please see comments above re. roof runoff discharge, in this instance to Str. B 1 on Lockwood
Drive. Roof leader lines may not discharge to turf areas fronting units given risk of freezing
sidewalk conditions in winter. Provide additional plan detail.
d. LD-229: Check table values, possible error, total flow Al to AO, given other 2 table flow values.
Please feel free to call if any questions: 434.296-5832 -x3069
Thank you
SDP2020-00063 HTC Area C Townhomes block II III ESP 102720