HomeMy WebLinkAboutSUB202000098 Review Comments Road Plan and Comps. 2020-10-16� AI
�h
�lRGIN�P
COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road, Room 227
Charlottesville, Virginia 22902-4596
Phone (434) 296-5832 Fax (434) 972-4126
Subdivision Plan Review
Project title:
Galaxie Farm ROAD Plan
Project file number:
SUB2020-00098
Plan prepares
Shimp Engineering, Justin M.
Owner or rep.:
Jasper L or Mallie P Haynes,
Plan received date:
21 May 2019
(Rev. 1)
3 Aug 2020
(Rev. 2)
13 Oct 2020
Date of comments:
16 Jul 2020
(Rev. 1)
3 Sep 2020
(Rev. 2)
16 Oct 2020
Reviewer:
John Anderson
SUB2020-00098
e
Shimp [ iustin shimp-engineering.com ]
P.O. Box 422, Charlottesville, VA 22902
(Rev. 2) Note: A few comments may overlap preliminary plat Engineering review comments
(SUB201900198, 2/l/20). To the extent design was revised in response to preliminary plat (road -related)
comments, please disregard comments that are repetitive, or not applicable.
C1
C2
1. Ensure land use schedule impervious area is consistent with WPO plan for this development. (Rev. 1)
Addressed. Applicant response (7/31/20 letter): `Area reviewed for consistency.'
2. New- mei,.8P gt1b...:. men plan r . development Par' est WPO received WP0202000
3. C2 does not clearly indicate two parcels. There are two parcels. Please show current parcel boundaries.
(Rev. 1) Addressed.
4. Label Cow Branch. (Rev. 1) Addressed.
5. Label steep slopes (preserved /managed). (Rev. 1) Partially addressed. As follow-up: Provide Exhibit for
portions of slopes currently shown on steep slopes overlay district that design wishes to consider < 25%
(for example, Lot 65). A plan label does not effect removal of steep slopes from the overlay district.
Provide field survey elevations, steepest grade, date of survey, survey firm, area (sf) and limits of steep
slopes proposed to be removed from the overlay district. (Rev. 2) NA. Applicant response (SE letter,
9/21/20): `Disturbance of preserved slopes overlay (regardless of actual slope) is no longer proposed.
Removal/revision of overlay no longer proposed. Notation revised for consistency.'
6. Note: If roof runoff is proposed to be collected and conveyed via leader lines to drop inlets or will intersect
proposed 15" DIA stone lines, show leader lines. (Rev. 1) Addressed. Applicant: `Only lots 46-48 require
roof drain routing, leaders have been shown. Drains (intentionally) outlet to front yards.'
7. Please consider recent Building Inspections Div. guidance which may influence design of retaining walls or
affect plan approval. Albemarle County Building Official advises that: "Retaining walls shall either be
independent and terminate at the property [read, lot] line or an easement and maintenance agreement shall
be executed between property owners involved." We mention this now so that it does not cause issues, or
delay or impede subsequent plan (or building application) reviews /approvals. (Rev. 1) Persists.
Applicant: '...we have notified the developer of this condition. Developer is preparing retaining wall deed
and maintenance agreements to be submitted with the subdivision plat. For now, wall Maintenance
easement, with access from ROW, added to plans. We will finalize deed/agreements by the time the
Engineering Review Comments
Page 2 of 13
subdivision plat is filed.' As follow-uo: Please see item 11, Albemarle is not party to wall Maintenance
Agreements, but needs to confirm Agreement is recorded (with covenants and restrictions, for example).
(Rev. 2) Persists. Applicant: `Noted, we appreciate the advance notification on this. Agreement will be
completed before subdivision plat approval, legal references will be listed on subdivision plan. We have
added this to our internal management checklist to avoid future plat approval delay.'
C4:
8. Label lots. Also applies to C7 C8C8. (Rev. 1) Addressed,
9. Please examine remnant existing and proposed contours on Lots 7-11. Provide storm runoff capture
/conveyance such that surface runoff does not cross more than 3 lots without capture /conveyance. Ref.
Drainage Plan Checklist for plan reviewers, p. 1, Drainage section, last item [ yard inlets appear to be
required ] (Rev. 1) Addressed. Applicant: `The grading on these lots was slightly revised to ensure
sheetflow does not cross more than 3 lots.'
10. Lots 53-56 runoff is shown sheeting across Road E. Provide drainage to intercept sheet runoff and convey
via street -side pipes or yard inlet pipe system. Design must prevent offsite runoff from traversing Road E
street surface. (Rev. 1) Withdrawn. Applicant: `This design is intentional as part of a low impact design
strategy. As par[ of the rezoning application, we were granted a curb & gutter waiver for Road E. So we
were allowed to have the small amount of water from Lots 53-56 sheetflow across Road E. And although
the CG-7 on the downhill side is not required, we judged that this design would provide better public
benefit for runoff control than if no curb & gutter were provided. So as it has been designed, this street
section goes above what is required by the zoning requirements for this road.'
11. Provide temporary (off -site) construction /permanent grading easement/s as needed to construct proposed
retaining wall across parcel lines, Lots 1-7. (Rev. 1) Partially addressed. Applicant: `Permanent wall
maintenance easement added. While we anticipate minor construction disturbance in the Galaxie Farm
ROW, this activity is permitted as long as full access is provided for the residents who use the road.
Grading will not disturb past the existing fence, thus fall access is ensured, thus no other easements are
necessary for construction.' Asfollow-u : While Albemarle is not party to wall maintenance agreements,
per building inspections division directive, CDD must confirm an agreement exists, and is recorded. Please
provide deed book -page ref. to retaining wall maintenance agreement prior to final plat approval. (Rev. 2)
Persists. Applicant: `Noted, we appreciate the advance notification on this. Agreement will be completed
before subdivision plat approval, legal references will be listed on subdivision plan.'
12. (C7 C 12): Calculate depth in roll-top gutter, Road E. Ensure runoff does not enter driveways (esp. Lots
57, 58). (Rev. 1) Addressed. Applicant: `Acknowledged, this calculation was added to the LD-204 page.
The curb is adequate per VDOT standards —with a flow depth of 0.21' (2.5") for a storm with I=6.0.'
13. C3 C4C4: 8' wide ditch crossing lots 23 thru 38 is an infeasible design. Revise surface ditch to subsurface
drainage (inlet /pipes). Owner of multiple lots may flatten obscure ditch and disrupt drainage since each lot
has such limited lawn area. A surface ditch design crossing 15 lots will not in this instance be approved.
(Recall homeowner resistance to swale construction across lawn areas at Hillbrook Subdivision.) (Rev. 1)
Addressed. Applicant: `Ditch removed from Lots 23-38 and replaced with yard drains & storm pipe. Yard
drains placed to ensure flow does not cross more than 3 lots. Drains daylight in Open Space B past the
(revised) emergency connection.'
14. Similarly, provide subsurface storm runoff collection /conveyance for Lots 15-22. (Rev. 1) Withdrawn.
Applicant: `For these lots, runoff does not cross more than 3 lots, but sheetflows into a natural channel just
behind the rear property line. The runoff is captured at structure EX where this channel re-enters the
property.'
15. Ensure storm runoff from impervious areas, Lots 15-38 is conveyed and treated or detained, as needed, to
comply with state or local code, including MS-19. It appears a necessity that given close proximity to
property line to SW that impervious rooftop storm runoff must be collected, since splash block -only
discharge cannot transition to sheet flow in limited space available (Lots 15-22, especially). (Rev. 1)
Partially addressed. Applicant: `Acknowledged, this runoff is captured in EX (serves lots 15-22) and in
yard drains (serves lots 23-58). Since 15-22 sheetflows into a natural channel, with no downstream impact
(since this channel is re -captured at Lot 22), MS-19 requirements are met.' As ollow-up: Per county
Engineering Review Comments
Page 3 of 13
engineer guidance, provide spot elevations and proposed grade lines to ensure capture at Str. EX. (Rev. 2)
Addressed. Applicant: `Additional grading details/considerations added to this area.'
16. C4:
17. Provide guardrail, Road F, at stream crossing. Alternatively, provide 12:1, 4'-wide graded shoulders before
transitioning to steeper embankment grades. Infrequent use reduces but does not eliminate risk posed by
unrecoverable slope with z7.25' vertical drop to streambed. (Rev. 1) NA. Applicant: `Noted, however
Road F has been removed and replaced with a superior connection that utilizes the existing fire access road
for Avinity subdivision.' As follow-up: Please provide deeded easement across Avinity property that grants
Galaxie Farm right of access to off -site fire access. (Rev. 2) Persists. Applicant: `Easement will be
provided prior to approval, we are in the process of obtaining this.'
18. C4 (C6. C8): Ensure lots are located entirely outside the (100') stream buffer. Ref. ZMA Sheet 7, Note F.
Portions of Lots 57, 58, 59 appear to be within stream buffer. (Rev. 1) Addressed. Lots 57-59 revised to
be outside the stream buffer.
19. C5: Provide additional preliminary design detail for transition from Road A2 to Ex. Galaxie Farm Lane
which provides access to multiple parcels beyond proposed development. Note reading Connect Galaxie
Farm Lane to new road is insufficient for an existing road that must remain in continuous use. Compare
spot grade at transition to Galaxie Farm Lane at end of Road A2 to existing Elev. of Galaxie Farm Lane.
Provide preliminary travel way design and drainage to ensure smooth transition. (Rev. 1) Partially
addressed. Applicant: `Acknowledged, additional detail added to plan & profiles. While exact extent of
grading will be based on field conditions (survey w. 2' contours allows only an estimate of how far mill &
overlay extends), more direction has now been provided.' As follow-up please see item 52 below. (Rev. 2)
Persists. Applicant: `Acknowledged, please see response to comment 52, below.' As ollow-up: Please see
follow-up at item 52, below.
20. C5. C6 (Subdivision Layout)- and CZ C8 (Grading and Utility Plans) mix incomplete views of easements,
and utilities. For example, C5, C6 show ACSA easements, but not all. For example, C5 does not provide
ACSA waterline easement south of Road Al in the direction of Rt. 20, to include new FH near Int. Rt. 20.
New ACSA water easement is shown along Road E, with utility schematic (C7), allowing easy check of
easement. Provide and label all utility easements on C7C8. (Rev. 1) Addressed. Applicant: `Easements
now properly shown.'
C5/C6
21. Show /label CG-12 ramps wherever sidewalks intersect roads [@ intersections of Roads: B 1-A2, 132-A2,
B1-Al, Al-D, B2-C, C-E, at entrance to parking area SE of Open Space C ]. (Rev. 1) Addressed. Also,
see items 53, 54, 55,
22. Provide and label traffic control signs: stop, no parking, speed limit. (Rev. 1) Addressed.
23. Provide and label street name signs. (Rev. 1) Addressed.
24. Show intersection sight distance lines for internal street intersections. (Rev. 1) Addressed,
25. C5
a. Lot 60: Provide Auto -turn figure to show vehicle reversing from driveway clears N-bound lane
completely before advancing in a forward direction. If Road E is insufficient length, a typical
passenger vehicle will strike curb or run off Road E before it clears N-bound (in -bound) lane.
(Rev. 1) Addressed. Applicant: `House & driveway orientation have been reversed to provide
adequate reversal space.'
b. Provide fixed barriers both as pedestrian protection and to prevent vehicles from running off the
end of Road E. A curb -less design at N end of Road E cannot be approved. Provide guardrail
pedestrian protection between end Road E, and Road Al sidewalk. Provide curb at end Road E.
(Rev. 1) Addressed. Guardrail provided. Applicant: `GR-2 guardrail provided. Curb was not
provided as this is an uphill section, and guardrail serves as a more sturdy and effective barrier.'
Engineering appreciates this response.
26.
27
Engineering Review Comments
Page 4 of 13
c. Lots 57, 58: Drive entrances propose acute angles (>90-deg). Provide Auto -tam figures to show a
typical passenger vehicle may enter driveways without running off paved drives and onto lawns.
(Rev. 1) Addressed. Applicant: `Lot 58 driveway is no longer acute; lot 57 driveway revised for
better maneuverability. These revisions should provide a solution to Engineering's concerns,
however auto -turn diagrams are not required for private driveways on private streets, and are not
provided.' Thank you. Auto -turn is a graphic tool, but will try to request verification of driveway
entrance design adequacy using alternate methods in the future, while the objective is unchanged.
d. All subdivision Lots: Related to 25.e., revise all driveway widths to 12' (Absolute Minimum, see
VDOT CG-9D). Also, item 40 below. Please apply CG-9D Min. drive width to this/future design.
(Rev. 1) Addressed. Applicant: `All driveways now have min. 12' width.'
e. Lots 48-50: Driveway entrances problematic relative to angle with cul-de-sac, or location in radius
curve sections of curb. Provide perpendicular driveway /street intersections. Relocate driveways
out of curved sections of cul-de-sac curb. (Rev. 1) Withdrawn. Albemarle has approved similar
driveway entrance designs for developments, Rivanna Village 1, for example (SUB201500119).
f Show sight distance lines (left/right, NE/SW) at Int. Road Al and Route 20. (Rev. 1) Partially
addressed. As follow-np: C20 indicates `topo profile from GIS, data to be verified.' Please verify
design provides adequate sight distance at Rt. 20 development entrance based on field survey data.
(Rev. 2) Addressed. Applicant: `Subsequent field visits by Shimp Engineering staff have
verified the physical sight distance.'
g. Label highlight line -type, image belom. [ Image removed with Rev. 1 comments ] If an easement
or setback, this line intersects structures (likely impermissible). (Rev. 1) Withdrawn. Applicant:
`That unlabeled line is the 18' garage setback, label has now been added. House can encroach
garage setback, but the garage must provide min. 18' of driveway from back of sidewalk.'
C5(-C13, 8 sheets): Show driveway entrance radii graphically. Additional comments possible. (Rev. 1)
Addressed.
Cam -over review comment, SUB201900198: `(2/20/20, Revised) Revise oul de saus, Rea.d.. P I And Pa to
Inaeal Roadways, 1. i "A single unit (SU) tFuek designvehiele, as def4ned by AAS140T, should be used feF
AASHTO Ceemetw Design of l4igW,ays and Streets 2011, shavqi in Figine 1. Notei Fig. 1 shows path 0
t _... O..,._hang of a si..,.l_ tinif (SU) Ifee , d..,.:..n vehicle rein. _..a:.... —e a c• i&,w, Feb12, 2020 1:54 PM
email) Using a SU design vehicle then, there is option of: 45' R, which meets VDOT RDM B(1)-24 with
proposed Road D.1 / D.2 FC/FC street width =24'; or 30' R cul-de-sac with FC/FC street width =30'.
Either is acceptable. To provide neither would not meet AASHTO /VDOT RDM, or ACDSM
requirements. To provide one or the other also alleviates concern relating to parcel deliveries (ever more
common) and waste management access needs outlined in email sent 2/7/2020 8:48 AM (below).
Albemarle defers to VDOT /ACF&R should either impose requirement for radius > 30'. Road plan design
should accommodate whatever these review, transportation, and emergency response agencies require.'
(Rev. 1) Not addressed. Applicant response: `Noted, we have coordinated with, and received blessing
form VDOT & Fire Rescue on cul-de-sac radii.' 30' R cul-de-sac corresponds with FC/FC street width
>_30'. Revise street width to 30', FC/FC. Also, email sent 2/12/2020 1:54 PM (re. SUB201900198),
8/31/2020 8:01 PM. (Rev. 2) Not addressed. Applicant: `These AASHTO guidelines cover vehicle turn
paths, not necessarily turnaround requirements. This subdivision street (nor most subdivision streets) is
not designed for single unit truck continuous turn, rather, to allow single unit truck adequate space to turn
around using a 3-point maneuver. Reference VDOT appendix B(1) text on page B(1)-24: a. Circular type
turnaround: "For circular turnarounds on short low volume residential cul-de-sac streets, this minimum
radius may be reduced to 30 feet when specifically approved by the locality in consultation with emergency
services. (See FIGURE 4 CUL-DE-SAC AND TURNAROUNDS)" (Figure 4 Image on next sheet). Turn
radius dictates CL and curb radii, and informs cul-de-sac sizing, however regulations do not require a box
truck to turn around without reversal at the termination of a short low -volume subdivision street.
Figure 4 from Appendix B(1) page 25 sheet specifically shows that the circular cul-de-sac turnaround
movement utilizes a 3-point maneuver, not a continuous turn. These are VDOT subdivision regulations,
Engineering Review Comments
Page 5 of 13
and this particular design for Road B 1 and D has been accepted by VDOT staff. This has been accepted on
other short low -volume subdivision public streets (for example Crozet Court). Design will not be revised,
as it meets regulations.' As follow-up, several points:
a. The Road plan will not be approved unless applicable valid review comments are addressed.
b. AASHTO Fig. 5-1 relies upon 3-point maneuver, not a continuous turn. Please see image, below.
c. Albemarle County is a locality, not VDOT. Albemarle County issues road plan design approval,
not VDOT.
d. All manner of vehicles are constrained by a 30'R: waste management vehicles, school buses (think
short length buses [disabled] that drive door-to-door), delivery vehicles (SU vehicle), snowplows,
private passenger vehicles that increasingly reflect pickup /SUV lines rather than cars of the past.
Sedans have lost popularity, their manufacture is nearly discontinued in N. American. GM has
just 3 sedans left (Oct 5 2020). Google: `Ford is no longer making sedans...' (2018/04/26)
e. VDOT expresses design preference for Galaxie Farm Subdivision 45'R cul-de-sac. See, below
(SUB201900198, email, M. Greene to J. Shimp, February 10, 2020 8:44 AM).
f. Request pertains to Road B1, not Road D.
g. Engineering may re -review plan and request revision for Road D, but does not for the moment
request geometric revision for Road D.
h. Engineering appreciates reference to a road plan design that should not have been approved, as it
did not meet AASHTO technical guidelines, we will be more mindful of future road plan designs.
i. Road plan reviews aim for consistency, but requirements missed in the past should not grant leave
to continue with a deficient design or review practice. Oversights are just that: mistakes.
j. This specific request was shared with Shimp Engineering Feb 12, 2020. There has been ample
time to revise development projections, plans, etc. in response to AASHTO design requirements.
k. ZMA201800012 approval does not relieve design of VDOT roadway geometric requirements.
1. M. Greene, VDOT, in email to Justin Shimp writes (February 10, 2020 8:44 AM): `
John's copy of the RDM, page B(t)-24 - Subdivision Street Design Guide is correct.
If the locality wants a 30'radius (with approval from emergency services), then it may be
allowed for short, low volume, residential cul-de-sac streets.
Excerpt from page B(t)-25 - For circular turnarounds on short low volume residential
cul-de-sac streets, the 45 ft minimum radius may be reduced to 30 feet when
specifically approved by the locality in consultation with emergency services.
However, the 45' radii is required and preferred.'
m. Albemarle is not opposed to, but instead encourages high -density development consistent with the
county's comprehensive plan, and economic and development goals. At times, however, there
may be conflict between proposed density/number of lots (or lot size) that contrive to create more
salable area than can be supported (more than is possible) once technical, zoning, site plan,
setback, or geometric requirements are taken into consideration, which may be the case here.
n. MS -Teams video conference may be helpful; the County Engineer (CE) may elect to participate,
and if we schedule a conference, I will brief the CE on AASHTO, VDOT short low volume
residential cul-de-sac street design preference (45' R), and February 2020 outreach to SE.
o. Please let us know if you would like to schedule a videoconference to discuss.
P. Image immediately below from email to Justin Shimp, 2/12/2020 1:54 PM (AASHTO Fig. 5-1):
Engineering Review Comments
Page 6 of 13
vmT,Rad ueS�goemv,I.L wppeWue(U[yUOT aun<e111 v zal;uat.m... ynre,pl.. m�mWmumaa�uzm,Yee,muemmwr�meeo:pa��,�wr rev M1vw.mm�rym
cooswutiov xiW e®vgmry amim.•
" Americm Aexciafimof5lMh 1[19!w YTwspwlatiouMW,.APdln'mC.eaernriv Hein, elHialn,mvmNSrcrcn (rQWp 1, Fl[.SI
Chapter S—1 IROadsand Streen I S-17
PMgPVNty I—W y
RaN I I
III I}I
I I I I \i
ll
I
-A SOuared EM -a
DeeiOn VPM1itle Mabic lml U.S. cuoN lnl
W L w L
P 10 A POI IBBI
SU 15 30 I Im (1001
__�Zl Pam GP W11i9e
N\ / j \/ \ II R-10m1
ill 11i �\ i�i p. vm \I / I
I I I I I I I
I�
tOmlMgb811
CYCWv CYUM-0aM Cvwbr—NI P.
C- -0- -E-
Oealpn VeM1iGa LIaVB Im) U.S. cu-wR 11q
R W R W
P 10 8 Pal 1181
W 121WBJ01 1 13 B 1 f421 In]
SU3WB-Iswa-% I t5 10 1 Inl 1301
RDM- Appendix BM Fig. 1
A single -unit (SU) truck design vehicle, as defined by AASHTO, should be used for
the design of all local subdivision streets. Dimensions for this vehicle are depicted
in Figure 2-2 of the AASHTO Geometric Design of Highways and Streets 2011,
shown as Figure 1.
FIGURE 1 — "FIGURE 2-2•• SCANNED FROM "A POLICY ON GEOMETRIC
DESIGN OF HIGHWAYS AND STREETS,' AASHTO, 2011
28. Provide _ is, plan lab,.. . both) for: (Rev. 1) Address
a. Knox box (Road F),
b. Bollards (Road F).
Engineering Review Comments
Page 7 of 13
29. Label distance along Route 20 to nearest street intersection (both directions). (Rev. 1) Addressed.
30. Provide curb extensions for parallel parking, Road B2, see design standard at VDOT RDM, B(1), pg. 59
(Rev. 1) Addressed. (pg. 61 of .PDF /Link:
https://www.virginiadot.ore/business/resources/LocDes/RDM/AppendBl.pddf 1
F. Curb Extensions — Curb extensions at intersections are frequently used in
Traditional Neighborhood Developments. Curb Extensions are also used to
protect parking areas and to reduce pedestrian crossing times.
WR
1o•H Minimum
25' F MiMmYm
EflttWO flaNue
MM IIYi41flx11
Curb Extension (Bulb -Out)
31. C7/C8 Grading and Utility Plan: [SUB201900198 review. If addressed w/ ROAD plan- please disregardl:
a. (2/20/20. Revised) n_,....__':__ eannat _,.,._........__a .._,a:.....:_,..., fin.! plat ,....._,....a oft ., 60"
ur.nn .., 1 headvell at Cav, Branch. Please provide additional design information for this
crossing' design for the 25-yr event. For perspective, please see photo d. 7127,119 (by A "--1 ea -le),
blew [ photo removed w/ Rev. 2], which shows drainage structure beneath Rt. 20 upstream of
proposed Road A.1 crossing. (Rev. 1) Partially addressed. Applicant: `Hydraulic design
provided, which shows this design accommodates the 25-year event.' As follow-up: Pg. 12, 13 of
Road Plan SWM Calculation packet (7/31/20) clearly indicate Q25,, design, but LD-229 table
values (p. 15 /Calc. report) are confusing since pipe capacities (culverts A, B, Qjo) appear <total
10-yr design values. Engineering assumes Q25 design would similarly exceed culvert A, B pipe
capacity since Q10 appears to exceed pipe capacity. Engineering may be misinterpreting LD-229
table, would be grateful for clarification. (Rev. 2) Addressed. Also, item 47 below.
b A CS A c....:...... Easement may impode ability to develop rots 29, 41, 31, 33, z<o 30e and 39, .,
intended with e t design.
B. A CS A RL»o.G..o Easement ....,.. impede .Milt to develop rots 58 61 .,....6.yal
d. Label reads. New: Label lots. (Rev. 1) Addressed.
e. Note existing natural drainage that clips end of Road A2. Provide conveyance of storm runoff that
transits this natural drainage feature in the post -developed condition. (Rev. 1) Addressed.
Applicant: `This is provided by a combination of F2 & F3 inlets.'
f Avoid nuisance ponding on any private or public road; f . example in ,. oul ._ n ulb paFtion a
Road P (soush end Road 9). Provide inlet uaptwe and adequate convoyanee A this . (Rev.
1) Addressed. Applicant: `This is provided by current inlet design (ref. LD-204, inlet drainage
map).
g. /19e Rl1 D,.� PFay:de :.Jots and piped drainage afF..no ff, Road B Withd........ (OMn:r
2 <12n < 2pfn Applicant: `NA, but note that Road E runoff routed to storm system via CG-7
curb and gutter.
dwellings along Road P. Stwm Funegeolleetion and conveyanee applies to Road 9. Also,
i. Provide /show /label public drainage easement at NE corner Int. Road D and Road Al (Open
Space). Note: A portion of public drainage, Str. D3 — DI, lies outside public ROW. (Rev. 1)
Addressed. Also, review item 51, below. As follow-up: WPO proposes and WPO plan review
discusses natural stream restoration, which may require separate access easement to Cow Branch
Engineering Review Comments
Page 8 of 13
for a period of time, until restored stream reach is stable (3-5 years). (Rev. 2) NA —
WPO202000037 abandons stream restoration along portion of Cow Branch.
j. Provide Ahavmublie image easements uFossi ng—LT ots �9 And 61
k. Provide storm drain inlets at low point /sag, Road Al. (Rev. 1) Addressed. As ollow-:Depict
Cl outfall at headwall in Road Al profile between 48"-60" dbl. pipes. Also, please depict
headwall spanning 48"-60" dbl. storm culverts in this profile view. lRiages, below. [ prior image
removed with Rev. 2 comments ] (Rev. 2) Partially Addressed. Ref.follow- u above, new
image, below. Please show C 1 outfall in headwall.
ROAD Al
3B' PUBUC ROW
ROAD Al
28' PAVEMENT
38PUBNC ROW
25 MPH DEVON
20' PAVEMENT
SPEED
25 MPH DE9GN
MDT-592
SPEED
�'.L x]YOrtx
AADT-592
1'.�tl M11Yx
W''orMMH\
Nan ec
� 1I
+
6
48- ooUc LE
sA�W
SW GEVX64B2
-]G4@
.,,. IR
/
NEW 20' PUBLIC
DRAINAGE ESM
/ /
2KING* /
R8-3
_ 90' BEIry T. 9
TD M T. M� ....
�n
2.00 Q.51
/
33 L,P/CLAS'
T RIP�-'t20 P Oyy
p
/11
/, LTER PABF
P[�'EAST CO C.
HEADWALL /
T r —
�P OXOXXSmEXM Q'n
i
i
/NEW V.W. PUBLI(
DRAINAGE ESMT
61
GM18 �
v �
i�J 66 6320 �_ r�•;�.` :�---O-6: _64a'l \`
\JPRFE'CAST CBON
5HgADWALLS
ff LA57 'NO PARK G'
RIP- P MUTCO R 3 11 F
I. Remove entirety of proposed SWM facilities from stream -ward 50' of Cow Branch stream buffer.
(Rev. 1) Applicant: `No SWM facilities lie within 50' of Cow Branch.'
M. Show proposed gFading, FSe@4:E; utilize 1, design sentows, if neeossal-y.
n. (2/20/20, Revised Provide design for Cow Branch crossing, Road F. Size pipe /culvert to pass the
25-yr event without overtopping Road F (Emergency Access). New: County email to Shawn
Maddox, ACF&R, 2/20/2020 11:07 AM requests guidance on ACF&R access needs relative to
existing pipe at stream crossing along dedicated fire -rescue access (2' point of subdivision
access). (Rev. 1) Addressed. Applicant: `Road F removed. Second crossing of Cow Branch no
longer proposed.'
Engineering Review Comments
Page 9 of 13
o. New: Relocate private waterline laterals outside public ROW, all lots. (Rev. 1) Withdrawn.
Applicant: `This is not a requirement and is the purview of ACSA.' Engineering defers to ACSA
/VDOT.
p. New: Coordinate with USACE. Provide copy of Nationwide or Virginia General Permit to
perform construction in live stream (Cow Branch). (Rev. 1) Persists. Applicant: `Acknowledged,
nationwide 18 permit exhibit submitted. Will send confirmation when received.' (Rev. 2)
Addressed. K. Rucker /SE email correspondence w/ V. Pero, USACE, rcvd 10/7/2020 9:49 AM.
C9
32. Provide Class B — Type I primitive trail section (Ref. ZMA, sheet 9. image below). (Rev. 1) Addressed.
33. Road Al profile: Label drainage structure dimensions /material type, INV elev., top of structure elevation
(at sag curve). Ensure adequate cover, given 10-Y:" pavement section, subgrade CBR requirement, and
apparent —1' distance between top of culvert and road finished grade. Cover appears inadequate. (Rev. 1)
Addressed,
34. Road Al profile: Show double -line culverts as two lines, not one line. (Rev. 1) Addressed.
35. Road Al profile: Label drainage structures. (Rev. 1) Addressed.
36. Show Road A2-Ex. Galaxie Farm Road transition. Provide grading /design that ensure smooth transition.
(Rev. 1) Addressed.
C10
37. Road B 1 /Road B2 include sag curves that do not meet Min. K value =15, provide Min. K-value. Also, ref.
VDOT Road Design Manual, Appendix B(1), Table 1 reference to 2011 AASHTO Green Book. See also,
2011 AASHTO Green Book, Table 5-3. Albemarle may at times rely on 2001 AASHTO Guidelines for
Geometric Design of Very Low Volume Local Roads (ADT<400 ADT), which lists Min, rate of vertical
curvature for Crest Vertical Curves (Exhibit 12), and refences Ch. 5 of Green Book for sag curve Min, rate
of vertical curvature. Albemarle requires Min. K-values of 5 and 15 for crest and sag curves, respectively.
(Rev. 1) Addressed. Applicant response: `Road B vertical curves revised to fully comply with VDOT
standards for a 25 mph road. Since this street is expected to handle future traffic which would likely put
the daily trip count over 400, crest K of 12 and sag K of 26 have been provided. For Road D, since trip
count <100, AASHTO Guidelines for Very Low Volume Local Roads were used to determine sight
distance. Sheet 35 of this book states that a sight distance of 125' is appropriate for this scenario.'
38. C 12: Road D, Revise to provide Min. K-value /sag curve > 15. (Rev. 1) Addressed,
39. C 13: Road F profile: Label drainage structure dimensions/material type, INV elevation, top of structure
elevation (at sag curve). Ensure adequate cover. (Rev. 1) NA. Road F profile removed along with the
road.
40. C15: Include VDOT CG-9D Standard Entrance Gutter —Ref. 2016 VDOT R&B Standards, Rev. d. 07/15.
(Rev. 1) Addressed.
41. C18 (Rev. 1) Addressed.
a. Add SL-1 or Y2" steel plate labels to MHs, as needed (for example, Str. E7, which requires both).
b. Profile Al-A2: Provide wingwall design.
c. Ensure proposed culvert INV elevation comports with USACE countersinking requirements.
d. If culvert is a double line (B 1— B2, for example), label profile for clarity ( dbl. line).
e. Revise profile F1-F2 caption to read F1-F4.
ZMA201800012 Sheet 7-related comments relating to SUB201900198 /ref. sheet 7 Notes, image below
43. Note F: Remove lots from stream buffer. Also, item 18 4-5, above. (Rev. 1) Addressed,
44. Note G: Also, item 7 48, above. (Rev. 1) Applicant: `Acknowledged.' As ollow-up: Please ensure Max.
wall In. does not exceed 10" it does not, as currently proposed. Please ref. code 18-4.3.3, rev. 7/15/20.
https7HIibrary.municode.com/va/albemarle county/codes/code of ordinances?nodeld=COALCOVI CH18ZO S4GER
Engineering Review Comments
Page 10 of 13
E S4.3TRCU S4.3.3GRST (Rev. 2) Addressed. Applicant: `Acknowledged, thanks for the reference to the
recently revised code. Ret. Wall (and walls in future designs) shall not exceed 10' height.' [ Rev. 1 image
removed. ]
46. Also, please consider Albemarle County Engineer's comments on ZM4.201800012, 9/23/19, which appear
relevant to preliminary plat, and subsequent plan applications, reprinted as text, below:
`Waiver Requests:
(1) Double Fronted Lots: No objection. (Rev. 1) Applicant: `Acknowledged, thank you.'
(2) Private Streets:
- Road D: The Design Standards Manual requires private streets to meet VDOT minimum standards,
however, the County has allowed by policy the use of ASHTO Geometric Design of Very Low Local
Roads for private streets with an ADT under 400 trips per day. If Block 1 is modified to serve only multi-
family (i.e. a site plan), standards may be reduced further as shown in the Design Standards Manual. (Rev.
1) Addressed. Applicant: `Acknowledged, Road D revised to meet standard.'
- Road E: Must also meet low volume road standards. Identify if any additional waivers are required.
(3) Private Street Design Requirements: (Rev. 1) Applicant: `Acknowledged, no additional waivers
required.'
- Road D: Street must meet design standards noted above, unless serving multi -family only.
- Road E: Identify the purpose of the "bulb" on this road. Parking must meet County design requirements.
Has VDOT approved spacing requirements for public road intersections? (Rev. 1) Applicant:
`Acknowledged, Road D revised to meet standard. Road E bulb/cul-de-sac is to provide ease of turnaround
for residents. Parking meets county requirements (no parking on the Road E bulb/cul-de-sac). VDOT had
no objection for spacing requirements.'
(4) Modification of Setbacks: No objection.
The road exhibits show a comer lot in Block 1, a few lots in Block 2, and the sidewalk in Block 2 within
the stream buffer. These improvements are not exempt and cannot be located in a stream buffer. This
comment was previously made during the ZMA review, which did not (does not) show these impacts.'
(Rev. 1) Addressed. Applicant: `Acknowledged, these have been revised —all are moved out of stream
buffer.'
ZMA sheets (for reference)
Sheet 7, Notes
v
NOTES:
A) For front loaded garages, the porch or building face shall be a minimum of 3 feet closer to the street as measured from the face of the garage door.
B) For those units that (1) do not front Roads A.2" or "B , and (2) are located in Block 2, utilizing Private Road "E", shall have a minim= front setback of 3 feet
from the right-of-way of Private Road "E" All other units shall have a minimum front setback of 5 feet, per Section 4.19 of the Zoning Ordinance.
C) AB Blocks except 7 and 8 may be used for residential uses as noted by the unit types listed above.
D) All rear yards (except those adjoining Road "E") shall have a minimum setback of 20 feel
E) Structures along Road "E" shall have a minimum rear setback of 5 feet.
F) No structures or lots shall be permitted in the stream buffer or on preserved slopes. No preserved slopes within the development shall be disturbed.
G) As applicable, retaining walls within the development shall meet the design standards required for the disturbance of managed slopes in Section 30.7.5 of the
Zoning Ordinance.
H) Total allowable residential units shall be 65.
I) Road "C" is shown as a possible future connection to Tax Map Parcel 91-13 to be extended and dedicated upon demand of the County.
1) Road "D.1" is shown as a possible future connection to Tax Map Parcel 91-10 to be extended and dedicated upon demand of the County.
K) 25% of the required stormwater quality treatment shall be provided onsite.
Sheet 8
Sheet 9
Engineering Review Comments
Page 11 of 13
All sections to comply with V DOT and/or Albemarle
County standards, as applicable
CLASS B - TYPE 1
PRIMITIVE NATURE TRAIL -Private
EASEMENT
1— 5'—I
CLASS B - TYPE 7
PRIMITIVE NATURE TRAIL
47. Calculation packet:
a. Confirm that 10-yr event is design basis of LD-229, p. 13 of packet. (Rev. 1) Addressed.
b. If so, please revise design of culverts to ensure pipe capacity ? calculated peak discharge during
design event, for example, please examine and revise as needed design of.
(Rev. 1) Partially addressed. Applicant response: `Culvert designs revised to provide full
capacity for thee pipes.' As ollow-qp please clarify /explain items b.i, ii, vi, vii, Qlo,, values that
appear to exceed capacity (Qlo,, vs. pipe capacity /p. 15, Cale. report).: (Rev. 2) Addressed.
Applicant: `For pipes A & B, capacities were listed incorrectly. These have been fixed. For 172-
F 1, this pipe will backfill from Detention, and has been designed as a detention pipe. Tailwater
effect accounted for in LD-347. Storm F design will still work with future road extension. G2-GI
is now a different pipe system, and has capacity.'
I. G2 to GI 198.08 v. 146.4 (all values, cfs)
ii. F2 to F 1 (unless designed as detention pipe), 42.96 v. 34.7
iii. E5 to E4
iv. E4 to E3
v. E3 to E2
vi. B2 to B 1 269.63 v. 18.7
vii. A2 to Al 140.70 v. 19.0
Engineering Review Comments
Page 12 of 13
New / Rev.1
48. It appears sidewalk is proposed to cross lots 57 thru 60—unless walks are exclusive to these lots, or even
each lot, this is unconventional. Engineering defers to Planning on what Agreements may be required to
ensure public right to use sidewalks located on privately -owned lots. (Rev. 2) Withdrawn. Applicant:
`This is unconventional but was required by ZMA 2018-12, reference ZMA Sheet C7 page transcribed on
Road Plan Sheet C23.'
49. C9: Plan view text is upside down (understand why, to correspond with profile). Recommend rotate text
180-deg. so more easily readable. Plan view information is important and should be readable. (Rev. 2)
Addressed.
50. Restore N arrow to road plan sheets that depict plan views. (Rev. 2) Addressed.
51. CT Label public drainage easement crossing lots 12, 13, 14 and 39, show and label public drainage
easement between E6Z and E6. (Rev. 2) Addressed.
C5
52. Provide horizontal curve at transition, Road A2 to Ex. Galaxie Farm Lane, an existing roadway anticipated
to see daily use. Use 25 mph design speed, minimum, when designing horizontal curve at transition. This
is not a request for change to Road A2; rather, grading, CL alignment, and notes that revise Galaxie Farm
Lane may suffice. When approaching A2 from Galaxie Farm Lane, horizontal /vertical curves must provide
safe transition at 25 mph, or higher design speed. Proposed abrupt transition is depicted below, sheet C5.
(Rev. 2) Partially addressed. Applicant: `Acknowledge, however existing road is not designed to 25 mph
design speed, so drivers must reduce speed (as is natural) at transition to the old road. To ensure safe
transition, we analyzed the centerline conditions and found that the design provides a "s" curve with each
radius at 100' This is appropriate for such a transition (effectively, public street to driveway). Alignment
is intentionally chosen to allow effective street extension in the future, but in the meantime the transition
remains safe for the users of unimproved Galaxie Farm Lane.' As follow-up: Engineering maintains that
drivers who will be unfamiliar at first with proposed TV' curve design merit design remedy to what is an
abrupt transition. Designers may see a sensible facility from an aerial vantage, but current design
(comment response) does not adequately mitigate avoidable risk to unsuspecting or young or elderly
drivers, or delivery drivers. Please consider and elect one of these options:
a. Provide signs (one or more) that clearly indicate change in pavement /alignment exists ahead.
Position sign/s viewable if approaching transition on Road A2. Propose clear forewarning to
drivers.
b. Revise design per initial comment, above.
c. Mix combination of a., b.
� ,
�Cf A TO � a�
-
�-
�--
x
---
IT.--
_
FARM ONE
I
GALAXIE
µ
/
IIrtJ
TOT.
L}l9Y�m
]y.0
r
I
�VT
//
f101�E5u1
OEM
53. Provide CG-12 ramps and pedestrian crossing of Road Al at intersect . twad D on west side of
Road D. Ramps and crossing are requisite for safe intercom n network, which includes trails
and walks. (Rev. 2) Withdrawn. Applicant: `Acknowledged, this crossing is provided at the Road B
intersection to avoid mid -block crossings which are not preferred for this location by VDOT.'
54. Provide CG-12 ramps and pedestrian crossing of Road A2 at intersection with Road 131-132, either side of
intersection, voc blue lines,- bel [ Image removed with Rev. 2 ] (Rev. 2) Addressed.
Engineering Review Comments
Page 13 of 13
55. Recommend CG-12 at primitive trail Road Al intersection. Pedestrian facilities typically may not intersect
public roads without FIC-accessible ramps, which, in this instance, appear more necessary since trail -Al
intersection is at radius return at development entrance at Rt. 20, and drivers may be distracted by braking,
accelerating, steering, oncoming traffic, etc., whether entering or exiting Galaxie Farm. (Rev. 2)
Addressed. Applicant: `Acknowledged, we do not deem that this revision would add public benefit, (CG-
12 does not make pedestrians more visible to drivers, nor does it give drivers more warning than the trail
clearing itself) however Engineering's desire to optimize pedestrian safety at this crossing is met by
moving he crossing location away from Route 20. Physically, for drivers entering, they will have slowed
down enough (to achieve the turn through a 25' curb radius) where they will have adequate distance and
sight to avoid collision with pedestrians at the new crossing location. Additionally, signage is specified on
Road A to further notify drivers.' Engineering appreciates this position.
56. Also recommend, if VDOT permits, sign on Rt. 20 (blue circle) depicting graphically pedestrian with right
arrow to indicate pedestrians may be encountered immediately upon entering the development on Road Al.
Engineering believes it is critical to plan for conflicts that multiply at intersections, with transitional speed
limits, with road -trail networks that serve different purposes. A recreational trail for walking, running, and
space where children or pets may become separated from guardians are proposed within feet of Rt. 20, a
high-speed primary route. Quite dissimilar, trail and Rt. 20 nearly immediately intersect one another. [
Rev. 1 image removed with Rev. 2 ] (Rev. 2) Withdrawn. Applicant: `Noted, as mentioned above
crossing location moved for safety. There is now 75' distance from route 20, so the signs as positioned will
be adequate for the vehicles entering at <25 mph into the subdivision. We do not want to put sign on route
20 as that could be misleading to the southbound drivers which make up the vast majority of users at the
entrance —this is a subdivision driver warning not a route 20 warning, so signage within Road A seems
more appropriate than signage on route 20.' Engineering appreciates this position. Thank you.
57. Provide and label CG-6 wipe down at Rt. 20. (Rev. 2) Addressed.
58. Provide wipe down detail, unless overlooked. (Rev. 2) Addressed.
Please feel free to call if any questions.
Thank you. I Anderson
434.296-5832 -x3069
SUB202000098 Galaxie Farm ROAD plan 101620rev2